Mars Science Laboratory Archives

November 7, 2014December 23, 2015 by Bob King

Mind-blowing Meteor Shower on Mars During Comet Flyby, Say NASA Scientists

We can only imagine what the meteor storm from Comet Siding Spring must have looked like standing on the surface of Mars on October 19, 2014. NASA scientists announced today that the planet experienced an exceptional shower during the comet's flyby, saturating the sky. Source: Stellarium

“Thousands of meteors per hour would have been visible — truly astounding to the human eye.” That’s Nick Schneider’s description of what you and I would have seen standing on Mars during Comet Siding Spring’s close flyby last month. “It would have been really mind-blowing,” he added. Schneider is instrument lead for MAVEN’s Imaging Ultraviolet Spectrograph (IUVS).

He and a group of scientists who work as lead investigators for instruments on the MAVEN and Mars Reconnaissance Orbiter (MRO) spacecraft shared the latest results from the comet flyby during a media teleconference earlier today. There were many surprises. Would we expect anything less from a comet?

Here’s a summary of the results:

A very dusty ice ball – The comet’s dust tail and the amount of dust in its coma were much larger than expected, prompting Jim Green, director of NASA’s Planetary Science Division in Washington, to remark: “It makes me very happy we hid them (the spacecraft) on the backside of Mars. That really saved them.” Siding Spring dumped several tons of fine dust into the Martian atmosphere prompting a spectacular meteor shower and possibly causing a yellow, twilight afterglow above the Curiosity landing site from vaporizing sodium atoms contained in the minerals. That, and dust in the mid-levels of the atmosphere at the time contributed to the rover’s difficulty in getting good photos of the comet itself. Scientists are still examining the images.

MAVEN's Ultraviolet Imaging Spectrograph (IUVS) uses limb scans to map the chemical makeup and vertical structure across Mars' upper atmosphere. It detected strong enhancements of magnesium and iron from ablating incandescing dust from Comet Siding Spring. Credit: NASA — MAVEN’s Ultraviolet Imaging Spectrograph (IUVS) uses limb scans to map the chemical makeup and vertical structure across Mars’ upper atmosphere. It detected strong enhancements of magnesium and iron from ablating incandescing dust from Comet Siding Spring. Credit: NASA

I'm not big into graphs either, but check out the heavy metal drama in this. On the left is the "before" scan from MAVEN's IUVS instrument; on the right, during the comet's close approach. The spike in magnesium from vaporizing comet dust is impressive. Ionized magnesium is the strongest spike with neutral and ionized iron on the left in smaller amounts. Both elements are common in meteorites as well as on Earth. Credit: NASA — I’m not big into graphs either, but check out the heavy metal drama going on here. On the left is the “before” scan from MAVEN’s IUVS instrument; on the right, during the comet’s close approach. The spike in magnesium from vaporizing comet dust is impressive. Ionized magnesium is the strongest spike with neutral and ionized iron on the left in smaller amounts. Both elements are common in meteorites as well as on Earth. Credit: NASA

Profiles showing spikes in the amounts of eight different metals detected in Mars' atmosphere during the flyby by MAVEN's Neutral Gas and Ion Mass Spectrometer (NGIMS). The emissions faded with a short time. Credit: NASA — Profiles showing spikes in the amounts of eight different metals over time detected in Mars’ atmosphere by MAVEN’s Neutral Gas and Ion Mass Spectrometer (NGIMS). The emissions faded within a short time, but chemicals from the comet will continue to interact with the Martian atmosphere over time. Credit: NASA

Chemistry of Mars’ atmosphere changed – Dust vaporized in the intense meteor shower produced a striking increase in the amount of magnesium, iron and others metals in Mars’ upper atmosphere. “We were pressed back in our chairs,” said Mike Schneider. The bombardment created a temporary new layer of comet-tainted air and may have acted as condensation nuclei for the formation of high-altitude clouds. MAVEN’s Neutral Gas and Ion Mass Spectrometer (NGIMS) recorded huge spikes in the levels of eight different metals during the comet’s passage and then trailed off a day or so later. “They came to MAVEN as a free sample from no less than an Oort Cloud comet,” said Mehdi Benna, instrument scientist for MAVEN’s Neutral Gas and Ion Mass Spectrometer.

