Wednesday, August 6, 2014
Close-up View of a Comet
Today the Rosetta spacecraft closed in on Comet 67P (the P stands for periodic comet, meaning it comes around again and again every six and a half years. ) It's also known as Comet Churyumov–Gerasimenko (C-G). Look at the amazing image our cameras sent back, taken from a distance of only 177 miles.
The comet and the spacecraft are currently still about half way between the orbit of Jupiter and the orbit of Mars. In this exciting rendezvous, Rosetta will match course with the icy comet and then stay with it as it gets closer and closer to the Sun and its ice begins to "sublimate" (turn from ice directly to a vapor in the vacuum of space.)
We hope to stay with the comet for a year, as it goes inward and then swings back outward again, watching the Sun's light and heat playing with the comet all the while. In November, part of Rosetta will actually land on the icy surface of Comet 67P.
But for now, just enjoy the weird and wonderful image. The comet's shape is definitely not symmetrical. Is it two ice pieces that stuck together in an ancient collision? Have past encounters with the Sun's heat resulted in this odd shape?
The comet is 2.5 miles wide, and you can see details as small as 17 feet (5.3 meters) across on our picture. Can you see the individual "boulders" or "ice rocks" sitting on the comet's surface?
If you'll pardon the expression, what a cool picture!
By the way, click on the photo to see it bigger and with more detail.