Mars Spacecraft reveal comet flyby effects on Martian atmosphere

Two NASA and one European spacecraft, including NASA's MAVEN mission led by the University of Colorado Boulder, have gathered new information about the basic properties of a wayward comet that buzzed by Mars Oct. 19, directly detecting its effects on the Martian atmosphere.

Data from observations carried out by MAVEN, NASA's Mars Reconnaissance Orbiter (MRO) and the ESA's Mars Express spacecraft revealed that debris from the comet, known officially as Comet C/2013 A1 Siding Spring, caused an intense meteor shower and added a new layer of ions, or charged particles, to the ionosphere.

The ionosphere is an electrically charged region in the atmosphere that reaches from about 75 miles (120 kilometers) to several hundred miles above the Martian surface.

ESA's Mars Express spacecraft

Using the observations, scientists were able to make a direct connection between the input of debris from the meteor shower to the subsequent formation of the transient layer of ions, the first time such an event has been observed on any planet, including Earth, said the MAVEN research team.

The comet traveled from the most distant region of our solar system called the Oort Cloud and made a close approach at 2:27 p.m. EDT within about 87,000 miles (139,500 kilometers) of the Red Planet.

That is less than half the distance between Earth and our moon and less than one-tenth the distance of any known comet flyby of Earth.

"MAVEN is well suited for studying the effects of the dust from the comet in the Martian atmosphere, because it makes measurements at the altitudes where the dust was expected to have an effect," said CU-Boulder Professor Bruce Jakosky of the Laboratory for Atmospheric and Space Physics, the principal investigator on the $671 million Mars Atmosphere and Volatile EvolutioN (MAVEN) mission.

"We also should be able to see if there are long-term effects from the comet dust in that same region of the atmosphere."

The places where the red line on this graph extends higher than the blue line show detection of metals added to the Martian atmosphere from dust particles released by a passing comet. 

The graphed data are from the Imaging Ultraviolet Spectrograph (IUVS) on NASA's MAVEN spacecraft, which recorded the intensities of emission by ingredients in the Martian atmosphere just before (blue line) and after (red line) comet C/2013 A1 Siding Spring sped within about 87,000 miles (139,500 kilometers) of Mars on Oct. 19, 2014. 

The "before" line records the usual main gases in the atmosphere, primarily carbon dioxide and its byproducts.

The "after" line includes those plus peaks at 280 nanometer wavelength, a fingerprint of ionized magnesium, and other wavelengths that are fingerprints of iron.

Researchers interpret this change as a result of vaporisation of dust particles that came from the comet and entered the Martian atmosphere at high speed.

Imaging Ultraviolet Spectrograph (IUVS)

IUVS uses limb scans to map the chemical makeup and vertical structure across Mars' upper atmosphere.

Dust from the comet was vaporized high in the Martian atmosphere, producing what was likely an impressive meteor shower.

The debris resulted in significant but temporary changes to the planet's upper atmosphere and possible longer-term changes.

A host of Earth-based and orbiting telescopes also observed the unique celestial event.

The MAVEN spacecraft, recently arrived at Mars, detected the comet encounter in two ways.

The remote-sensing Imaging Ultraviolet Spectrograph (IUVS) designed and built at CU-Boulder observed intense ultraviolet emissions from magnesium and iron ions high in the atmosphere in the aftermath of the meteor shower.

Not even the most intense meteor storms on Earth have produced as strong a response as this one:

The emission dominated Mars' ultraviolet spectrum for several hours after the encounter and then dissipated over the next two days, according to the MAVEN science team.

MAVEN also was able to directly sample and help scientists determine the composition of some of the vaporised comet dust in Mars' atmosphere.

Analysis of these samples by the spacecraft's Neutral Gas and Ion Mass Spectrometer (NGIMS) designed and developed at NASA Goddard Space Flight Center in Greenbelt, Maryland, detected eight different types of metal ions, including sodium, magnesium and iron.

These are the first direct measurements of the composition of dust from an Oort Cloud comet.

The Oort Cloud, well beyond the outermost planets that surround our sun, is a spherical region of icy objects believed to be material left over from the formation of the solar system.

An illustration of Maven spacecraft at Mars. Credit: NASA

"They call this comet encounter a once-in-a-lifetime event, but it's more like once-in-a-million years," said CU-Boulder Associate Professor Nick Schneider, a LASP research associate and lead IUVS scientist for the mission.

"MAVEN got there just in time, and we were ready.

The numbers suggest a Martian would have seen many thousands of shooting stars per hour, possibly enough to be called a meteor storm, so it must have been a spectacular event that night on Mars."

Elsewhere above Mars, a joint U.S. and Italian instrument on Mars Express observed a huge increase in the density of electrons in the Martian ionosphere following the comet's close approach.