The MARSIS instrument on the Mars Express is a ground penetrating radar sounder used to look for subsurface water and ice. It can also make soundings of the ionosphere. It was used to see the new ionospheric layer formed by vaporizing comet dust on October 19th. Credit: ESA

The Mars Express radar probed the ionosphere (upper atmosphere) at three different times. At top, before the comet arrived; middle, 7 hours later after the comet's closest approach and bottom, hours later after the comet had departed. The middle graph shows a strong signal (blue horizontal bar) from the creation of newly-ionized layer of the planet's lower atmosphere from hot, fast-moving comet dust. Credit: ESA — The Mars Express radar probed the ionosphere (upper atmosphere) at three different times. At top, before the comet arrived; middle, 7 hours later after the comet’s closest approach and bottom, hours later after the comet had departed. The middle graph shows a strong signal (blue horizontal bar) from the creation of a newly-ionized layer of the planet’s lower atmosphere from hot, fast-moving comet dust. Credit: ESA

Flaming comet dust creates new ionospheric layer – Comet dust slamming into the atmosphere at 125,000 mph (56 km/sec) knocked electrons loose from atoms in the thin Martian air 50-60 miles (80-100 km) high, ionizing them and creating a very dense ionization layer in the planet’s lower ionosphere seven hours after the comet’s closest approach. Normally, Mars ionosphere is only seen on the dayside of the planet, but even when the MARSIS instrument on Mars Express beamed radio waves through the atmosphere on the nightside of the planet, it picked up a very strong signal.

54 red-filtered images of the comet's nucleus-coma taken by the MRO's HiRISE camera show changes in the flow of material leaving the comet. Credit: NASA — 54 red-filtered, false-color images of the comet’s nucleus-coma taken by the MRO’s HiRISE camera show changes in the flow of material leaving the comet. Based on the photos, the comet’s nucleus spins once every 8 hours. Credit: NASA

The five closest photos made with the HiRISE camera show the combined light of the nucleus and coma. Scale is 140-meter per pixel at top and 177-meters at bottom. Scientists will further process these images to separate the nucleus from the coma. Credit: NASA

Nucleus spins once during your work day – Comet Siding Spring’s icy core spins once every 8 hours and its irregular shape causes strong variations in the comet’s brightness. The comet’s size appears less certain – at least for the moment – with estimates anywhere between a few hundred meters to 2 km (1.2 miles). More analysis on images taken by MRO’s HiRISE camera should narrow that number soon.

CRISM photo and spectrum of Comet Siding Spring. The spectrum is "flat", indicating we're seeing sunlight reflected off comet dust. The intriguing color variations in the image tell of dust particles of varying size leaving the nucleus. Credit: NASA — CRISM photo and spectrum of Comet Siding Spring. The spectrum is “flat”, indicating we’re seeing ordinary sunlight reflecting off comet dust. The intriguing color variations in the image tell us the comet’s spewing dust particles of many sizes. Credit: NASA

Dust motes of many sizes – Color variations across Siding Spring’s coma seen by Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) indicate it’s releasing dust particles of different sizes – big and little.

The scientists involved in the encounter couldn’t be happier with how the instruments functioned and the amount of hard data returned. Said Jim Green: “We are so lucky to observe this once-in-a-lifetime event.” How true when you consider that it takes about 8 million years for a comet from the Oort Cloud, that vast reservoir of frozen comets extending nearly a light year from the Sun, to get here in the first place. Nick Schneider put it another way:

“Not only is this a free sample of the Oort Cloud in Mars’ atmosphere, but it gives us a chance to learn more about Mars itself.”

If you’d like to listen in to the hour-long teleconference at any time, it’ll be up for the next week or so HERE.

November 6, 2014December 23, 2015 by Bob King

Curiosity Rover Sees a Pixel’s-Worth of Comet Siding Spring

In this panoramic view taken by NASA's Curiosity Rover on October 19th shortly after local sunset (6:11 p.m.), Comet Siding Spring is the single bright pixel at far upper left. Click for a high resolution version. Credit: NASA/JPL-Caltech/Malin Space Science Systems/James Sorenson

When Comet Siding Spring skimmed just 84,500 miles from Mars last month, NASA’s Opportunity and Curiosity Rovers – along with several orbiting Mars spacecraft – readied their cameras to record the historic flyby. Opportunity’s photos revealed a small, fuzzy blob against the stars of Cetus the Whale, but most of us searched in vain to find any trace of the comet among the blizzard of noise in pictures snapped by Curiosity. Yet it may be there after all.

In this before and after animation, you can see how much noise needed to be cleaned from one of the original photos to uncover the the comet. Credit: NASA/JPL-Caltech/Malin Space Science Systems/James Sorenson — In this before-and-after animation, you can see how much noise needed to be cleaned from the original photos to uncover the the comet. Credit: NASA/JPL-Caltech/Malin Space Science Systems/James Sorenson

In this panoramic image at top, assembled and processed by James Sorenson to remove the pervasive noise in the original photos, we see with a twilit landscape just after sundown. Look closely in the upper left hand corner and you’ll see a speck of light. That’s it! Combined with positional information, Sorenson tentatively identified that pixel as Comet C/2013 A1 Siding Spring. OK, it’s not much to look at but may be our best candidate for the hoped-for photo from Curiosity.

