Friday, December 30, 2011

Will NASA’s Kepler find another Earth? Possibly in 2012 say scientists

It’s the question the entire scientific community is asking: Will NASA’s Kepler find another Earth, and how soon?

2011 was full of reports that astronomers are one step closer to discovering another habitable Earth-like planet outside of our own solar system. NASA earlier this year confirmed the discovery of the first-ever planet in a habitable zone outside our solar system. That planet is roughly twice the size of Earth. French astronomers earlier this year confirmed the first exoplanet to meet key requirements for sustaining life, and just last week NASA announced the discovery of the first two Earth-sized planets orbiting a sun-like star.

In September, Kepler scientists turned science fiction into reality when they announced the first observation of a planet with two suns — such as Luke Skywalker’s home planet Tatooine in the “Star Wars” film series. Such planets are called “circumbinary” planets because they orbit a “binary pair” of stars. Until a few months ago, people only suspected two-star planets might exist.

The latest batch of discovery has left NASA clamoring for more. Speaking earlier this year, Geoffrey Marcy of the University of California, Berkeley, said he expects NASA’s Kepler Telescope to discover a habitable planet within the coming year.

“Sooner or later, Kepler will find a lukewarm planet with a size making it probably Earthlike,” said Geoffrey Marcy of the University of California, Berkeley. “We’re no more than a year away” from such a discovery, he said.

“We are finally there,” said David Charbonneau, an astronomer at the Harvard-Smithsonian Center for Astrophysics, who is part of the team leading the Kepler mission, led by colleague Francois Fressin. “This demonstrates for the first time that Earth-size planets exist around other stars and that we can detect them,” Fressin said.

NASA officials announced earlier this year that the Kepler telescope, which has reportedly already discovered more than 2,000 new planet candidates, is nearly doubling its previously known count. Still, scientists said the space agency should focus on identifying which planets are most likely to maintain the environment necessary for water to exist, and, possibly, life.

Meanwhile, a number of scientists said the latest news is exciting in that Kepler’s batch of discoveries show a number of Earth-like planets exist outside of the Solar System. Astronomers says the number of discoveries in 2011 prove that Kepler can indeed find planets as small as our own, an encouraging sign that planet hunters would someday succeed in the goal of finding Earth-like abodes in the heavens. Since the first Jupiter-size exoplanets, as they are known, were discovered nearly 15 years ago, astronomers have been chipping away at the sky, finding smaller and smaller planets.

“The primary goal of the Kepler mission is to find Earth-sized planets in the habitable zone,” said Francois Fressin of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, lead author of a new study published in the journal Nature. “This discovery demonstrates for the first time that Earth-size planets exist around other stars, and that we are able to detect them.”

The Kepler science team uses ground-based telescopes and the Spitzer Space Telescope to review observations on planet candidates the spacecraft finds. The star field that Kepler observes in the constellations Cygnus and Lyra can only be seen from ground-based observatories in spring through early fall. The data from these other observations help determine which candidates can be validated as planets.

Tuesday, December 27, 2011

Astronomers using NASA’s Spitzer and Hubble space telescopes have discovered that one of the most distant galaxies known is churning out stars at a shockingly high rate. The blob-shaped galaxy, called GN-108036, is the brightest galaxy found to date at such great distances.

The galaxy, which was discovered and confirmed using ground-based telescopes, is 12.9 billion light-years away. Data from Spitzer and Hubble were used to measure the galaxy’s high star production rate, equivalent to about 100 Suns per year. For reference, our Milky Way Galaxy is about five times larger and 100 times more massive than GN-108036, but makes roughly 30 times fewer stars per year.

“The discovery is surprising because previous surveys had not found galaxies this bright so early in the history of the universe,” said Mark Dickinson from the National Optical Astronomy Observatory in Tucson, Arizona. “Perhaps those surveys were just too small to find galaxies like GN-108036. It may be a special, rare object that we just happened to catch during an extreme burst of star formation.”

The international team of astronomers, led by Masami Ouchi from the University of Tokyo, Japan, first identified the remote galaxy after scanning a large patch of sky with the Subaru Telescope atop Mauna Kea in Hawaii. Its great distance was then carefully confirmed with the W.M. Keck Observatory, also on Mauna Kea.

“We checked our results on three different occasions over two years, and each time confirmed the previous measurement,” said Yoshiaki Ono from the University of Tokyo.

GN-108036 lies near the beginning of time itself, a mere 750 million years after our universe was created 13.7 billion years ago in the “Big Bang.” Its light has taken 12.9 billion years to reach us, so we are seeing it as it existed in the distant past.

Astronomers refer to the object’s distance by a number called its “redshift,” which relates to how much of its light has stretched to longer, redder wavelengths due to the expansion of the universe.

Monday, December 19, 2011

NASA shuts doors, pulls plug on shuttle Discovery

NASA powered down the space shuttle Discovery for a final time Friday , more than 28 years after the agency's retired fleet leader first came alive. The vehicle was "unplugged" inside Orbiter Processing Facility-1 (OPF-1) at the Kennedy Space Center in Florida.

The electrical shutdown, which came soon after technicians closed the shuttle's twin 60-foot long payload bay doors, was a milestone in Discovery's transition from a space-worthy orbiter to a museum exhibit. The shuttle, the oldest of NASA's remaining orbiters, is destined for display next spring at the Smithsonian National Air and Space Museum's Steven F. Udvar-Hazy Center in Virginia.

Discovery's cargo hold — which carried to orbit the Hubble Space Telescope and Ulysses solar probe along with modules for the International Space Station and more than a dozen satellites — was closed for what may be its last time. The Smithsonian plans to display the shuttle with its bay doors shut, at least initially.

The power down was much more permanent. Though Discovery's three electricity-generating fuel cells were reinstalled last week, they were first drained of all their reactants, and their feed lines were purged. Other than serving as an engineering example for researchers, they will never work again.

Since landing back on Earth after its 39th and final mission in March, Discovery has been carefully taken apart to preserve some of its components for future use while making the vehicle safe for public display. Its engines have been removed and replaced with replicas and its thrusters cleaned of their hazardous materials.

Inside its crew cabin, Discovery's waste collection system — otherwise known as its toilet — was removed, cleaned, and replaced, and its flight deck configured to appear ready for another mission, one that will never come. As with the fuel cells, the Smithsonian requested NASA keep Discovery as complete as possible so as to serve as a resource for future study.

Discovery is targeted to make one last flight in April 2012, though not under its own power and well within the atmosphere.

Monday, December 5, 2011

NASA ISS On-Orbit Status

All ISS systems continue to function nominally, except those noted previously or below. Sunday - Crew off day. Ahead: Week 3 of Increment 30 (three-person crew).

* Today 13 years ago (1998), the US-built Node-1 "Unity", 2nd component of ISS, was launched on STS-88/Endeavour, crewed by CDR Bob Cabana (today Director of NASA/KSC), PLT Fred Sturckow, and Mission Specialists Jerry Ross, Nancy Currie, Jim Newman & Sergey Krikalev (today Director of GCTC/Gagarin Cosmonaut Training Center, Star City, Russia). "Unity" was mated to the Russian-built FGB "Zarya" by Currie on 12/6, and Bob & Sergey entered the rudimentary space station jointly.

After wakeup, FE-1 Shkaplerov performed the routine inspection of the SM (Service Module) PSS Caution & Warning panel as part of regular Daily Morning Inspection.

Anton also conducted the routine daily servicing of the SOZh system (Environment Control & Life Support System, ECLSS) in the SM. This included the weekly collection of the toilet flush (SP) counter and water supply (SVO) readings for calldown to TsUP-Moscow, as well as the weekly checkup on the Russian POTOK-150MK (150 micron) air filter unit of the SM's & FGB's SOGS air revitalization subsystem, gathering weekly data on total operating time & "On" durations for calldown. [SOZh servicing includes checking the ASU toilet facilities, replacement of the KTO & KBO solid waste containers and replacement of EDV-SV waste water and EDV-U urine containers].

CDR Burbank took the (approx.) monthly O-OHA (On-Orbit Hearing Assessment) test, his first, a 30-min NASA environmental health systems examination to assess the efficacy of acoustic countermeasures, using a special software application on the MEC (Medical Equipment Computer) laptop. [The O-OHA audiography test involves minimum audibility measurements for each ear over a wide range of frequencies (0.25-10 kHz) and sound pressure levels, with the crewmembers using individual-specific Prophonics earphones, new Bose ANC headsets (delivered on 30P) and the SLM (sound level meter). To conduct the testing, the experimenter is supported by special EarQ software on the MEC, featuring an up/down-arrow-operated slider for each test frequency that the crewmember moves to the lowest sound pressure level at which the tone can still be heard. The baseline test is required not later than about Flight Day 14 for each new Expedition and is then generally performed once per month. Note: There has been temporary hearing deficits documented on some U.S. and Russian crewmembers, all of which recovered to pre-mission levels.]

