Wednesday, April 4, 2012
and she beckons my return.
Since our departure I think of you
and yearn to fly across the heavens arm in arm.
I marvel at your figure,
defined by the edges of continents.
You gaze at me with turquoise eyes,
perhaps mistaken for ocean atolls.
You tease me to fall into your bosom,
sculptured by tectonic rifts,
only to move away as if playing some tantalizing game.
Time and time we turn together,
through day, and night, and day,
repeating encounters every 90 minutes with a freshness,
as if we have never seen our faces before.
We stroll outside together,
enveloped by naked cosmos,
filled with desire to be one.
you sense my every breath,
which masks your stare through visor haze.
We dance on the swirls of cloud tops,
while skirting the islands of blue.
You know my heart beats fast for you.
Oh, Space is my mistress,
and when our orbits coincide,
we will once again make streaks of aurora across the sky.
Tuesday, March 27, 2012
The image was taken by the MoonKam, or Moon Knowledge Acquired by Middle school students. Previously named Gravity Recovery And Interior Laboratory (GRAIL) A and B, the twin spacecraft are now called Ebb and Flow. Both washing-machine-sized orbiters carry a small MoonKAM camera. Over 60 student–requested images were taken by the Ebb spacecraft from March 15-17 and downlinked to Earth March 20.
"MoonKAM is based on the premise that if your average picture is worth a thousand words, then a picture from lunar orbit may be worth a classroom full of engineering and science degrees," said Maria Zuber, GRAIL mission principal investigator from the Massachusetts Institute of Technology in Cambridge, Mass. "Through MoonKAM, we have an opportunity to reach out to the next generation of scientists and engineers. It is great to see things off to such a positive start."
GRAIL is NASA's first planetary mission to carry instruments fully dedicated to education and public outreach. Students will select target areas on the lunar surface and request images to study from the GRAIL MoonKAM Mission Operations Center in San Diego.
The MoonKAM program is led by Sally Ride, America's first woman in space, and her team at Sally Ride Science in collaboration with undergraduate students at the University of California in San Diego. More than 2,700 schools spanning 52 countries are using the MoonKAM cameras.
"What might seem like just a cool activity for these kids may very well have a profound impact on their futures," Ride said. "The students really are excited about MoonKAM, and that translates into an excitement about science and engineering."
Launched in September 2011, Ebb and Flow will answer longstanding questions about the moon and give scientists a better understanding of how Earth and other rocky planets in the solar system formed.
NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the GRAIL mission for NASA's Science Mission Directorate in Washington. The Massachusetts Institute of Technology, Cambridge, is home to the mission's principal investigator, Maria Zuber. GRAIL is part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems in Denver built the spacecraft. The California Institute of Technology in Pasadena manages JPL for NASA.
Saturday, March 24, 2012
Monday, March 19, 2012
The end of the space shuttle program does not mean the end of NASA, or even of NASA sending humans into space. NASA has a robust program of exploration, technology development and scientific research that will last for years to come. Here is what's next for NASA:
NASA is designing and building the capabilities to send humans to explore the solar system, working toward a goal of landing humans on Mars. We will build the Multi-Purpose Crew Vehicle, based on the design for the Orion capsule, with a capacity to take four astronauts on 21-day missions.
NASA is also moving forward with the development of the Space Launch System -- an advanced heavy-lift launch vehicle that will provide an entirely new national capability for human exploration beyond Earth's orbit. The SLS rocket will use a liquid hydrogen and liquid oxygen propulsion system, which will include shuttle engines for the core stage and the J-2X engine for the upper stage.
We are developing the technologies we will need for human exploration of the solar system, including solar electric propulsion, refueling depots in orbit, radiation protection and high-reliability life support systems.
International Space Station
The International Space Station is the centerpiece of our human spaceflight activities in low Earth orbit. The ISS is fully staffed with a crew of six, and American astronauts will continue to live and work there in space 24 hours a day, 365 days a year. Part of the U.S. portion of the station has been designated as a national laboratory, and NASA is committed to using this unique resource for scientific research.
