Mysterious Cosmic Explosion Puzzles Astronomers

NASA - Chandra X-ray Observatory patch.

March 31, 2017

A mysterious flash of X-rays has been discovered by NASA’s Chandra X-ray Observatory in the deepest X-ray image ever obtained. This source likely comes from some sort of destructive event, but may be of a variety that scientists have never seen before.

The X-ray source, located in a region of the sky known as the Chandra Deep Field-South (CDF-S), has remarkable properties. Prior to October 2014, this source was not detected in X-rays, but then it erupted and became at least a factor of 1,000 brighter in a few hours. After about a day, the source had faded completely below the sensitivity of Chandra.

Animation above: Animation of CDF-S Transient. Animation Credits: X-ray: NASA/CXC/Pontifical Catholic University/F. Bauer et al.

Thousands of hours of legacy data from the Hubble and Spitzer Space Telescopes helped determine that the event likely came from a faint, small galaxy about 10.7 billion light years from Earth. For a few minutes, the X-ray source produced a thousand times more energy than all the stars in this galaxy.

“Ever since discovering this source, we’ve been struggling to understand its origin,” said Franz Bauer of the Pontifical Catholic University of Chile in Santiago, Chile. “It’s like we have a jigsaw puzzle but we don’t have all of the pieces.”

Two of the three main possibilities to explain the X-ray source invoke gamma-ray burst (GRB) events. GRBs are jetted explosions triggered either by the collapse of a massive star or by the merger of a neutron star with another neutron star or a black hole. If the jet is pointing towards the Earth, a burst of gamma rays is detected. As the jet expands, it loses energy and produces weaker, more isotropic radiation at X-ray and other wavelengths.

Possible explanations for the CDF-S X-ray source, according to the researchers, are a GRB that is not pointed toward Earth, or a GRB that lies beyond the small galaxy. A third possibility is that a medium-sized black hole shredded a white dwarf star.

Image above: Still Image of CDF-S Transient. Image Credits: X-ray: NASA/CXC/Pontifical Catholic University/F. Bauer et al.

“None of these ideas fits the data perfectly,” said co-author Ezequiel Treister, also of the Pontifical Catholic University, “but then again, we’ve rarely if ever seen any of the proposed possibilities in actual data, so we don’t understand them well at all.”

The mysterious X-ray source was not seen at any other time during the two and a half months of exposure time Chandra has observed the CDF-S region, which has been spread out over the past 17 years. Moreover, no similar events have yet to be found in Chandra observations of other parts of the sky.

This X-ray source in the CDF-S has different properties from the as yet unexplained variable X-ray sources discovered in the elliptical galaxies NGC 5128 and NGC 4636 by Jimmy Irwin and collaborators. In particular, the CDF-S source is likely associated with the destruction of a neutron star, white dwarf, or massive star, and is roughly 100,000 times more luminous in X-rays. It is also located in a much smaller and younger host galaxy, and is only detected during a single, several-hour burst.

“We may have observed a completely new type of cataclysmic event,” said co-author Kevin Schawinski, of ETH Zurich in Switzerland. “Whatever it is, a lot more observations are needed to work out what we’re seeing.”

 Chandra X-ray Observatory. Image Credits: NASA/CXC

Additional highly targeted searches through the Chandra archive and those of ESA’s XMM-Newton and NASA’s Swift satellite may uncover more examples of this type of variable object that have until now gone unnoticed. Future X-ray observations by Chandra and other X-ray telescopes may also reveal the same phenomenon from other objects.

If the X-ray source was caused by a GRB triggered by the merger of a neutron star with a black hole or another neutron star, then gravitational waves would also have been produced. If such an event were to occur much closer to Earth, within a few hundred million light years, it may be detectable with the Laser Interferometer Gravitational-Wave Observatory (LIGO).

A paper describing this result appears in the June 2017 issue of the Monthly Notices of the Royal Astronomical Society and is available online. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra’s science and flight operations.

For more Chandra images, multimedia and related materials, visit: http://www.nasa.gov/chandra

Images (mentioned),, Animation (mentioned), Text, Credits: NASA/Lee Mohon/Marshall Space Flight Center/Molly Porter/Chandra X-ray Center/Megan Watzke.