Later, Dan performed the VolSci (Voluntary Weekend Science) activity selected for today, an EPO (Educational Payload Operations) demo of 3 student-designed games,- Save the World, Alligator Clip Capture, and Independence Day. The demos were filmed with the G1 camcorder for subsequent downlink via HD MPC (Multi-Protocol Converter) on Ku-band. [EPO Demos are educational videos conducted by crewmembers on-board the ISS. Today's video is intended to be edited on the ground and will be seen by grade 5-8 students and educators. Demo 1: Using a dartboard, Dan demonstrated "sports in space", showing how Newton's Laws of Motion are applied to games in microgravity space. This video will be used on the Space Out Sports Website at . Demo 2: Crewmember was to release 5 alligator clips in the cabin, allowing them to float, then floated up to capture each alligator clip, from underneath and above the clip (created by students at Kinser Elementary {Department of Defense} School in Okinawa, Japan. Demo 3: Earning points by successfully tossing a baton-like object through a floating ring, cut from a sheet of paper and pasted appropriately. Crewmember then was to repeatedly toss unsharpened pencil (or like object) through the floating paper rings (created by students at Manhattan Beach Middle, Manhattan Beach, CA.]

Anton & Anatoly finished up their lengthy IFM (Inflight Maintenance) on the TVIS treadmill, performing the long-term periodic chassis Inspection which they had been unable to finish on 12/2. Afterwards, Anatoly was to perform the speed characterization test while recording acoustic survey data, which of course was also not done on 12/2. [The inspection included the belt slats, weld nuts, treadbelt, drum set screws, 50 truss blue roller assemblies, side black rollers, and bottom black rollers. The crew also replaced 3 misaligned belt slat screws.]

At ~4:45am EST, Anton Shkaplerov & Anatoly Ivanishin participated in an event set up for them in Moscow to cast their ballot in the Elections to the 6th State Duma of the Russian Federation Federal Assembly and Moscow Regional Duma Elections, formally authorizing their proxy agent Dmitry Alexandrovich Zhukov to fill out the ballot for them, with the required confidentiality being observed. [Alexander Ivanovich Popkov, chairman of the local election committee of Korolev City, Moscow Region, explained the ballot procedure and read out the ballot bulletin, then asked "Dear Anton Nikolayevich and Anatoly Alexeyevich, do you authorize Dmitry Alexandrovich Zhukov to fill out ballot bulletins thus giving effect to your will?" After filling out the forms in secrecy, D. A. Zhukov invited the participants to the voting room and dropped the ballots in a portable box while providing voice commentary of his actions to Anton & Anatoly, who thanked them thusly: "Participation in Russia's political life is a crucial right of every citizen of the country! By casting our vote we shape the direction our nation will take in the future. Our future depends on our vote!" Besides a group of political and communal VIPs, assembled media included "Novosti Cosmonavtiki" magazine; "Russia Today" TV company; ZVEZDA TV Channel; ITAR-TASS news agency; Branch of "Podmoskovye" TV Channel (City of Losino-Petrovsky); NTV TV company; Channel 1 TV company; and RIA Novosti.]

The crew worked out with their regular 2-hr physical exercise protocol on the CEVIS cycle ergometer with vibration isolation (CDR), ARED advanced resistive exercise device (CDR, FE-1, FE-2) and T2/COLBERT advanced treadmill (FE-1, FE-2).

Friday, December 2, 2011

Lightning-made Waves in Earth's Atmosphere Leak Into Space

At any given moment about 2,000 thunderstorms roll over Earth, producing some 50 flashes of lightning every second. Each lightning burst creates electromagnetic waves that begin to circle around Earth captured between Earth's surface and a boundary about 60 miles up. Some of the waves – if they have just the right wavelength – combine, increasing in strength, to create a repeating atmospheric heartbeat known as Schumann resonance. This resonance provides a useful tool to analyze Earth's weather, its electric environment, and to even help determine what types of atoms and molecules exist in Earth's atmosphere, but until now they have only ever been observed from below.

Now, NASA's Vector Electric Field Instrument (VEFI) aboard the U.S. Air Force's Communications/Navigation Outage Forecast System (C/NOFS) satellite has detected Schumann resonance from space. This comes as a surprise, since current models of Schumann resonance predict these waves should be caged at lower altitude, between the ground and a layer of Earth's atmosphere called the ionosphere.

"Researchers didn't expect to observe these resonances in space," says Fernando Simoes, a scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "But it turns out that energy is leaking out and this opens up many other possibilities to study our planet from above."

Simoes is the first author on a paper about these observations that appeared online in the journal Geophysical Research Letters on November 16 and will appear in the print publication in December. He explains that the concept of resonance in general is fairly simple: adding energy at the right time will help any given phenomenon grow. Think of a swing – if you push it back just as it hits the top of its arc, you add speed. Push it backwards in the middle of its swing, and you will slow it down. When it comes to waves, resonance doesn't occur because of a swing-like push, but because a series of overlapping waves are synchronized such that the crests line up with the other crests and the troughs line up with the other troughs. This naturally leads to a much larger wave than one where the crests and troughs cancel each other out.

The waves created by lightning do not look like the up and down waves of the ocean, but they still oscillate with regions of greater energy and lesser energy. These waves remain trapped inside an atmospheric ceiling created by the lower edge of the "ionosphere" – a part of the atmosphere filled with charged particles, which begins about 60 miles up into the sky. In this case, the sweet spot for resonance requires the wave to be as long (or twice, three times as long, etc) as the circumference of Earth. This is an extremely low frequency wave that can be as low as 8 Hertz (Hz) – some one hundred thousand times lower than the lowest frequency radio waves used to send signals to your AM/FM radio. As this wave flows around Earth, it hits itself again at the perfect spot such that the crests and troughs are aligned. Voila, waves acting in resonance with each other to pump up the original signal.

Wednesday, November 30, 2011

UK space radar project initiated

The UK government is to kick-start an innovative project to fly radar satellites around the Earth, with an initial investment of £21m.

Radar spacecraft can see the planet's surface in all weathers, day and night.It is hoped that a series of satellites could eventually be launched, enabling any place on Earth to be imaged inside 24 hours - a powerful capability.

The radar money is part of a £200m boost for science announced by the Chancellor in his Autumn Statement.George Osborne's investment will be matched by industry.

Radar is one of the most useful tools in Earth observation because of its ability to track objects and events on the ground even when there is thick cloud.

The project being backed by government has been developed by Surrey Satellite Technology Limited (SSTL), which specialises in building small, low-cost spacecraft, and its parent company, Astrium, which makes some of the biggest satellites in orbit today.

Engineers at the two firms have produced a compact radar platform they believe could win many overseas orders, and are keen to demonstrate its capabilities in space.

The new S-band radar satellite is called NovaSar-S ("Sar" stands for synthetic aperture radar). It is a 3m-by-1m spacecraft with a plank-like appearance, weighing just shy of 400kg.

Engineers have found a way to make it considerably smaller than most radar platforms in operation today, and with a price tag that would also be a fraction of that charged for bigger radar satellites.

SSTL says it can build, launch and insure a NovaSar-S for a customer for about £45m.

Mr Osborne's investment, together with SSTL's and Astrium's own money, will enable the first NovaSar-S to be put in orbit. It will be ready for launch in two to three years' time.

Assuming this pathfinder meets its design performance and begins to earn money from the sale of its imagery, SSTL plans to launch further spacecraft, to create a constellation in the sky.

Prof Sir Martin Sweeting is the executive chairman of SSTL. He told BBC News: "We're hoping we can use this commitment from the UK government to go out to our international customers, who we know have had an interest in radar for a long time, and get them to participate in the first mission, to start with, but then to take up one or two of the other satellites so that we can build a constellation in orbit."

A NovaSar-S will produce what are termed medium-resolution images, meaning details on the ground larger than 6m across would be discernable.

Monday, November 28, 2011

NASA Launches Super-Size Mars Rover to Red Planet

CAPE CANAVERAL, Fla. – The world's biggest extraterrestrial explorer, NASA's Curiosity rover, rocketed toward Mars on Saturday on a search for evidence that the red planet might once have been home to itsy-bitsy life.

It will take 8 1/2 months for Curiosity to reach Mars following a journey of 354 million miles.

An unmanned Atlas V rocket hoisted the rover, officially known as Mars Science Laboratory, into a cloudy late morning sky. A Mars frenzy gripped the launch site, with more than 13,000 guests jamming the space center for NASA's first launch to Earth's next-door neighbor in four years, and the first send-off of a Martian rover in eight years.

