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On the 14th July 1965 NASA’s Mariner 4 flew past Mars and kicked off humankind’s exploration of the red planet with robotic spacecraft*. In the 43 years since that event, our knowledge of Mars has grown at an incredible rate. Not only do we now know a great deal about Mars’ fascinating past but we can get daily (sol-ly?) updates from a small flotilla of spacecraft, on the surface and orbiting the planet. From those early grainy monochrome images of the martian surface we have come all the way to snapping images of our own craft parachuting to the surface; to explore in situ and see much more too. Our missions have captured images from Mars that have shown us: landslides falling down cliffs, dust devils whipping across the martian plains and have generally opened our eyes to the desolate (but stunning) world with which we have become fascinated over the centuries.

For me though one of the best things about our exploration of Mars, aside from the science, is how the images have been able to convey the beauty of the red planet. Not only from a purely aesthetic viewpoint either. The images we see put the complex scientific information we receive into a human context. A high silica content in a region of soil may mean little to anyone but a specialist. But if we can look at an image and say: “that white patch there shows that this region might once have been home to a warm pool of standing water, perhaps even with a bubbling hydrothermal vent” then the whole scene jumps to life.

So it’s with this in mind that I’m posting this image above, one of the Mars Express spacecraft’s latest images. You can view the big version here, to get the full effect. It’s part of a region called Echus Chasma on Mars and has been shaped by all sorts of processes from volcanic events to water erosion. However my favourite quote about the image below, from the ESA news article about these new images, has to be this: “Gigantic water falls may have once plunged over these cliffs on to the valley floor. The original shoreline is still partially visible. The remarkably smooth valley floor was later flooded by basaltic lava.” The fact that we can make such an incredible comment about Mars, to me, shows just how far we’ve come from those early Mariner days.

*There is of course a grand history of observing Mars, with telescopes from Earth, that dates back many decades prior to this.

Image credits: Credits: ESA/ DLR/ FU Berlin (G. Neukum)

Clandestine agents and heroic citizens of blockbuster sci-fi movies are often portrayed as defending the Earth from the alien miscreants of the Universe. Blasting slimy green extraterrestrials might be great cinema, but it doesn’t always represent the shrewdest of scientific moves. That’s because whilst the chances of ne’er-do-well space-faring aliens wondering around our towns and cities can be safely relegated to science-fiction, the reality is that it’s the Universe, not us, that needs defending from visitors from Earth. So how do we clean our spacecraft when we send them out into space? To answer that question here’s the result of an interview I did with NASA’s Planetary Protection Officer a few months ago. This concern is particularly relevant given Phoenix’s current mission and that of the Mars Exploration Rovers on Mars, who are studying locales on Mars which might be hospitable to life.

Ever since the first robotic missions to the planets we’ve also been inadvertently sending small amounts of microbes up there too. It wasn’t until the last few decades (when we began scouting for microbial life elsewhere in the Solar System) that this started to become a major headache for space agencies around the globe. The last thing we want to do in our search for life in the Solar System is discover the disastrously familiar sign of life which has piggybacked its way millions of kilometres from Earth.

Spacecraft like Spirit and Opportunity are allowed to take only a certain level of spores with them.
Courtesy: NASA/JPL/Caltech.

Today the responsibility for keeping NASA’s spacecraft clean (and in some ways protecting any alien life in the Solar System) falls on its Planetary Protection Officer Dr Catharine Conley. Her job is to see that NASA spacecraft are kept free from microbes from Earth that might be spread into space by our space-faring endeavours…well almost. It might surprise you that already we’ve let countless microbial ‘spores’ into the Cosmos. “There were probably viable spores on spacecraft that were launched over the past few decades, however we are quite careful to monitor the trajectories and subsequent disposition of the spacecraft, so that we know what has happened to them,” says Dr Conley.

The reason these microbes got out is that it’s not yet possible to completely sterilise a spacecraft before an interplanetary voyage. But all is not lost as Dr Conley explains. “From everything we have seen so far, it’s quite unlikely that any spores carried on those spacecraft have actually landed in a place where they might grow.”

So how exactly do you clean a spacecraft? If you’re now imagining a multi-million dollar probe being lathered in disinfectant by a group of fastidious sponge brandishing scientists, then you’re in for a shock. The reality is much more bizarre. “A variety of cleaning procedures are used, depending on the material requiring cleaning” explains Dr Conley. The aim is to make sure that the number of microbes on the spacecraft does not exceed pre-determined levels. Of all the methods used, the one that has thus far proved most effective is ‘dry heat’ sterilization. Put simply the spacecraft is baked in a giant oven at temperatures of several hundred degrees Celsius, killing most lurking micro-organisms.

