Meteorite Ahead!

There has been a flurry of emails going around among the MER team about a certain rock ahead of the Opportunity rover that looks like it may be yet another meteorite.  It certainly doesn’t look much like the local meridiani rocks, which are the light-toned patches in the photo above. Meteorites are interesting because they provide information about the weathering environment on mars. We know that Mars is all rusty, but iron meteorites are nice and fresh when they fall, so by studying how rusted they are we can learn about the martian atmosphere.

Another thing that strikes me in the photo above is how close Endeavor’s rim looks! I’ve been a bad martian and haven’t looked at the photos from Opportunity for a while, so it’s great to see those distant hills looking not-so-distant. Of course, they’re still a long way off, they’re just really big. It’s like driving toward a mountain range here on earth. You can see your destination long before you get there, and then it seems to taunt you as you creep closer and closer.

For more information about the meteorite sighting, check the NASA press release.

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Seeing Early 20th Century Russia Like a Rover

Hello folks! Apologies for the lack of posts lately, I had to go get married and go on a honeymoon! But I’m back now, and adjusting to the real world again. As I sifted through my inbox earlier this week, I came across a link to a fascinating collection of photographs. These are color photos of the Russian Empire taken by Sergei Mikhailovich Prokudin-Gorskii. But wait! How could he have taken color photographs of Russia in 1910 if Kodachrome wasn’t released until 1935?

By taking them like a rover, of course! By photographing the same scene three times, each with a red, green or blue filter, Produkin-Gorskii was able to create realistic color images by using a trio of projectors.This is almost identical to the process used by the MER rovers to acquire color images. The Pancam CCD takes greyscale images through a variety of filters, and these can be used to construct various true- or false-color views of Mars!

The Library of Congress has digitized all of Produkin-Gorskii’s photos of early 20th century Russia, and you can browse them here. Or, you can head over to The Big Picture which recently featured some of the best shots.

Spirit Rover Discovers Carbonates

Big news from Mars today, Spirit has found evidence for significant amounts of carbonates in the rocks of Gusev crater! Carbonates are really important for two reasons: first of all, Mars has a very thin CO2 atmosphere right now. Too thin for water to remain as a liquid on the surface: it would just boil away and freeze at the same time! But there is lots of evidence that water once flowed on the surface. That means it must have been warmer and the atmospheric pressure must have been higher.  A good way to get higher pressure and temperature on the planet would be to have more CO2 in the atmosphere (just take a look at Venus!). But then the question becomes “where did it go”? On Earth a lot of our CO2 is trapped in carbonate rocks like limestone, so the thought was that maybe carbonates could store some of the CO2 on Mars. But until now they have been very hard to find. The Phoenix lander found evidence for a little bit, and orbiting spectrometers have identified some tiny patches that look like carbonates, but this finding by Spirit is much more conclusive.

Carbonates are also important because they dissolve quite easily in acid. The fact that there are rocks on the surface at Gusev Crater that have carbonate minerals in them means that they have not been exposed to much acid, and therefore the environment was much less hostile to life.

I’m going to paste the full press release here, but I also want to note how cool it is that my adviser at NASA, Dick Morris, is the lead author of this study! He does extremely careful and detailed work, so if he is confident enough to publish this finding, I have no doubt that it is true. Congrats to everyone involved on this awesome discovery!

NASA Rovers Finds Clue to Mars’ Past and Environment for Life

The "Comanche" outcrop may be up to one-quarter carbonates. Image Credit: NASA/JPL-Caltech/Cornell University

PASADENA, Calif. — Rocks examined by NASA’s Spirit Mars Rover hold evidence of a wet, non-acidic ancient environment that may have been favorable for life. Confirming this mineral clue took four years of analysis by several scientists.

An outcrop that Spirit examined in late 2005 revealed high concentrations of carbonate, which originates in wet, near-neutral conditions, but dissolves in acid. The ancient water indicated by this find was not acidic.

NASA’s rovers have found other evidence of formerly wet Martian environments. However, the data for those environments indicate conditions that may have been acidic. In other cases, the conditions were definitely acidic, and therefore less favorable as habitats for life.

