Space Exploration – Spacecraft

Spitzer Telescope Maps Super Earth’s Climate

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The varying brightness of an exoplanet called 55 Cancri e is shown in this plot of infrared data captured by NASA’s Spitzer Space Telescope. Credits: NASA/JPL-Caltech/University of Cambridge

 

Observations from NASA’s Spitzer Space Telescope have led to the first temperature map of a super-Earth planet — a rocky planet nearly two times as big as ours. The map reveals extreme temperature swings from one side of the planet to the other, and hints that a possible reason for this is the presence of lava flows. 

 
 
 
 This animated illustration shows one possible scenario for the rocky exoplanet 55 Cancri e, nearly two times the size of Earth. New Spitzer data show that one side of the planet is much hotter than the other – which could be explained by a possible presence of lava pools.

Credits: NASA/JPL-Caltech

“Our view of this planet keeps evolving,” said Brice Olivier Demory of the University of Cambridge, England, lead author of a new report appearing in the March 30 issue of the journal Nature. “The latest findings tell us the planet has hot nights and significantly hotter days. This indicates the planet inefficiently transports heat around the planet. We propose this could be explained by an atmosphere that would exist only on the day side of the planet, or by lava flows at the planet surface.” 

The toasty super-Earth 55 Cancri e is relatively close to Earth at 40 light-years away. It orbits very close to its star, whipping around it every 18 hours. Because of the planet’s proximity to the star, it is tidally locked by gravity just as our moon is to Earth. That means one side of 55 Cancri, referred to as the day side, is always cooking under the intense heat of its star, while the night side remains in the dark and is much cooler. 

“Spitzer observed the phases of 55 Cancri e, similar to the phases of the moon as seen from the Earth. We were able to observe the first, last quarters, new and full phases of this small exoplanet,” said Demory. “In return, these observations helped us build a map of the planet. This map informs us which regions are hot on the planet.”

Spitzer stared at the planet with its infrared vision for a total of 80 hours, watching it orbit all the way around its star multiple times. These data allowed scientists to map temperature changes across the entire planet. To their surprise, they found a dramatic temperature difference of 2,340 degrees Fahrenheit (1,300 Kelvin) from one side of the planet to the other. The hottest side is nearly 4,400 degrees Fahrenheit (2,700 Kelvin), and the coolest is 2,060 degrees Fahrenheit (1,400 Kelvin). 

The fact Spitzer found the night side to be significantly colder than the day side means heat is not being distributed around the planet very well. The data argues against the notion that a thick atmosphere and winds are moving heat around the planet as previously thought. Instead, the findings suggest a planet devoid of a massive atmosphere, and possibly hint at a lava world where the lava would become hardened on the night side and unable to transport heat.

“The day side could possibly have rivers of lava and big pools of extremely hot magma, but we think the night side would have solidified lava flows like those found in Hawaii,” said Michael Gillon, University of Liège, Belgium. 

The Spitzer data also revealed the hottest spot on the planet has shifted over a bit from where it was expected to be: directly under the blazing star. This shift either indicates some degree of heat recirculation confined to the day side, or points to surface features with extremely high temperatures, such as lava flows. 

Additional observations, including from NASA’s upcoming James Webb Space Telescope, will help to confirm the true nature of 55 Cancrie. 

The new Spitzer observations of 55 Cancri are more detailed thanks to the telescope’s increased sensitivity to exoplanets. Over the past several years, scientists and engineers have figured out new ways to enhance Spitzer’s ability to measure changes in the brightness of exoplanet systems. One method involves precisely characterizing Spitzer’s detectors, specifically measuring “the sweet spot” — a single pixel on the detector — which was determined to be optimal for exoplanet studies. 

“By understanding the characteristics of the instrument — and using novel calibration techniques of a small region of a single pixel — we are attempting to eke out every bit of science possible from a detector that was not designed for this type of high-precision observation,” said Jessica Krick of NASA’s Spitzer Space Science Center, at the California Institute of Technology in Pasadena.

NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.