The ISS is a test bed for exploration technologies such as autonomous refueling of spacecraft, advanced life support systems and human/robotic interfaces. Commercial companies are well on their way to providing cargo and crew flights to the ISS, allowing NASA to focus its attention on the next steps into our solar system.
NASA is researching ways to design and build aircraft that are safer, more fuel-efficient, quieter, and environmentally responsible. We are also working to create traffic management systems that are safer, more efficient and more flexible. We are developing technologies that improve routing during flights and enable aircraft to climb to and descend from their cruising altitude without interruption.
We believe it is possible to build an aircraft that uses less fuel, gives off fewer emissions, and is quieter, and we are working on the technologies to create that aircraft. NASA is also part of the government team that is working to develop the Next Generation Air Transportation System, or NextGen, to be in place by the year 2025. We will continue to validate new, complex aircraft and air traffic control systems to ensure that they meet extremely high safety levels.
NASA is conducting an unprecedented array of missions that will seek new knowledge and understanding of Earth, the solar system and the universe. NASA has observatories in Earth orbit and deep space, spacecraft visiting the moon and other planetary bodies, and robotic landers, rovers, and sample return missions. NASA's science vision encompasses questions as practical as hurricane formation, as enticing as the prospect of lunar resources, and as profound as the origin of the Universe.
Thursday, March 15, 2012
The bright phenomenon will be caused by NASA's Anomalous Transport Rocket Experiment (ATREX), which will launch five chemical-bearing suborbital rockets in about five minutes to test the flow of winds and electrical currents at high altitudes. The rockets will blast off from NASA's Wallops Flight Facility on Wallops Island, Va., on the Atlantic coast during a window that opens tonight at midnight EDT and closes at 1:30 a.m. EDT Thursday.
As part of the mission, the five rockets will each release a chemical tracer that should inscribe brilliant milky white trails in the nighttime sky and allow scientists and the general public to actually "see" high-altitude winds at the edge of space, according to a NASA description.
Midnight launch lights
If all goes well, NASA intends to photograph the trails from three different sites: Wallops Island, southern New Jersey and the outer banks of North Carolina. Should weather conditions be unfavorable, the firings will be delayed to another night, with alternate launch dates available between March 16 and April 3.
Three different types of sounding rockets will be used to create the five cloud trails: two Terrier Improved Malemutes, two Terrier Improved Orions and one Terrier Oriole. These small rockets are powerful enough to launch instruments off the planet on short flights, but not strong enough to reach orbit and circle the Earth.
Each rocket will eject a stream of the chemical trimethyl aluminum (TMA), which will be illuminated at high altitudes by the sun (which will be below the local horizon at ground level). Initially, the clouds are expected to glow in reddish hues, then quickly turn to white, They could persist in the sky for as long as 20 minutes before fading completely away.
The ATREX project is aimed at gathering information to better understand the processes responsible for the high-altitude jet stream winds located 60 to 65 miles (97 to 105 kilometers) above the surface of the Earth.
That works out to a potential viewing radius of up to 450 miles (725 km), suggesting that the resultant cloud trails might be glimpsed from perhaps as far north as southern Vermont and New Hampshire, as far south as the border of coastal North and South Carolina and as far west as central West Virginia.
Monday, March 12, 2012
A fogbank is the least useful location for a telescope, yet today's space observatories effectively operate inside one. That's because Venus, Earth and Mars orbit within a vast dust cloud produced by comets and occasional collisions among asteroids. After the sun, this so-called zodiacal cloud is the solar system's most luminous feature, and its light has interfered with infrared, optical and ultraviolet observations made by every astronomical space mission to date.