Comet Siding Spring near Mars in a composite image by the Hubble Space Telescope, capturing their positions between Oct. 18 8:06 a.m. EDT (12:06 p.m. UTC) and Oct. 19 11:17 p.m. EDT (Oct. 20, 3:17 a.m. UTC). Credit: NASA, ESA, PSI, JHU/APL, STScI/AURA

Remember that conditions were far from ideal when the picture was taken. There was considerable dust and haze in the Martian atmosphere over Gale Crater. Dust effectively absorbs and also scatters light. The bright twilight sky only made the comet more difficult to discern. If you’ve ever struggled to see Mercury at dusk on a hazy summer evening, you’ll understand what our robot was up against.

This animation combines multiple images that were acquired by the HRSC camera on board Mars Express during the comet Siding Spring flyby on October 19, 2014. Click to animate Credit: ESA/DLR/FU Berlin — This single image is one of series that were acquired by the HRSC camera on board Mars Express during the comet Siding Spring flyby on October 19, 2014. Click to animate. Credit: ESA/DLR/FU Berlin

The European Space Agency’s Mars Express orbiter also chimed in with a recent set of comet images. As it flew by, Siding Spring was traveling at around 35 miles per second (56 km/sec) relative to Mars. Images were acquired at 17-second intervals at a resolution of 10.5 miles (17 km) per pixel. What do they show? The irregular shape might make you might think you’re seeing the actual shape of the comet’s nucleus. Unfortunately, that’s impossible because it’s less than a kilometer across and each pixel in the photo spans 17 km. Instead, we’re seeing the combined light of the nucleus and extended coma, the surrounding cloud of gas and dust. Why the images are pure black and white with no grey tones is unclear.

Two photos of comet C/2013 A1 Siding Spring taken 37 minutes apart by the CRISM imager. The subtle coloration of the comet indicates the abundance of different molecules. Credit: NASA / JPL / JHUAPL — Two photos of comet C/2013 A1 Siding Spring taken 37 minutes apart by the CRISM imager when the comet was closest to Mars. The subtle colors seen are likely related to dust grain size or composition. The nucleus itself is not resolved. Credit: NASA/JPL/JHUAPL

Besides the the close-up photo taken with the HiRISE camera on NASA’s Mars Reconnaissance Orbiter, its Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) got busy photographing the dusty inner coma generated when sunlight warms and vaporizes dust-laden ice in the nucleus. The scale of the left image is approximately 2.5 miles (4 km) per pixel; for the right image, it is about 3 miles (5 km) per pixel.

According to NASA, CRISM observed 107 different wavelengths of light in each pixel. Here, only three colors are shown. Researchers think the appearance of color variations in the inner coma could be due to the properties of the comet’s dust, possibly dust grain size or composition. More photos and results from all the spacecraft will appear in the weeks and months ahead as scientists continue their analyses.

Comet Siding Spring shows a condensed coma and a short, faint tail in this photo taken on November 5, 2014. Credit: Alfons Diepvens — Comet Siding Spring shows a condensed coma and hint of a tail in this photo taken on November 5, 2014. Credit: Alfons Diepvens

Comet Siding Spring has left Mars and its crew of robotic eyes behind as it crawls north into the constellation Serpens low in the southwest at dusk. Amateur astronomers are still keen to photograph it at every opportunity. Recent observations indicate a temporary re-brightening, though the comet remains a dim 11th magnitude object.

November 6, 2014December 23, 2015 by Elizabeth Howell

Mars Habitability? Curiosity Rover Spots Intriguing Mineral On Red Planet

A view from the Curiosity rover on Sol 794 (Oct. 31, 2014) from its outpost at the base of Mount Sharp (Aeolis Mons). Credit: NASA/JPL-Caltech

NASA’s Curiosity rover has struck hematite — an iron-oxide mineral often associated with water-soaked environments — in its first drill hole inside the huge Mount Sharp (Aeolis Mons) on Mars. While in this case oxidization is more important to its formation, the sample’s oxidization shows that the area had enough chemical energy to support microbes, NASA said.

Hematite is not a new discovery for Curiosity or Mars rovers generally, but what excites scientists is this confirms observations from the Mars Reconnaissance Orbiter that spotted hematite from orbit in the Pahrump Hills, the area that Curiosity is currently roving.