 For more information about Spitzer, visit: http://www.nasa.gov/spitzer

Galaxy Clusters Reveal New Dark Matter Insights

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This comparison of galaxy clusters from the Sloan Digital Sky Survey DR8 galaxy catalog shows a spread-out cluster (left) and a more densely-packed cluster (right). A new study shows that these differences are related to the surrounding dark-matter environment. Credit: Sloan Digital Sky Survey


Editor’s Note: This story would have been up at 3:30pm on Monday, however, my tablet kept rebooting itself after an iOS update. Here it is, and it very interesting.


Dark matter is a mysterious cosmic phenomenon that accounts for 27 percent of all matter and energy. Though dark matter is all around us, we cannot see it or feel it. But scientists can infer the presence of dark matter by looking at how normal matter behaves around it.

Galaxy clusters, which consist of thousands of galaxies, are important for exploring dark matter because they reside in a region where such matter is much denser than average. Scientists believe that the heavier a cluster is, the more dark matter it has in its environment. But new research suggests the connection is more complicated than that. 

“Galaxy clusters are like the large cities of our universe. In the same way that you can look at the lights of a city at night from a plane and infer its size, these clusters give us a sense of the distribution of the dark matter that we can’t see,” said Hironao Miyatake at NASA’s Jet Propulsion Laboratory, Pasadena, California.

A new study in Physical Review Letters, led by Miyatake, suggests that the internal structure of a galaxy cluster is linked to the dark matter environment surrounding it. This is the first time that a property besides the mass of a cluster has been shown to be associated with surrounding dark matter.

Warping Galaxies
This image from NASA’s Hubble Space Telescope shows the inner region of Abell 1689, an immense cluster of galaxies. Scientists say the galaxy clusters we see today have resulted from fluctuations in the density of matter in the early universe. Credit: NASA/ESA/JPL-Caltech/Yale/CNRS

Researchers studied approximately 9,000 galaxy clusters from the Sloan Digital Sky Survey DR8 galaxy catalog, and divided them into two groups by their internal structures: one in which the individual galaxies within clusters were more spread out, and one in which they were closely packed together. The scientists used a technique called gravitational lensing — looking at how the gravity of clusters bends light from other objects — to confirm that both groups had similar masses.

But when the researchers compared the two groups, they found an important difference in the distribution of galaxy clusters. Normally, galaxy clusters are separated from other clusters by 100 million light-years on average. But for the group of clusters with closely packed galaxies, there were fewer neighboring clusters at this distance than for the sparser clusters. In other words, the surrounding dark-matter environment determines how packed a cluster is with galaxies.

“This difference is a result of the different dark-matter environments in which the groups of clusters formed. Our results indicate that the connection between a galaxy cluster and surrounding dark matter is not characterized solely by cluster mass, but also its formation history,” Miyatake said.

Study co-author David Spergel, professor of astronomy at Princeton University in New Jersey, added, “Previous observational studies had shown that the cluster’s mass is the most important factor in determining its global properties. Our work has shown that ‘age matters’: Younger clusters live in different large-scale dark-matter environments than older clusters.”

The results are in line with predictions from the leading theory about the origins of our universe. After an event called cosmic inflation, a period of less than a trillionth of a second after the big bang, there were small changes in the energy of space called quantum fluctuations. These changes then triggered a non-uniform distribution of matter. Scientists say the galaxy clusters we see today have resulted from fluctuations in the density of matter in the early universe.

“The connection between the internal structure of galaxy clusters and the distribution of surrounding dark matter is a consequence of the nature of the initial density fluctuations established before the universe was even one second old,” Miyatake said. 

Researchers will continue to explore these connections.

“Galaxy clusters are remarkable windows into the mysteries of the universe. By studying them, we can learn more about the evolution of large-scale structure of the universe, and its early history, as well as dark matter and dark energy,” Miyatake said.

 

 

 

 

NASA Telescopes Detect Jupiter-Like Storm on Small Star

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This illustration shows a cool star, called W1906+40, marked by a raging storm near one of its poles. Image credit: NASA/JPL-Caltech

 

Astronomers have discovered what appears to be a tiny star with a giant, cloudy storm, using data from NASA’s Spitzer and Kepler space telescopes. The dark storm is akin to Jupiter’s Great Red Spot: a persistent, raging storm larger than Earth.

