ESA astonomers excited about Rosetta comet reaching orbit position closest to sun

A comet being tracked by the European Space Agency's (ESA) Rosetta spacecraft was due to reach the closest point of its orbit to the sun at about 2am today (13 August).

ESA scientists were looking forward to a peak of activity from the 67P comet after it reached the 'perihelion': the point of its orbit nearest to the sun. But, as Rosetta flight director Andrea Accomazzo explained, they will have to wait a while for the most spectacular results.

Accomazzo said: ''Perihelion is the closest point of the orbit of the comet to the sun, and when the comet reaches this point it is receiving the highest energy from the sun. But it is not necessary the point where the comet is at its most active – actually, the comet keeps warming up after this point and we expect the highest activity a few weeks later.

"The highest activity of the comet around perihelion is very important because it is basically throwing out all the material that is really inside the comet and this is what our instruments want to see and measure. The other important factor that we want to monitor is how the comet has changed through this perihelion pass, so this will monitor it in the coming months."

Although it is unlikely that there will be anything to see from the Earth, Accomazzo said there was plenty of excitement still to come for astronomy enthusiasts following Rosetta's progress in monitoring the comet.

"In the coming months the comet will cool down, we will fly again closer to the comet. Hopefully in spring 2016 we are again in orbit around the comet and we intend to fly closer and closer in the course of 2016. So there is much more to come," he said.

Fans of Philae, the washing machine-sized craft that landed on the 67P comet in November, will be hoping that she might come back to life in time to send information about the comet's latest activity.

After a seven-hour descent from Rosetta, the probe floated away from its planned landing site into the shadow of a cliff, preventing sunlight from reaching the solar panels that should power it. Philae's current status is uncertain, and no contact has been made since July 9, but the ESA is still hopeful that the craft could restart scientific measurements soon.