Rosetta Probe's Comet Reaches Closest Approach To the Sun

An anonymous reader writes: The European Space Agency has released pictures taken by the Rosetta probe at comet 67P/Churyumov–Gerasimenko as it reached closest approach to the Sun. The comet has now travelled 750 million kilometers since Rosetta arrived, and the increased solar radiation has caused ices to sublimate and create jets of gas. "The activity reaches its peak intensity around perihelion and in the weeks that follow – and is clearly visible in the spectacular images returned by the spacecraft in the last months. One image taken by Rosetta's navigation camera was acquired at 01:04 GMT, just an hour before the moment of perihelion, from a distance of around 327 km." They've released both still images and animations of the comet's outgassing. "Rosetta's measurements suggest the comet is spewing up to 300 kg of water vapor – roughly the equivalent of two bathtubs – every second. This is a thousand times more than was observed this time last year when Rosetta first approached the comet. ... Along with gas, the nucleus is also estimated to be shedding up to 1000 kg of dust per second, creating dangerous working conditions for Rosetta." It's a fascinating, close-up look at a comet during its most volatile time.

Comments

Interesting variation!

[Geoffrey.landis]

Interesting variation in the outgassing rate as the comet rotates! And it's quite clear that the outgassing comes from localized jets, and not from broad areas of the comet, although we'd already seen that from earlier images.

By looking at a very low phase angle (almost into the sun), we're seeing the forward scattering, so the dust shows up brightly-- a good way to look at very fine particles.