"To put it simply, it has never been night for space astronomers," said Matthew Greenhouse, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Md. Light from zodiacal dust can be a thousand times brighter than the sources astronomers actually target, limiting sensitivity in much the same way that bright moonlight hampers ground-based observatories. The dust and its unwanted illumination are greatest in the plane of Earth's orbit, the same plane in which every space telescope operates.
Placing future astronomy missions on more tilted orbits would let spacecraft spend significant amounts of time above and below the thickest dust and thereby reduce its impact on observations. So Greenhouse teamed with Scott Benson at NASA's Glenn Research Center in Cleveland, Ohio, to investigate how these "dark sky" or extra-zodiacal orbits might improve mission science and to develop a means of cost-effectively reaching them.
"Just by placing a space telescope on these inclined orbits, we can improve its sensitivity by a factor of two in the near-ultraviolet and by 13 times in the infrared," Greenhouse explained. "That's a breakthrough in science capability with absolutely no increase in the size of the telescope's mirror."
Greenhouse, Benson and the COllaborative Modeling and Parametric Assessment of Space Systems (COMPASS) study team at NASA Glenn designed a mission that utilizes new developments in solar arrays, electric propulsion and lower-cost expendable launch vehicles. Their proof-of-concept mission is the Extra-Zodiacal Explorer (EZE), a 1,500-pound EX-class observatory that could accommodate a telescope in the size range of the recently completed WISE mission — all within the cost and schedule constraints of NASA’s Explorer Program.
Launched on a SpaceX Falcon 9 rocket, EZE would use a powerful new solar-electric drive as an upper stage to direct the spacecraft on a gravity-assist maneuver past Earth or Mars. This flyby would redirect the mission into an orbit inclined by as much as 30 degrees to Earth's.
The result, the scientists say, will be the highest-performance observatory ever achieved in the decades-long history of NASA's Explorer program.
"We see EZE as a game-changer, the first step on a new path for NASA Explorers that will yield major science goals despite limited resources," said Benson, who previously managed the new electric propulsion technology project.
Friday, March 9, 2012
WASHINGTON (AP) — A solar storm shook the Earth's magnetic field early Friday, but scientists said they had no reports of any problems with electrical systems.
After reports Thursday of the storm fizzling out, a surge of activity prompted space weather forecasters to issue alerts about changes in the magnetic field.
"We really haven't had any reports from power system operators yet," Rob Steenburgh, a space weather forecaster at the National Oceanic and Atmospheric Administration's Space Weather Prediction Center in Boulder, Colo., said early Friday. "But sometimes they don't come in until after the storm."
He said the storm reached a moderate level late Thursday, before going to a strong level early Friday. For most of Thursday, it was rated as minor.
Scientists say such storms don't pose a threat to people, just technology.
The space weather center's website says a storm rated as strong could force corrections to voltage systems and trigger false alarms on some protection devices, as well as increase drag on satellites and affect their orientation.
The forecasters weren't aware of any significant impact to electrical or technological systems, but said there was a two-hour blackout of high frequency radio communications — affecting mainly ham radio operations — stretching from eastern Africa to eastern Australia.
Steenburgh also said that there was another solar flare late Thursday, similar to the one a few days ago that set off the current storm.
"Right now we're still analyzing when it will arrive" and how strong it could be, he said.
The space weather center had reports of Northern Lights across Canada and dipping into the northern tier of U.S. states, Steenburgh said.
While some experts thought the threat from the solar storm passed by earlier Thursday, the space weather center maintained the storm's effects could continue through Friday morning.
The current storm, which started with a solar flare Tuesday evening, caused a stir Wednesday because forecasts were for a strong storm with the potential to knock electrical grids offline, mess with GPS and harm satellites. It even forced airlines to reroute a few flights on Thursday.
It was never seen as a threat to people, just technology, and teased skywatchers with the prospect of colorful Northern Lights dipping further south.
