In March 2004, the European Space Agency launched the ambitious Rosetta mission, which will visit a comet named 67P/Churyumov-Gerasimenko. Rosetta will orbit the comet and then land on it, the first time this will have ever been attempted.
Very cool.
Comets are basically lumps of rocks frozen together in a matrix of ice made of water, hydrogen, and other things that would normally be a gas at room temperature. When they get near the Sun, those ices sublimate (turn from solid to gas), and the comet nucleus (the solid part) gets enveloped in a fuzzy ball of gas (called the coma). Studying the comet when it’s near the Sun, then, makes it hard to study the solid part.
So duh, study it when it’s far away from the Sun. But that’s a problem because comets are dinky and faint, and when they’re far from the Sun they are really hard to observe. You need a big ’scope.
Hey, the Very Large Telescope has an 8 meter mirror! Is that big enough?
Click it for a higher-res version. The tiny dot in the center (I added green crosshairs; they used a thin circle that’s hard to see) is the comet in May 2006 when it was 680 million kilometers from the Sun. That’s out past Jupiter! Observations over time revealed the comet is rotating; its brightness goes up and down. It takes about 12.8 hours to spin once, and the brightness variation indicates its an irregular shape, which is expected. Halley’s comet has a nucleus shaped like a potato, so there you go.
They also found a dust trail from the comet, probably from bits ejected over millennia that have spread out over that time:
The dust trail is the fuzzy part extending from the nucleus to the lower right (the picture is a time exposure, so stars and everything streak in the same direction, making the dust trail easier to see since it points off to the side). Mind you, the comet was 680 million kilometers away when that image was taken. In astronomy, you’d better believe bigger is better, and the VLT has 8 meters of bignitude. That’s a lot of ’scope and it can see very faint stuff.
All this information is pretty useful when you’re trying to land a probe on the comet… and you’re attempting this when the probe is 600 million kilometers away! That’ll happen in 2014, and when it does, the images will be HAWESOME*. I’m sure we’ll learn a lot about comets, and that’s good, because they’re cool, and they can hit the Earth, and learning more about them will help us understand how to prevent that, but c’mon, honestly: the images will be HAWESOME.
I can’t wait!
* OK, I know you’ll ask, so here. NSFW words. Hat tip to my ManCrush Wil Wheaton for that link, BTW.
August 21st, 2007 at 9:56 pm
Hawesome. I love it. By the way Phil you are one of my 4 year old daughters heroes. I just read this article to her,and I think shes permanantly added “hawesome” to her vocabulary. She also keeps asking when your going to do more videos on you tube…
August 21st, 2007 at 10:22 pm
That’s sweet! Don’t show her that link though.
I want to do videos, but they will have to wait for me to get the book done. Then I’m gonna do a lot.
August 21st, 2007 at 10:36 pm
“Halley’s comet has a nucleus shaped like a potato, so there you go.”
Russet or Yukon Gold?
August 21st, 2007 at 10:47 pm
Really neat! A quick question regarding comet composition: how much of the average comet evaporates per revolution? Presumably comets have a finite life-span.
August 21st, 2007 at 11:42 pm
Maybe a ‘purple peruvian potato’? http://www.foodsubs.com/Potatoes.html
August 22nd, 2007 at 6:11 am
“Rosetta will orbit the comet and then land on it,”
Don’t you mean “dock with it”? I can’t find an estimated mass anywhere, but it can’t have too much gravitational pull.
August 22nd, 2007 at 6:18 am
“Don’t you mean “dock with itâ€?”
I think, since this is the first time a spacecraft will be landed on a coment, we should use a new term. I vote for “snuggle,” as used in the following sentence.
The Rosetta probe will snuggle up to the comet.
Words and stuff,
Big Frankie C
P.S.: As I read and reply to this, I happen to be watching the Star Trek TNG episode “The Final Mission” which aparrantly was the last episode that featured Wil Wheaton as a regular cast member.
August 22nd, 2007 at 6:31 am
>Rosetta will orbit the comet and then land on it, the first time this will
>have ever been attempted.
Don’t forget the Japanese spacecraft Hayabusa visiting asteroid Itokawa. A very similar mission.
August 22nd, 2007 at 9:33 am
Hey now, as someone who played a very, very, very tiny role in the Deep Impact mission, I have to take issue with this. Sure we crashed into a comet, but isn’t a crash landing still a landing?
Maybe they can claim the first “soft” landing…
August 22nd, 2007 at 10:07 am
Dave, hence my suggested use of the word “snuggling” instead of landing, crashing, or docking.
Also, I really want to see a news anchor say it with a straight face.
August 22nd, 2007 at 2:49 pm
Before I watched the video, I assumed “hawsome” meant “hella awesome”.
And I agree with Dave W: Deep Impact was there first.
August 22nd, 2007 at 3:30 pm
[...] A distant target for Rosetta no Bad Astronomy [...]
August 22nd, 2007 at 3:48 pm
Big Frankie,
As much as I like the term Snuggle for a nice soft landing, it makes me cringe to think what DI did would be called. Can you pimp slap a comet?
August 22nd, 2007 at 4:17 pm
I am going to have to start using the word “bignitude” with some regularity.
August 22nd, 2007 at 5:08 pm
I’m a bit confused is Rosetta going to land on it soon?
August 22nd, 2007 at 10:32 pm
Dave,
I do believe that one can pimp slap anything. Given the right level of technology, or a Green Lantern Ring of Power, but since the Emerald Sentinel isn’t real, we’re gonna have to develop actual cometary pimp slapping technology.
When you said “we crashed into a comet” I think that’s the appropriate term. At least for a family friendly website. You guys did naughty things to that comet… Deep Impact indeed…
August 23rd, 2007 at 6:37 am
Troy: The landing will be in 2014 after ten years of travel…680 million kilometers away..
If they pull that off I’ll be impressed.
And hopefully, since it’s ESA, they work in metric/Si units exclusively.
August 23rd, 2007 at 7:24 pm
Rosetta is named for a stone and it sounds like it will rock!
(Sorry, I couldn’t resist the archeology joke.)
This mythology hobbist perfers Marvel to DC, Big Frankie C, but Green Lantern is probably my favorite DC hero. Either him or the Martian Manhunter. That pledge would work quite well as a motto for this website:
“In brightest day, in darkest night, no evil shall escape my sight. Let those who worship evil’s might, beware my power- The BA’s light!”