"This historic event allowed us to observe the details of this fast moving Oort Cloud comet in a way never before possible using our existing Mars missions," said Jim Green, director of NASA's Planetary Science Division at the agency's headquarters in Washington.

"Observing the effects on Mars of the comet's dust slamming into the upper atmosphere makes me very happy that we decided to put our spacecraft on the other side of Mars at the peak of the dust tail passage and out of harms way."

There are three CU-Boulder undergraduates and two graduate students on the IUVS science team, said Schneider, and there will be a number of additional CU-Boulder students working on MAVEN in the coming years.

Currently there are more than 100 students working on research projects at LASP, which provides hands-on training for future careers as engineers and scientists.

ISRO’s Mars Orbiter: Olympus Mons, Tharsis Bulge and Valles Marineris trio of volcanoes

Olympus Mons, Tharsis Bulge trio of volcanoes, and Valles Marineris from ISRO’s Mars Orbiter Mission. 

Note the clouds and south polar ice cap. 

Credit: ISRO

India's Mars Orbiter Mission (MOM) has delivered another sweet treat – a stunning view of our Solar System's largest volcano and the largest canyon.

Just days ago, MOM captured a new global image of the Red Planet dominated by Olympus Mons and Valles Marineris, which is the largest known volcano and the largest known canyon in the Solar System, respectively.

Situated right in between lies a vast volcanic plateau holding a trio of huge volcanoes comprising the Tharsis Bulge: Arsia Mons, Pavonis Mons, and Ascraeus Mons. All three are shield volcanoes.

To give an idea of its enormity, Olympus Mons stands about three times taller than Mount Everest and is about the size of Arizona.

Olympus Mons is located in Mars' western hemisphere and measures 624 kilometers (374 miles) in diameter, 25 km (16 mi) high, and is rimmed by a 6 km (4 mi) high scarp.

Valles Marineris is often called the "Grand Canyon of Mars." It spans about as wide as the entire United States.

The Indian Space Research Organization (ISRO), India's space agency which designed and developed the orbiter released the image on Oct. 17, barely two days ahead of the planet's and spacecrafts' extremely close encounter with comet Siding Spring.

Olympus Mons from Mars orbit compared to the state of Arizona. 

Credit: NASA

By the way, a relieved ISRO tweeted MOM's survival of her close shave with the once-in-a-lifetime cometary passage with gusto, soon after the swingby:
"Phew! Experience of a lifetime. Watched the #MarsComet #SidingSpring whizzing past the planet. I'm in my orbit, safe and sound."

The new global image was taken by the tri-color camera as MOM swooped around the Red Planet in a highly elliptical orbit whose nearest point to Mars (periapsis) is at 421.7 km and farthest point (apoapsis) at 76,993.6 km, according to ISRO.

To date ISRO has released four global images of the Red Planet, including a 3-D view.

Olympus Mons, the Tharsis Bulge, and Valles Marineris are near the equator.

Valles Marineris stretches over 4,000 km (2,500 mi) across the Red Planet, is as much as 600 km wide, and measures as much as 7 kilometers (4 mi) deep.

Global Mosaic of Mars Centered on Valles Marineris from NASA’s Viking 1 orbiter. 

Credit: NASA

Here's a comparison view of the region taken by NASA's Viking 1 orbiter in the 1970s.

MOM is India's first deep space voyager to explore beyond the confines of her home planet's influence and successfully arrived at the Red Planet only one month ago after the "history creating" orbital insertion maneuver on Sept. 23/24 following a ten month journey.

The $73 million MOM mission is expected to last at least six months.

ISRO’s Mars Orbiter Mission captures spectacular portrait of the Red Planet and swirling dust storms with the on-board Mars Color Camera from an altitude of 74,500 km on Sept. 28, 2014. 

Credit: ISRO

MOM's success follows closely on the heels of NASA's MAVEN orbiter which also successfully achieved orbit barely two days earlier on Sept. 21 and could last 10 years or more.

With MOM's arrival, India became the newest member of an elite club of only four entities that have launched probes that successfully investigated Mars, following the Soviet Union, the United States, and the European Space Agency (ESA).

NASA MAVEN: Studying the passing of comet C/2013 A1 Siding Spring and its effects

This image shows an artist concept of NASA's Mars Atmosphere and Volatile Evolution (MAVEN) mission. 

Image Credit: NASA/GSFC

NASA's newest orbiter at Mars, MAVEN, took precautions to avoid harm from a dust-spewing comet that flew near Mars today and is studying the flyby's effects on the Red Planet's atmosphere.

The MAVEN spacecraft reported back to Earth in good health after about three hours of precautions against a possible collision with high-velocity dust particles released by comet C/2013 A1 Siding Spring.