But when the storm finally arrived around 6 a.m. EST Thursday, after traveling at 2.7 million mph, it was more a magnetic breeze than a gale. The power stayed on. So did GPS and satellites. And the promise of auroras seemed to be more of a mirage.
Scientists initially figured the storm would be the worst since 2006, but now seems only as bad as ones a few months ago, said Joe Kunches, a scientist at the NOAA center. The strongest storm in recorded history was probably in 1859, he said.
"It's not a terribly strong event. It's a very interesting event," Kunches said.
Forecasters can predict the speed a solar storm travels and its strength, but the north-south orientation is the wild card. This time it was a northern orientation, which is "pretty benign," Kunches said. Southern would have caused the most damaging technological disruption and biggest auroras.
On Thursday, North American utilities didn't report any problems, said Kimberly Mielcarek, spokeswoman for the North American Electric Reliability Corporation, a consortium of electricity grid operators. Her office didn't respond to a phone call early Friday.
Wednesday, March 7, 2012
HiRISE captured the image on Feb. 16, 2012, while the orbiter passed over the Amazonis Planitia region of northern Mars. In the area observed, paths of many previous whirlwinds, or dust devils, are visible as streaks on the dusty surface.
The active dust devil displays a delicate arc produced by a westerly breeze partway up its height. The dust plume is about 30 yards or meters in diameter.
The image was taken during the time of Martian year when that planet is farthest from the sun. Just as on Earth, winds on Mars are powered by solar heating. Exposure to the sun's rays declines during this season, yet even now, dust devils act relentlessly to clean the surface of freshly deposited dust, a little at a time.
Dust devils occur on Earth as well as on Mars. They are spinning columns of air, made visible by the dust they pull off the ground. Unlike a tornado, a dust devil typically forms on a clear day when the ground is heated by the sun, warming the air just above the ground. As heated air near the surface rises quickly through a small pocket of cooler air above it, the air may begin to rotate, if conditions are just right.
The Mars Reconnaissance Orbiter has been examining Mars with six science instruments since 2006. Now in an extended mission, the orbiter continues to provide insights into the planet's ancient environments and how processes such as wind, meteorite impacts and seasonal frosts continue to affect the Martian surface today. This mission has returned more data about Mars than all other orbital and surface missions combined.
More than 21,700 images taken by HiRISE are available for viewing on the instrument team's website: http://hirise.lpl.arizona.edu . Each observation by this telescopic camera covers several square miles, or square kilometers, and can reveal features as small as a desk.
Thursday, March 1, 2012
The new research takes a closer look at how multi-year ice, ice that has made it through at least two summers, has diminished with each passing winter over the last three decades. Multi-year ice "extent" -- which includes all areas of the Arctic Ocean where multi-year ice covers at least 15 percent of the ocean surface -- is diminishing at a rate of -15.1 percent per decade, the study found.
There's another measurement that allows researchers to analyze how the ice cap evolves: multi-year ice "area," which discards areas of open water among ice floes and focuses exclusively on the regions of the Arctic Ocean that are completely covered by multi-year ice. Sea ice area is always smaller than sea ice extent, and it gives scientists the information needed to estimate the total volume of ice in the Arctic Ocean. Comiso found that multi-year ice area is shrinking even faster than multi-year ice extent, by -17.2 percent per decade.
"The average thickness of the Arctic sea ice cover is declining because it is rapidly losing its thick component, the multi-year ice. At the same time, the surface temperature in the Arctic is going up, which results in a shorter ice-forming season," Comiso said. "It would take a persistent cold spell for most multi-year sea ice and other ice types to grow thick enough in the winter to survive the summer melt season and reverse the trend."
Scientists differentiate multi-year ice from both seasonal ice, which comes and goes each year, and "perennial" ice, defined as all ice that has survived at least one summer. In other words: all multi-year ice is perennial ice, but not all perennial ice is multi-year ice (it can also be second-year ice).
