The image on the left was taken on the day of Rosetta’s rendezvous from about 121 kilometres out.
The image on the right was taken exactly a year later from a distance of 261 kilometres. During this time, the comet has moved from almost 540 million kilometres from the Sun last year to around 186 million kilometres this week.
As the intensity of the sunlight has increased 700% over the year, ices have sublimated, turning into gas, and pouring out into space. The gas drags the dust along with it and together they form the comet’s fuzzy atmosphere, or coma.
The comet today reaches its closest point to the Sun along its orbit, known as perihelion. The European Space Agency is celebrating with a Google+ Hangout scheduled for 13:00–15:00 GMT (15:00–17:00 CEST).
Originally published by Cosmos as Rosetta images show how comet has changed over a year
Bill Condie
Bill Condie is a science journalist based in Adelaide, Australia.
Read science facts, not fiction...
There’s never been a more important time to explain the facts, cherish evidence-based knowledge and to showcase the latest scientific, technological and engineering breakthroughs. Cosmos is published by The Royal Institution of Australia, a charity dedicated to connecting people with the world of science. Financial contributions, however big or small, help us provide access to trusted science information at a time when the world needs it most. Please support us by making a donation or purchasing a subscription today.