NASA astrobiologist Pan Conrad, whose carbon compound-seeking instrument is on the rover, had a shirt custom made for the occasion. Her bright blue, short-sleeve blouse was emblazoned with rockets, planets and the words, "Next stop Mars!"

The 1-ton Curiosity -- as large as a car -- is a mobile, nuclear-powered laboratory holding 10 science instruments that will sample Martian soil and rocks, and analyze them right on the spot.

There's a drill as well as a stone-zapping laser machine.

It's "really a rover on steroids," said NASA's Colleen Hartman, assistant associate administrator for science. "It's an order of magnitude more capable than anything we have ever launched to any planet in the solar system."

The primary goal of the $2.5 billion mission is to see whether cold, dry, barren Mars might have been hospitable for microbial life once upon a time -- or might even still be conducive to life now.

No actual life detectors are on board; rather, the instruments will hunt for organic compounds.

Curiosity's 7-foot arm has a jackhammer on the end to drill into the Martian red rock, and the 7-foot mast on the rover is topped with high-definition and laser cameras. No previous Martian rover has been so sophisticated or capable.

With Mars the ultimate goal for astronauts, NASA also will use Curiosity to measure radiation at the red planet. The rover also has a weather station on board that will provide temperature, wind and humidity readings; a computer software app with daily weather updates is planned.

The world has launched more than three dozen missions to the ever-alluring Mars, most like Earth than the other solar-system planets. Yet fewer than half of those quests have succeeded.

Just two weeks ago, a Russian spacecraft ended up stuck in orbit around Earth, rather than en route to the Martian moon Phobos.

"Mars really is the Bermuda Triangle of the solar system," Hartman said. "It's the death planet, and the United States of America is the only nation in the world that has ever landed and driven robotic explorers on the surface of Mars, and now we're set to do it again."

Curiosity's arrival next August will be particularly hair-raising.

In a spacecraft first, the rover will be lowered onto the Martian surface via a jet pack and tether system similar to the sky cranes used to lower heavy equipment into remote areas on Earth.

Curiosity is too heavy to use air bags like its much smaller predecessors, Spirit and Opportunity, did in 2004. Besides, this new way should provide for a more accurate landing.

Thursday, November 24, 2011

Mars Science Laboratory Launch Milestones

PASADENA, Calif. -- NASA's Mars Science Laboratory is tucked inside its Atlas V rocket, ready for launch on Saturday, Nov. 26, 2011 from Cape Canaveral Air Force Station in Florida. The Nov. 26 launch window extends from 7:02 a.m. to 8:45 a.m. PST (10:02 a.m. to 11:45 a.m. EST). The launch period for the mission extends through Dec. 18.

The spacecraft, which will arrive at Mars in August 2012, is equipped with the most advanced rover ever to land on another planet. Named Curiosity, the rover will investigate whether the landing region has had environmental conditions favorable for supporting microbial life, and favorable for preserving clues about whether life existed.

On Nov. 26, NASA Television coverage of the launch will begin at 4:30 a.m. PST (7:30 a.m. EST). Live launch coverage will be carried on all NASA Television channels.

If the spacecraft lifts off at the start of the launch window on Nov. 26, the following milestones are anticipated. Times would vary for other launch times and dates.

The rocket's first-stage common core booster, and the four solid rocket boosters, will ignite before liftoff. Launch, or "T Zero", actually occurs before the rocket leaves the ground. The four solid rocket boosters jettison at launch plus one minute and 52 seconds.

Fairing Separation
The nose cone, or fairing, carrying Mars Science Laboratory will open like a clamshell and fall away at about three minutes and 25 seconds after launch. After this, the rocket's first stage will cut off and then drop into the Atlantic Ocean.

Parking Orbit
The rocket's second stage, a Centaur engine, is started for the first time at about four minutes and 38 seconds after launch. After it completes its first burn of about 7 minutes, the rocket will be in a parking orbit around Earth at an altitude that varies from 102 miles (165 kilometers) to 201 miles (324 kilometers). It will remain there from 14 to 30 minutes, depending on the launch date and time. If launch occurs at the beginning of the launch Nov. 26 launch window, this stage will last about 21 minutes.

On the Way to Mars
The second Centaur burn, continuing for nearly 8 minutes (for a launch at the opening of the Nov. 26 launch window), lofts the spacecraft out of Earth orbit and sends it toward Mars.

Tuesday, November 22, 2011

Using Satellites to Help the Earth Sustain Seven Billion People

With seven billion people now living on Earth, the expanding demand for resources is exerting unprecedented pressure on global resources, especially forests, water and food. NASA and the U.S. Geological Survey are using satellite technology to monitor the changing resources.

Every three seconds, the world loses a football-field sized swath of forest. As forests are cut for fuel or burned to allow the planting of crops, the Earth loses the ability of forests to capture carbon from the atmosphere or to support biodiversity with an untold loss of plant and animal species.

The fate of world forests is just one concern linked to population growth. With the United Nations (U.N.) declaring that seven billion people now live on our planet, the question becomes: How can Earth resources be managed best to support so many?

"Feeding the people of the world requires not only land for agriculture, but it also requires fresh water and energy," said James Irons, Landsat project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.

About half of the seven billion were added in the past 40 years and although birth rates in many countries are stabilizing, the U.N. estimates that three billion more people are expected by 2100.

This expanding demand will exert unprecedented pressure on global natural resources, Irons said, especially forests, water and agriculture. To support a world population expected to reach eight billion as soon as 2025, these crucial resources need to be closely monitored and sustained.

"What we've done with satellites over the past 40 years is to revolutionize how we monitor agriculture, forests, fresh water consumption and other Earth resources required by the global population," Irons said, adding that the worldwide pressure of feeding everyone requires a tool that has a whole-world view, making satellites a unique resource for scientists and policy makers alike.

The Landsat Program is a series of Earth-observing satellite missions jointly managed by NASA and the U.S. Geological Survey. Since 1972, the Landsat Earth observation satellites have monitored changes at the Earth's land surface, including changes in forests, water bodies and agricultural and urban areas.

"For example, it's only by viewing Landsat data that we would know how quickly the world's forests are being destroyed," said Alan Belward, of the European Commission Joint Research Centre. "More than 80 percent of the rural population in Africa relies exclusively on forests and woodland for all their energy needs."

Belward joins NASA's James Irons and other experts in mapping and monitoring our planet to describe present conditions and outline the future of many of Earth's natural resources at a noon press conference at the Pecora Remote Sensing Symposium, held Wednesday, November 16, 2011 in Herndon, Va.

Belward says that verifying how many countries manage their forest data has historically been a challenge.

"But with open and freely available scientific data, anyone and everyone can track these resources and see how they're being used or abused," Belward said.

"Different countries manage their forests, their property rights laws and their conservation efforts differently," he added, "making it important that precise scientific assessments are widely distributed and freely available to everyone in the research and public policy community."

In addition to forests, satellite data provide a 'big picture' view that includes an exquisite level of detail on crops being planted worldwide. For example, the United States Department of Agriculture uses satellite data extensively to help determine where, when and which crops are planted each year and to predict production and make commodity forecasts.

Precise observations of irrigated agriculture taken year after year by the Landsat series of satellites, for example, clearly show how fresh water consumption varies annually and spatially across the landscape.

Monday, November 21, 2011

NASA's TRMM satellite sees deadly tornadic thunderstorms in Southeastern US

Tornadoes are expected to accompany severe storms in the springtime in the U.S., but this time of year they also usually happen. When a line of severe thunderstorms associated with a cold front swept through the U.S. southeast on Nov. 16, TRMM collected rainfall data on the dangerous storms from space. NASA's Tropical Rainfall Measuring Mission (TRMM) satellite flew over the southeastern United States on November 16, 2011 at 2310 UTC (6:10 p.m. EST) when tornadoes were occurring with a line of thunderstorms that stretched from western Florida north through North Carolina. At least six deaths were caused by one of these tornadoes that destroyed three homes near Rock Hill, South Carolina.

Typically in the fall, the transition from warm air to cooler air occurs as Canadian cold air moves down into the U.S. The combination of a strong cold front with warm, moist air in its path enables the creation of strong to severe storms at this time of year.

TRMM data was used to create a rainfall analysis of the line of severe thunderstorms associated with the cold front. The analysis showed that the area of moderate to very heavy rainfall (falling at more than 2 inches or 50 mm per hour) with this frontal system was only located in a narrow line. In addition to heavy rain and some tornadoes, the strong cold front brought winds gusting over 30 mph, and a temperature drop of as much as 20 degrees as the front passed.