Comiso found that perennial ice extent is shrinking at a rate of -12.2 percent per decade, while its area is declining at a rate of -13.5 percent per decade. These numbers indicate that the thickest ice, multiyear-ice, is declining faster than the other perennial ice that surrounds it.
As perennial ice retreated in the last three decades, it opened up new areas of the Arctic Ocean that could then be covered by seasonal ice in the winter. A larger volume of younger ice meant that a larger portion of it made it through the summer and was available to form second-year ice. This is likely the reason why the perennial ice cover, which includes second year ice, is not declining as rapidly as the multiyear ice cover, Comiso said.
Multi-year sea ice hit its record minimum extent in the winter of 2008. That is when it was reduced to about 55 percent of its average extent since the late 1970s, when satellite measurements of the ice cap began. Multi-year sea ice then recovered slightly in the three following years, ultimately reaching an extent 34 percent larger than in 2008, but it dipped again in winter of 2012, to its second lowest extent ever.
Tuesday, February 28, 2012
One of the interesting topics discussed during a public event featuring biologist Richard Dawkins and physicist Lawrence Krauss was the thought that life could be built with an alien biochemistry. The event was attended by more than 3,000 people and was held at Arizona State University in Tempe.
Dawkins said that 99 percent of living things that used to exist are no longer in existence.
Krauss said that laws of physics and chemistry might favor carbon-based life resembling human.
Dawkins said that it is possible that life could exist in more diverse forms, provided that it has a code-carrying system just like DNA, copying itself with high fidelity.
In the same university, biochemist John Chaput was creating what he called TNA, an alternative version of DNA. He published the first evidence that TNA can undergo Darwinian evolution in January. Chaput agrees to Dawkins the need for genetic material for life to exist in more diverse forms just like DNA and RNA.
Alternative code-carriers were also experimented by NASA. The space agency claimed that scientists tried to substitute arsenic phosphorus of bacteria in their DNA. However, they never presented enough evidence that alternative life really existed, according to chemist Steve Benner.
Biochemist Rosemary Redfield duplicated the same process but the bacteria failed to grow when fed arsenic and no phosphorus.
Lunar Reconnaissance Orbiter (LRO) of NASA is most likely the most productive among all moon explorations as it already gathered almost a million pictures on the surface of the moon that are so vivid, even a coffee table can be seen in the midst of boulders.
Citizen science program has been encouraged by physicist and astrobiologist Paul Davies to examine closely these public-accessible photos of LRO to locate any artifacts that are extraterrestrial in origin.
However, parapsychology followers believe that NASA has been hiding evidence of aliens discovered on the surface of the moon. They say mind-travelers, who use a psychic technique known as remote viewing to travel other planets, have seen alien-looking things on the lunar surface.
The popularity of remote viewing started when U.S. government supported different parapsychology studies in 1970s and lasted until 1990s. After the funding was ended, an executive summary concluded that the psychic technique test results were “vague and ambiguous.”
Monday, February 20, 2012
Astronomers know how massive stars collapse to form black holes but it is not clear how supermassive black holes, which can weigh billions of times the mass of our sun, form in the cores of galaxies. One idea is that supermassive black holes may build up through the merger of smaller black holes.
Sean Farrell of the Sydney Institute for Astronomy in Australia discovered a middleweight black hole in 2009 using the European Space Agency’s XMM-Newton X-ray space telescope. Known as HLX-1 (Hyper-Luminous X-ray source 1), the black hole has an estimated weight of about 20,000 solar masses. It lies towards the edge of the galaxy ESO 243-49, 290 million light-years from Earth.
Farrell then observed HLX-1 simultaneously with NASA’s Swift observatory in X-ray and Hubble in near infrared, optical and ultraviolet wavelengths. The intensity and the color of the light may indicate the presence of a young, massive cluster of blue stars, perhaps 250-light-years across, encircling the black hole. Hubble can’t resolve the stars individually because the suspected cluster is too far away. The brightness and color is consistent with other clusters of stars seen in other galaxies, but some of the light may be coming from the gaseous disk around the black hole.