"We're glad the spacecraft came through, we're excited to complete our observations of how the comet affects Mars, and we're eager to get to our primary science phase," said MAVEN Principal Investigator Bruce Jakosky of the University of Colorado, Boulder.

MAVEN began orbiting Mars on Sept. 21. The opportunity to study this rare near-miss of a planet by a comet comes during the project's commissioning phase.

A few weeks of instrument calibration and orbit fine-tuning remain before the start of the primary science phase. The mission will study the upper atmosphere of Mars and its interaction with the solar wind.

Comet Siding Spring hurtled past Mars today at about 125,000 mph (56 kilometers per second), coming within about 87,000 miles (139,500 kilometers) of the planet.

That is equivalent to about one-third of the distance between Earth and Earth's moon. The closest approach by the comet's nucleus came at about 11:27 a.m. PDT (2:27 p.m. EDT).

The period when dust from the comet was most likely to reach Mars and the orbits of spacecraft around Mars peaked about 100 minutes later.

From about 10:45 a.m. to 2 p.m. PDT (1:45 p.m. to 5:00 p.m. EDT) MAVEN kept in a defensive posture to reduce its profile relative to the direction from which the comet's high-velocity dust particles would come.

In that "hunkered down" orientation, its main antenna was not facing the right way for transmitting to Earth, so communications were maintained at low data rate via a secondary antenna.

Also, the mission performed a maneuver on Oct. 2 that set its orbit timing so that the spacecraft was behind Mars, relative to the possible dust flow, from about 12:53 p.m. to 1:23 p.m. PDT (3:53 p.m. to 4:23 p.m. EDT).

Downlink of data has begun from MAVEN observations of the comet and Mars' atmosphere. Some observations are designed to provide information about the composition of the gases and dust being released by the comet.

Others are investigating possible interaction between material from the comet and the atmosphere of Mars.

Three NASA Mars orbiters (MAVEN, Mars Reconnaisance Orbiter and Odyssey Orbiter), two Mars rovers (Curiosity and Opportunity) and other assets on Earth and in space are studying comet Siding Spring.

This comet is making its first visit this close to the sun from the outer solar system's Oort Cloud, so the concerted campaign of observations may yield fresh clues to our solar system's earliest days more than 4 billion years ago.

MAVEN's principal investigator is based at the University of Colorado's Laboratory for Atmospheric and Space Physics.

The university provided two science instruments and leads science operations, as well as education and public outreach, for the mission.

NASA's Mars Odyssey spacecraft watches comet flyby

Artist's concept of NASA's Mars Odyssey spacecraft. 

Credit: NASA/JPL-Caltech

The longest-lived robot ever sent to Mars came through its latest challenge in good health, reporting home on schedule after sheltering behind Mars from possible comet dust.

NASA's Mars Odyssey was out of communications with Earth, as planned, while conducting observations of comet C/2013 A1 Siding Spring on Sunday, Oct. 19, as the comet flew near Mars.

The comet sped within about 88,000 miles (139,500 kilometers) of Mars, equivalent to about one-third of the distance between Earth and Earth's moon.

Mars Odyssey had performed a maneuver on Aug. 5 to adjust the timing of its orbit so that it would be shielded by Mars itself during the minutes, around 1 p.m. PDT (4 p.m. EDT) today, when computer modeling projected a slight risk from high-velocity dust particles in the comet's tail.

"The telemetry received from Mars Odyssey this afternoon confirms not only that the spacecraft is in fine health but also that it conducted the planned observations of comet C/2013 A1 Siding Spring within hours of the comet's closest approach to Mars," said Odyssey Mission Manager Chris Potts of NASA's Jet Propulsion Laboratory, Pasadena, Calif., speaking from mission operations center at Lockheed Martin Space Systems, Denver.

THEMIS

Comet C/2013 A1 Siding Spring observations were made by the orbiter's Thermal Emission Imaging System (THEMIS).

Resulting images are expected in coming days after the data is downlinked to Earth and processed.

THEMIS is also scheduled to record a combined image of the comet and a portion of Mars later this week.

In addition, the Odyssey mission is using the spacecraft's Neutron Spectrometer (NS) and the Russian-made, High Energy Neutron detector (HEND) to assess possible effects on Mars' atmosphere of dust and gas from the comet.

Three NASA Mars orbiters, two Mars rovers and other assets on Earth and in space are studying comet Siding Spring.

This comet is making its first visit this close to the sun from the outer solar system's Oort Cloud, so the concerted campaign of observations may yield fresh clues to our solar system's earliest days more than 4 billion years ago.

Following the comet flyby, operations teams have also confirmed the good health of NASA's Mars Reconnaissance Orbiter and of NASA's Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiter.