TRMM rainfall imagery is created at the NASA Goddard Space Flight Center in Greenbelt, Md. To create the images, rain rates in the center swaths are taken from the TRMM Precipitation Radar (PR), a unique space-borne precipitation radar, while rain rates in the outer swath are from the TRMM Microwave Imager (TMI). The rain rates are overlaid on infrared (IR) data from the TRMM Visible Infrared Scanner (VIRS) to form a complete picture of the rainfall in a storm or storm system like this one.

Thursday, November 17, 2011

Mobile Launcher Moves to Launch Pad

The mobile launcher is making the longest trip of its young life today to begin a two-week series of structural tests at Launch Pad 39B at NASA's Kennedy Space Center in Florida.

In anticipation of launching the Space Launch System later this decade, engineers wanted to check the mobile launcher, or ML, in a number of categories ranging from how it would behave moving atop a crawler-transporter to how well its systems mesh with the infrastructure at Pad B, which has undergone extensive renovations during the past year.

"We have the time and will be able to gain significant knowledge that will assist in the development of the ML," said Larry Schultz, ML project manager.

The ML began its 14-hour move at 9:15 a.m. on Nov. 16. The trip will cover about 4.2 miles from a work site beside the Vehicle Assembly Building to the launch pad.

Schultz said the team will get its first look at the information after the move is complete.

Rising 400 feet above the rocky crawlerway, the mobile launcher is substantially different than the mobile launcher platforms that carried space shuttles to the launch pads for 30 years. The dominant feature is the ML's tower, a 355-foot-high gray, steel tower reminiscent of the ones that serviced the Saturn V rockets headed to the moon in the 1960s and 70s.

In fact, not since 1975 has a launch structure as tall as the ML stood at either of Kennedy's launch pads.

The ML had been moved once before, but not very far. It was repositioned at its worksite beside the Vehicle Assembly Building in October 2010.

Although it was originally envisioned to host a slim rocket, the structure's design was flexible enough that it can be modified to support the Space Launch System, or SLS, a rocket that is in the same lifting category as the Saturn V.

The modifications to come include strengthening the supports in the base and widening the exhaust port the rocket will stand over. The ML's exhaust port now is a 22-foot square. It will be made into a 60-foot-by-30-foot rectangle.

Swing arms will be added to the tower in the 2015 timeframe, modified to provide fueling and venting along with electrical and communication links to the different stages of the rocket, along with a crew access arm reaching out to NASA's new Orion spacecraft at the top of the rocket. Even with the modifications, the structure will be lighter than the shuttle's mobile launcher platform.

The tower was built atop a 47-foot-tall base of steel that is 165 feet long and 135 feet wide. Altogether, the ML weighs in at 6.75 million pounds.

Tuesday, November 15, 2011

NASA grows audience, credibility through tweetups

HAMPTON, Va. (AP) — Rocket science isn't easily explainable in 140 characters, but NASA is asking a group of people to do just that with a series of VIP tours for some of its ardent Twitter followers.

The events called tweetups offer ordinary science fans a behind-the-scenes look at the space agency's facilities that can include its astronauts and scientists. In exchange, many participants — whose day jobs range from church office worker to baker — narrate their day through tweets, photographs and videos.

NASA's imagination-grabbing work gives it a bigger pool of fans to draw from than many companies or government agencies, and it sets itself apart further with its egalitarian approach to social media. While it's not unusual for an organization to give special access to journalists or influential bloggers, experts say NASA sets itself apart by inviting people who may only have a few dozen followers.

"It goes against the grain of only talking to people that have a lot of influence," said William Ward, a social media professor at Syracuse University.

Participants are chosen through a lottery. While some end up being self-described techies who blog regularly about space, it's important to NASA that it draws people with a wide range of interests who can tweet with authentic voices to a varied audience.

"I think everybody knows if you hear it from a friend or a family member, you see it as being much more credible than it being from a government organization like NASA," said Stephanie Schierholz, NASA's social media manager.

The sentiment was echoed by a participant in a tweetup held last week at Langley Research Center in Hampton.

"I know I have friends at home who are following every word here. And they're not normally space enthusiasts, but it's just something that, 'Hey, David's going down there. Let's see what he's up to.' And they're following my photos and my tweets and they get excited, too," said David Parmet, from Westchester County, N.Y.

NASA's first tweetup was in 2009, and it's held a total of 30. Some have coincided with news events like rocket launches, and one is planned in Florida the week of Thanksgiving for the Mars rover launch. The events can last from two hours to two days, ranging from a few dozen participants to more than 100. Participants pay their own travel expenses.

While it's not clear how many new Twitter followers NASA has gained from the tweetups, the number is expanding rapidly. Since June, nearly 600,000 people have started following the agency — about 4,000 to 5,000 per day — for a total of about 1.6 million.

NASA tweetup alumni closely monitor their reach and noted that when 150 participants were invited to Kennedy Space Center in Florida this August for the Juno spacecraft launch their tweets — through the power of retweets — had 29.9 million potential views.

"This is pretty small from a resource perspective, yet it has this huge impact," Schierholz said.

The tweetup has become a prime example of how NASA is harnessing social media to keep the agency in the public's imagination in an era where its most recognizable program, the space shuttle, has come to an end.

"We know more about Kim Kardashian than we do important scientific events that are happening in our country," said Donna Hoffman, a marketing professor at the University of California at Riverside. "This is NASA's opportunity, I think, to educate a new demographic."

Schierholz said the public generally has a strong positive reaction to NASA, but is unfamiliar with a lot of its work.

That is particularly true at Langley. Among other things, the center's research has resulted in wing design that allows airplanes to use less fuel. It's currently testing whether a craft designed to send astronauts into deep space can survive falling into the Pacific Ocean.

The work is important, but it rarely generates public excitement.

"We really do live in a visual society and people want to be able to see things," said Rob Wyman, Langley's news chief. "One of our challenges here is that there's a sort of latency to the work that we do here. There's a very deliberative process that research follows that tends to take a lot more time."

Illustrating the center's lack of fame, one participant at last week's tweetup from Maine was late because he thought the center was across the state in Langley, Va., the same place that's home to the CIA. It's a common mistake.

Even for those who live near one, opportunities to visit a NASA facility are limited.

Monday, November 14, 2011

NASA Ready for November Launch of Car-Size Mars Rover

PASADENA, Calif. -- NASA's most advanced mobile robotic laboratory, which will examine one of the most intriguing areas on Mars, is in final preparations for a launch from Florida's Space Coast at 10:25 a.m. EST (7:25 a.m. PST) on Nov. 25.

The Mars Science Laboratory mission will carry Curiosity, a rover with more scientific capability than any ever sent to another planet. The rover is now sitting atop an Atlas V rocket awaiting liftoff from Cape Canaveral Air Force Station.

"Preparations are on track for launching at our first opportunity," said Pete Theisinger, Mars Science Laboratory project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "If weather or other factors prevent launching then, we have more opportunities through Dec. 18."

Scheduled to land on the Red Planet in August 2012, the one-ton rover will examine Gale Crater during a nearly two-year prime mission. Curiosity will land near the base of a layered mountain 3 miles (5 kilometers) high inside the crater. The rover will investigate whether environmental conditions ever have been favorable for development of microbial life and preserved evidence of those conditions.

"Gale gives us a superb opportunity to test multiple potentially habitable environments and the context to understand a very long record of early environmental evolution of the planet," said John Grotzinger, project scientist for the Mars Science Laboratory at the California Institute of Technology in Pasadena. "The portion of the crater where Curiosity will land has an alluvial fan likely formed by water-carried sediments. Layers at the base of the mountain contain clays and sulfates, both known to form in water."

Curiosity is twice as long and five times as heavy as earlier Mars rovers Spirit and Opportunity. The rover will carry a set of 10 science instruments weighing 15 times as much as its predecessors' science payloads.

A mast extending to 7 feet (2.1 meters) above ground provides height for cameras and a laser-firing instrument to study targets from a distance. Instruments on a 7-foot-long (2.1-meter-long) arm will study targets up close. Analytical instruments inside the rover will determine the composition of rock and soil samples acquired with the arm's powdering drill and scoop. Other instruments will characterize the environment, including the weather and natural radiation that will affect future human missions.

"Mars Science Laboratory builds upon the improved understanding about Mars gained from current and recent missions," said Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters in Washington. "This mission advances technologies and science that will move us toward missions to return samples from, and eventually send humans to, Mars."

The mission is challenging and risky. Because Curiosity is too heavy to use an air-bag cushioned touchdown, the mission will use a new landing method, with a rocket-powered descent stage lowering the rover on a tether like a kind of sky-crane.

Tuesday, November 8, 2011

Space shuttle data leads to better model for solar power production in California

The space shuttle program may have ended, but data the space craft collected over the past three decades are still helping advance science. Researchers at the Jacobs School of Engineering at UC San Diego recently used measurements from NASA's Shuttle Radar Topography Mission to predict how changes in elevation, such as hills and valleys, and the shadows they create, impact power output in California's solar grid.