Best regards, Orbiter.ch

SpaceX SES-10 Mission successfully Launch

SpaceX - Falcon 9 / SES-10 Mission patch.

March 31, 2017

Falcon 9 carrying SES-10 satellite launch

SpaceX took a step into the future Thursday as it reused – for the first time – a recovered first stage of a previously-flown Falcon 9 rocket. Thursday’s mission, carrying the SES-10 communications satellite, lifted off from Pad 39A at Florida’s Kennedy Space Center Thursday 30 March at 18:27 local time (22:27 UTC) and once again landed the booster.

Falcon 9 launch of SES-10

Thursday’s mission made use Falcon 9 the second orbit-capable rocket – after the Space Shuttle – to achieve partial reusability. The Falcon 9 flew from Launch Complex 39A at the Kennedy Space Center, the same pad from which the Shuttle began eighty-two of its missions, including its first and final flights.

Reusability has long been a key objective for SpaceX. Making the company’s first launch in March 2006, the small Falcon 1 vehicle carried a parachute system intended to bring its spent first stage back to Earth.

Falcon 9 first stage landed on drone barge

SpaceX’s Falcon 9 rocket deliver SES-10, a commercial communications satellite for SES, to a Geostationary Transfer Orbit (GTO). SES is a world-leading satellite operator, providing reliable and secure satellite communications solutions across the globe.

SES-10 satellite

The SES-10 mission mark a historic milestone on the road to full and rapid reusability as the world’s first reflight of an orbital class rocket. Falcon 9’s first stage for the SES-10 mission previously supported the successful CRS-8 mission in April 2016.

For more information about SpaceX, visit: http://www.spacex.com/

Images, Video, Text, Credits: SpaceX/SES.

Greetings, Orbiter.ch

Spacewalkers Successfully Connect Adapter for Commercial Crew Vehicles

ISS - Expedition 50 Mission patch / EVA - Extra Vehicular Activities patch.

March 30, 2017

Expedition 50 Commander Shane Kimbrough and Flight Engineer Peggy Whitson of NASA concluded their spacewalk at 2:33 p.m. EDT. During the spacewalk, which lasted just over seven hours, the two astronauts successfully reconnected cables and electrical connections on the Pressurized Mating Adapter-3. PMA-3 will provide the pressurized interface between the station and the second of two international docking adapters to be delivered to the complex to support the dockings of U.S. commercial crew spacecraft in the future.

Image above: Spacewalkers Shane Kimbrough (spacesuit with red stripe on legs) and Peggy Whitson are pictured shortly after exiting the Quest airlock this morning. Image Credits: @Thom_Astro.

The duo were also tasked with installing four thermal protection shields on the Tranquility module of the International Space Station. The shields were required to cover the port where the PMA-3 was removed earlier in the week and robotically installed on the Harmony module. During the spacewalk, one of the shields was inadvertently lost. The loss posed no immediate danger to the astronauts and Kimbrough and Whitson went on to successfully install the remaining shields on the common berthing mechanism port.

A team from the Mission Control Center at NASA’s Johnson Space Center in Houston devised a plan for the astronauts to finish covering the port with the PMA-3 cover Whitson removed earlier in the day. The plan worked, and the cover was successfully installed, providing thermal protection and micrometeoroid and orbital debris cover for the port.

To round out the spacewalk, Kimbrough and Whitson also installed a different shield around the base of the PMA-3 adapter for micrometeoroid protection. The shield was nicknamed a cummerbund as it fits around the adapter similar to a tuxedo’s cummerbund worn around the waist.

Image above: Astronaut Peggy Whitson signs her autograph near an Expedition 50 mission patch attached to the inside the International Space Station. Image Credit: NASA.

Having completed her eighth spacewalk, Whitson now holds the record for the most spacewalks and accumulated time spacewalking by a female astronaut.

Spacewalkers have now spent a total of 1,243 hours and 42 minutes outside the station during 199 spacewalks in support of assembly and maintenance of the orbiting laboratory.