Mars Odyssey has worked at the Red Planet longer than any other Mars mission in history.

NASA launched the spacecraft on April 7, 2001, and Mars Odyssey arrived at Mars Oct. 24, 2001.

Besides conducting its own scientific observations, the mission provides a communication relay for robots on the Martian surface.

Comet Siding Spring Buzzes C2013 A1 Mars in Once-in-a-Lifetime Flyby

Credit: SLOOH

Comet Siding Spring C2013 A1 zoomed by Mars today (Oct. 19) in an extremely rare close encounter that scientists billed as a "once-in-a-lifetime" event that may help researchers better understand the earliest days of our solar system.

Comet Siding Spring C2013 A1 came within just 87,000 miles (139,500 kilometers) of the Martian surface at 2:27 p.m. EDT (1827 GMT) today, about one-third of the distance between Earth and the moon.

At the time of closest approach, the comet barreled by at 126,000 mph (203,000 km/h) relative to the Red Planet, NASA officials said.

All seven spacecraft currently operating on or around Mars were scheduled to observe the close shave, with the aim of learning more about comet composition and behaviour.

The US Deep Space Network monitored the NASA Mars satellites currently orbiting Mars.

Credit: SLOOH

NASA's Mars Reconnaissance Orbiter safely watches Comet Siding Spring FlyBy

NASA's Mars Reconnaissance Orbiter, which has sent home more data about Mars than all other missions combined, is also now providing data about a comet that buzzed The Red Planet today (Oct. 19).

The orbiter continues operating in good health after sheltering behind Mars during the half hour when high-velocity dust particles from comet C/2013 A1 Siding Spring had the most chance of reaching the paths of Mars orbiters.

The Comet Siding Spring C/2013 A1 is indicated on this image as it passes Mars, seen here shining brightly on the bottom left.

Credit: Slooh

maintained radio communications with Earth throughout the comet's closest approach, at 11:27 a.m. PDT (2:27 p.m. EDT), and the peak dust-risk period centered about 100 minutes later.

"The spacecraft performed flawlessly throughout the comet flyby," said Mars Reconnaissance Orbiter Project Manager Dan Johnston of NASA's Jet Propulsion Laboratory, Pasadena, California. "It maneuvered for the planned observations of the comet and emerged unscathed."

Following the critical period of dust flux, the orbiter is communicating at 1.5 megabits per second with NASA's Deep Space Network.

It remained on Side A of its two redundant computers, and all subsystems are working as expected.

The remainder of the NASA Mars orbiters, Mars Express and ISRO's MOM, appear to be in good health and unaffected by the comet flyby.

An artist impression of the passing of Comet Siding Spring as seen by Curiosity Rover on Mars.

Credit: SLOOH

Comet Siding Spring C2013 A1 has flown past Mars

Comet Siding Spring has made a close pass with Mars, the Red Planet, flying only 87,000 miles (139,500 kilometers) from the surface. 

Mars is seen as a bright object in these images because of the sun.

Officials monitoring spacecraft orbiting Mars maneuvered them into safe positions on the furthest side of the planet, so that they did not experience any ill affects from the icy wanderer's dust.

An hour after the passing of the comet, observers are awaiting the bombardment of the Mars atmosphere by the debris ejected from the comet's tail.

Mars is, in this image the much brighter object. Siding Spring - here, it's marked in red. 

Credit: ESA/M. Micheli/D. Abreu

This image of comet C/2013 A1 (Siding Spring) at 4.8 arcminutes from Mars, as seen on 2014 October 19 at 20:20 UT via ESA's Optical Ground Station, equipped with a 1-meter telescope, on Tenerife, Canary Islands.

North is to the left of the frame. The comet was imaged under poor sky conditions, while it was 17° above the southwestern horizon.

High humidity and strong winds also affected the image quality, giving a "fuzzy" appearance to the nearby stars.

Colliding Atmospheres: Comet C/2013 A1 Siding Spring vs Mars - Video

Incoming: NEOWise spies Comet A1 Siding Spring in early August of 2014. Credit: NASA

This week, the skies over Mars will also be graced by an unforgettable and spectacular sight: the extremely close passage of Comet C/2013 A1 Siding Spring.

The first comet discovered in 2013, A1 Siding Spring was spotted by veteran comet hunter Robert McNaught from the Siding Spring Observatory in Australia.

Dozens of comets are discovered in any given year, but this one soon gained the attention of astronomers when it was found that the comet could possibly hit Mars in October 2014.

And although further observations refined A1 Siding Spring's orbit and ruled out such an impact, the particulars of the close passage of the comet past Mars are still stunning: A1 Siding Spring will pass within 87,000 miles (139,500 kilometres) from the center of Mars on Sunday, October 19th at 18:27 Universal Time (UT) or 2:27 PM EDT.