“The star is the size of Jupiter, and its storm is the size of Jupiter’s Great Red Spot,” said John Gizis of the University of Delaware, Newark. “We know this newfound storm has lasted at least two years, and probably longer.” Gizis is the lead author of a new study appearing in The Astrophysical Journal.

While planets have been known to have cloudy storms, this is the best evidence yet for a star that has one. The star, referred to as W1906+40, belongs to a thermally cool class of objects called L-dwarfs. Some L-dwarfs are considered stars because they fuse atoms and generate light, as our sun does, while others, called brown dwarfs, are known as “failed stars” for their lack of atomic fusion.

The L-dwarf in the study, W1906+40, is thought to be a star based on estimates of its age (the older the L-dwarf, the more likely it is a star). Its temperature is about 3,500 degrees Fahrenheit (2,200 Kelvin). That may sound scorching hot, but as far as stars go, it is relatively cool. Cool enough, in fact, for clouds to form in its atmosphere.

“The L-dwarf’s clouds are made of tiny minerals,” said Gizis.

Spitzer has observed other cloudy brown dwarfs before, finding evidence for short-lived storms lasting hours and perhaps days.

In the new study, the astronomers were able to study changes in the atmosphere of W1906+40 for two years. The L-dwarf had initially been discovered by NASA’s Wide-field Infrared Survey Explorer in 2011. Later, Gizis and his team realized that this object happened to be located in the same area of the sky where NASA’s Kepler mission had been staring at stars for years to hunt for planets.

Kepler identifies planets by looking for dips in starlight as planets pass in front of their stars. In this case, astronomers knew observed dips in starlight weren’t coming from planets, but they thought they might be looking at a star spot — which, like our sun’s “sunspots,” are a result of concentrated magnetic fields. Star spots would also cause dips in starlight as they rotate around the star.

Follow-up observations with Spitzer, which detects infrared light, revealed that the dark patch was not a magnetic star spot but a colossal, cloudy storm with a diameter that could hold three Earths. The storm rotates around the star about every 9 hours. Spitzer’s infrared measurements at two infrared wavelengths probed different layers of the atmosphere and, together with the Kepler visible-light data, helped reveal the presence of the storm.

While this storm looks different when viewed at various wavelengths, astronomers say that if we could somehow travel there in a starship, it would look like a dark mark near the polar top of the star.

The researchers plan to look for other stormy stars and brown dwarfs using Spitzer and Kepler in the future.

“We don’t know if this kind of star storm is unique or common, and we don’t why it persists for so long,” said Gizis.

NASA’s Ames Research Center in Moffett Field, California, manages the Kepler and K2 missions for NASA’s Science Mission Directorate. JPL managed Kepler mission development. Ball Aerospace & Technologies Corp. operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

JPL manages the Spitzer Space Telescope mission for NASA. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech.

Caltech manages JPL for NASA.

For more information about Kepler and Spitzer visit: http://www.nasa.gov/kepler ohttp://www.nasa.gov/spitzer

 

NASA Hosts Media Call on Draft Solicitation for New Class of Launch Services 

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May 07, 2015
NASA Media Advisory M15-073

 

M-Cubed/COVE-2 is the reflightof a 1U CubeSat developed by U. Michigan to image the Earth at mid-resolution, approximately 200m per pixel, carrying the JPL developed COVE technology validation experiment.

Credits: NASA/JPL

NASA’s Launch Services Program has issued a draft Request for Proposal (RFP) for a new Venture Class Launch Services (VCLS), which would be commercial launch services for small satellites and experiments on science missions using a smaller than currently available class of rockets.

NASA will host a media teleconference at 1 p.m. EDT Monday, May 11 to discuss this strategic initiative, the RFP and the expectation for this class of launch services.

At present, launch opportunities for small satellites — often called CubeSats or nanosatellites — and small science missions are mostly limited to ride-share type arrangements, flying only when space is available on NASA and other launches. The Launch Services Program seeks to develop alternatives to this approach and help foster other launch services dedicated to transporting smaller payloads into orbit. The services acquired through such a contract will constitute the smallest class of launch services used by NASA.