Current large-scale models used to calculate solar power output do not take elevation into account. The California Public Utilities Commission asked Jan Kleissl, a professor of environmental engineering at the Jacobs School of Engineering at UC San Diego, and postdoctoral researcher Juan Luis Bosch, from the department of mechanical and aerospace engineering, to build a model that does.

This is the first time this kind of model will be made available publicly on such a large scale, including all of Southern California, as well as the San Francisco Bay Area. It took the Triton Supercomputer at the San Diego Supercomputer Center here at UCSD 60,000 processor hours to run calculations for the model. Utility companies and homeowners can use the model to get a more realistic picture of the solar power output they can typically expect to produce. This is an especially important tool for utilities, because it gives them a better idea of how much revenue they can actually generate, Kleissl said.

Changes in elevation can have a significant impact on solar power output. The longer it takes for the sun to rise above the local horizon in the morning and the earlier it sets in the evening, the more solar fuel is lost. Solar days are longest on top of tall mountains. They are shortest in steep valleys oriented north-south, where it can take more than an hour longer for the sun to appear in the east.

Monday, October 31, 2011

Progress Launch: Russia successfully resumes Soyuz booster flights to the ISS

Russia’s space agency Roscosmos has successfully returned the venerable Soyuz booster to flight via the launch of the Soyuz-U booster carrying the uncrewed Progress M-13M/45P resupply spacecraft to the International Space Station (ISS). The launch is the first successful Soyuz booster flight to the ISS since the 24th August failure of the Soyuz-U booster carrying the Progress M-12M/44P spacecraft.

Previous failure:
Following the 24th August liftoff of the Soyuz-U booster carrying the Progress M-12M/44P resupply spacecraft to the ISS, the booster’s third stage unexpectedly shut down shortly after ignition, causing the third stage with attached Progress spacecraft to fall back to Earth and disintegrate in the atmosphere.

The failure could not have come at a worse time for the ISS, with the workhorse Space Shuttle having been retired only the previous month, and commercial resupply spacecraft still engaged in preparations for their debut launches to the station.

While the loss of supplies from Progress M-12M wasn’t a huge concern to the ISS due to the “heavy” delivery of cargo by the final Space Shuttle mission in July, more concerning was the fact that the third stage of the Soyuz-U booster used to launch unmanned spacecraft to the ISS shares a lot of commonality with the third stage of the Soyuz-FG booster used to launch crews to the station.

Following the launch failure, all Soyuz boosters were grounded pending an investigation, a move which forced delays to other crew and cargo flights to the ISS.

With impressive speed, a Russian commission quickly determined the cause of the failure to be a blocked fuel line leading to the gas generator in the Soyuz-U third stage’s RD-0110 engine. The blocked fuel line caused a loss of pressure in the gas generator, which in turn caused a shutdown of the RD-0110 engine’s turbopump, leading to a total loss of thrust.

While the blocked fuel line was attributed to a random, one-off event caused by human error in vehicle processing, all Soyuz third stages were ordered to be sent back to their assembly plant for through testing. With the tests confirming that the previous defect was indeed a one-off, Russia cleared the Soyuz booster for resumption of flights.

In order to prevent a re-occurrence of the defect, numerous new safety measures were implemented, including video cameras to record all stages of Soyuz booster assembly.

Numerous Russian media reports have cited ageing workforces, poor salaries, and a lack of investment as causes for the decline in the quality of the usually highly reliable Soyuz booster, which has completed well over one-thousand successful flights.

Fallout from the failure:
The largest concern resulting from the launch failure was that the Soyuz booster would not be returned to flight in time to launch a new crew to the ISS before the current one had to return to Earth, leading to a de-crewing of the station.

While operating the ISS in an un-crewed configuration is technically possible, it is highly undesirable due to the loss of scientific research and increased risk resulting from on-board failures, as detailed at length in previous articles on this site.

Thursday, October 27, 2011

NASA-backed space taxi to fly in test next summer

Sierra Nevada Corp's "Dream Chaser" space plane, which resembles a miniature space shuttle, is one of four space taxis being developed by private industry with backing from the U.S. government.

For the unmanned test flight, it will be carried into the skies by WhiteKnightTwo, the carrier aircraft for the commercial suborbital passenger ship SpaceShipTwo, backed by Virgin Galactic, a U.S. company owned by Richard Branson's London-based Virgin Group.

The test flight was added after privately held Sierra Nevada got a $25.6-million boost to its existing $80 million contract with NASA.

The test flight will take place from either Edwards Air Force Base in California's Mojave Desert, or from the White Sands Missile Range in New Mexico, Ed Mango, manager of NASA's Commercial Crew Program, said at a community briefing at the Kennedy Space Center in Florida.

With the retirement of the space shuttles this summer, NASA is now dependent on Russia to fly astronauts to the space station, at a cost of more than $50 million per person.

The agency hopes to turn over crew transportation services to one or more commercial firms before the end of 2016, Mango said.

In addition to Sierra Nevada, NASA is funding spaceship development work at Boeing Co, Space Exploration Technologies, and Blue Origin, a start-up firm owned by Amazon founder Jeff Bezos.

"Having only one way to get crew to the station is a limitation," NASA astronaut Mike Fossum, who is currently living aboard the outpost, said during an in-flight interview last week.

Thursday, October 20, 2011

China Will Own the Moon, Space Entrepreneur Worries

LAS CRUCES, N.M. — A new game of "Solar System Monopoly" is under way, and the United States is losing, commercial space entrepreneur Robert Bigelow said today (Oct. 19).

The first prize, ownership of the moon, is up for grabs, and China will likely snag it, Bigelow said here at the 2011 International Symposium for Personal and Commercial Spaceflight.

Bigelow's Las Vegas-based company, Bigelow Aerospace, is constructing private inflatable space modules that it hopes to rent out to government and commercial customers. The firm is even working on a series of labs for a human lunar colony.

But by the time the America gets into gear to build its own moon base, large swaths of lunar territory may already be claimed, Bigelow said in a talk that the firebrand entrepreneur warned the audience would be "controversial."

"Americans are still basking in the lunar glory from 40 years ago," Bigelow said. "But we don’t own one square foot of the damn place. NASA is a shadow of the space agency it once was in the 1960s and 1970s."

In contrast, he argued, China has the motivation and ability to win the next space race and claim ownership of much of the moon. Bigelow argued that international law would allow a nation to make such a claim, especially if it were able to enforce it through continuous human lunar presence.

Owning the moon would be a windfall both financially and for international prestige, he said. Not only does it offer a jumping off point for further exploration of the solar system, but it also contains vast stores of valuable resources such as water and helium-3, a possible fuel for nuclear fusion.

Moreover, the symbolic and global psychological impact would be huge, Bigelow said. "I think nothing else China could possibly do in the next 15 years would cause as great a benefit for China."

In addition to China's growing technological prowess, the country has the cash, the lack of debt and the national will to become the owner of the moon, Bigelow argued. He predicted China could claim ownership of vast swaths of lunar territory by 2022 to 2026.

"Hopefully this will produce the fear factor necessary to motivate the Americans," Bigelow said.

But while the U.S. could be losing the race to own the moon, Bigelow said that Mars offers another frontier up for grabs.

Wednesday, October 19, 2011

Arctic Sea Ice Continues Decline, Hits 2nd-Lowest Level

Last month the extent of sea ice covering the Arctic Ocean declined to the second-lowest extent on record. Satellite data from NASA and the NASA-supported National Snow and Ice Data Center (NSIDC) at the University of Colorado in Boulder showed that the summertime sea ice cover narrowly avoided a new record low.

The Arctic ice cap grows each winter as the sun sets for several months and shrinks each summer as the sun rises higher in the northern sky. Each year the Arctic sea ice reaches its annual minimum extent in September. It hit a record low in 2007.

The near-record ice-melt followed higher-than-average summer temperatures, but without the unusual weather conditions that contributed to the extreme melt of 2007. "Atmospheric and oceanic conditions were not as conducive to ice loss this year, but the melt still neared 2007 levels," said NSIDC scientist Walt Meier. "This probably reflects loss of multiyear ice in the Beaufort and Chukchi seas as well as other factors that are making the ice more vulnerable."

Joey Comiso, senior scientist at NASA's Goddard Space Flight Center in Greenbelt, Md., said the continued low minimum sea ice levels fits into the large-scale decline pattern that scientists have watched unfold over the past three decades.

"The sea ice is not only declining, the pace of the decline is becoming more drastic," Comiso said. "The older, thicker ice is declining faster than the rest, making for a more vulnerable perennial ice cover."