And although we've yet to set "boots" on Mars, a fleet of spacecraft arrayed throughout the inner solar system are set to study the comet from both near and far.



NASA has taken measures to assure that spacecraft in orbit are afforded maximum protection from incoming cometary debris, and the exciting possibility exists that we'll be able to study first-hand the interaction of the comet's tail with the Martian atmosphere.

Mars-based spacecraft set to observe Comet A1 Siding Spring: a scorecard. 

Credit: NASA

The nucleus of A1 Siding Spring is thought to be 700 metres across, and the coma extends 19,300 km in diameter.

The comet's closest passage is just under six times the distance of Mars' outer moon Deimos, and at closest approach, the coma will appear almost 8 degrees in size to any would-be Martian, that's 16 times the diameter of a Full Moon as seen from the Earth, and will be crossing the skies at a staggering 1.5 degrees a minute.

You would be able to easily see the motion of the comet as it moves across the Martian sky with the unaided eye after just a few dozen seconds worth of watching!

The comet's magnitude may reach -5 as seen from Mars, though that would also be extended over its huge expanded surface area.

NASA MAVEN Mars Probe Beams Home First Results

MAVEN spacecraft orbits Mars in this artist's illustration. Image released Oct. 14, 2014. 

Credit: University of Colorado/NASA

NASA's MAVEN Mars orbiter has been busy since it arrived at the Red Planet late last month.

NASA's Mars Atmosphere and Volatile EvolutioN mission (MAVEN) is designed to probe Mars' thin atmosphere, to help scientists understand what caused the planet to change from a warm, wet world long ago to the cold and dry one it is today. 

The spacecraft entered into orbit around Mars on Sept. 21, and it has already beamed back some amazing new data about Mars' upper atmosphere, researchers said.

In MAVEN's first few weeks of instrument testing at the Red Planet, scientists have already created some of the most complete maps of atomic hydrogen, oxygen, carbon and ozone in the Martian atmosphere ever made. 

One of MAVEN's instruments even collected data as energetic particles blasted out by a massive solar eruption made it to Mars. 


MAVEN is still in the "commissioning phase" of its mission, meaning that the probe hasn't started collecting science full-time. 

The new data were gathered as the spacecraft's ground controllers began turning on its instruments after it arrived at Mars.

This graph shows atomic hydrogen scattering ultraviolet sunlight in the upper atmosphere of Mars, with data obtained by MAVEN’s Imaging Ultraviolet Spectrograph. 

Credit: University of Colorado, NASA


Scientists working with MAVEN weren't able to see exactly how the solar energetic particles (SEPs) affected Mars' atmosphere on Sept. 29 because the instruments necessary for that kind of observation weren't functioning in tandem at that time. 

MAVEN researchers expect, however, that the spacecraft's instruments will be ready to observe the atmosphere during the next Mars-directed solar event.

"After traveling through interplanetary space, these energetic particles of mostly protons deposit their energy in the upper atmosphere of Mars," SEP instrument lead Davin Larson, of the University of California, Berkeley's Space Sciences Laboratory, said in a statement. 

"An SEP event like this typically occurs every couple weeks. Once all the instruments are turned on, we expect to also be able to track the response of the upper atmosphere to them."

This image shows atomic carbon scattering ultraviolet sunlight in the upper atmosphere of Mars, as observed by MAVEN’s Imaging Ultraviolet Spectrograph. A red circle indicates Mars. Sunlight illuminates the planet from the right.

Credit: University of Colorado; NASA

This image shows atomic oxygen scattering ultraviolet sunlight in the upper atmosphere of Mars, as observed by MAVEN’s Imaging Ultraviolet Spectrograph. 

Most oxygen appears trapped near the planet, marked by the red circle.

Credit: University of Colorado; NASA

NASA Science Fleet: Comet Siding Spring C/2013 A1

Credit: NASA

NASA's extensive fleet of science assets, particularly those orbiting and roving Mars, have front row seats to image and study a once-in-a-lifetime comet flyby on Sunday, Oct. 19.

Comet C/2013 A1, also known as comet Siding Spring, will pass within about 87,000 miles (139,500 kilometers) of the Red Planet, less than half the distance between Earth and our moon and less than one-tenth the distance of any known comet flyby of Earth.

Siding Spring's nucleus will come closest to Mars around 2:27 p.m. EDT, hurtling at about 126,000 mph (56 kilometers per second).

This proximity will provide an unprecedented opportunity for researchers to gather data on both the comet and its effect on the Martian atmosphere.