“Before this latest discovery, we suspected that intermediate-mass black holes could exist, but now we understand where they may have come from,” Farrell said. “The fact that there seems to be a very young cluster of stars indicates that the intermediate-mass black hole may have originated as the central black hole in a very-low-mass dwarf galaxy. The dwarf galaxy might then have been swallowed by the more massive galaxy, just as happens in our Milky Way.”
From the signature of the X-rays, Farrell’s team knew there would be some blue light emitted from the high temperature of the hot gas in the disk swirling around the black hole. They couldn’t account for the red light coming from the disk. It would have to be produced by a much cooler gas, and they concluded this would most likely come from stars.
Thursday, February 9, 2012
The Cross-track Infrared Sounder (CrIS) joins four other new instruments aboard the Suomi National Polar-orbiting Partnership (NPP) satellite, which NASA launched on Oct. 28, 2011 from Vandenberg Air Force Base in California. The Suomi NPP mission is the bridge between NOAA's Polar Operational Environmental Satellite (POES) and NASA's Earth Observing System satellites and the next-generation Joint Polar Satellite System (JPSS).
Since it reached orbit, Suomi NPP and its suite of five instruments are undergoing extensive checkouts before starting regular science observations. Suomi NPP is the result of a partnership between NASA, NOAA and the Department of Defense.
CrIS, an advanced spectrometer with 1,305 infrared spectral channels, is designed to provide high vertical resolution information on the atmosphere's three-dimensional structure of temperature and water vapor. The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua mission, launched in 2002, demonstrated how useful this type of data could be for understanding the atmosphere. CrIS will continue this data record and provide data for use in NOAA's numerical weather prediction models to forecast severe weather days in advance.
"Significant overlap between AIRS and CrIS will provide the Earth science research community the ability to maintain the unprecedented accuracy and stability of the temperature and moisture data record initiated by AIRS," said Diane Wickland, Suomi NPP program scientist at NASA Headquarters.
"Having data from CrIS will only improve the quality, timeliness and accuracy of NOAA's weather and climate predictions, which directly affect everyone in America," said Mary Kicza, assistant administrator for NOAA's Satellite and Information Service (NESDIS).
"Over longer periods, data from CrIS will help NOAA to better understand climate phenomena such as El Niño and La Niña that impact global weather patterns," said Mitch Goldberg, NOAA's JPSS program scientist.
The Advanced Technology Microwave Sounder (ATMS), which measures temperature and humidity in both clear and cloudy conditions, was the first Suomi NPP instrument activated. ATMS and CrIS data together will be used operationally in weather forecasts beginning in the Spring of 2012.
Wednesday, February 1, 2012
Saturday, January 21, 2012
The three planets, discovered by scientists led by Philip Muirhead from the University of California, all orbit a single star, are smaller than Earth and appear to be rocky with a solid surface.
Until now, astronomers have found at most only four other rocky planets, also called terrestrial planets, around other stars.
The trio of new planets is too close to the central star to be in its habitable zone, the ring-shaped region around a star where the temperature is mild enough for liquid water, and possibly life, to exist.
However, the planets are the first rocky ones to be found orbiting a type of dim, small star called a red dwarf, the most common kind in the Milky Way. Their existence suggests that the galaxy could be teeming with similarly rocky planets and that there’s a good chance that many are in the habitable zone.
The red dwarf, called KOI-961, was first flagged as a potential planetary system by the Kepler mission, a space telescope that looks for planets around sunlike stars by scanning the sky for stars that periodically dip in brightness—the result of one or more planets passing in front of them.
Although Kepler reported 900 potential planetary systems in February, only about 85 of those were red-dwarf systems. The fact that a relatively small sample of red dwarfs produced three terrestrial planets means that either the Caltech-led team was really lucky or, more likely, that these planets are commonly found around red dwarfs.