Related links:

International docking adapters: https://www.nasa.gov/feature/meet-the-international-docking-adapter

Peggy Whitson spacewalk record: https://blogs.nasa.gov/spacestation/2017/03/29/astronaut-peggy-whitson-set-to-break-spacewalk-record-thursday/

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Text, Credits: NASA/Mark Garcia.

Best regards, Orbiter.ch

NASA's MAVEN Reveals Most of Mars' Atmosphere Was Lost to Space

NASA - MAVEN Mission logo.

March 30, 2017

Image above: This artist’s concept depicts the early Martian environment (right) – believed to contain liquid water and a thicker atmosphere – versus the cold, dry environment seen at Mars today (left). NASA's Mars Atmosphere and Volatile Evolution is in orbit of the Red Planet to study its upper atmosphere, ionosphere and interactions with the sun and solar wind. Image Credits: NASA’s Goddard Space Flight Center.

Solar wind and radiation are responsible for stripping the Martian atmosphere, transforming Mars from a planet that could have supported life billions of years ago into a frigid desert world, according to new results from NASA's MAVEN spacecraft.

"We've determined that most of the gas ever present in the Mars atmosphere has been lost to space," said Bruce Jakosky, principal investigator for the Mars Atmosphere and Volatile Evolution Mission (MAVEN), University of Colorado in Boulder. The team made this determination from the latest results, which reveal that about 65 percent of the argon that was ever in the atmosphere has been lost to space. Jakosky is lead author of a paper on this research to be published in Science on Friday, March 31.

In 2015, MAVEN team members previously announced results that showed atmospheric gas is being lost to space today and described how atmosphere is stripped away. The present analysis uses measurements of today’s atmosphere for the first estimate of how much gas was lost through time.

Liquid water, essential for life, is not stable on Mars' surface today because the atmosphere is too cold and thin to support it. However, evidence such as features resembling dry riverbeds and minerals that only form in the presence of liquid water indicates the ancient Martian climate was much different – warm enough for water to flow on the surface for extended periods.

“This discovery is a significant step toward unraveling the mystery of Mars' past environments,“ said Elsayed Talaat, MAVEN Program Scientist, at NASA Headquarters in Washington. “In a broader context, this information teaches us about the processes that can change a planet’s habitability over time.”

There are many ways a planet can lose some of its atmosphere. For example, chemical reactions can lock gas away in surface rocks, or an atmosphere can be eroded by radiation and a stellar wind from a planet's parent star. The new result reveals that solar wind and radiation were responsible for most of the atmospheric loss on Mars, and the depletion was enough to transform the Martian climate. The solar wind is a thin stream of electrically conducting gas constantly blowing out from the surface of the sun.

Image above: This infographic shows how Mars lost argon and other gasses over time due to ‘sputtering.’ Click to enlarge. Image Credits: NASA’s Goddard Space Flight Center.

The early Sun had far more intense ultraviolet radiation and solar wind, so atmospheric loss by these processes was likely much greater in Mars' history. According to the team, these processes may have been the dominant ones controlling the planet's climate and habitability. It's possible microbial life could have existed at the surface early in Mars’ history. As the planet cooled off and dried up, any life could have been driven underground or forced into rare surface oases.

Jakosky and his team got the new result by measuring the atmospheric abundance of two different isotopes of argon gas. Isotopes are atoms of the same element with different masses. Since the lighter of the two isotopes escapes to space more readily, it will leave the gas remaining behind enriched in the heavier isotope. The team used the relative abundance of the two isotopes measured in the upper atmosphere and at the surface to estimate the fraction of the atmospheric gas that has been lost to space.

As a "noble gas" argon cannot react chemically, so it cannot be sequestered in rocks; the only process that can remove noble gases into space is a physical process called "sputtering" by the solar wind. In sputtering, ions picked up by the solar wind can impact Mars at high speeds and physically knock atmospheric gas into space. The team tracked argon because it can be removed only by sputtering. Once they determined the amount of argon lost by sputtering, they could use this information to determine the sputtering loss of other atoms and molecules, including carbon dioxide (CO₂). 