While the sea ice extent did not dip below the 2007 record, the sea ice area as measured by the microwave radiometer on NASA's Aqua satellite did drop slightly lower than 2007 levels for about 10 days in early September, Comiso said. Sea ice "area" differs from extent in that it equals the actual surface area covered by ice, while extent includes any area where ice covers at least 15 percent of the ocean.

Arctic sea ice extent on Sept. 9, the lowest point this year, was 4.33 million square kilometers (1.67 million square miles). Averaged over the month of September, ice extent was 4.61 million square kilometers (1.78 million square miles). This places 2011 as the second lowest ice extent both for the daily minimum extent and the monthly average. Ice extent was 2.43 million square kilometers (938,000 square miles) below the 1979 to 2000 average.

This summer's low ice extent continued the downward trend seen over the last 30 years, which scientists attribute largely to warming temperatures caused by climate change. Data show that Arctic sea ice has been declining both in extent and thickness. Since 1979, September Arctic sea ice extent has declined by 12 percent per decade.

Friday, October 14, 2011

Indo-French satellite put into orbit

SRIHARIKOTA: Despite gray skies on Wednesday morning, Indian Space Research Organisation’s (ISRO) trusted carrier, the Polar Satellite Launch Vehicle (PSLV), successfully carried an Indo-French joint satellite into space and placed it in orbit.
Besides this satellite, Megha-Tropiques, which will be used to provide groundbreaking real-time information about water cycles in the tropics, three other satellites— part of the vehicle’s 1,947 kg payload— were put in orbit.
The PSLV was launched from the Satish Dhawan Space Centre (SHAR) here.
Just over 21 minutes after the launch, ISRO chairman Dr K Radhakrishnan smilingly announced that the mission was a “grand success”. He described it as “a new phase of co-operation between India and France”.
This was the 20th PSLV launch.
It was also the 19th consecutive one that made it to orbit. Celebrations rang out at the control centre of the SDSC after the last satellite - Jugnu, developed by students of IIT-Kanpur, was deployed.
A representative from the Centre National d’Etudes Spatiales (CNES), the French space agency, said that he was impressed by the “professional launch”.
Radhakrishnan described Megha- Tropiques as “unique” and said it was of tremendous interest to the scientific community globally.
Explaining that the satellite would record and transmit parameters relating to tropical weather and climate to aid prediction, he said this was the “beginning of a new era in science”.

Wednesday, October 12, 2011

Surprisingly Earth-like features revealed on Saturn's moon

After meticulously stitching together images that were gathered over six years by a NASA spacecraft in orbit around Saturn, astronomers have created a global map of the surface of Titan, the ringed planet's largest moon, and it features some surprisingly Earth-like geological features.

An international team of astronomers, led by the University of Nantes in France, created the striking mosaic of Titan's surface using infrared images taken by the Visual and Infrared Mapping Spectrometer (VIMS) aboard NASA's Cassini spacecraft.

The global map and animations were presented Oct. 4 at the European Planetary Science Congress and the American Astronomical Society's Division of Planetary Science in Nantes, France.

The researchers used images that were taken during the Cassini mission's first 70 flybys of Titan. But, piecing together the map was an intricate and painstaking project because scientists had to comb through the pictures on a pixel-by-pixel basis to adjust illumination differences and other distortions caused by Titan's thick and hazy atmosphere, said Stéphane Le Mouélic, of the University of Nantes.

"As Cassini is orbiting Saturn and not Titan, we can observe Titan only once a month on average," Le Mouélic said in a statement. "The surface of Titan is therefore revealed year after year, as pieces of the puzzle are progressively put together. Deriving a final map with no seams is challenging due to the effects of the atmosphere — clouds, mist etc. — and due to the changing geometries of observation between each flyby."

Lifting the veil on Saturn's largest moon
Titan is the only moon known to be cloaked in a dense atmosphere, which is composed mainly of nitrogen. It also has clouds of methane and ethane, and ongoing research has presented increasing evidence for methane rain on the large, frigid moon.

Since Titan is veiled in an opaque atmosphere, its surface is difficult to study with visible light cameras, and only a few specific infrared wavelengths can penetrate the haze. Cassini's infrared instruments and radar signals provide an intriguing glimpse down to the surface of the frozen body, which, as the new global map reveals, has some interesting Earth-like features.

Tuesday, October 11, 2011

Antarctic underground lake could hold secrets of Earth's past

A lake hidden beneath three kilometres of ice in the western Antarctic could reveal what life on Earth looked like up to a million years ago and narrow down the search for extraterrestrial life.

A team of British scientists will arrive in Antarctica next week in the hope of becoming the first people to reach one of the frozen continent's 387 underground lakes.

Lake Ellsworth is likely to contain bacteria, microbes and other simple life forms which experts believe will have been sealed away from the rest of the Earth for up to a million years.

Samples of water and sediment to be collected from the lake could reveal undiscovered life forms which existed on Earth before the lake froze over, and what the planet's past climate was like.

The sediment collected from the bed of the lake is expected to support the theory that the West Antarctic Ice Sheet, which is currently on the wane thanks to higher global temperatures, has melted and collapsed in the past.

Scientists also hope to learn how any life is able to exist in one of the most extreme environments on the planet – a clue which could help astronomers searching for life beyond Earth.

A similar operation being carried out at Vostok, a different underground Antarctic lake, by Russian scientists has been beset by delays and technical problems for several years, but the British team hope to drill through the ice, obtain their samples and bring them to the surface in a matter of hours.

The expedition marks the climax of a 15-year project by eight British universities, the British Antarctic Survey and the National Oceanography Centre, funded principally by a £7 million grant from the National Environment Research Council.

Monday, October 10, 2011

Earth: History, Composition and Atmosphere

Earth – Overview

Physical Characteristics

Earth, our home, is the third planet from the sun. It is the only planet known to have an atmosphere containing free oxygen, oceans of liquid water on its surface, and, of course, life.

Earth is the fifth largest of the planets in the solar system — smaller than the four gas giants, Jupiter, Saturn, Uranus and Neptune, but larger than the three other rocky planets, Mercury, Mars and Venus. It has a diameter of roughly 8,000 miles (13,000 kilometers), and is round because gravity pulls matter into a ball, although it is not perfectly round, instead being more of an "oblate spheroid" whose spin causes it to be squashed at its poles and swollen at the equator.

Roughly 71 percent of Earth's surface is covered by water, most of it in the oceans. About a fifth of its atmosphere is made up of oxygen, produced by plants.

Orbital Characteristics
The Earth spins on an imaginary line called an axis that runs from the north pole to the south pole, while also orbiting the sun. It takes Earth 24 hours to complete a rotation on its axis, and roughly 365 days to complete an orbit around the sun.

The Earth's axis of rotation is tilted in relation to the ecliptic plane, an imaginary surface through Earth's orbit around the sun. This means the northern and southern hemispheres will sometimes point toward or away from the sun depending on the time of year, varying the amount of light they receive and causing the seasons.

Earth's orbit is not a perfect circle, but is rather an oval-shaped ellipse, like that of the orbits of all the other planets. Earth is a bit closer to the sun in early January and farther away in July, although this variation has a much smaller effect than the heating and cooling caused by the tilt of Earth's axis. Earth happens to lie within the so-called "Goldilocks zone" around its star, where temperatures are just right to maintain liquid water on its surface.

Earth probably formed at roughly the same time as the sun and other planets some 4.6 billion years ago, when the solar system coalesced from a giant, rotating cloud of gas and dust known as the solar nebula. As the nebula collapsed because of its gravity, it spun faster and flattened into a disk. Most of the material was pulled toward the center to form the sun. Other particles within the disk collided and stuck together to form ever-larger bodies, including the Earth. The solar wind from the sun was so powerful that it swept away most of the lighter elements, such as hydrogen and helium, from the innermost worlds, rendering Earth and its siblings into small, rocky planets.

Scientists think Earth started off as a waterless mass of rock. Radioactive materials in the rock and increasing pressure deep within the Earth generated enough heat to melt Earth's interior, causing some chemicals to rise to the surface and form water, while others became the gases of the atmosphere. Recent evidence suggests that Earth's crust and oceans may have formed within about 200 million years after the planet had taken shape.

The history of Earth is divided into four eons — starting with the earliest, these are the Hadean, Archean, Proterozoic, and Phanerozoic. The first three eons, which together lasted nearly 4 billion years, are together known as the Precambrian. Evidence for life has bee found in the Archaean about 3.8 billion years ago, but life did not become abundant until the Phanerozoic.

The Phanerozoic is divided into three eras — starting with the earliest, these are the Paleozoic, Mesozoic, and Cenozoic. The Paleozoic Era saw the development of many kinds of animals and plants in the seas and on land, the Mesozoic Era was the age of dinosaurs, and the Cenozoic Era we are in currently is the age of mammals.