“This connects us with the mineral identifications from orbit, which can now help guide our investigations as we climb the slope and test hypotheses derived from the orbital mapping,” stated John Grotzinger, Curiosity project scientist at the California Institute of Technology in Pasadena.

This is the latest in a series of finds for the rover related to habitability. In December 2013, scientists announced it found a zone (dubbed Yellowknife Bay) that was likely an ancient lakebed. But Yellowknife’s mineralogy eluded detection from orbit, likely due to dust covering the rocks.

Photo mosaic shows NASA’s Curiosity Mars rover in action reaching out to investigate rocks at a location called Yellowknife Bay on Sol 132, Dec 19, 2012 in search of first drilling target. The view is reminiscent of a dried up shoreline. Curiosity’s navigation camera captured the scene surrounding the rover with the arm deployed and the APXS and MAHLI science instruments on tool turret collecting microscopic imaging and X-ray spectroscopic data. The mosaic is colorized. See the full 360 degree panoramic and black & white versions below. Credit: NASA/JPL-Caltech/Ken Kremer/Marco Di Lorenzo — Photo mosaic shows NASA’s Curiosity Mars rover in action reaching out to investigate rocks at a location called Yellowknife Bay on Sol 132, Dec 19, 2012, in search of first drilling target. The view is reminiscent of a dried up shoreline. Curiosity’s navigation camera captured the scene surrounding the rover with the arm deployed and the APXS and MAHLI science instruments on tool turret collecting microscopic imaging and X-ray spectroscopic data. The mosaic is colorized. See the full 360 degree panoramic and black & white versions below. Credit: NASA/JPL-Caltech/Ken Kremer/Marco Di Lorenzo

Hematite is perhaps most closely associated with spherical rocks called “blueberries” that the Opportunity rover discovered on Mars in 2004. While Opportunity’s discovery showed clear evidence of water, the new Curiosity find is more closely associated with oxidization, NASA said.

The new find, contained in a pinch of dust analyzed in Curiosity’s internal Chemistry and Mineralogy (CheMin) instrument, yielded 8% and 4% magnetite. The latter mineral is one way that hematite can be created, should magnetite be placed in “oxidizing conditions”, NASA stated. Previous samples en route to Mount Sharp had concentrations only as high as 1% hematite, but more magnetite. This shows more oxidization took place in this new sample, NASA stated.

Curiosity will likely stick around Pahrump Hills for at least weeks, perhaps months, until it climbs further up the mountain. Among Mount Sharp’s many layers is one that contains so much hematite (as predicted from orbit) that NASA calls it “Hematite Ridge.”

Source: NASA

October 20, 2014December 23, 2015 by Bob King

MRO Spies Tiny, Bright Nucleus During Comet Flyby of Mars

High resolution image pairs made with HiRISE camera on MRO during Comet Siding Spring's closest approach to Mars on October 19. Shown at top are images of the nucleus region and inner coma. Those at bottom were exposed to show the bigger coma beginning of a tail. Credit: NASA/JPL/Univ. of Arizona

Not to be outdone by the feisty Opportunity Rover, the HiRISE camera on NASA’s Mars Reconnaissance Orbiter (MRO) turned in its homework this evening with a fine image of comet C/2013 Siding Spring taken during closest approach on October 19.

The highest-resolution images were acquired by HiRISE at the minimum distance of 85,750 miles (138,000 km). The image has a scale of 453 feet (138-m) per pixel.

The top set of photos uses the full dynamic range of the camera to accurately depict brightness and detail in the nuclear region and inner coma. Prior to its arrival near Mars astronomers estimated the nucleus or comet’s core diameter at around 0.6 mile (1 km). Based on these images, where the brightest feature is only 2-3 pixels across, its true size is shy of 1/3 mile or 0.5 km. The bottom photos overexpose the comet’s innards but reveal an extended coma and the beginning of a tail extending to the right.

Annotated photo of Comet Siding Spring taken by the Opportunity Rover on October 19 when near closest approach. Credit: NASA/JPL-Caltech/Cornell Univ./ASU/TAMU

To photograph a fast-moving target from orbit, engineers at Lockheed-Martin in Denver precisely pointed and slewed the spacecraft based on comet position calculations by engineers at JPL. To make sure they knew exactly where the comet was, the team photographed the comet 12 days in advance when it was barely bright enough to register above the detector’s noise level. To their surprise, it was not exactly where orbital calculations had predicted it to be. Using the new positions, MRO succeeded in locking onto the comet during the flyby. Without this “double check” its cameras may have missed seeing Siding Spring altogether!