CO₂ is of interest because it is the major constituent of Mars' atmosphere and because it's an efficient greenhouse gas that can retain heat and warm the planet. "We determined that the majority of the planet's CO₂ was also lost to space by sputtering," said Jakosky. "There are other processes that can remove CO₂, so this gives the minimum amount of CO₂ that's been lost to space."

Mars Atmosphere Loss: Sputtering

Video above: This 2013 video explains how the process called "sputtering" may have caused Mars to lose its atmosphere. Video Credits: NASA Goddard.

The team made its estimate using data from the Martian upper atmosphere, which was collected by MAVEN's Neutral Gas and Ion Mass Spectrometer (NGIMS). This analysis included measurements from the Martian surface made by NASA's Sample Analysis at Mars (SAM) instrument on board the Curiosity rover.

"The combined measurements enable a better determination of how much Martian argon has been lost to space over billions of years," said Paul Mahaffy of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Using measurements from both platforms points to the value of having multiple missions that make complementary measurements." Mahaffy, a co-author of the paper, is principal investigator on the SAM instrument and lead on the NGIMS instrument, both of which were developed at NASA Goddard.

The research was funded by the MAVEN mission. MAVEN's principal investigator is based at the University of Colorado's Laboratory for Atmospheric and Space Physics, Boulder, and NASA Goddard manages the MAVEN project. MSL/Curiosity is managed by NASA's Jet Propulsion Laboratory, Pasadena, California.

For more information on MAVEN, visit: http://www.nasa.gov/maven

Images (mentioned), Text, Credits: NASA/Jim Wilson/Katherine Brown/Goddard Space Flight Center/Bill Steigerwald/Nancy Jones.

Greetings, Orbiter.ch

Search for stellar survivor of a supernova explosion

ESA - Hubble Space Telescope logo.

30 March 2017

Supernova remnant N103B

Astronomers have used the NASA/ESA Hubble Space Telescope to observe the remnant of a supernova explosion in the Large Magellanic Cloud. Beyond just delivering a beautiful image, Hubble may well have traced the surviving remains of the exploded star’s companion.

A group of astronomers used Hubble to study the remnant of the Type Ia supernova explosion SNR 0509-68.7 — also known as N103B (seen at the top). The supernova remnant is located in the Large Magellanic Cloud, just over 160 000 light-years from Earth. In contrast to many other Supernova remnants N103B does not appear to have a spherical shape but is strongly elliptical. Astronomers assume that part of material ejected by the explosion hit a denser cloud of interstellar material, which slowed its speed. The shell of expanding material being open to one side supports this idea.

The relative proximity of N103B allows astronomers to study the life cycles of stars in another galaxy in great detail. And probably even to lift the veil on questions surrounding this type of supernova. The predictable luminosity of Type Ia supernovae means that astronomers can use them as cosmic standard candles to measure their distances, making them useful tools in studying the cosmos. Their exact nature, however, is still a matter of debate. Astronomers suspect Type Ia supernovae occur in binary systems in which at least one of the stars in the pair is a white dwarf [1].

Wide-field image of Magellanic clouds (ground-based image)

There are currently two main theories describing how these binary systems become supernovae. Studies like the one that has provided the new image of N103B — that involve searching for remnants of past explosions — can help astronomers to finally confirm one of the two theories.

One theory assumes that both stars in the binary are white dwarfs. If the stars merge with one another it would ultimately lead to a supernova explosion of type Ia.

The second theory proposes that only one star in the system is a white dwarf, while its companion is a normal star. In this theory material from the companion star is accreted onto the white dwarf until its mass reaches a limit, leading to a dramatic explosion. In that scenario, the theory indicates that the normal star should survive the blast in at least some form. However, to date no residual companion around any type Ia supernova has been found.

Zoom into N103B

Astronomers observed the N103B supernova remnant in a search for such a companion. They looked at the region in H-alpha — which highlights regions of gas ionised by the radiation from nearby stars —  to locate supernova shock fronts. They hoped to find a star near the centre of the explosion which is indicated by the curved shock fronts. The discovery of a surviving companion would put an end to the ongoing discussion about the origin of type Ia supernova.

