This time last year, millions of us watched live (online and late at night, in my case) as a portable science lab the size of a family car landed on the surface of Mars. Now Curiosity, the Mars science laboratory, is celebrating its first birthday and a year of successful science.
— A self-portrait composite image of Curiosity. Credit: NASA/JPL-Caltech/MSSS
I hope that the event of the landing itself will go down in scientific history. Although not as iconic as the Moon landing, Curiosity’s touchdown was extremely ambitious – Nasa’s engineers devised a controlled descent system that involved lowering the rover from a rocket powered ‘sky crane’, so that it could be placed with its wheels on the ground, ready to rove. The entire process took just a few minutes, now dubbed the ‘7 minutes of terror’. Watch a video of the event and you’ll see that this isn’t a bad description – there’s more tension packed into those 420 seconds than in any feature-length Hollywood thriller.
It’s apt that the landing should be something out of the ordinary, as the rover itself is also unique. At almost twice the length and five times the weight of the largest previous rovers (Nasa’s own Spirit and Opportunity), it is packed with scientific instruments for imaging, sampling and studying the soil and atmosphere. Crammed into the rover are several types of equipment that would not look out of place in a university lab, including a gas chromatograph, a quadrupole mass spectrometer and a tuneable laser spectrometer as well as high-definition cameras. Other, more exotic kit includes a neutron source and detector for measuring hydrogen near the surface and a robotic arm complete with scoops, cameras and a heavily modified drill.
In the past 12 months, Curiosity has made some headway in achieving its scientific goals. Among the objectives were:
- To investigate the geology of Martian soil, delving into the chemistry and mineralogy of the rocks at and just below the surface
- Understand the long term atmospheric evolution
- Determine the water and CO2 cycles, past and present
- Characterise the levels and spectrum of radiation present on the surface
Although Nasa was very clear that Curiosity is not looking for direct evidence of life, it did set out to look for the chemical signs of past biological activity, as well as the presence of the chemical building blocks of life.
And there have been results. We now have strong geological evidence of ancient streams and an unexpected range of soil and rock types that tell the story of Mars’s watery past. Curiosity also found carbon, hydrogen, oxygen, phosphorus and sulfur in rocks known to have been formed in water. From this it’s possible to conclude that Mars has, at some point, had all of the chemical necessities for life. But before you get too excited, there’s also a complete lack of methane, a key marker for biology, so the surface remains sterile.
A search for Mars science laboratory on Web of Knowledge (not a definitive measure, I’ll grant you, but a nice indication) renders over 300 journal articles. Not all of these will be primary research from real Curiosity data (others are reviews, theoretical studies or models that may help us direct future missions) but this does suggest that Curiosity is asking the right questions and leading to genuine scientific discovery and exploration here on Earth.
There is a greater ambition behind all of this research. Every sample, spectrograph, photograph, published paper and each of the myriad small observations, takes us a step closer to a manned Mars mission. In a press release celebrating the anniversary, Nasa Administrator Charles Bolden confirmed this by saying ‘successes of our Curiosity — that dramatic touchdown a year ago and the science findings since then — advance us toward further exploration, including sending humans to an asteroid and Mars … Wheel tracks now, will lead to boot prints later.’
And it may be a nuclear-powered chemistry and geology lab, plonked on the surface of an alien planet by a massive rocket powered crane, but that doesn’t mean it’s all business. This week, a vibrating (and therefore noisy) component in SAM, the Sample Analysis at Mars module, was re-tuned to play the tune of ‘happy birthday’. It’s a shame that, for now, there’s nobody there to hear it.