"This is a cosmic science gift that could potentially keep on giving, and the agency's diverse science missions will be in full receive mode," said John Grunsfeld, astronaut and associate administrator for NASA's Science Mission Directorate in Washington.

"This particular comet has never before entered the inner solar system, so it will provide a fresh source of clues to our solar system's earliest days."

Siding Spring came from the Oort Cloud, a spherical region of space surrounding our sun and occupying space at a distance between 5,000 and 100,000 astronomical units.

It is a giant swarm of icy objects believed to be material left over from the formation of the solar system.

Siding Spring will be the first comet from the Oort Cloud to be studied up close by spacecraft, giving scientists an invaluable opportunity to learn more about the materials, including water and carbon compounds, that existed during the formation of the solar system 4.6 billion years ago.

Some of the best and most revealing images and science data will come from assets orbiting and roving the surface of Mars.

Mars Atmosphere and Volatile EvolutioN (MAVEN)

In preparation for the comet flyby, NASA maneuvered its Mars Odyssey orbiter, Mars Reconnaissance Orbiter (MRO), and the newest member of the Mars fleet, Mars Atmosphere and Volatile EvolutioN (MAVEN), to reduce the risk of impact with high-velocity dust particles coming off the comet.

The period of greatest risk to orbiting spacecraft will start about 90 minutes after the closest approach of the comet's nucleus and will last about 20 minutes, when Mars will come closest to the center of the widening trail of dust flying from the comet's nucleus.

"The hazard is not an impact of the comet nucleus itself, but the trail of debris coming from it. Using constraints provided by Earth-based observations, the modeling results indicate that the hazard is not as great as first anticipated."

"Mars will be right at the edge of the debris cloud, so it might encounter some of the particles, or it might not," said Rich Zurek, chief scientist for the Mars Exploration Program at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California.

The atmosphere of Mars, though much thinner that Earth's, will shield NASA Mars rovers Opportunity and Curiosity from comet dust, if any reaches the planet. Both rovers are scheduled to make observations of the comet.

NASA's Mars orbiters will gather information before, during and after the flyby about the size, rotation and activity of the comet's nucleus, the variability and gas composition of the coma around the nucleus, and the size and distribution of dust particles in the comet's tail.

Observations of the Martian atmosphere are designed to check for possible meteor trails, changes in distribution of neutral and charged particles, and effects of the comet on air temperature and clouds.

MAVEN will have a particularly good opportunity to study the comet, and how its tenuous atmosphere, or coma, interacts with Mars' upper atmosphere.

Earth-based and space telescopes, including NASA and ESA's iconic Hubble Space Telescope, also will be in position to observe the unique celestial object.

The agency's astrophysics space observatories, Kepler, Swift, Spitzer, Chandra, and the ground-based Infrared Telescope Facility on Mauna Kea, Hawaii, also will be tracking the event.

NASA's asteroid hunter, the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE), has been imaging, and will continue to image, the comet as part of its operations, and the agency's two Heliophysics spacecraft, Solar TErrestrial RElations Observatory (STEREO) and Solar and Heliophysics Observatory (SOHO), also will image the comet.

The agency's Balloon Observation Platform for Planetary Science (BOPPS), a sub-orbital balloon-carried telescope, already has provided observations of the comet in the lead-up to the close encounter with Mars.

Images and updates will be posted online before and after the comet flyby. Several pre-flyby images of Siding Spring, as well as information about the comet and NASA's planned observations of the event, are available online.

NASA MAVEN: Probe Snaps 1st Red Planet Images

The first observations of Mars' upper atmosphere made by NASA's MAVEN probe, which reached the Red Planet on Sept. 21, 2014.

Credit: Laboratory for Atmospheric and Space Physics, University of Colorado; NASA

NASA's MAVEN spacecraft isn't wasting any time at Mars.

MAVEN sent home its first images of Mars' upper atmosphere early Monday morning (Sept. 22), just eight hours after entering orbit around the Red Planet.

The false-colour images, which NASA released Wednesday (Sept. 24), were captured by MAVEN's Imaging Ultraviolet Spectrograph (IVS) instrument when the probe was 22,680 miles (36,500 kilometers) above the surface of Mars, agency officials said.

"Blue shows the ultraviolet light from the sun scattered from atomic hydrogen gas in an extended cloud that goes to thousands of kilometers above the planet’s surface," NASA officials wrote in an online description of the image.

"Green shows a different wavelength of ultraviolet light that is primarily sunlight reflected off of atomic oxygen, showing the smaller oxygen cloud," they added.

"Red shows ultraviolet sunlight reflected from the planet’s surface; the bright spot in the lower right is light reflected either from polar ice or clouds."



The $671 million MAVEN mission is NASA's first effort to study the Red Planet's upper atmosphere.