Meanwhile, the Jet Propulsion Lab has released an annotated image showing the stars around the comet in the photo taken by NASA’s Opportunity Rover during closest approach. From Mars’ perspective the comet passed near Alpha Ceti in the constellation Cetus, but here on Earth we see it in southern Ophiuchus not far from Sagittarius.

Comet Siding Spring continues on its way today past the planet Mars in this photo taken on October 20. Copyright: Rolando Ligustri

“It’s excitingly fortunate that this comet came so close to Mars to give us a chance to study it with the instruments we’re using to study Mars,” said Opportunity science team member Mark Lemmon of Texas A&M University, who coordinated the camera pointing. “The views from Mars rovers, in particular, give us a human perspective, because they are about as sensitive to light as our eyes would be.”

After seeing photos from both Earth and Mars I swear I’m that close to picturing this comet in 3D in my mind’s eye. NASA engineers and scientists deserve a huge thanks for their amazing and successful effort to turn rovers and spacecraft, intended for other purposes, into comet observatories in a pinch and then deliver results within 24 hours. Nice work!

October 19, 2014December 23, 2015 by Bob King

Astrophotographers Capture Dramatic Photos of Comet Siding Spring Approaching Mars

Comet Siding Spring approaches within a degree of Mars at 5:07 a.m. CDT today October 19. Closest approach happens around 1:28 p.m. CDT (18:28 UT) when the comet will brush about 83,240 miles from the planet's surface. Image copyright SEN / Damian Peach

Astrophotographer Damian Peach shares this spectacular image of comet C/2013 A1 Siding Spring approaching Mars taken just hours ago. The faint comet shows a small, condensed coma and bent tail against the glaring orange glow of the brilliant planet. Most photos of comets passing by a planet or deep sky object are lucky line-of-sight pairings with the comet in the foreground and object light years away in the background. Not this one. Both Siding Spring and Mars lie at nearly the identical distance from Earth of 151 million miles (243 million km).

Artist view of the comet passing closest to Mars this Sunday. At the time, the Mars orbiters from the U.S., Europe and India will be huddled on the opposite side of the planet to avoid possible impacts from comet dust. Credit: NASA — Artist view of the comet passing closest to Mars this afternoon October 19. At the time, the Mars orbiters from the U.S., Europe and India will be huddled on the opposite side of the planet to avoid possible impacts from comet dust. Credit: NASA

When closest to Mars this afternoon, Siding Spring is expected to shine at around magnitude -5 or about twice as bright as Venus. Mind you, that estimate considers the entire comet crunched down into a dot. But for those who remember, Comet Hale-Bopp remained at zero magnitude, 100 times fainter than Siding Spring, and made for one of the most impressive naked eye sights on spring evenings in 1997.

More recently, Comet McNaught climaxed at magnitude -5 in the daytime sky near the Sun in January 2007. It was plainly visible in binoculars and telescopes in a blue sky if you knew exactly where to look and took care to avoid the Sun. Would-be Martians are far more fortunate, with Siding Spring appearing high overhead in a dark sky from some locations, including that of NASA’s Curiosity Rover.

Comet C/2013 Siding Spring as it rises and sets over the Curiosity Rover this weekend October 18-19. Credit: Solarsystemscope.com

Right on time for today’s encounter, the folks at Solarsystemscope.com have rolled out an interactive simulation of Comet Siding Spring’s appearance in the sky above Curiosity. Just click the play button on the control panel above to run it live. Seen from Mars, the comet bobs along Eridanus the River southwest of Orion, passing high in the southern sky overnight. What a sight!

Another photo, just in, taken of the comet and Mars today by Rolando Ligustri. Beautiful!

The comet nucleus is only about 0.4 miles (700 meters) across, but the coma or atmosphere fluffs out to around 12,000 miles (19,300 km). Seen from the ground, Siding Spring would span about 8°of sky or 16 full Moons from head to tail. Moving at 1.5° per minute, we could watch crawl across the heavens in real time with the naked eye. Wish I zoom to Mars for a look, but the rovers and orbiters will be our eyes as they study and photograph the comet during its brief flyby. As soon as those pictures become available, we’ll publish them here. Can’t wait!

Come Siding Spring comes out the other side!

While we’re waiting, amateur astronomers have been busy shooting additional photos and creating videos from their images. Fritz Helmut Hemmerich made this video from 1200-meters at Tenerife in the Canary Islands showing Comet Siding Spring immediately after its Mars encounter. One thing we know for certain is that the comet is intact after its close brush.

Negative image showing Comet Siding Spring closely approaching Mars today. Credit: Peter Lake

And find our more amazing photos and information at Sen TV, and you can follow them on Twitter at @sen.