Laboratory tests helped confirm the carbonate identification. The findings were published online Thursday, June 3 by the journal Science.

“This is one of the most significant findings by the rovers,” said Steve Squyres of Cornell University in Ithaca, N.Y. Squyres is principal investigator for the Mars twin rovers, Spirit and Opportunity, and a co-author of the new report. “A substantial carbonate deposit in a Mars outcrop tells us that conditions that could have been quite favorable for life were present at one time in that place.”

Spirit inspected rock outcrops, including one scientists called Comanche, along the rover’s route from the top of Husband Hill to the vicinity of the Home Plate plateau that Spirit has studied since 2006. Magnesium iron carbonate makes up about one-fourth of the measured volume in Comanche. That is a tenfold higher concentration than any previously identified for carbonate in a Martian rock.

“We used detective work combining results from three spectrometers to lock this down,” said Dick Morris, lead author of the report and a member of a rover science team at NASA’s Johnson Space Center in Houston.”The instruments gave us multiple, interlocking ways of confirming the magnesium iron carbonate, with a good handle on how much there is.”

Massive carbonate deposits on Mars have been sought for years without much success. Numerous channels apparently carved by flows of liquid water on ancient Mars suggest the planet was formerly warmer, thanks to greenhouse warming from a thicker atmosphere than exists now. The ancient, dense Martian atmosphere was probably rich in carbon dioxide, because that gas makes up nearly all the modern, very thin atmosphere.

It is important to determine where most of the carbon dioxide went. Some theorize it departed to space. Others hypothesize that it left the atmosphere by the mixing of carbon dioxide with water under conditions that led to forming carbonate minerals. That possibility, plus finding small amounts of carbonate in meteorites that originated from Mars, led to expectations in the 1990s that carbonate would be abundant on Mars. However, mineral-mapping spectrometers on orbiters since then have found evidence of localized carbonate deposits in only one area, plus small amounts distributed globally in Martian dust.

Morris suspected iron-bearing carbonate at Comanche years ago from inspection of the rock with Spirit’s Mössbauer Spectrometer, which provides information about iron-containing minerals. Confirming evidence from other instruments emerged slowly. The instrument with the best capability for detecting carbonates, the Miniature Thermal Emission Spectrometer, had its mirror contaminated with dust earlier in 2005, during a wind event that also cleaned Spirit’s solar panels.

“It was like looking through dirty glasses,” said Steve Ruff of Arizona State University in Tempe, Ariz., another co-author of the report. “We could tell there was something very different about Comanche compared with other outcrops we had seen, but we couldn’t tell what it was until we developed a correction method to account for the dust on the mirror.”

Spirit’s Alpha Particle X-ray Spectrometer instrument detected a high concentration of light elements, a group including carbon and oxygen, that helped quantify the carbonate content.

The rovers landed on Mars in January 2004 for missions originally planned to last three months. Spirit has been out of communication since March 22 and is in a low-power hibernation status during Martian winter. Opportunity is making steady progress toward a large crater, Endeavour, which is about 11 kilometers (7 miles) away.

Carnival of Space 152

Welcome to The Martian Chronicles and the 152nd edition of the Carnival of Space! As always, we’ve got a great bunch of space-related posts from across the blogosphere, ranging from life on Mars to the age of the universe to Science Ninjas!

I’ll get things started with a pair of posts from right here at The Martian Chronicles. A couple weeks ago I went on a cool geology field trip in the El Paso/Carlsbad area along with a whole bunch of other martian and terrestrial geologists. Among other things, we learned that printed Mars panoramas make good raincoats, that graduate students are ideal for menial labor like counting hundreds of thousands of layers of rock, and that ancient reefs have a surprising amount to teach us about stratigraphy on Mars. Check out my summaries of Day 1 and Day 2 of the field trip! Day three is coming soon, with lots of pretty pictures of Carlsbad Caverns!

Speaking of rocks and Mars, Paul Scott Anderson at Planetaria has a post about another Mars meteorite that might have evidence of life! He includes a few very nice electron microscope images of the meteorite for your consideration. Personally, I’m not convinced, but I’m also not an expert on this corner of Mars science. Take a look for yourself!