And indeed they found one candidate star that meets the criteria — for star type, temperature, luminosity and distance from the centre of the original supernova explosion. This star has approximately the same mass as the Sun, but it is surrounded by an envelope of hot material that was likely ejected from the pre-supernova system.

Pan across N103B

Although this star is a reasonable contender for N103B’s surviving companion, its status cannot be confirmed yet without further investigation and a spectroscopic confirmation. The search is still ongoing.

Notes:

[1] A white dwarf is the small, dense core of a medium-mass star that is left behind after it has reached the end of its main-sequence lifetime and blown off its outer layers. Our own Sun is expected to become a white dwarf in around five billion years.

More information:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

Links:

Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/

Link to science paper: http://www.spacetelescope.org/static/archives/releases/science_papers/heic1707/heic1707a.pdf

Images, Videos, Text, Credits: ESA/NASA/A. Fujii/Nick Risinger (skysurvey.org), R. Gendler & ESO/Music: Johan Monell.

Best regards, Orbiter.ch

Weekly Recap From the Expedition Lead Scientist, Week of March 20, 2017

ISS - Expedition 50 Mission patch.

March 29, 2017

(Highlights: Week of March 20, 2017) - While preparing for a March 24 spacewalk outside the International Space Station, crew members used the microgravity environment of the orbiting laboratory to better examine how metals are formed as they cool from a liquid to a solid.

NASA astronaut Peggy Whitson exchanged sample cartridges for the Materials Science Lab Batch 2b (MSL SCA Batch 2b), which serves two projects investigating how different phases of matter organize into a structure when metallic alloys are solidified. Both projects will provide data to help develop new light-weight, high-performance structural material for space and Earth applications.

Image above: European Space Agency astronaut Thomas Pesquet works on the Canadarm2 during a spacewalk outside the International Space Station on March 24. Canadarm2 is a remote-controlled arm used to transfer cargo and release satellites on the space station. Image Credit: NASA.

The Metastable Solidification of Composites (METCOMP) project studies how the remaining liquid bronze reacts with an already formed solid as the liquid bronze is cooling to become a second solid. The other project, Solidification along a Eutectic path in Ternary Alloys (SETA), looks at how two phases that form together organize into aluminum fiber structures when cooling.

ESA (European Space Agency) astronaut Thomas Pesquet inspected the Bigelow Expandable Activity Module (BEAM) attached to the orbiting laboratory. Expandable habitats are designed to take up less room on a spacecraft while providing greater volume for living and working in space once expanded. Pesquet was conducting a periodic checkup of BEAM, which was deployed May 28, 2016. He inspected the various sensors and radiation monitors, checking for leaks and taking surface samples to assess the microbe environment inside the expandable node.

Image above: Pesquet captured this nighttime image of Mount Etna in Sicily from the International Space Station. The bright red lines in the lower left quadrant is a lava flow from an active volcano that can be seen from space. Image Credit: NASA.

BEAM, the first test of an expandable module, allows investigators to gauge how well the habitat performs -- specifically, how well it protects against solar radiation, space debris and the temperature extremes of space. Crew members will continue to inspect the module every three months to check for stability. Durable, reliable and safe expandable structures have applications on Earth as well. Expandable modules can be used as pop-up habitats in disaster areas or remote locations; storm surge protection devices; pipeline or subway system plugs to prevent flooding; fluid storage containers; or hyperbaric chambers for pressurized oxygen delivery.

Whitson prepared the ultrasound equipment for Russian cosmonaut Sergey Ryzhikov to take measurements for the study of Fluid Shifts Before, During, and After Prolonged Space Flight and Their Association with Intracranial Pressure and Visual Impairment (Fluid Shifts). One of the main risks for humans during long-duration space missions is change in vision. More than half of American astronauts experience vision changes and other physical alterations to parts of their eyes during and after long-duration spaceflight. It is hypothesized that the fluid shift toward the head that occurs during spaceflight leads to increased pressure in the brain, which may push on the back of the eye, causing it to change shape. Fluid Shifts measures how much fluid moves from the lower body to the upper body, in or out of cells and blood vessels, and determines the impact these shifts have on fluid pressure in the head, changes in vision and eye structures.