Other methods such as swabbing exposed surface panels with alcohol are sometimes used and NASA is also developing other new methods to reduce the amount of potential microbial contaminants. One proposed method involves firing cold plasma at spacecraft, zapping any microbes. Another involves dousing any bacterial stowaways with hydrogen peroxide vapour. “The type of mission and the conditions we find at other planetary bodies are what dictates the level of protection,” explains Dr Conley. Yet, according to Dr Conley, in this article in NASA’s Astrobiology magazine these important protection regulations might generate complications when astronauts want to start exploring worlds like Mars; worlds which might harbour primitive life.

For the most part Mars’ surface is thought to be inhospitable to life, so astronauts will most likely be allowed to roam free over large areas of the barren ochre surface. But what if we actually want them to look at and explore the sites where living microbial life might be found?

That might not be so easy to do warns Dr Conley. “Humans will not be allowed to contaminate locations where Earth life might survive before we have a chance to study them sufficiently for signs of extraterrestrial life,” a proposition that is as reasonable as it is frustrating. If life is present on the red planet then it looks like it will be the electronic eyes of a rover, a wheeled robotic ambassador, which will glimpse the first signs of it. With the future of whole worlds at stake scientists can’t risk forgetting to wash its wheels.

Phoenix has now been on Mars for 21 sols (I guess that’s still 3 Mars weeks right?!) and it’s great to see the probe doing so well. At first it sent back some brilliant pictures (and even seems to have spotted ice underneath itself!) and now is sending back the real science - the results from the microscope, weather station and hopefully soon some results from TEGA (Thermal and Evolved Gas Analyzer), which has a little set of ovens used to bake and study the martian soil. Originally there was a snag in that clumpy, cohesive soil clogged up the sieve which is used to weed out the larger particles from going into the oven (where they might block it). At one point it looked as if that oven would be blocked. Thankfully though the Phoenix team used a spinning mechanism on the TEGA instrument to vibrate the sieve and after a few days of shaking and vibrating the oven canister was suddenly filled with batch of martian soil. The team will be using a different method of sprinkling the soil (see the animation below) into the TEGA ovens in future, to assure that this doesn’t happen again.

One particular thing that has struck me about this mission, so far, is how well it has been covered in new media outlets. If you have already seen it Mars Phoenix has a Twitter feed here and it even has several blogs and a (iTunes) podcast here. Oh yes and NASA and the Phoenix team sure know how to make an outreach movie! Have a look at the video below to recall those few minutes of sheer excitement (and a similar amount of nerves) that we all shared a few weeks ago.

Top image credit: NASA/JPL-Caltech/University of Arizona
Lower image credit: NASA/JPL-Caltech/University of Arizona/Texas A&M
Video credit: NASA/JPL/University of Arizona

I’ve spent a good part of today marvelling at this image (below) from the Mars Reconnaissance Orbiter (MRO). I simply can’t take my eyes off it. It’s just stunning. Two nights ago NASA’s Mars Phoenix lander tore through the martian atmosphere on its way to the northern plains of Mars. As it unfurled its parachute it descended down to the surface a tremendous speeds. At the same time MRO was orbiting above relaying the signal from Phoenix to teams on Earth. Luckily its camera was also pointing in the direction of Phoenix and in one of the most remarkable, stunning [insert more superlatives here] images I have ever seen, the MRO team snapped this picture; Phoenix encased in its backshell, with parachute billowing above it, as it fell to the surface. You can even see the thin tethers that are connecting the parachute to the lander! Phil has a great video on his site here which sums up brilliantly what a lot of us are feeling about this image right now.

Phoenix with parachute on its way down to the surface.
Credit: NASA/JPL-Caltech/University of Arizona.

The MRO team also released this image this evening, during the last press conference, (small version below) of Phoenix on the surface with its solar panels outstretched and gathering the sullen Arctic sunlight. Click on the image (below) to go to a larger labelled image, showing the position of the parachute and backshell. If this and all the other images, so far sent back, are a taster of things to come then this is going to be an incredible 90 days with Phoenix and its friends, at Mars.

Phoenix on the surface from MRO.
Credit: NASA/JPL-Caltech/University of Arizona.