It has been a year since the European Space Agency made history by putting its Philae lander on the surface of comet 67P/Churyumov-Gerasimenko.
The craft bounced twice, then its batteries ran out of power, but both the lander and its mothership Rosetta, which has continued to orbit the comet, are still sending back important scientific data.
The mission has found 16 organic compounds on the comet, some of which are considered to be the basic building blocks needed for life.
Flying at different altitiudes above the comet, Rosetta was able to study the gas and dust coming from it and found pure oxygen at unexpected levels in its thin atmoshere - something it was thought could not survive in that form in space.
Rosetta has also mapped the flow of water from inside the comet, which causes jets of vapour to burst from its surface, and it has been revealed that the comet was probably formed from the collision of two separate balls of ice.
In an exclusive interview with Al Jazeera, mission scientist Matt Taylor says in the next few weeks he hopes the team will be able to make contact with the Philea lander one final time.
AJE: It has been a year since the European Space Agency landed a spacecraft on comet 67P Churyumov–Gerasimenko, what has been the focus of the mission since?
Matt Taylor: The mission isn't over, that's the key thing. It's a year [since] the landing and the mission still has another year in it. We still hope to hear from the lander, maybe this week, hopefully in the next month or so. So everything is still going on. The core ethos of this mission was to study a comet … how it works when it goes around the Sun. And that's what we are still doing. We went through the closest approach to the Sun in August this year … the perihelion, and now we are following the comet away from the Sun to see how this interaction works. The comet is driven by the Sun and we've been discovering fantastic things about the comet that we are studying.
AJE: What are the most important of those findings?
MT: The measurements that we have made show that the object is very, very old, 4.6 billion years old, as old as the solar system and possibly even older. The material that we are finding inside it is really primordial and indicates the ingredients that went into making the solar system. That's why we study comets, to see what was there at the beginning, and put them into the context of what we have now as a solar system; and see how things evolved; why is it that the Earth is so special that it's full or water? That kind of thing.
AJE: Earlier this month, you revealed that the comet has pure oxygen on it - something it was thought could not survive in that form in space. How important is this?
MT: There have been a number of results touching on what we call the origins of the solar system. The oxygen result was one of these. We also had a detection of molecular nitrogen, as well as looking at the different flavours of water that have come off the comet. And all of these put into context where the comet came from, what its evolution has been. And in particular all of these have ticked the box that this is a very, very old object, is very primordial [and] is pretty pristine in terms of a comet. It hasn't been toyed with much so the stuff that we find on there is really old, possibly pre-dating the formation of the Sun.
AJE: Why are you still hopeful that you will be able to resume contact with the Philae lander?
MT: Philae did what it was supposed to do after its bouncing last year. It went into sleep, into hibernation. It came back out of hibernation in June this year, but we were challenged with a very active comet. We had to fly further away with the Rosetta orbiter and that put us out of range of the signal. It's a bit like your wi-fi signal if you move too far from your house, it's basically what was happening. We couldn't contact accurately the lander ... [But] hopefully this week we will go below 200km altitude, so we are back to within the range that we think we will be able to hear from Philae. If it has lasted through perihelion, [and] we have a strong belief that it will do that, it's a pretty hardy spacecraft, then we will hear from it in the next month or so.
AJE: How much longer do you expect Philae to operate?
MT: Ultimately, if and when we do hear from [Philae], it will only last until January or February next year, because at that point the temperature and the amount of solar illumination - the power available to the lander - will be too low. So we have this window of opportunity coming up in the next months to add to the fantastic science that we have already got.
Source: Al Jazeera