22.1.07

Comet Halley


The nucleus of Halley's Comet as imaged by the ESA probe, Giotto. The nucleus is the bit on the far right, a dark and irregular (Arthur C. Clarke called it peanut-shaped) chunk of primordial ice and dust. Comets are believed to exist in vast numbers in parts of the solar system called the Kuiper Belt and the Oort Cloud, but when some event sends them careering through parts more local to us, they react pretty badly: coming to pieces as their ice sublimes away and forms a conspicuous cloud.

The picture above is a great example of robot bravery - Giotto was seriously knocked around by debris from the comet, including one impact that put it into a spin so that its Kevlar dust shield was no longer constantly protecting its sensitive bits. The camera that took this image was eventually destroyed by another impact.

4 comments:

susanna said...

Hey there, Pacian! You know, I was thinking about you today before your visit to my blog. Really, I was! I had just read on Yahoo! that the moon is on a path to destruction. Something about the sun expanding. Thankfully it's not going to happen for a few billion years so I can sleep at night. Then I saw a photo of Carl Sagan on the front of a magazine at the library. I thought of you again! Apparently, you and Carl are linked together in my brain.
PS - I like your new banner.

zhoen said...

Robot bravery.

Geosomin said...

My husband found this the other day and after I had a look I thought you might be interested- someone has put together panoramas of all the photos from the moonlanding missions Apollo 11-17. Rather nifty.

http://www.panoramas.dk/moon/mission-apollo.html

I've found out so many interesting things and seen beautiful images of the universe through links from your weblog (And was able to pass them on to my husband who is also a planetary buff-he says thanks!)- I wanted to try and return the favour (although I'm betting you may have already found them).

Pacian said...

Thank you Geosomin. I have enough trouble keeping up with everything that's happening right now in space exploration - so I tend to miss out on the great missions of the past that are still paying dividends.

eg. here is a guy who's finding and recalibrating Soviet images of the surface of Venus. I've been meaning to check it out for ages, but only got around to it just now when you reminded me of this sort of thing.