October 19, 2014December 23, 2015 by Tim Reyes

A Compendium of Universe Today Comet Siding Spring Articles: January 2013 – October 2014

Comet C/2013 A1 Siding Spring passed between the Small Magellanic Cloud (left) and the rich globular cluster NGC 130 on August 29, 2014. Credit: Rolando Ligustri

We present here a compendium of Universe Today articles on comet Siding Spring. Altogether 18 Universe Today stories and counting have represented our on-going coverage of a once in a lifetime event. The articles beginning in February 2013, just days after its discovery, lead to the comet’s penultimate event – the flyby of Mars, October 19, 2014. While comet Siding Spring will reach perihelion just 6 days later, October 25, 2014, it will hardly have sensed the true power and impact that our Sun can have on a comet.

Siding Spring’s Oort Cloud cousin, Comet ISON in November 2013 encountered the Sun at a mere 1.86 million km. The intensity of the Sun’s glare was 12,600 times greater than what Siding Spring will experience in a few days. Comet ISON did not survive its passage around the Sun but Comet Siding Spring will soon turn back and begin a very long journey to its place of origin, the Oort Cloud far beyond Pluto.

An animation of comet Siding Springs passage through the inner Solar System. The scale size of its place of origin would dwarf the orbits of the Solar System to little more than a small dot. (Illustration Credit: Near-Earth Object (NEO) office, NASA/JPL)

The closest approach for comet Siding Spring with the Sun – perihelion is at a distance of 1.39875 Astronomical Units (1 AU being the distance between the Earth and Sun), still 209 million km (130 million miles). The exact period of the comet is not exactly known but it is measured in millions of years. In my childhood astronomy book, it stated that comet Halley, when it is at its furthest distance from the Sun, is moving no faster than a galloping horse. This has also been all that comet Siding Spring could muster for millions of years – the slightest of movement in the direction of the Sun.

It is only in the last 3 years, out all the millions spent on its journey, that it has felt the heat of the Sun and been in proximity to the planetary bodies of our Solar System. This is story of all long period comets. A video camera on Siding Spring would have recorded the emergence and evolution of one primate out of several, one that left the trees to stand on two legs, whose brain grew in size and complexity and has achieved all the technological wonders (and horrors) we know of today.

Now with its close encounter with Mars, the planet’s gravity will bend the trajectory of the comet and reduce its orbital period to approximately one million years. No one will be waiting up late for its next return to the inner Solar System.

It is also unknown what force in the depths of the Oort cloud nudged the comet into its encounter with Mars and the Sun. Like the millions of other Oort cloud objects, Siding Spring has spent its existence – 4.5 Billion years, in the darkness of deep space, with its parent star, the Sun, nothing more than a point of light, the brightest star in its sky. The gravitational force that nudged it may have been a passing star, another cometary body or possibly a larger trans-Neptunian object the size of Pluto and even as large as Mars or the Earth.

The forces of nature on Earth cause a constant turning over geological features. Our oceans and atmosphere are constantly recycling water and gases. The comets that we receive from the Oort Cloud are objects as old as our Solar System. Yet it is the close encounter with Mars that has raised the specter of an otherwise small ordinary comet. All these comets from deep space are fascinating gems nearly unaltered for 1/3rd of the time span of the known Universe.

Universe Today’s Siding Spring Compendium

2014/10/17: Here’s A Look At Comet Siding Spring Two Days Before Its Encounter With Mars

2014/10/17: Weekly Space Hangout Oct 17 2014

2014/10/15: Comet A1 Siding Spring vs Mars Views In Space And Time

2014/10/10: How To See Comet Siding Spring As It Encounters Mars

2014/10/08: Comet Siding Spring Close Call For Mars Wake Up Call For Earth

2014/09/19: How NASA’s Next Mars Spacecraft Will Greet The Red Planet On Sunday

2014/09/09: Tales Tails Of Three Comets

2014/09/05: Maven Mars Orbiter Ideally Poised To Uniquely Map Comet Siding Spring Composition Exclusive Interview With Principal Investigator Bruce Jakosky

2014/08/30: Caterpillar Comet Poses For Pictures En Route To Mars

2014/07/26: NASA Preps For Nail Biting Comet Flyby Of Mars

2014/05/08: Interesting Prospects For Comet A1 Siding Spring Versus The Martian Atmosphere

2014/03/27: Mars Bound Comet Siding Spring Sprouts Multiple Jets

2014/01/29: Neowise Spots Mars Crossing Comet

2014/01/02: Comets Prospects For 2014 A Look Into The Crystal Ball

2013/04/12: New Calculations Effectively Rule Out Comet Impacting Mars In 2014

2013/03/28: NASA Scientists Discuss Potential Comet Impact On Mars

2013/03/05: Update On The Comet That Might Hit Mars

2013/02/26: Is A Comet On A Collision Course With Mars

October 9, 2014December 23, 2015 by Elizabeth Howell

Among the Martian Hills: Curiosity Rover Peers At Rocks Of Mount Sharp

Rover tracks and Martian sand as seen from the rear hazcam of NASA's Curiosity rover. Credit: NASA/JPL-Caltech

After a couple of years of racing towards Mount Sharp (Aeolis Mons), now it’s time for the Curiosity rover to get a better look at its Martian surroundings. The rover has reached its stated science destination and mission planners say now is the time to stop the driving and get deep into the science.

