space missions

New EPOXI images of Comet Hartley 2

This afternoon, 21 million kilometres from the Earth, NASA’s EPOXI mission flew by Comet Hartley 2. In the process, it captured some of the most stunning close-up pictures of an active comet ever seen.

Hartley 2 as seen by the EPOXI mission. Credit: NASA/JPL-Caltech/UMD

Hartley 2 has been visible in the night sky for many weeks now, and there have been some stunning images, taken by amateur astronomers, of its visit into the inner Solar System. While they have their own beauty, none can compare to the remarkable pictures sent back today by EPOXI. They show the 2.2km wide nucleus of the comet, from a distance of around 700km, covered in what look like boulders and effervescing with great jets of material erupting from its surface.

Jets erupting from Comet Hartley 2’s surface. Credit: NASA/JPL-Caltech/UMD

Some might think of the Solar System we live in as a rather quiet unchanging place, where nothing happens for eons. Well, these stunning images help refute that idea very easily. This is partly why I particularly like the image below, showing the jets bursting into sunlight. It really shows how dynamic these fascinating objects can be.

Comet Hartley 2: an active comet up close. Credit: NASA/JPL-Caltech/UMD

Tomorrow night we’ll be celebrating Bonfire Night here in the UK, where tradition dictates that we let off fireworks and light bonfires. For me though, that manmade spectacle won’t be anywhere near as impressive as the truly awesome natural one we witnessed today.

Doug Ellison’s Open University Mars talk

I’ve just started ‘following’ unmanned spaceflight expert Doug Ellison on Twitter and, out of curiosity, I went back and had a look at a few of his most recent tweets. I’m glad I did, because I spotted a mention from him about a talk he recently gave to the Open University about Mars. Entitled “Exploring Mars – A crash course on the Red Planet”, the talk is a comprehensive run down on the exploration of Mars from Schiaparelli’s ‘canali’ and ground based images of Mars to the up close exploration of the MERs.

Doug is the founder of the Unmanned Spaceflight forum and his expertise and enthusiasm really comes through in this talk. He uses images and animations from the recent Mars missions, to illustrate the talk, which he sews together with his commentary. If you want a summary of humankind’s recent robotic exploration of Mars, this video is a great way to spend an hour on a wintry Saturday afternoon. The video is available in an high quality version as well, so you can read the notes that Doug occasionally puts up on the screen. The video is below (wide-screen & high quality version on the YouTube site) and a link to Doug’s Twitter feed is here.

“Exploring Mars”. Credit: Doug Ellison/The Open University

Tool infinity and beyond

I’m getting a few emails asking about the toolkit that an astronaut dropped from the International Space Station last week, and whether it is visible from the Earth. Well the answer, apparently, is yes it is. According to the website the bag has been spotted by amateur astronomers and should be visible from the UK this week through a good pair of binoculars, if you know where to look.

shuttlests-126A stunning view from the Space Shuttle Endeavour (STS-126). Credit: NASA

If you haven’t been following the story then here’s a quick refresher: last week whilst on a spacewalk to repair part of the, now 10 year old, space station an astronaut let go one of the station’s toolbags and it gently floated away and out of reach. It’s now moving away from the space station all on its own, appearing around five minutes before the ISS as it crosses the sky. You can watch a video of the errant toolbag here on the Daily Telegraph website.

If you want to find out when the ISS (and the toolbag) will be flying over your site then have a look at the Spaceweather alerts page here. This story has been getting a lot of attention in the national media and press; but let’s not lose sight of the fact that the ISS has just passed an important milestone this month (10 years in space) and that this extended shuttle mission has already accomplished a great deal during its 12 days in orbit, including the repair of a urine-recycling unit (and other crucial upgrades) which will mean that the ISS crew can be doubled in 2009.

Look back – you never know what you might see

Often the most captivating space pictures come, not from looking out into the depths of the Universe, but back towards home and the Earth – our little round oasis in space. I say this particularly today in light of two images I chanced across whilst researching on the web. The first is from the brilliant Japan Aerospace Exploration Agency (JAXA) probe KAGUYA (also known as SELENE). It’s a picture of the full Earth rising over the lunar limb. It was taken a few weeks ago (September 30th) by the probe’s high definition video camera, as it passed over the Moon’s north pole, at a height of about 100km from the surface. JAXA released it today and well…see for yourself…wow!

The Full Earth rising over the Moon. Credit: JAXA/NHK

In the full sized image you can clearly see Australia against the blue of the oceans and beneath the swirls of the white clouds. What I wouldn’t give to see that view with my own eyes! If you look closely I think that’s the mountainous central peak, of a vast foreground crater, you can see towards the centre of the image. It certainly looks like the centre of the bowl of a crater in reflief running through there. The images from this mission are incredible and you can see many more, as well as some amazing videos, on the JAXA site here. But if you want to feel like you are really floating with the craft over the surface then the HD camera’s video of this ‘Earthrise’ is here (video link).

Lastly then is the second image that caught my eye today – it’s the image at the top of this page (big version here). That’s a picture from the EUMETSAT Meteosat-8 satellite. That orange/white pixelated blob below-centre in the image is, incredibly, the fireball that ensued when a 2-metre wide chunk of rock entered the Earth’s atmosphere and exploded in a searing flash of light. The rock designated 2008 TC3 was picked up by astronomers several hours before it was due to hit the Earth. There wasn’t really any risk to us and the rock most likely broke up in the atmosphere high over a sparsely populated region of Sudan. It would be interesting to know if any parts of the object reached the ground, as meteorites, as they will no doubt be important given that their meteoroid progenitor was relatively well observed prior to impact.