Most of the fossils seen in Paleozoic rocks are invertebrate animals lacking backbones, such as corals, mollusks and trilobites. Fish are first found about 450 million years ago, while amphibians appear roughly 380 million years ago. By 300 million years ago, large forests and swamps covered the land, and the earliest fossils of reptiles appear during this period as well.

Thursday, October 6, 2011

The Universe, Dark Energy and Us

ALMOST every scientific talk or seminar in astronomy today starts from the idea that we live in a universe in which a mysterious force known as dark energy makes up about 70 percent of the total cosmic amount of everything. A mysterious substance known as dark matter makes up about 25 percent. And ordinary matter — the stuff of the periodic table, including interesting assemblies of matter like galaxies, stars, planets and people — is a paltry 5 percent.

If this is right, the things we observe in the universe are not the important things. Think of it this way: when you look at a snow-covered mountain, what you see is the snow, but the snow is not the mountain. In the cosmic setting, the fate of the universe depends on a tug of war between dark matter, which is trying to slow down the expansion of the universe, and dark energy, which is trying to speed things up. We see the motion of galaxies as the space between them stretches out and the light from exploding stars to judge their distances, but they are just tracers of the underlying reality.

Some people are upset by the idea that we are made up of material — atoms — that is a minor part of the cosmic scheme. Personally, it makes me feel special.

This week, the Nobel Prize in Physics was awarded for the discovery, by two separate teams of astronomers, that the expansion of the universe is speeding up as a result of the force of dark energy. Saul Perlmutter of the Supernova Cosmology Project shared the prize with Brian P. Schmidt and Adam G. Riess of the High-Z Supernova team. Mr. Schmidt and Mr. Riess were graduate students of mine at Harvard, and I participated in this scientific adventure.

Both teams found, while they were taking measurements of distant exploding stars in 1997, that the expansion of the universe seemed to be speeding up, but at first neither team believed it. The energy needed to drive this acceleration seemed too crazy. It smelled of the notorious “cosmological constant,” a kind of energy associated with empty space, which Einstein proposed in 1917 to guarantee a static universe and then later banished from polite company when the universe was observed to be not static, but expanding. “Away with the cosmological constant,” Einstein said. As my mother said to me (more than once), “Do you think you are smarter than Einstein?”

Yet just a decade after the first inklings, this is the standard picture, secure enough for cautious Swedish academicians to select for this year’s prize.

How did this happen? Not by persuasive argument, but by evidence. If the expansion of the universe is the result of a battle between dark energy speeding things up and dark matter slowing things down, then the history of cosmic expansion will have a record of which entity was winning at various points. Because light takes time to get to us, we can see into the past by observing distant objects. In the recent past (say, the last five billion years) we see acceleration. But if we could look far enough into the past, then the balance should tip — the dark matter should be denser when the universe was a smaller place, while the dark energy, if it resembles the cosmological constant, should hold steady. This would make the universe slow down. Mr. Riess led a group that carried out these observations with the Hubble Space Telescope. In 2004 and in 2007, his team showed that the change from deceleration to acceleration really happened: the predictions for a dark energy/dark matter universe match the observations.

Wednesday, October 5, 2011

Spectacular Photo Captures Astronaut's Last Day in Space

he scene could be straight out of a science fiction film: A solitary astronaut gazes longingly at his home planet below from a spaceship observation deck — a tiny bubble of light in the vast ocean of space. But this isn't a sci-fi scene at all; it's a real-life photo from a NASA astronaut.

In the photo, American astronaut Ron Garan is looking down at Earth from the International Space Station. The photo was taken by a crewmate from a different part of the space station and shows Garan awash in bright light as he snaps his own photos from the orbiting lab's seven-window observation room, called the Cupola. Bright stars shine in the background, with Earth's atmosphere aglow and city lights visible on the Earth.

"How I spent my last day in space," Garan wrote in a Twitter post recently when he uploaded the image. "That's me in the cupola off the coast of Australia taking my last of >25K pics." [Amazing Space Photos by Astronaut Ron Garan]

Garan, who spent more than five months living and working on the space station, was a prolific space photographer and posted many stunning views of space, Earth and auroras during his stay.

Garan returned to Earth on Sept. 16 aboard a Russian Soyuz capsule, but during his spaceflight (as well as before and after it) he chronicled his work on Twitter under the moniker @Astro_Ron, He also runs a separate website called Fragile Oasis, which is dedicated to raising awareness about Earth and its environment.

Garan spent 164 days in space as part of the space station's Expedition 27 and Expedition 28 crews. He launched into orbit aboard a Russian Soyuz capsule on April 4.

Like all astronauts, Garan has said the views of Earth from space are awe-inspiring.

" I think it's very difficult not to be moved when you look at our planet from space. You see how beautiful it is, how fragile it is. You really get this feeling of, we've been given an incredible gift," Garan told after returning to Earth. "We are very, very fortunate."

Tuesday, October 4, 2011

Secret mission of X-37B may go into overtime

After nearly seven months of flight, the U.S. Air Force's latest X-37 robotic space plane is nearing a milestone in its secret mission in Earth orbit as it chalks up mileage and operational experience.

As of last week, the reusable X-37B space plane had been in orbit for more than 206 days, two months shy of its 270-day mission design lifetime. The spacecraft, which looks like a miniature space shuttle, launched on its clandestine mission on March 5 from Cape Canaveral, Fla.

The space plane is the second X-37B spacecraft built for the Air Force by Boeing's Phantom Works and carries the name Orbital Test Vehicle 2, or OTV-2.

The X-37B — like the now- retired NASA space shuttles — is capable of returning experiments to Earth for further inspection and analysis, as well as re-flight of equipment. [ Photos: Air Force's 2nd Secret X-37B Mission ]

Extended flight possible
"On-orbit experimentation is continuing, though we cannot predict accurately when that will be complete," said Air Force Lt. Col. Tom McIntyre, the X-37 systems program director. “We are learning new things about the vehicle every day, which makes the mission a very dynamic process."

McIntyre told that X-37B controllers initially planned a nine-month mission "but will try to extend it as circumstances allow." Doing so would provide program officials with additional experimentation opportunities "and allow us to extract the maximum value out of the mission," he said. [ Infographic: Inside the X-37B Space Plane ]

The X-37B is being operated under the direction of Air Force Space Command's 3rd Space Experimentation Squadron, a space control unit located at Schriever Air Force Base in Colorado.

These hush-hush missions fall under the auspices of the Air Force Rapid Capabilities Office.

Mystery mission
The X-37B spacecraft is about 29 feet long and 15 feet wide. It has a payload bay about the size of a pickup truck bed. Thanks to a deployable solar array power system, the vehicle can fly a mission for up to 270 days, project officials have said in the past.

What exactly the vehicle does while circling the Earth is a mystery, since the spacecraft's cargo is consistently classified. Payloads may well involve high-tech testing of photoreconnaissance gear, but other hardware for intelligence-gathering could be onboard.

The first flight of an X-37B space plane, in 2010, entailed a mission that lasted 225 days. The spacecraft was lofted on April 22 and landed on Dec. 3, gliding onto a specially prepared runway at Vandenberg Air Force Base in California.

When this second X-37B mission draws to a close, a "do-it-itself" guided entry and wheels-down runway landing and similar to the end of the first mission are expected at Vandenberg Air Force Base, with neighboring Edwards Air Force Base as an alternate site.

If the incoming space plane strays off its auto-pilot trajectory zooming in over the Pacific Ocean, the craft is outfitted with a destruct mechanism.

Monday, October 3, 2011

NASA’s Dawn Spacecraft Moves Closer To Giant Vesta Asteroid

NASA’s Dawn spacecraft has travelled to within 420 miles of the giant asteroid Vesta.

The spacecraft this week completed its gentle spiral into its new science orbit, known as the high altitude mapping orbit (HAMO), to obtain an even closer view of the asteroid.

In this orbit, the average distance from the spacecraft to the Vesta surface is 420 miles (680 kilometers), which is four times closer than the previous survey orbit.

The spacecraft’s orbit around the asteroid will take a little over 12 hours, compared to three days previously. HAMO is scheduled to last about 30 Earth days, during which Dawn will circle Vesta more than 60 times.

When Dawn is over Vesta’s dayside, it will point its science instruments to the giant asteroid and acquire data, and when the spacecraft flies over the nightside, it will beam that data back to Earth.

Scientists will combine the pictures to create topographic maps, revealing the heights of mountains, the depths of craters and the slopes of plains. This will help scientists understand the geological processes that shaped Vesta.