Image above: NASA astronaut Shane Kimbrough captured this image he took from the space station looking west over the Red Sea, with Saudi Arabia on the bottom of the picture and Egypt on the top. He shared it to his social media account on Twitter, tagging it #EarthArt. Image Credits: Twitter.com/astro_kimbrough.

Scientists want to develop preventive measures against these and other physiological changes during spaceflight. Results from the Fluid Shifts investigation may also improve understanding of how blood pressure in the brain specifically affects eye shape and vision, which could benefit people confined to long-term bed rest, or suffering from disease states that increase swelling and pressure in the brain.

International Space Station (ISS). Image Credit: NASA

Other human research investigations conducted this week include Intracranial Pressure & Visual Impairment (IPVI), Habitability, Space Headaches, and Dose Tracker.

Progress was made on other investigations, outreach activities, and facilities this week, including Google Street View, ISS Ham Radio, MAGVECTOR, and Manufacturing Device.

Related links:

Materials Science Lab Batch 2b (MSL SCA Batch 2b): https://www.nasa.gov/mission_pages/station/research/experiments/1978.html

Bigelow Expandable Activity Module (BEAM): http://www.nasa.gov/mission_pages/station/research/experiments/1804.html

Fluid Shifts: http://www.nasa.gov/mission_pages/station/research/experiments/1257.html

Intracranial Pressure & Visual Impairment (IPVI): https://www.nasa.gov/mission_pages/station/research/experiments/1950.html

Habitability: https://www.nasa.gov/mission_pages/station/research/experiments/1772.html

Space Headaches: https://www.nasa.gov/mission_pages/station/research/experiments/181.html


Dose Tracker: http://www.nasa.gov/mission_pages/station/research/experiments/1933.html

ISS Ham Radio: http://www.nasa.gov/mission_pages/station/research/experiments/346.html

MAGVECTOR: https://www.nasa.gov/mission_pages/station/research/experiments/1176.html

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Text, Credits: NASA/Kristine Rainey/Jorge Sotomayor, Lead Increment Scientist Expeditions 49 & 50.

Best regards, Orbiter.ch

Prolific Mars Orbiter Completes 50,000 Orbits

NASA - Mars Reconnaissance Orbiter (MRO) logo.

March 29, 2017

The most data-productive spacecraft yet at Mars swept past its 50,000th orbit this week, continuing to compile the most sharp-eyed global coverage ever accomplished by a camera at the Red Planet.

In addition, the spacecraft -- NASA's Mars Reconnaissance Orbiter (MRO) -- recently aided preparations for NASA's next mission to Mars, the InSight lander. Insight will launch next year on a mission to study the planet's deep interior. Meanwhile, the orbiter continues diverse science observations of Mars and communications-relay service for two active Mars rovers, Curiosity and Opportunity.

Animation above: The Context Camera on NASA's Mars Reconnaissance Orbiter has been taking images of Mars since 2006. This animation shows, at one frame per month, how these observations have accumulated to cover more than 99 percent of Mars. No other camera has ever shown so much of Mars in such high resolution. Animation Credits: NASA/JPL-Caltech/MSSS.

MRO's Context Camera (CTX) exploits a sweet spot in the balance between resolution and image file size. With a resolution of about 20 feet (6 meters) per pixel in images of the Martian surface, it has provided a library of images now covering 99.1 percent of Mars. That is approximately equivalent to the land area of Earth. No other camera ever sent to Mars has photographed so much of the planet in such high resolution.

The Context Camera has taken about 90,000 images since the spacecraft began examining Mars from orbit in late 2006. Each one reveals shapes of features down to sizes smaller than a tennis court, in a swath of ground about 18.6 miles (30 kilometers) wide.

"Reaching 99.1-percent coverage has been tricky because a number of factors, including weather conditions, coordination with other instruments, downlink limitations, and orbital constraints, tend to limit where we can image and when," said Context Camera Team Leader Michael Malin of Malin Space Science Systems, San Diego.