NASA is on the hunt for signs of habitability on the Red Planet, and officials hope that the layers of this big mountain will yield a wealth of information on Martian history.

“This first look at rocks we believe to underlie Mount Sharp is exciting because it will begin to form a picture of the environment at the time the mountain formed, and what led to its growth,” stated Ashwin Vasavada, Curiosity’s deputy project scientist in a press release from late September.

As Curiosity drills and analyzes rocks at its feet, it continues to send back stunning pictures of its surroundings. Check out a sample from this week below.

Mars Curiosity peers over a craggy ridge on Oct. 7, 2014 (Sol 771). Credit: NASA/JPL-Caltech/MSSS

Hills beckon in this photo from the Curiosity rover taken Oct. 7, 2014, on Sol 771. Credit: NASA/JPL-Caltech/MSSS — Martian hills beckon in this photo from the Curiosity rover taken Oct. 7, 2014, on Sol 771. Credit: NASA/JPL-Caltech/MSSS

Close-up of a brush instrument on the Mars Curiosity rover on Oct. 3 (Sol 767). Credit: NASA/JPL-Caltech/MSSS

Cracked terrain underfoot seen by the Martian Curiosity rover on Oct. 7, 2014 (Sol 771). Credit: NASA/JPL-Caltech/MSSS

October 6, 2014December 23, 2015 by Elizabeth Howell

Could Martian Volcanoes Help With Search For Water On The Red Planet?

Mars volcanoes Ceraunius Tholus and Uranius Tholus, as seen by Mars Express. Credits: ESA/DLR/FU Berlin (G. Neukum). Click for larger version.

Could a Martian volcanic explosion show off the path to water? One research team thinks so. They analyzed volcanic rock samples on Earth and Mars and came up with a way of predicting which ones touched water during their formation.

The Mars results are so far negative: no water using this method was found at the Curiosity rover’s landing site at Gale Crater and the Spirit rover’s former stomping grounds at Gusev Crater. That said, the science team believes this could supplement existing searches for water on Mars in sedimentary rock.

“I think this quantification of volcanic textures is a new facet of the water story that hasn’t yet been explored,” stated Kellie Wall, a geology undergraduate student at Washington State University who led the research.

“Most of the studies searching for water have focused on either looking for sedimentary structures—large- and small-scale—for evidence of water, or looking for rocks like limestones that actually would have formed in a water-rich environment.”

The ultimate Selfie - a self-protrait taken on anoher planet. This is the capability of the Mars Hand Lens Imager (MAHLI) camera, one of 5 instruments on the turret at the end of the 2.1 meter (7 ft), 30 kg (66 lb) Robotic Arm. On numerous occasions, Curiosity has taken self-portraits, many as mosaics. This on is on Sol (Mars day) 85, post landing, showing Curiosity with its destination - Aeolis Mons (Mt. Sharp) in the background. (Credit: NASA/JPL-Caltech/MSSS/Ken Kremer/Marco Di Lorenzo, "Curiosity Celebrates 90 Sols Scooping Mars and Snapping Amazing Self-Portrait with Mount Sharp") — The ultimate Selfie – a self-portrait taken on another planet. This is the capability of the Mars Hand Lens Imager (MAHLI) camera, one of 5 instruments on the turret at the end of the 2.1 meter (7 ft), 30 kg (66 lb) Robotic Arm. On numerous occasions, Curiosity has taken self-portraits, many as mosaics. This on is on Sol (Mars day) 85, post landing, showing Curiosity with its destination – Aeolis Mons (Mt. Sharp) in the background. (Credit: NASA/JPL-Caltech/MSSS/Ken Kremer/Marco Di Lorenzo, “Curiosity Celebrates 90 Sols Scooping Mars and Snapping Amazing Self-Portrait with Mount Sharp”)

There is abundant evidence that water flowed on Mars in the distant past, implying the planet had a thicker atmosphere that allowed liquid water to flow and pool abundantly on the surface. NASA’s rovers and several orbiting vehicles have seen evidence of rocks that formed in water (such as this rock Curiosity recently spotted) as well as features such as chasms that were likely cut by running water, long ago.

