Europe will tomorrow make its first attempt to land on Mars since the UK’s ill-fated Beagle 2, with the latest mission to look for evidence of alien life on the Red Planet.
And a leading Oxford scientist who lost his work on Beagle is crossing his fingers that all will go well this time with the European Space Agency’s Schiaparelli lander. He has a replica of his lost experiment on the new probe.
Dr Colin Wilson, of Oxford University’s Department of Physics, has had a run of bad luck with the Red Planet. His experiment to measure winds failed on Beagle 2 after he had already experienced failures with two NASA probes, one of which crashed while the other was lost in space.
Dr Wilson told Skymania today: “My lab has had particularly bad luck at Mars. In addition to Beagle 2, which crashed on Christmas Day, 2003, we also had an instrument on Mars Observer in 1992 and Mars Climate Orbiter in 1999, and both of those NASA spacecraft failed.
“So yes, we are very apprehensive. I should probably point out that we have also had successes – for example Mars Reconnaissance Orbiter in 2006, we have an instrument on that, and that has gone all right, so we know it is possible to succeed at Mars.”
Dr Wilson has been focusing on studying Venus since Beagle 2 crashed but is excited to be about to study Mars again, both with Schiaparelli and also its sister probe, Trace Gas Orbiter, which will circle the planet to check out less common gases in its atmosphere – including possibly from “windy” aliens. Together they form ESA’s ExoMars 2016 mission that was launched in March.
Dr Wilson, who will be at Mission Control, in Darmstadt for today’s landing, said: “We’re used to long waits in the planetary exploration business but this is getting ridiculous. Beagle 2 crashed on Christmas Day 2003 and it has taken ESA until now to get to the next Mars lander. So I’m very much looking forward to this. I would say we’ve been holding our breath – but for 15 years that wouldn’t be advisable.”
Dr Wilson’s experiment is as light as a feather but will boost understanding of Mars. He said: I’ve built a wind sensor which is going to measure the horizontal wind speed and direction on Mars. It is a very small sensor – the head itself weighs less than seven tenths of a gram – and it will tell us how windy it is.
“We know that Mars has winds. The weather is a bit like you would find in a desert on Earth that it is very dry. You have winds which might be typically blowing at a couple of metres a second or gusting up to maybe even tens of metres a second. These are very earthlike wind speeds – the difference is that the Martian atmosphere is 50 times less dense than it is on Earth, so even if you have gale force winds on Mars, which can arise, they wouldn’t push you over.
“But they are sufficient to lift dust and to move sand particles. We think that, as the sand and dust particles knock against each other in turbulent winds, they can get charged up, just like static electricity. What is really exciting about this lander is that, unlike previous landers, this will measure electrostatic charging for the first time.”
Dr Wilson said understanding the electrical fields could also indirectly help answer the question of whether there has ever been alien life on Mars.
He said: “This electrostatic charging is important for a couple of reasons. If you ever wanted to explore Mars, having high electric fields may interfere with your lander equipment, with your spacecraft, and might also cause static clinging so your systems get covered with dust.
“But equally, electric fields can get so high that they can break apart molecules and create unexpected chemistry. We need to understand what roles the electric fields may have in that chemistry, and that will very much help us to understand the methane variations that may tell us about life of Mars.”
Dr Wilson is also involved with Schiaparelli’s companion probe, the Trace Gas Orbiter, which goes into orbit today (Weds) to seek out methane which, even if not produced by belching Martian bugs, might be a clue to alien life.
He said: “Mars’ atmosphere is composed mainly of carbon dioxide, but one of the results which actually came from the last European mission to the planet, called Mars Express, was the detection of methane too.
How TGO will fire its engine to go into orbit as Schiaparelli lands on Mars. Credit: ESA
“Now this was very much at the limit of detectability, and the tiny amounts of methane detected were about one molecule in a billion in the atmosphere! That makes it incredibly difficult to detect and Mars Express, which wasn’t designed for this task specifically, found it very difficult to map where methane was occurring.
“But follow-up observations using powerful ground-based telescopes in Hawaii and Chile confirmed that there was in fact methane at certain times of the year, in some places, but not in others. So this is really a mystery and we needed a dedicated observatory to try to find out what is going on here. (Note: The presence of methane has also been confirmed by NASA’s Curiosity.)
“The reason methane is exciting is that because the main source of methane on Earth is biological, so ants, cows, rotting vegetation, all these kinds of things could produce methane, and the possibility of life on Mars as a source of methane is clearly very enticing.”
But Dr Wilson cautions that methane can be produced in another way. “It is important to point out that life is not the only source of methane. You can have certain types of rock which, when water flows past them, can release methane. That does require liquid water, but we know that Mars, a long time ago, had much more liquid water on its surface – something we can tell from its enormous canyons and other water-carved features.
“And so finding out where and when liquid water existed on Mars, that would also be very interesting in terms of finding where life might have been able to flourish, either in the past or today on Mars.”
The case against alien life
Dr Wilson told Skymania: “I think there are a lot of reasons why life on Mars now is extraordinarily challenging. Life as we know it requires liquid water. Liquid water on Mars today, if there is any, is in underground niches. Near the surface there is lots of water in ice form.
“It is possible to find niches below the surface where liquid water is still percolating through rocks, though it’s not a great place for life to develop in much complexity. So I think a more likely explanation may be that when Mars, a long time ago, had much more liquid water on its surface, that water flowed past rocks at that time and produced methane.
“If some of that methane it is still dissolved in the rocks, still trapped in rocks which were formed at that time, then erosion of those rocks today could be letting methane into the atmosphere. So my best guess is that the methane is of mineralogical origin is from non-biotic origin, and I think formed in a time long gone by, but finding out where these methane-rich rocks are will tell us about where liquid water was in his past.”
For those hoping that alien life will be found, Dr Wilson added: “I think all the possibilities are exciting. I’ve just put forward a guess. The way science works is by looking at other people’s guesses and finding out which are supported by the evidence.”