Ian O’Neill at Discovery News also has been thinking about martian microbes, and whether germs from Earth might have hitched a ride on our rovers, set up camp on Mars and wiped out the locals. It would sure be disappointing if we discover life on Mars only to learn that someone at JPL forgot to wash their hands! Of course, there are also those who think we should stop bothering with all this planetary protection business and deliberately seed Mars with Earth life. What do you think?

While we’re on the topic of our potentially infectious little rovers, Stuart Atkinson has some beautiful pictures from the Opportunity rover. Oppy is slowly making her way across the Meridiani Plains, and has a tantalizing view of the distant hills that are her ultimate destination. As Stu says, “The far horizon is calling…”

But this is the Carnival of Space, not the Carnival of Rocks and Bugs and Rovers, so let’s get on to the more “spacey” stuff! I’m a big fan of stuff, and so is Steve Nerlich at Cheap Astronomy! This week they have a great podcast about “stuff” in space and the surprisingly limited number of shapes in which it can be found.

A radar "image" of an asteroid and its two tiny moons. Credit: NASA / JPL / GSSR / Emily Lakdawalla

While we’re on the topic of stuff and its various shapes, I should point out that radar is a great way to find out the shape of stuff in space like asteroids. If you’ve ever seen one of the “images” of an asteroid taken by a telescope like Arecibo and wondered how a radar antenna can be used to take a picture, then wonder no longer! Just take a look at Emily Lakdawalla’s post about radar imaging and all your questions will be answered.

If radar images are not your cup of tea, then maybe you’d prefer to learn about an old-school optical telescope: the Radcliffe 1.9 meter telescope. Markus shares the joy of handling the massive old wrought iron telescope in this post at Supernova Condensate.

Not a fan of old school ‘scopes? Well, perhaps I can interest you in some futuristic  Hypertelescopes? Next Big Future also has some cool posts about even more far-out ideas like Dyson Swarms and Dyson bubbles and “statites” – structures that hover above a star by balancing its gravitational force with its radiation pressure.

We’re a long way from that level of engineering, but solar sail technologies are getting more advanced. Centauri Dreams has a post about the Japanese IKAROS mission: an interplanetary solar sail that also uses its sail as a solar panel to generate electricity! I hadn’t heard of this mission, but it sounds really cool!

Whether you’re talking about star-enveloping Dyson spheres or relatively simpler missions, you have to wonder what drives exploration, particularly since big steps forward like the Apollo program come so rarely. Well, 21st Century waves talks about the idea that what we’re really dealing with is a chaotic system in this post on how complexity drives exploration.

Of course, sometimes it’s just the brilliance of one person that makes the difference, and lights the path forward, and Robert Goddard is a great example. Over at Music of the Spheres, there’s a great post about Goddard that takes a look as some of his earliest thoughts on space and also some of his inventions, which are now available online thanks to Google Patents.

Weird Sciences contributed three posts this week: First up, some thoughts on why Stephen Hawking is wrong about aliens and the threat they pose. Also, some thoughts on the implications of self-replicating machines. And third, visualizing the fourth spatial dimension.

Speaking of weird, what does Weird Warp have for us this week? Why it’s a nice, informative (and actually not very weird!) post all about the ins and outs of comets, everyone’s favorite icy visitors to the inner solar system.

While we’re back on the subject of “things that are in the inner solar system”, let’s take a look at Astroblogger Ian Musgrave’s post about how to use the moon to find stuff in the night sky. Ian even provides some scripts for the free programs Celestia and Stellarium!

Once you have rounded up your friends and family and taken them on a tour of the night sky using the moon as your guide, you’re bound to start getting pelted with questions. Luckily, “We are all in the gutter” has started a new “how do we know” feature. Their first post in the series is an answer to the question: “How do we know how old the universe is?” Do you have other “how do we know”-type questions? Contact the “We are all in the gutter” folks and get your answer!

Our penultimate post is from Steinn Sigurdsson, who reports on the unfortunate incident of the Nuclear Compton Telescope: a balloon-borne telescope that crashed in Australia during an attempted launch earlier this week. Condolences for those on the telescope team; it’s painful to watch so much work fall apart at its culmination.