But volcanic rock remains a less explored frontier on Mars, the team argues. It’s known that water on Earth can speed up the cooling process of volcanic rock, creating glass. Without water, cooling slows and more crystals are formed. The team then compared observations from two sites on Mars with x-ray diffraction observations they performed on samples they had from New Zealand and Italy’s Mount Etna.

They found that Earth rocks that included water in their formation had crystallinity ranging from 8% to 35%, while those without water had crystals composing 45% of the material and up. And the Mars samples? You guessed it, they had fewer crystals, implying the volcanoes erupted with no water interaction.

A paper based on the research was published in Nature Communications.

Source: Washington State University

September 30, 2014December 23, 2015 by Ken Kremer

India’s MOM Snaps Spectacular Portrait of New Home – the Red Planet

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 74500 km on Sept. 28, 2014. Credit: ISRO

MOM is truly something special.

For her latest eye popping feat, India’s Mars Orbiter Mission (MOM) has snapped the first global portrait of her new Home – the Red Planet.

MOM is India’s first interplanetary voyager and took the stupendous new image on Sept. 28, barely four days after her historic arrival on Sept. 23/24 following the successful Mars Orbital Insertion (MOI) braking maneuver.

The MOM orbiter was designed and developed by the Indian Space Research Organization (ISRO), India’s space agency, which released the image on Sept. 29.

Even more impressive is that MOM’s Martian portrait shows a dramatic view of a huge dust storm swirling over a large patch of the planet’s Northern Hemisphere against the blackness of space. Luckily, NASA’s Opportunity and Curiosity surface rovers are nowhere nearby.

“Something’s brewing here!” ISRO tweeted.

The southern polar ice cap is also clearly visible.

It was taken by the probe’s on-board Mars Color Camera from a very high altitude of 74,500 kilometers.

ISRO's Mars Orbiter Mission captures the limb of Mars with the Mars Color Camera from an altitude of 8449 km soon after achieving orbit on Sept. 23/24, 2014. . Credit: ISRO — ISRO’s Mars Orbiter Mission captures the limb of Mars with the Mars Color Camera from an altitude of 8449 km soon after achieving orbit on Sept. 23/24, 2014. Credit: ISRO

When MOM met Mars, the thrusters placed the probe into a highly elliptical orbit whose nearest point to Mars (periapsis) is at 421.7 km and farthest point (apoapsis) at 76,993.6 km. The inclination of the orbit with respect to the equatorial plane of Mars is 150 degrees, as intended, ISRO reported.

So the Red Planet portrait was captured nearly at apoapsis.

This is the third MOM image released by ISRO thus far, and my personal favorite. And its very reminiscent of whole globe Mars shots taken by Hubble.

MOM’s goal is to study Mars’ atmosphere, surface environments, morphology, and mineralogy with a 15 kg (33 lb) suite of five indigenously built science instruments. It will also sniff for methane, a potential marker for biological activity.

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

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 who have launched probes that successfully investigated Mars – following the Soviet Union, the United States and the European Space Agency (ESA).

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

September 26, 2014December 23, 2015 by Elizabeth Howell

What Is This Bizarre Ball That The Curiosity Rover Found On Mars?

A "ball" of material on Mars taken by the Curiosity rover on Sol 746. Credit: NASA/JPL-Caltech/MSSS

It seems too round to be true — the Curiosity rover has found a ball-shaped object among the craggy rocks in its picture. This image was taken on Sol 746 of the rover’s mission on Mars, which so far has extended over two Earth years.

No, it’s not the leftover of a Martian baseball game and nor is it aliens. In fact, according to Discovery News (who is quoting NASA) it’s a kind of rock that shows evidence of water in the ancient past.

Ian O’Neill writes:

According to MSL scientists based at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif., the ball isn’t as big as it looks — it’s approximately one centimeter wide. Their explanation is that it is most likely something known as a “concretion.” Other examples of concretions have been found on the Martian surface before — take, for example, the tiny haematite concretions, or “blueberries”, observed by Mars rover Opportunity in 2004 — and they were created during sedimentary rock formation when Mars was abundant in liquid water many millions of years ago.

Curiosity is now at the base of Mount Sharp (Aeolis Mons) — its main science goal — and scientists are hoping to find more signs of habitable environments as the rover slowly prepares for the climb up the slope. Mission managers will need to be careful as the rover has battered wheels from rougher terrain than expected.

The rover already has found other evidence of water in its landing site of Gale Crater, such as this ancient lakebed that could have supported life.