MAVEN will use its three onboard instrument suites to measure the rate of gas escape into space, in an attempt to better understand why Mars lost most of its atmosphere over the eons.

NB: The planet's air was relatively thick in the ancient past but is now just 1 percent as dense as that of Earth.

MAVEN's observations should shed light on how and why Mars transitioned from a warm and wet world billions of years ago to the cold, dry planet we know today, mission scientists have said.

The spacecraft is now in a commissioning phase, during which mission team members will lower MAVEN to its final orbit and check out its science gear.

The probe's one-year science mission is scheduled to start in early November.

NASA Maven: Sensing Mars Atmosphere from orbit - Video

NASA's Mars Atmosphere and Volatile Evolution (MAVEN) mission will take measurements with its Neutral Gas and Ion Mass Spectrometer (NGIMS) that have never been collected before. Dr. James Garvin speaks to reporters.

NASA Maven: Set to slide into orbit around Mars

NASA's MAVEN spacecraft is quickly approaching Mars on a mission to study its upper atmosphere. 

When it arrives on September 21, 2014, MAVEN's winding journey from Earth will culminate with a dramatic engine burn, pulling the spacecraft into an elliptical orbit.

On Sept. 21, 2014, the Mars Atmosphere and Volatile Evolution spacecraft will complete roughly 10 months of travel and enter orbit around the Red Planet.

The orbit-insertion maneuver will be carried out as the spacecraft approaches Mars, wrapping up an interplanetary journey of 442 million miles (711 million kilometers).

Six thruster engines will fire briefly for a “settling” burn that damps out deviations in pointing.

Then the six main engines will ignite two by two in quick succession and will burn for 33 minutes to slow the craft, allowing it to be captured in an elliptical orbit.

This milestone will mark the culmination of 11 years of concept and development for MAVEN, setting the stage for the mission’s science phase, which will investigate Mars as no other mission has.

“We’re the first mission devoted to observing the upper atmosphere of Mars and how it interacts with the sun and the solar wind,” said Bruce Jakosky, principal investigator for MAVEN at the University of Colorado in Boulder.

These observations will help scientists determine how much gas from Mars’ atmosphere has been lost to space throughout the planet’s history and which processes have driven that loss.

Procedures to line up MAVEN for proper orbit insertion began shortly after MAVEN launched in November 2013. These included two trajectory-correction maneuvers, performed in December 2013 and February 2014.

MAVEN's instrument payload

Calibration of the mission’s three suites of science instruments, the Particles and Fields Package, the Remote Sensing Package and the Neutral Gas and Ion Mass Spectrometer (NGIMS), was completed during the cruise phase to Mars.

“Every day at Mars is gold,” said David Mitchell, MAVEN’s project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

“The early checks of instrument and spacecraft systems during cruise phase enable us to move into the science collection phase shortly after MAVEN arrives at Mars.”

The voyage also gave the team an opportunity to take data on the interplanetary solar wind using the Fields and Particles Package.

Meanwhile, teams in California, Colorado and Maryland carried out rehearsals of the entire orbit insertion twice.

The science team also performed a weeklong simulation of the planning and implementation required to obtain science data. Two months prior to arrival at Mars, all instruments were turned off, in preparation for orbit insertion.

Mars Probes MAVEN and MOM Arrive at Red Planet This Month

An artist's interpretation of NASA's MAVEN mission, with Mars in the background. 

The probe is scheduled to start orbiting Mars on Sept. 21.

Credit: NASA's Goddard Space Flight Center

The planet Mars is about to have some company. Two new spacecraft, one from the United States and the other from India, are closing in on the Red Planet and poised to begin orbiting Mars by the end of this month.

The U.S.-built probe, NASA's Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft, is expected to enter orbit around Mars on Sept. 21.

Just days later, on Sept. 24, India's Mars Orbiter Mission (MOM) orbiter is due to make its own Mars arrival when it enters orbit. Both MOM and MAVEN launched to space in 2013.

MAVEN is the first mission devoted to probing the Martian atmosphere, particularly to understand how it has changed during the planet's history.

An artist's view of India's first Mars probe, the heart of the Mars Orbiter Mission, in orbit around the Red Planet. 

India's first Mars orbiter will arrive at its target on Sept. 24, 2014.

Credit: India Space Research Organisation

Before that happens, however, the spacecraft must burn its engines to go into orbit around the planet, and pass a commissioning phase while taking a few precautions for a "low-risk" situation where a comet will pass fairly close to Mars.

"We've been developing MAVEN for about 11 years, and it comes down to a 33-minute rocket burn on Sept. 21," MAVEN principal investigator Bruce Jakosky, of the University of Colorado, Boulder, told Space.com.