And finally, on a (much) lighter note, what you’ve all been waiting for. Toothpaste ingredients! Which of course, logically, lead us to discover Amanda Bauer’s secret alter ego: the Science Ninja. This post makes me wish that a) all products had ingredient lists like the one on that toothpaste, and b) that I, too, was a science ninja.

Update: one late addition to the carnival! Nancy Atkinson at Universe Today is working on a series of posts entitled “13 Things that Saved Apollo 13“. The main article has link to the rest of the articles. Very interesting stuff!

Update 2: One more latebreaking addition! Out of the Cradle has a nice review of the book “The Big Splat, or How the Moon Came to Be”.

Phew! Well, that does it for this week’s Carnival of Space! It’s been a wild ride, as always. Thanks again to Fraser for letting me host, and thanks to all the space bloggers who contributed!

Hailing Frequencies Open!

Check this out, Star Trek’s Uhura (Nichelle Nichols) at JPL, ready to communicate with the rovers!

LPSC 2010 – Day 3: Rover Update, Mafic Mars and Atmospheres

Wednesday started off with a summary of results from the Opportunity rover, given by Steve Squyres. He started off talking about the several iron meteorites discovered in the past year. I thought it was particularly interesting that there are hematite blueberries on top of some of the meteorites: the blueberries are way too big to be lifted by the wind, so that means the meteorite must have been buried and then exhumed! Another find out on Meridiani Planum was Marquette Island: a strange rock that is unlike any other seen on Mars, or any of the Mars meteorites. It is probably a chunk of ejecta from a distant impact crater, but it isn’t clear exactly what kind of rock it is. Squyres suggested that it was a crystalline igneous rock, but in a later talk Duck Mittlefehldt seemed to favor a “clastic” origin, meaning that the rock is made of small fragments stuck together.

Finally, Squyres talked a bit about Opportunity’s current location, Concepcion crater, which is the youngest crater ever encountered by either rover. The coolest thing that he showed was a block of ejecta which had one side coated with a plate of blueberries, probably the result of hematite precipitating out of solution along a fracture.

[Update: Emily has an excellent and more detailed summary of Steve’s rover update and the debate over what the heck Marquette actually is.]

A later talk by Hap McSween took a look at the composition results derived from the TES and GRS instruments in orbit and the APXS on the ground. TES is an infrared spectrometer so it only sees the upper few microns of Mars, while the Gamma Ray Spectrometer samples tens of centimeters into the surface. The two datasets give different predictions for the surface composition. Oddly enough, even though surface APXS measurements only detect the upper few microns, they match more closely with the GRS results. McSween suggested that perhaps thin, ubiquitous layers of dust were tainting the infrared signals, but not the GRS or the brushed surfaces of rocks analyzed by APXS. Another possibility suggested by Steve Ruff was that sulfates can actually look quite similar to silica in TES spectra! If that’s the case, sulfur might be messing up the calculated compositions from TES and Mini TES.

The rest of the morning was filled with quite a few other talks about iron and magnesium-bearing minerals on Mars, but some of the most interesting talks of the day were in the afternoon planetary atmospheres section.

The first atmospheres talk was given by James Lyons for Kevin Zahnle, who wasn’t able to make it. Zahle called the recent methane detections into question by pointing out that the observed methane band might be due to methane in the Earth’s atmosphere that wasn’t properly removed from the spectrum. Unfortunately the authors of the Mars Methane paper that was being questioned weren’t there to respond, so I don’t know whether they took this into account in their atmospheric corrections.

Localized regions of possible methane production on Mars.

Another talk by Malynda Chyzek focused on modeling methane on Mars. She found that, with some assumptions about the rate of methane destruction, the rate of methane production predicted in previous papers might be about 30 times too low! To put the revised production rate into perspective, she calculated that it would require about 5 million cows to produce the same amount of methane, placing the population density of cows on Mars at about 2 millicattle per acre.

