Since you asked…Philae comet lander

According to Stam, this is the first time there has been a ‘soft landing’ on a comet. The purpose of the mission was to drill into comet 67P and discover its make-up. However, when Philae touched down in November 2014 many feared the mission was doomed. Thanks to a broken thruster, the spacecraft bounced from the original landing spot, ending up between rocks where its solar-charged batteries couldn’t recharge enough to send data packets back to Earth.

As of June 13 this year, the lander woke from hibernation and was able to resume its research, part of the Rosetta mission, launched by the European Space Operations Centre (ESOC). When asked why this information is important, Dr. Stam explained that one of the primary themes of the Rosetta mission is to discover where water on Earth came from. “According to some, the earth has much more water than you would expect after planet formation,” she said. “One of the theories is that most of this water was brought in by comets and asteroids.” Additionally, comets are dangerous as they have the potential to impact with Earth, so whether we want to blow one up or change its course, it is important to understand what they are made of.

While it looks unlikely that any complex molecules – for example, peptides – will be found on comet 67P, Dr. Stam explained how scientists can work out the likelihood of comets bringing water to Earth. There is normal hydrogen, with one proton in the nucleus and also hydrogen with both a proton and neutron in the nucleus, around twice as heavy as normal hydrogen. “Depending on where you are in the solar system the ratio of normal to the heavy hydrogen differs, and by looking at this ratio in different bodies you can find out whether it’s likely that comets like 67P brought water to the Earth.” The water found on comet 67P is in fact very different from the water we have here on earth, meaning that it is unlikely comets of this type are the origins of our oceans, but as Dr. Stam emphasised, this is still a very interesting result, and the Philae has many months left to make valuable discoveries about the structure and material that makes up comets.