Participants in the media briefing are:

  • Mark Wiese, chief, Flight Projects Branch, Launch Services Program Business Office, NASA’s Kennedy Space Center 
  • Garrett Skrobot, mission manager, Educational Launch of Nanosatellites (ELaNa), Launch Services Program, NASA’s Kennedy Space Center

This solicitation, and resulting contract or contracts, is intended to demonstrate a dedicated launch capability for smaller payloads that NASA anticipates it will require on a recurring basis for future science and CubeSat missions. CubeSats already are used in markets, such as imagery collection and analysis. In the future, CubeSat capabilities will include abilities, such as ship and aircraft tracking, improved weather prediction, and broader Internet coverage.

NASA intends to award one or more firm fixed-price VCLS contracts to accommodate 132 pounds (60 kilograms) of CubeSats a single launch or two launches carrying 66 pounds (30 kilograms) each. The launch provider will determine the launch location and date, but the launch must occur by April 15, 2018.

The public may watch or listen to the conference on either the phone or on NASA’s newsaudio website. Members of the media have received other information in order to participate, which has been excluded from this release.

However, the public is allowed to listen to the conference. To listen to teleconference, call 321-867-1220321-867-1240 or 321-867-1260 (usually reserved for members of the media), or the public and media members without proper credentials may listen online at: http://www.nasa.gov/newsaudio

For businessness interested in bidding process, the draft RFP is open for written questions and comments from industry entities until Wednesday, May 20. The final RFP, if issued, is anticipated to be released in June. The draft RFP may be accessed at: http://go.nasa.gov/1KMTeDR

For more information about NASA’s CubeSat Launch Initiative, visit: http://www.nasa.gov/directorates/heo/home/CubeSats_initiative.html

NASA’s Launch Services Program is focused on assuring the availability of long-term launch services for NASA while also promoting the continued evolution of the U.S. commercial space launch market. The capability anticipated to meet the requirement for a smaller launch vehicle represents an emerging category of launch services. 

For more information about NASA’s Launch Services Program, visit: http://www.nasa.gov/centers/kennedy/launchingrockets/index.html



NASA’s New Horizons Spacecraft Nears Historic July 14 Encounter with Pluto

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Artist’s impression of NASA’s New Horizons spacecraft encountering Pluto and its largest moon, Charon, in July 2015. Image Credit: NASA/Applied Physics Laboratory/Southwest Research Institute
 


(PRESS RELEASE) – NASA’s New Horizons spacecraft is three months from returning to humanity the first-ever close up images and scientific observations of distant Pluto and its system of large and small moons.

“Scientific literature is filled with papers on the characteristics of Pluto and its moons from ground based and Earth orbiting space observations, but we’ve never studied Pluto up close and personal,” said John Grunsfeld, astronaut, and associate administrator of the NASA Science Mission Directorate at the agency’s Headquarters in Washington.  “In an unprecedented flyby this July, our knowledge of what the Pluto systems is really like will expand exponentially and I have no doubt there will be exciting discoveries.”  

The fastest spacecraft ever launched, New Horizons has traveled a longer time and farther away – more than nine years and three billion miles – than any space mission in history to reach its primary target. Its flyby of Pluto and its system of at least five moons on July 14 will complete the initial reconnaissance of the classical solar system. This mission also opens the door to an entirely new “third” zone of mysterious small planets and planetary building blocks in the Kuiper Belt, a large area with numerous objects beyond Neptune’s orbit.

The flyby caps a five-decade-long era of reconnaissance that began with Venus and Mars in the early 1960s, and continued through first looks at Mercury, Jupiter and Saturn in the 1970s and Uranus and Neptune in the 1980s.

Reaching this third zone of our solar system – beyond the inner, rocky planets and outer gas giants – has been a space science priority for years. In the early 2000s the National Academy of Sciences ranked the exploration of the Kuiper Belt – and particularly Pluto and its largest moon, Charon – as its top priority planetary mission for the coming decade.

New Horizons – a compact, lightweight, powerfully equipped probe packing the most advanced suite of cameras and spectrometers ever sent on a first reconnaissance mission – is NASA’s answer to that call.