Another really interesting atmospheres talk by Spiga (I missed his first name) showed the effect of Katabatic winds on surface temperature. Katabatic winds are winds that blow downhill due to gravity, and they occur on broad high slopes like those on the polar caps or Olympus Mons. The thing is, as the wind heads down in elevation it gets compressed and compressing gas heats it up. The warmer gas then warms the surface, which can have a big effect on orbital measurements of thermal inertia, and that means that we have to be careful about using thermal inertia to infer what type of material the surface is made of in locations with strong downward winds.

There were several talks about modeling the water cycle and rainfall on early Mars. Soto (again I missed his first name) made an interesting comparison between areas of predicted rainfall and areas where valley networks are visible. He found that with just wt soil, there isn’t much precipitation, but with a northern ocean, the rainfall patterns match pretty well with the location of valley networks. The lack of valley networks toward the south pole makes sense in a model like this because all the water is in the northern hemisphere, and it would rain out on the slope up to the southern highlands, leaving a desert in the center of the highlands (the south pole).

A map of the valley networks on mars, and the possible extent of a northern ocean.

Some of the other atomospheres talks considered the early atmospheres of rocky planets. Jenny Suckale gave an interesting presentation about the possibility that early atmospheres formed by “catastrophic degassing” of the magma ocean rather than gradual release of the gases. The idea is that as the magma ocean is cooling, it solidifies from below. That pushes the volatiles in the magma up into the upper layers until it becomes saturated and bubbles begin to form. Once the bubbles start to form, they can cause parts of the magma to become more buoyant, and as the magma rises more bubbles form. This might cause sudden a sudden violent release of gas from the magma (similar to the sudden catastrophic release of gas from a shaken can of pop).

xkcd Spirit

xkcd (a comic which you should all be reading if you aren’t already) has a nice comic up today about Spirit. Click the image to see the whole thing.

So we’ll go no more a roving…

With yesterday’s news of Spirit’s defeat at the hands of the sulfury sands of Mars, I was reminded of this poem. It is by Lord Byron, but I first encountered it in one of my favorite short stories in this blog’s namesake, Ray Bradbury’s The Martian Chronicles. The story is entitled “And the Moon be Still as Bright”, and the poem is “So we’ll go no more a-roving”:

So, we’ll go no more a-roving
So late into the night,
Though the heart be still as loving,
And the moon be still as bright.

For the sword outwears its sheath,
And the soul wears out the breast,
And the heart must pause to breathe,
And love itself have rest.

Though the night was made for loving,
And the day returns too soon,
Yet we’ll go no more a-roving
By the light of the moon.

Lord Byron (1788-1824)

Spirit is no longer a Rover

An animation of Spirit's final attempts to adjust its position in the soft soil of "Troy". Image credit: NASA/JPL-Caltech (click to view if the image is not animating)

In a news conference yesterday, NASA announced that Spirit’s driving days are likely over, but by virtue of remaining stationary, new science possibilities are opened up. Here’s the text from the press release:

After six years of unprecedented exploration of the Red Planet, NASA’s Mars Exploration Rover Spirit no longer will be a fully mobile robot. NASA has designated the once-roving scientific explorer a stationary science platform after efforts during the past several months to free it from a sand trap have been unsuccessful.

The venerable robot’s primary task in the next few weeks will be to position itself to combat the severe Martian winter. If Spirit survives, it will continue conducting significant new science from its final location. The rover’s mission could continue for several months to years.

“Spirit is not dead; it has just entered another phase of its long life,” said Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters in Washington. “We told the world last year that attempts to set the beloved robot free may not be successful. It looks like Spirit’s current location on Mars will be its final resting place.”

Ten months ago, as Spirit was driving south beside the western edge of a low plateau called Home Plate, its wheels broke through a crusty surface and churned into soft sand hidden underneath.

After Spirit became embedded, the rover team crafted plans for trying to get the six-wheeled vehicle free using its five functioning wheels – the sixth wheel quit working in 2006, limiting Spirit’s mobility. The planning included experiments with a test rover in a sandbox at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., plus analysis, modeling and reviews. In November, another wheel quit working, making a difficult situation even worse.