“The team has been in awe of what they have seen on the surface of Vesta,” said Christopher Russell, Dawn principal investigator, at UCLA. “We are sharing those discoveries with the greater scientific community and with the public.”

Dawn launched in September 2007 and arrived at Vesta in July 2011. Following a year at Vesta, the spacecraft will depart in July 2012 for Ceres, where it will arrive in 2015

Meanwhile, NASA has announced that a Dawn mission news conference will be held Monday, Oct. 3, 2011 at 12:15 p.m. CEST (3:15 a.m. PDT/6:15 a.m. EDT). The conference will be streamed live online.

Friday, September 30, 2011

NASA Space Telescope Finds Fewer Asteroids Near Earth

Pasadena, CA – New observations by NASA’s Wide-field Infrared Survey Explorer, or WISE, show there are significantly fewer near-Earth asteroids in the mid-size range than previously thought. The findings also indicate NASA has found more than 90 percent of the largest near-Earth asteroids, meeting a goal agreed to with Congress in 1998.

Astronomers now estimate there are roughly 19,500 — not 35,000 — mid-size near-Earth asteroids. Scientists say this improved understanding of the population may indicate the hazard to Earth could be somewhat less than previously thought.
NEOWISE observations indicate that there are at least 40 percent fewer near-Earth asteroids in total that are larger than 330 feet, or 100 meters. Our solar system's four inner planets are shown in green, and our sun is in the center. Each red dot represents one asteroid. Object sizes are not to scale. (Image credit: NASA/JPL-Caltech)

However, the majority of these mid-size asteroids remain to be discovered. More research also is needed to determine if fewer mid-size objects (between 330 and 3,300-feet wide) also mean fewer potentially hazardous asteroids, those that come closest to Earth.

The results come from the most accurate census to date of near-Earth asteroids, the space rocks that orbit within 120 million miles (195 million kilometers) of the sun into Earth’s orbital vicinity. WISE observed infrared light from those in the middle to large-size category. The survey project, called NEOWISE, is the asteroid-hunting portion of the WISE mission. Study results appear in the Astrophysical Journal.

“NEOWISE allowed us to take a look at a more representative slice of the near-Earth asteroid numbers and make better estimates about the whole population,” said Amy Mainzer, lead author of the new study and principal investigator for the NEOWISE project at NASA’s Jet Propulsion Laboratory in Pasadena, CA. “It’s like a population census, where you poll a small group of people to draw conclusions about the entire country.”

WISE scanned the entire celestial sky twice in infrared light between January 2010 and February 2011, continuously snapping pictures of everything from distant galaxies to near-Earth asteroids and comets. NEOWISE observed more than 100 thousand asteroids in the main belt between Mars and Jupiter, in addition to at least 585 near Earth.

WISE captured a more accurate sample of the asteroid population than previous visible-light surveys because its infrared detectors could see both dark and light objects. It is difficult for visible-light telescopes to see the dim amounts of visible-light reflected by dark asteroids. Infrared-sensing telescopes detect an object’s heat, which is dependent on size and not reflective properties.

Though the WISE data reveal only a small decline in the estimated numbers for the largest near-Earth asteroids, which are 3,300 feet (1 kilometer) and larger, they show 93 percent of the estimated population have been found. This fulfills the initial “Spaceguard” goal agreed to with Congress. These large asteroids are about the size of a small mountain and would have global consequences if they were to strike Earth. The new data revise their total numbers from about 1,000 down to 981, of which 911 already have been found. None of them represents a threat to Earth in the next few centuries. It is believed that all near-Earth asteroids approximately 6 miles (10 kilometers) across, as big as the one thought to have wiped out the dinosaurs, have been found.

“The risk of a really large asteroid impacting the Earth before we could find and warn of it has been substantially reduced,” said Tim Spahr, the director of the Minor Planet Center at the Harvard Smithsonian Center for Astrophysics in Cambridge, MA.

Thursday, September 29, 2011

Long way to the chemist’s: a rough guide to distances in the universe

Space is big. You just won’t believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space.”

Douglas Adams, The Hitchhikers Guide to the Galaxy

We all know the universe is large, very large, but is it possible to really comprehend just how large it really is? Sit down, take a deep breath, and we can give it a go.

In my previous scale article, we considered the sizes of stars, and finished by imagining the sun being the size of an orange. On this scale, the nearest star to the sun, also the size of an orange, would be 2,300 kilometres away.

Even through stars can be immense on human scales, they are dwarfed by the distances between them.

On a clear night, away from the lights of civilisation, we may be able to pick out a few thousand individual stars as mere points of light.

The smooth swathe of light that accompanies them, however, is the combined light of many more distant stars. How many? It turns out the Milky Way is home to more than 200 billion stars, lots of stars like the sun, a few spectacular giants, and many, many faint dwarfs.

To get a handle on the size of the Milky Way, let’s pretend the distance across it is 3,000km, roughly the distance between Sydney and Perth.

On this scale, the separation between the sun and its nearest neighbour would be about 100 metres, whereas the diameter of the sun itself would be about a tenth the thickness of a human hair. Other than a bit of tenuous gas, there’s a lot of empty space in the Milky Way.

For much of human history, we have prided ourselves on being at the centre of the universe, but as Douglas Adams pointed out, we live in the “unfashionable end of the Western Spiral arm of the Galaxy”.

If the small town of Ceduna in South Australia, sitting roughly midway between Sydney and Perth, was the centre of the Milky Way, our sun would be orbiting 850km away, somewhere beyond Mildura in north-western Victoria (and, no, I’m not suggesting Mildura is unfashionable!)

So the Milky Way is huge, and light, traveling at 300,000 kilometres a second, takes 100,000 years to cross from side to side.

But we know that we share the universe with many other galaxies, one of the nearest being a sister galaxy to our own, the large spiral galaxy in Andromeda.

Wednesday, September 28, 2011

'Accelerating universe' could be just an illusion

In 1929, cosmologists discovered that the universe is expanding — that space-time, the fabric of the cosmos, is stretching. Then in 1998, light coming from exploding stars called supernovas suggested that the universe is not only expanding, but that it has recently begun expanding faster and faster; its expansion has entered an "accelerating phase." This was bad news for the fate of the cosmos: An accelerating universe is ultimately racing toward a "Big Rip," the moment at which its size will become infinite and, in a flash, everything in it will be torn apart.

The discovery was bad news for the state of cosmology, too. Because gravity pulls stuff inward rather than pushing it out, cosmologists believed that the expansion of the universe ought to be slowing down, as everything in it felt the gravitational tug of everything else. They didn't understand the mechanism that seemed to be opposing the force of gravity, so to explain their observations, they invoked the existence of "dark energy," a mysterious, invisible substance that permeates space and drives its outward expansion.

Now, a new theory suggests that the accelerating expansion of the universe is merely an illusion, akin to a mirage in the desert. The false impression results from the way our particular region of the cosmos is drifting through the rest of space, said Christos Tsagas, a cosmologist at Aristotle University of Thessaloniki in Greece. Our relative motion makes it look like the universe as a whole is expanding faster and faster, while in actuality, its expansion is slowing down — just as would be expected from what we know about gravity.

If Tsagas' theory is correct, it would rid cosmology of its biggest headache, dark energy, and it might also save the universe from its harrowing fate: the Big Rip. Instead of ripping it to bits, the universe as Tsagas space-time envisions it would just roll to a standstill, then slowly start shrinking.

Cruising through space-time
Tsagas' alternative version of events, detailed in a recent issue of the peer-reviewed journal Physical Review D, builds on a recent discovery by Alexander Kashlinsky, a cosmologist at NASA's Observational Cosmology Laboratory. In a series of papers over the past three years, Kashlinsky and his colleagues have shown that the huge region of space-time in which we live — a region at least 2.5 billion light-years across — is moving relative to the rest of the universe, and fast.

Some cosmologists remain skeptical about the newfound "dark flow," as it's called, and say that more evidence is needed to persuade them that the strange phenomenon is real. But the evidence that does exist is compelling. Based on light collected from galaxy clusters, our enormous bubble of space-time appears to be drifting at a rapid clip of up to 2 million miles per hour. No one knows why, exactly — there may be something beyond the part of the universe we can see, tugging on us — but Tsagas argues that the dark flow is skewing our perspective on the behavior of the universe as a whole.

"My article discusses how observers living inside such a large-scale 'dark flow' could arrive at the (false) conclusion that the universe is accelerating, while it is actually decelerating," Tsagas told Life's Little Mysteries. In his paper, he illustrates that dark flow would cause the space-time within our moving bubble to expand faster than the space-time outside of it (which is not accelerating). Without considering the dark flow, but just knowing that light we observe from nearby galaxies left its source more recently than light from galaxies farther away, we get the false impression that the whole of space-time recently entered an accelerating phase.