“This is pure exploration; we’re going to turn points of light into a planet and a system of moons before your eyes!” said Alan Stern, New Horizons principal investigator from Southwest Research Institute (SwRI) in Boulder, Colorado. “New Horizons is flying to Pluto – the biggest, brightest and most complex of the dwarf planets in the Kuiper Belt. This 21st century encounter is going to be an exploration bonanza unparalleled in anticipation since the storied missions of Voyager in the 1980s.”

Pluto, the largest known body in the Kuiper Belt, offers a nitrogen atmosphere, complex seasons, distinct surface markings, an ice-rock interior that may harbor an ocean, and at least five moons. Among these moons, the largest – Charon – may itself sport an atmosphere or an interior ocean, and possibly even evidence of recent surface activity.

“There’s no doubt, Charon is a rising star in terms of scientific interest, and we can’t wait to reveal it in detail in July,” said Leslie Young, deputy project scientist at SwRI.

Pluto’s smaller moons also are likely to present scientific opportunities. When New Horizons was started in 2001, it was a mission to just Pluto and Charon, before the four smaller moons were discovered.

The spacecraft’s suite of seven science instruments – which includes cameras, spectrometers, and plasma and dust detectors – will map the geology of Pluto and Charon and map their surface compositions and temperatures; examine Pluto’s atmosphere, and search for an atmosphere around Charon; study Pluto’s smaller satellites; and look for rings and additional satellites around Pluto.

Currently, even with New Horizons closer to Pluto than the Earth is to the Sun, the Pluto system resembles little more than bright dots in the distance. But teams operating the spacecraft are using these views to refine their knowledge of Pluto’s location, and skillfully navigate New Horizons toward a precise target point 7,750 miles (12,500 kilometers) from Pluto’s surface. That targeting is critical, since the computer commands that will orient the spacecraft and point its science instruments are based on knowing the exact time and location that New Horizons passes Pluto.

“Our team has worked hard to get to this point, and we know we have just one shot to make this work,” said Alice Bowman, New Horizons mission operations manager at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, which built and operates the spacecraft. “We’ve plotted out each step of the Pluto encounter, practiced it over and over, and we’re excited the ‘real deal’ is finally here.”

The spacecraft’s work doesn’t end with the July flyby. Because it gets one shot at its target, New Horizons is designed to gather as much data as it can, as quickly as it can, taking about 100 times as much data on close approach as it can send home before flying away. And although the spacecraft will send select, high-priority datasets home in the days just before and after close approach, the mission will continue returning the data stored in onboard memory for a full 16 months.

“New Horizons is one of the great explorations of our time,” said New Horizons Project Scientist Hal Weaver at APL. “There’s so much we don’t know, not just about Pluto, but other worlds like it. We’re not rewriting textbooks with this historic mission – we’ll be writing them from scratch.”

APL manages the New Horizons mission for NASA’s Science Mission Directorate in Washington. Alan Stern of SwRI is the principal investigator. SwRI leads the science team, payload operations and encounter science planning. New Horizons is part of the New Frontiers Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama.

For more information on New Horizons, visit:

http://www.nasa.gov/newhorizons

and

http://pluto.jhuapl.edu

NASA Mars Rover’s Weather Data Bolster Case for Brine

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Scene From ‘Artist’s Drive’ on Mars (Stereo) Curiosity View Ahead Through ‘Artist’s Drive’ (Stereo) Mars Weather-Station Tools on Rover’s Mast Curiosity View Ahead Through ‘Artist’s Drive’Scene From ‘Artist’s Drive’ on Mars The Rover Environmental Monitoring Station (REMS) on NASA’s Curiosity Mars rover includes temperature and humidity sensors mounted on the rover’s mast. One of the REMS booms extends to the left from the mast in this view. Credit: NASA/JPL-Caltech/MSSS

Martian weather and soil conditions that NASA’s Curiosity rover has measured, together with a type of salt found in Martian soil, could put liquid brine in the soil at night.