Recent drives have yielded the best results since Spirit became embedded. However, the coming winter mandates a change in strategy. It is mid-autumn at the solar-powered robot’s home on Mars. Winter will begin in May. Solar energy is declining and expected to become insufficient to power further driving by mid-February. The rover team plans to use those remaining potential drives for improving the rover’s tilt. Spirit currently tilts slightly toward the south. The winter sun stays in the northern sky, so decreasing the southward tilt would boost the amount of sunshine on the rover’s solar panels.

“We need to lift the rear of the rover, or the left side of the rover, or both,” said Ashley Stroupe, a rover driver at JPL. “Lifting the rear wheels out of their ruts by driving backward and slightly uphill will help. If necessary, we can try to lower the front right of the rover by attempting to drop the right-front wheel into a rut or dig it into a hole.”

At its current angle, Spirit probably would not have enough power to keep communicating with Earth through the Martian winter. Even a few degrees of improvement in tilt might make enough difference to enable communication every few days.

“Getting through the winter will all come down to temperature and how cold the rover electronics will get,” said John Callas, project manager at JPL for Spirit and its twin rover, Opportunity. “Every bit of energy produced by Spirit’s solar arrays will go into keeping the rover’s critical electronics warm, either by having the electronics on or by turning on essential heaters.”

Even in a stationary state, Spirit continues scientific research.

“There’s a class of science we can do only with a stationary vehicle that we had put off during the years of driving,” said Steve Squyres, a researcher at Cornell University and principal investigator for Spirit and Opportunity. “Degraded mobility does not mean the mission ends abruptly. Instead, it lets us transition to stationary science.”

One stationary experiment Spirit has begun studies tiny wobbles in the rotation of Mars to gain insight about the planet’s core. This requires months of radio-tracking the motion of a point on the surface of Mars to calculate long-term motion with an accuracy of a few inches.

“If the final scientific feather in Spirit’s cap is determining whether the core of Mars is liquid or solid, that would be wonderful — it’s so different from the other knowledge we’ve gained from Spirit,” said Squyres.

Tools on Spirit’s robotic arm can study variations in the composition of nearby soil, which has been affected by water. Stationary science also includes watching how wind moves soil particles and monitoring the Martian atmosphere.

Spirit and Opportunity landed on Mars in January 2004. They have been exploring for six years, far surpassing their original 90-day mission. Opportunity currently is driving toward a large crater called Endeavor and continues to make scientific discoveries. It has driven approximately 12 miles and returned more than 133,000 images.

Time is Running out for Spirit Rover

JPL just released this update on Spirit’s status and it doesn’t look good:

The list of remaining maneuvers being considered for extricating Spirit is becoming shorter. Results are being analyzed Wednesday, Jan. 13, from a drive on Sol 2143 (Jan. 12, 2010) using intentionally very slow rotation of the wheels. Earlier drives in the past two weeks using wheel wiggles and slow wheel rotation produced only negligible progress toward extricating Spirit.

The right-front wheel has not rotated usefully since Sol 2117 (Dec. 16, 2009). With the right-rear wheel also inoperable since Sol 2099 (Nov. 28, 2009), Spirit now drives with only four wheels.

Pending results of the latest drive, the rover team is developing plans for their final few attempts, such as driving backwards and using Spirit’s robotic arm to sculpt the ground directly in front of the left-front wheel, the only working wheel the arm can reach. Such activities may take several sols to implement, but time is getting short as winter approaches and the team needs to focus on Spirit’s winter survival.

The amount of energy that Spirit has each day is declining as autumn days shorten on southern Mars. If NASA does determine that the rover will not be able to get away from its current location, some maneuvers to improve the tilt toward the winter sun might be attempted.

I’m on downlink duty for Pancam this week, and I can say that watching each day tick by with, often, just fractions of a millimeter of progress is painful. The team is generally upbeat in the meetings, but there’s a sense of urgency and all eyes are on the calendar as we inch closer to dark days on Mars. Spirit has survived previous Martian winters, but that was with the rover tilted toward the sun to maximize the power available. Right now, Spirit’s tilt is not so good, and I don’t know if we’ll be able to fix it in time.

For more thoughts on the current predicament, head over to the Planetary Society blog.