It’s all exciting stuff and reminds us that we should always remember how cool and interesting the Earth is, whilst we are appreciating other worlds and distant places in this incredible Universe we live in.

UPDATE (11.10.08): When I was writing this last night, I completely forgot about the other story which fits nicely into this ‘look back’ theme. It’s a story from ESA’s Venus Express about how astronomers are using the craft’s spectrometer to look at the fingerprints of key molecules in Earth’s atmosphere. The reason they’re doing this is to see if Earth is habitable! Odd, it might seem, but it’s a crucial thing to be able to do if astronomers are going to have any chance of success in determining if other exoplanets are habitable. That’s because from learning about what chemical signatures represent life on Earth, we can begin to formulate some ideas of what we should be looking for on other planets. You can read the full story here.

Now wash your wheels!

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 wandering 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 the current mission of NASA’s Phoenix Mars lander and that of the Mars Exploration Rovers, who are studying locales on the Red Planet that 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.

Spirit & Opportunity were only allowed to take 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 then, scientists can’t risk forgetting to wash their rovers’ wheels.

Phoenix: 21 sols in

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

An image that has to be seen to be believed…

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.

NASA’s Phoenix probe successfully lands on Mars

A few minutes ago NASA’s latest mission to Mars, Phoenix, successfully landed on the northern Arctic region of the red planet. The lander is now sitting almost exactly where it was expected to come down, on a slope which is tilting the lander by about a 0.25 degrees. Phoenix is also aligned beautifully east-west so should be perfectly positioned for catching the pale arctic sunlight with its solar panels.

I’ve been watching for a few hours and the last minutes of the descent, as Phoenix was travelling those last hundred or so metres, were truly exhilarating. A night I won’t forget in a while! It’s ten past one in the morning here in the UK so the first images won’t be in for another hour and a half.

We now have to wait for the solar panels to deploy but the hardest part is now over for Phoenix. Let’s look forward to 90 days (and hopefully more) of great images and even greater science.

Update: I’ve just added some of the first images which have just arrived (3:00am UK time).

Top image: The first horizon image from Phoenix
Lower image: One of Phoenix’s footpads on the martian surface.
Credits: NASA/JPL/University of Arizona

Phoenix lands tonight!

The NASA Phoenix probe will come to the end of its journey to Mars tonight/tomorrow morning, landing on Mars at about 12:53am UK time. To keep up-to-date with how the probe is doing there are lots of blogs and live TV feeds for you to read and ‘tune’ into. NASA will have a live feed on NASA TV starting at 6pm EDT (or 11pm tonight if you’re in the UK).

The University of Arizona has a blog here, though they might be a bit to busy to blog during the landing phase! Emily at The Planetary Society has lots of info. here and will be at JPL for the landing and press briefings. Last but by no means least Chris and Doug Ellison have a dedicated Mars Live website about the Phoenix landing here.

I’ll also be updating my shiny new Twitter feed with updates on how Phoenix is doing throughout the night. Oh yes and if it hasn’t already got enough work to do, the Phoenix probe has its own Twitter feed here.

The lure of ‘life’ on Mars

With less than two weeks until the NASA Mars Phoenix mission arrives on Mars there’s been a lot of news about how the probe is going to go about looking for life on the red planet. It’s an exciting mission and one I’m really interested in, but we have to be careful when talking about exactly what it is actually going to do. My worry is that, if people get fixed on the idea we are looking directly for ‘life’ with Phoenix they are going to miss the other important results that will, no doubt, come back from this mission.

Phoenix’s instruments will be examining the north polar regions of Mars, scrutinizing the soil there, hopefully taking the first ever direct sample of Martian ice and investigating the environment of the region. What it will not (at least intentionally*) be doing is carrying out a direct search for life, such as microbes or any other of microscopic living organism. We will almost certainly need a sample return or some extensive in-situ studies to prove that.

However, what Phoenix will be doing is using an advanced spectrometer to look for the fingerprints of important organic molecules in the gas of vaporised martian soil. A special instrument, called the Thermal and Evolved Gas Analyzer (TEGA), will be looking to see if there are any molecules or signatures in the soil samples which might signify past ‘biological processes’.

Those results will be extremely important. Previous probes such as the Viking spacecraft have done similar experiments with ambiguous results. It will be later missions (possibly the giant rover Mars Science Laboratory) that will tackle the direct search for life, potentially with a sample return mission. More importantly Phoenix will be looking at the broad overview of the martian north pole and its history.

By studying the geological history of this region it will be looking at whether the conditions for life were there in the past. That’s first and foremost a big question. If (and of course that is one big if) there was life on Mars in the past that would clearly have big implications on the search for it, on Mars, today. It’s fair to say as well that if life didn’t arise in the past, that would have just as big an implication. So how is it going to do this?

Phoenix is going to study the history of water around this region of Mars. With an advanced weather station and other sensing instruments its going to be examining both the atmosphere and the ground. With the robotic arm it will hopefully gather some of the ice and soil for analysis. These results will tell us a great deal about the habitability of the martain soil. It might be that only a few centimetres below the surface the conditions there permit life to survive against the paucity of water and harsh UV radiation. Most exciting for me is the possibility that there may be what the NASA scientists call ‘short-lived’ liquid water sitting in the cracked icy layers of soil. Although it won’t last long on the surface, if this water is there it might give us a fleeting hint of what lies beneath.

It’s certainly an exciting time for Phoenix, let’s just keep our fingers crossed for 25th May. Keep up with the mission here.

* There is a caveat here that a few missions have, through serendipitous discoveries, been able to make discoveries that they were never intended to make. It’s possible (I suppose) that Phoenix might make just such an interesting discovery.