Perchlorate identified in Martian soil by the Curiosity mission, and previously by NASA’s Phoenix Mars Lander mission, has properties of absorbing water vapor from the atmosphere and lowering the freezing temperature of water. This has been proposed for years as a mechanism for possible existence of transient liquid brines at higher latitudes on modern Mars, despite the Red Planet’s cold and dry conditions.

New calculations were based on more than a full Mars year of temperature and humidity measurements by Curiosity. They indicate that conditions at the rover’s near-equatorial location were favorable for small quantities of brine to form during some nights throughout the year, drying out again after sunrise. Conditions should be even more favorable at higher latitudes, where colder temperatures and more water vapor can result in higher relative humidity more often.

“Liquid water is a requirement for life as we know it, and a target for Mars exploration missions,” said the report’s lead author, Javier Martin-Torres of the Spanish Research Council, Spain, and Lulea University of Technology, Sweden, and a member of Curiosity’s science team. “Conditions near the surface of present-day Mars are hardly favorable for microbial life as we know it, but the possibility for liquid brines on Mars has wider implications for habitability and geological water-related processes.”

Fast Facts:

  • Conditions that might produce liquid brine in Martian soil extend closer to the equator than expected
  • Perchlorate salt in soil can pull water molecules from the atmosphere and act as anti-freeze
  • Presence of brine would not make Curiosity’s vicinity favorable for microbes

The weather data in the report published today in Nature Geosciences come from the Cuirosity’s Rover Environmental Monitoring Station (REMS), which was provided by Spain and includes a relative-humidity sensor and a ground-temperature sensor. NASA’s Mars Science Laboratory Project is using Curiosity to investigate both ancient and modern environmental conditions in Mars’ Gale Crater region. The report also draws on measurements of hydrogen in the ground by the rover’s Dynamic Albedo of Neutrons (DAN) instrument, from Russia.

“We have not detected brines, but calculating the possibility that they might exist in Gale Crater during some nights testifies to the value of the round-the-clock and year-round measurements REMS is providing,” said Curiosity Project Scientist Ashwin Vasavada of NASA’s Jet Propulsion Laboratory, Pasadena, California, one of the new report’s co-authors.

Curiosity is the first mission to measure relative humidity in the Martian atmosphere close to the surface and ground temperature through all times of day and all seasons of the Martian year. Relative humidity depends on the temperature of the air, as well as the amount of water vapor in it. Curiosity’s measurements of relative humidity range from about five percent on summer afternoons to 100 percent on autumn and winter nights.

Air filling pores in the soil interacts with air just above the ground. When its relative humidity gets above a threshold level, salts can absorb enough water molecules to become dissolved in liquid, a process called deliquescence. Perchlorate salts are especially good at this. Since perchlorate has been identified both at near-polar and near-equatorial sites, it may be present in soils all over the planet.

Researchers using the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter have in recent years documented numerous sites on Mars where dark flows appear and extend on slopes during warm seasons. These features are called recurring slope lineae, or RSL. A leading hypothesis for how they occur involves brines formed by deliquesence.

“Gale Crater is one of the least likely places on Mars to have conditions for brines to form, compared to sites at higher latitudes or with more shading. So if brines can exist there, that strengthens the case they could form and persist even longer at many other locations, perhaps enough to explain RSL activity,” said HiRISE Principal Investigator Alfred McEwen of the University of Arizona, Tucson, also a co-author of the new report.

In the 12 months following its August 2012 landing, Curiosity found evidence for ancient streambeds and a lakebed environment more than 3 billion years ago that offered conditions favorable for microbial life. Now, the rover is examining a layered mountain inside Gale Crater for evidence about how ancient environmental conditions evolved. JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Science Laboratory and Mars Reconnaissance Projects for NASA’s Science Mission Directorate, Washington.

For more information about Curiosity, visit:

http://www.nasa.gov/msl

and

http://mars.jpl.nasa.gov/msl/

 

NASA Holds Teleconference on Hubble Observations of Jupiter’s Largest Moon

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NASA Holds Teleconference on Hubble Observations of Jupiter’s Largest Moon
(March 9, 2015)

Image of Jupiter's moon, GanymedeThis image of Ganymede, one of Jupiter’s moons and the largest moon in our solar system was taken by NASA’s Galileo spacecraft. Image Credit: NASA

NASA will host a teleconference at 11 a.m. EDT on Thursday, March 12, to discuss Hubble Space Telescope’s observations of Ganymede, Jupiter’s largest moon. These results will help scientists in the search for habitable worlds beyond Earth.