The spacecraft can change tracks as late as 6 hours before entering orbit, but right now, it is so close to the correct path that a planned orbital maneuver on Sept. 12 won't be needed, Jakosky said.

Comet Siding Spring will pass near Mars on Oct. 19, and around that time, MAVEN will take a break from its commissioning to do observations of the comet and the planet's upper atmosphere.

Although not much dust is predicted to result from the event, as a precaution, controllers will turn off nonessential instruments and move the solar panels edge-on to the dust.

The spacecraft will also be behind Mars for 20 minutes during the comet's closest approach.

NASA MAVEN Spacecraft: Final Preparations For Mars

NASA's MAVEN spacecraft is quickly approaching Mars on a mission to study its upper atmosphere. 

When it arrives on September 21, 2014, MAVEN's winding journey from Earth will culminate with a dramatic engine burn, pulling the spacecraft into an elliptical orbit.

On Sept. 21, 2014, the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft will complete roughly 10 months of travel and enter orbit around the Red Planet.

The orbit-insertion maneuver will be carried out as the spacecraft approaches Mars, wrapping up an interplanetary journey of 442 million miles (711 million kilometers).

Six thruster engines will fire briefly for a “settling” burn that damps out deviations in pointing.

Then the six main engines will ignite two by two in quick succession and will burn for 33 minutes to slow the craft, allowing it to be captured in an elliptical orbit.

This milestone will mark the culmination of 11 years of concept and development for MAVEN, setting the stage for the mission’s science phase, which will investigate Mars as no other mission has.

“We’re the first mission devoted to observing the upper atmosphere of Mars and how it interacts with the sun and the solar wind,” said Bruce Jakosky, principal investigator for MAVEN at the University of Colorado in Boulder.

These observations will help scientists determine how much gas from Mars’ atmosphere has been lost to space throughout the planet’s history and which processes have driven that loss.

En route
Procedures to line up MAVEN for proper orbit insertion began shortly after MAVEN launched in November 2013. These included two trajectory-correction maneuvers, performed in December 2013 and February 2014.

Calibration of the mission’s three suites of science instruments, the Particles and Fields Package, the Remote Sensing Package and the Neutral Gas and Ion Mass Spectrometer, was completed during the cruise phase to Mars.

“Every day at Mars is gold,” said David Mitchell, MAVEN’s project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

“The early checks of instrument and spacecraft systems during cruise phase enable us to move into the science collection phase shortly after MAVEN arrives at Mars.”

The voyage also gave the team an opportunity to take data on the interplanetary solar wind using the Fields and Particles Package.

Meanwhile, teams in California, Colorado and Maryland carried out rehearsals of the entire orbit insertion twice.

The science team also performed a weeklong simulation of the planning and implementation required to obtain science data. Two months prior to arrival at Mars, all instruments were turned off, in preparation for orbit insertion.

Into orbit
During orbit insertion, MAVEN will be controlled by its on-board computers. By that time, the team will have uploaded the most up-to-date information about the spacecraft’s location, velocity and orientation.

The insertion instructions will have been updated, and the fuel valves will be open, to warm the fuel to an operating temperature of about 77 to 79 degrees Fahrenheit (25 to 26 degrees Celsius).

If all goes well, the spacecraft will need no further commands from the ground. The important exception is that final trajectory corrections could be made, if needed, 24 hours or 6 hours prior to insertion.

That would only happen, however, if the navigation team concluded that the spacecraft was coming in at too low of an altitude.

Otherwise, during the last 24 hours, the spacecraft will carry out preprogrammed procedures to make all systems as “quiet” as possible, which is the safest condition for orbit insertion.

These steps include automatically executing a new version of the fault protection, which will tell the craft how to react to an on-board component anomaly leading up to or during orbit insertion.

In addition, the spacecraft will have to reorient itself so that the thrusters are pointed in the correct direction for the burn.

In this final orientation, MAVEN’s high-gain antenna, which is used for most communication with the spacecraft, will point away from Earth.

During that period, MAVEN’s low-gain antenna will be used for limited communication capacity at a reduced data rate.

At last, the insertion will begin. For the next 33 minutes, the craft will burn more than half the fuel onboard as it enters an orbit 236 miles (380 kilometers) above the northern pole.

Three minutes after the engines turn off, the MAVEN computers will reinstate the normal safeguards, reorient the spacecraft to point the high-gain antenna toward Earth, and reestablish normal communications.

At that point, MAVEN will transmit the data obtained during the insertion back to Earth, along with information on the state of the spacecraft, and the MAVEN team will learn if everything worked properly.

“Then, there will be a sigh of relief,” said Carlos Gomez-Rosa, MAVEN mission and science operations manager at Goddard.

Later, the team will upload new instructions for the science portion of the mission, as well as turn on and check out the science instruments.