Image above: n early 2017, after more than a decade of observing Mars, the Context Camera on NASA's Mars Reconnaissance Orbiter (MRO) surpassed 99 percent coverage of the entire planet. This mosaic shows that global coverage. No other camera has ever imaged so much of Mars in such high resolution. Image Credits: NASA/JPL-Caltech/MSSS.

In addition to observing nearly the entire planet at least once, the Context Camera has observed 60.4 percent of the planet more than once. These observations aid science directly and also certify the safety of future landing sites.

Malin said, "Single coverage provides a baseline we can use for comparison with future observations, as we look for changes. Re-imaging areas serves two functions: looking for changes and acquiring stereoscopic views from which we can make topographic maps."

A dramatic type of change the Context Camera has documented more than 200 times is a fresh impact crater appearing between the times of two observations. These images enabled scientists to calculate the rate at which small asteroids, or bits of comets, are colliding with Mars. Some of the fresh impacts reveal white material interpreted as water ice. The latitudes and estimated depths of the ice-exposing craters provide evidence about the distribution of buried ice near the surface. MRO's Shallow Radar has found ice farther underground, but this very shallow ice would go undetected if not for its exposure by impacts.

Image above: This map shows the footprints of images taken by the HiRISE camera on NASA's Mars Reconnaissance Orbiter as part of advance analysis of the area where NASA's InSight mission will land in 2018. The final planned image of the set will fill in the yellow-outlined rectangle on March 30, 2017. Image Credits: NASA/JPL-Caltech/Univ. of Arizona.

One of MRO's other cameras, the High Resolution Imaging Science Experiment (HiRISE), can zoom in on the new impact craters found by the Context Camera. For some of these craters, HiRISE and MRO's Compact Reconnaissance Imaging Spectrometer for Mars have confirmed the presence of water ice. However, even though MRO has returned more than 300 terabits of science data, the much higher spatial resolution of HiRISE has limited its coverage of Mars' surface to about three percent. A third MRO camera, the Mars Color Imager, observes almost the entire planet every day to track weather change. Another instrument, the Mars Climate Sounder, records vertical profiles of the atmosphere's temperatures and suspended particles.

The spacecraft was launched Aug. 12, 2005. It entered an elongated orbit of Mars in March 2006, then spent several months using friction with Mars' upper atmosphere to revise its orbit. Since beginning its science operations in November 2006, MRO has been flying near-polar orbits lasting about two hours, at altitudes from 155 to 196 miles (250 to 316 kilometers). The mission completed its 50,000th orbit on Monday, March 27.

Mars Reconnaissance Orbiter (MRO). Image Credits: NASA/JPL

"After 11 and a half years in flight, the spacecraft is healthy and remains fully functional," said MRO Project Manager Dan Johnston at NASA's Jet Propulsion Laboratory, Pasadena, California. "It’s a marvelous vehicle that we expect will serve the Mars Exploration Program and Mars science for many more years to come."

On March 22, the mission made the latest adjustment to the orbit, with a 45.1-second burn of six intermediate-size rocket engines, each of which provides 5 pounds (22 newtons) of thrust. This maneuver revised the orbit orientation, so that the spacecraft can be at the right place at the right time, on Nov. 26, 2018, to receive critical radio transmissions from NASA's InSight Mars lander as it descends to the surface.

MRO has already provided more than 60 images from HiRISE for advance analysis of the landing region for InSight. In a broad plain of the Elysium Planitia region of equatorial Mars, InSight will use a seismometer and heat probe to examine the interior of Mars to better understand the formation process of rocky planets like Earth. The final MRO image for assessment of this landing area will be taken Thursday, March 30.

For additional information about Mars Reconnaissance Orbiter, visit: http://nasa.gov/mro

For additional information about InSight, visit: http://www.nasa.gov/insight 

Mars Reconnaissance Orbiter (MRO): http://www.nasa.gov/mission_pages/MRO/main/index.html

Animation (mentioned), Images (mentioned), Text, Credits: NASA/Laurie Cantillo/Dwayne Brown/JPL/Guy Webster.

Best regards, Orbiter.ch