Participants in the teleconference will be:

  • Jim Green, director of Planetary Science, NASA Headquarters, Washington
  • Joachim Saur, professor for geophysics, University of Cologne, Germany
  • Jennifer Wiseman, Hubble senior project scientist, NASA Goddard Space Flight Center, Greenbelt, Maryland
  • Heidi Hammel, executive vice president, Association of Universities for Research in Astronomy, Washington

To participate by phone, reporters must contact Felicia Chou at felicia.chou and provide their media affiliation no later than noon Wednesday.

Audio of the teleconference will be streamed live on NASA’s website at:

http://www.nasa.gov/newsaudio

For information about NASA’s Hubble Space Telescope, visit:

http://www.nasa.gov/hubble

For information about our solar system, including Jupiter and Ganymede, visit:

https://solarsystem.nasa.gov/planets/

Rosetta comet probe team narrows landing site to five locations

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This annotated image depicts four of the five potential landing sites for the Rosetta mission's Philae lander.
This annotated image depicts four of the five potential landing sites for the Rosetta mission’s Philae lander (Courtesy NASA/JPL-Caltech, Image by ESA/Rosetta/MPS for OSIRIS Team).

The European Space Agency’s Rosetta Comet mission has chosen five likely landing sites for its Philae’s lander on comet 67P/Churyumov-Gerasimenko. The lander is scheduled to descend down to the comet’s nucleus in November.

According to a press release by NASA’s Jet Propulsion Laboratory:

Rosetta is an international mission headed up by the ESA with support from NASA, and will be the first ever attempt to land on a comet.

Rosetta is an international mission headed up by the ESA with support from NASA, including providing instruments.

 The European Space Agency’s Rosetta mission has chosen five candidate landing sites on comet 67P/Churyumov-Gerasimenko for its Philae lander. Philae’s descent to the comet’s nucleus, scheduled for this November, will be the first such landing ever attempted. Rosetta is an international mission spearheaded by the European Space Agency with support and instruments provided by NASA.
Picking the landing site is complex and a balancing the technical issues of the orbiter and lander during the entire phases of separation, descent, landing, and all operations on the surface must be precise.

Due to the distance from Earth and the orbiter and lander creates uncertainties in navigating the orbiter close to the comet, the only way possible to pick a landing site in terms of an ellipse, which will cover up to six-tenths of a square mile (or one square kilometer) where the Philae lander might land.

“This is the first time landing sites on a comet have been considered,” said Stephan Ulamec, Philae Lander Manager at the German Aerospace Center, Cologne, Germany in a press release.

“The candidate sites that we want to follow up for further analysis are thought to be technically feasible on the basis of a preliminary analysis of flight dynamics and other key issues – for example, they all provide at least six hours of daylight per comet rotation and offer some flat terrain. Of course, every site has the potential for unique scientific discoveries.”
 For each possible zone, important questions must be asked:

Will the lander be able to maintain regular communications with Rosetta?

 How common are surface hazards such as large boulders, deep crevasses or steep slopes?

Is there sufficient illumination for scientific operations and enough sunlight to recharge the lander’s batteries beyond its initial 64-hour lifetime without causing overheating?

The team reduced the number of landing sites from 10 to five, and gave them letters that have no special meanings.

 Three of the landing sites (B, I and J) are on the smaller lobe of the comet, where the other two sites (A and C) are located on the larger lobe.

“The process of selecting a landing site is extremely complex and dynamic; as we get closer to the comet, we will see more and more details, which will influence the final decision on where and when we can land,” said Fred Jansen, Rosetta’s mission manager from the European Space Agency’s Science and Technology Centre in Noordwijk, The Netherlands, in the same press release.