This report comes just a few weeks after the Kepler team announced it had detected two rocky planets around a sunlike star—Kepler-20e and Kepler-20f—the first Earth-sized planets ever found and the smallest known at the time.
In January 2011, the Kepler team reported the discovery of the first unequivocally rocky planet around another star, Kepler-10b. Another planet—Corot-7b, which was found in 2009—could also be a rocky planet.
With the exception of Kepler-20e, which is about the size of Venus, the other previously discovered planets are all bigger than Earth. All three of the ones found by the Caltech-led team are smaller—the outermost one is about half the size of Earth and the other two are three-fourths the size of Earth.
In fact, the entire KOI-961 planetary system is remarkably tiny. KOI-961 has a diameter one-sixth that of the sun’s, making it just 70 percent bigger than Jupiter.
Each of the three planets needs less than two days to zip around their star, and all three are about one hundred times closer to that star than Earth is to the sun.
Since they’re so close to their star, they’re hot—the outermost planet is estimated to be about 200 degrees Celsius while the innermost planet is a scorching 500 degrees Celsius.
“The really amazing thing about this system is that the closest size comparison is to Jupiter and its moons,” John Johnson, one of the paper’s co-authors, said.
“This is causing me to have to fully recalibrate my notion of planetary and stellar systems,” he said.
Kepler’s initial measurements, which are automated to help it sift through roughly 150,000 stars, underestimated the size of KOI-961 and any planets it might have had.
No one realized this until amateur astronomer and paper coauthor Kevin Apps alerted Muirhead and his team to the idea that KOI-961 bore a remarkable resemblance to another red dwarf called Barnard''s Star, a nearby star that’s one of the most well-studied.
When the astronomers used telescopes at the Palomar and Keck Observatories to take a closer look at both stars, they found that the two are practically twins.
The characteristics of Barnard’s Star allowed the team to infer the properties of KOI-961, which is needed to deduce the nature of the planetary system from the star’s light curve, a plot of how the star dims over time due to transiting planets. In particular, the depth of the light curve, that is, how much the curve dips reveals the planets’ sizes.
Because the planets are so small, the only way they could have enough gravity to hold themselves together is if they are balls of rock, like Mercury, Venus, Earth, and Mars.
“Just three years ago, just talking about a rocky planet would have been pure speculation,” Johnson said.
“But these are unambiguously rocky,” he said.
Still, before they could make any conclusions, the researchers had to confirm that the dips in light detected by Kepler really were due to planets—and not something else, such as a pair of background stars in orbit around each other.
Tuesday, January 17, 2012
PASADENA, Calif. -- Engineers with NASA's Cassini mission are conducting diagnostic testing on a part of the spacecraft's radio system after its signal was not detected on Earth during a tracking pass in late December. The spacecraft has been communicating with Earth using a backup part.
The issue occurred with the ultra-stable oscillator, which is used for one type of radio science experiment and also as a means of sending data back to Earth. The spacecraft is currently using an auxiliary oscillator, whose frequency stability is adequate for transmitting data from the spacecraft to Earth. Tests later this month will help mission managers decide whether it will be possible to bring the ultra-stable oscillator back into service.
Some of the data collected for the radio science experiment using the auxiliary oscillator will be of lesser quality than that from the ultra-stable oscillator. Signals used for occultation experiments – where scientists analyze how radio signals are affected as they travel through Saturn's rings or the atmospheres of Saturn and its moons back to Earth – will be of lesser quality. A second kind of radio science investigation using gravity measurements to probe the internal structure of Saturn or its moons will not be affected. Cassini carries 12 science experiments.
The cause is still under investigation, but age may be a factor. The spacecraft launched in 1997 and has orbited Saturn since 2004. Cassini completed its prime mission in 2008 and has had two additional mission extensions. This is the first time its ultra-stable oscillator has had an issue.