 “We had to complete our preliminary analysis on candidate sites very quickly after arriving at the comet, and now we have just a few more weeks to determine the primary site. The clock is ticking and we now have to meet the challenge to pick the best possible landing site.”
This image of comet 67P/Churyumov-Gerasimenko shows the diversity of surface structures on the comet...
This image of comet 67P/Churyumov-Gerasimenko shows the diversity of surface structures on the comet’s nucleus. It was taken by the Rosetta spacecraft’s navigation camera on August 7, 2014. At the time, the spacecraft was 65 miles (104 kilometers) away from the 2.5 mile (4 kilometer) wide nucleus. Courtesy NASA/JPL-Caltech, Image by ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DAS
 The next thing the team must do is to prepare a comprehensive analysis of each of the five landing sites so they can determine the best orbital and operational strategies that could be used so Rosetta can deliver the lander to any one of them.

During the time the team is preparing their analysis, Rosetta will move to 31 miles (50 kilometers) of the comet allowing more detailed study of the five landing sites.

 The Rosetta team will have the complete assessments of all five landing sites completed by September 14, and they will be ranked in order to select a primary landing site, with both a full detailed strategy for landing the orbiter at the primary or selected site, along with a backup contingency.

The ESA Rosetta team plans to land the Philae lander sometime around mid-November when the comet will be about 280 million miles (450 million Kilometers). This means the comet will be three times the distance than the Earth is to the Sun (280 million miles also equals 3 astronomical units, where an astronomical unit is 93 million miles, or the distance between the Sun and the Earth).

At 3 AU, there should be little to no activity on the comet that would jeopardize the landing of the Philae lander on the comet’s surface, and just before the comet becomes active.

Launched in March 2004, Rosetta was reactivated in January 2014 after a record 957 days in hibernation. Composed of an orbiter and lander, Rosetta’s objectives since arriving at comet 67P/Churyumov-Gerasimenko earlier this month are to study the celestial object up close in unprecedented detail, prepare for landing a probe on the comet’s nucleus in November, and track its changes through 2015, as it sweeps past the sun.

Illustration of comet-seeker Rosetta with details of its progress
Illustration of comet-seeker Rosetta with details of its progress (AFP/File – P. Pizarro/A. Bommenel/K. Tian)
 Rosetta’s objectives as the spacecraft reached comet 67P/Churyumov-Gerasimenko earlier this month is to do a close up study of the comet in unprecedented detail and to prepare for landing the probe on the comet’s nucleus and track any changes through 2015 as it orbits comet 67P/Churyumov-Gerasimenko.

Cosmologists consider comets as time capsules containing materials left over from building of the Solar System 3.4 billion years ago. Rosetta’s lander will obtain the very first images taken from a comet’s primordial composition by drilling into the surface.

 Scientists will also be able to study how a comet changes its composition as it makes its way around the Sun. It is believed this will help scientists to understand more about the role of comets may have played in seeding the Earth with water, and even life. They will also be able to learn more about the evolution of our Solar System.

According to the press release:

 The scientific imaging system, OSIRIS, was built by a consortium led by the Max Planck Institute for Solar System Research (Germany) in collaboration with Center of Studies and Activities for Space, University of Padua (Italy), the Astrophysical Laboratory of Marseille (France), the Institute of Astrophysics of Andalusia, CSIC (Spain), the Scientific Support Office of the European Space Agency (Netherlands), the National Institute for Aerospace Technology (Spain), the Technical University of Madrid (Spain), the Department of Physics and Astronomy of Uppsala University (Sweden) and the Institute of Computer and Network Engineering of the TU Braunschweig (Germany). OSIRIS was financially supported by the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain, and Sweden and the ESA Technical Directorate.

Rosetta is an ESA mission with contributions from its member states and NASA. Rosetta’s Philae lander is provided by a consortium led by the German Aerospace Center, Cologne; Max Planck Institute for Solar System Research, Gottingen; French National Space Agency, Paris; and the Italian Space Agency, Rome. NASA’s Jet Propulsion Laboratory in Pasadena, California, a division of the California Institute of Technology, manages the U.S. participation in the Rosetta mission for NASA’s Science Mission Directorate in Washington.

For Specifications on: 67P/Churyumov-Gerasimenko