comets

Philae’s great leap – landing on Comet 67P

Credit: ESA/ATG medialab; Comet image: ESA/Rosetta/Navcam

Tomorrow ESA’s Philae lander will leave its mothership Rosetta and attempt to land on the surface of Comet 67P/Churyumov-Gerasimenko in what will undoubtedly be one of the most exciting, and nerve wracking, days in the history of space exploration. A few weeks ago I met some of the scientists working with Rosetta and Philae and spoke to them about this great adventure and their hopes for the mission. Here’s a video of my interviews with them:

I’ll be tweeting what’s happening throughout the day tomorrow from about 06:00UT. A few hours after the expected touchdown of Philae I’ll also be joining a live broadcast on the Slooh network, with host Geoff Fox, talking about the events of the day and what the Rosetta mission hopes to find out. You can tune in live from 19:00UT here.

New EPOXI images of Comet Hartley 2

This afternoon, 21 million kilometres from the Earth, NASA’s EPOXI mission flew by Comet Hartley 2. In the process, it captured some of the most stunning close-up pictures of an active comet ever seen.

Hartley 2 as seen by the EPOXI mission. Credit: NASA/JPL-Caltech/UMD

Hartley 2 has been visible in the night sky for many weeks now, and there have been some stunning images, taken by amateur astronomers, of its visit into the inner Solar System. While they have their own beauty, none can compare to the remarkable pictures sent back today by EPOXI. They show the 2.2km wide nucleus of the comet, from a distance of around 700km, covered in what look like boulders and effervescing with great jets of material erupting from its surface.

Jets erupting from Comet Hartley 2’s surface. Credit: NASA/JPL-Caltech/UMD

Some might think of the Solar System we live in as a rather quiet unchanging place, where nothing happens for eons. Well, these stunning images help refute that idea very easily. This is partly why I particularly like the image below, showing the jets bursting into sunlight. It really shows how dynamic these fascinating objects can be.

Comet Hartley 2: an active comet up close. Credit: NASA/JPL-Caltech/UMD

Tomorrow night we’ll be celebrating Bonfire Night here in the UK, where tradition dictates that we let off fireworks and light bonfires. For me though, that manmade spectacle won’t be anywhere near as impressive as the truly awesome natural one we witnessed today.

Spot Comet Hartley 2 as it passes Earth

Comet Hartley 2 can be seen with binoculars from dark skies. Credit: WillGater.com

Comet Hartley 2 is making its way through our neck of the planetary woods over the coming weeks, so now’s your chance to go out and see it.

I took the above picture of the comet last weekend. The comet itself is the green/grey smudge at the centre of the frame. The stars are trailed because the image has been processed in such a way that the comet remains stationary in the view. It’s a nice illustration of how the comet itself is zipping across the sky, against the background stars.

If you’re thinking of looking for the comet yourself, you’ll need a good pair of binoculars (or a small telescope) and some relatively dark skies. There’s a handy locator chart, showing you where to look, on Heavens-Above.com here. Don’t expect to see anything as impressive as Comet C/2006 P1 (McNaught) or Comet 17P/Holmes, from 2007, though. It appears as a faint grey smudge.

If you’re into astrophotography, the comet will also be passing close to the Double Cluster (NGC 884 & 869) on the 8 and 9 October, providing a superb celestial photo-op. Good luck, clear skies and happy comet hunting!

Update 10/10/10: Pete Lawrence caught this wonderful image of Comet Hartley 2 & the Double Cluster on the 7th October.

Catching Comet Lulin

Comet C/2007 N3 (Lulin) is currently putting on a good show in the night sky, having brightened as it makes its journey through the inner Solar System. Earlier this month Lulin had been fairly low down during the wee-small hours, for us UK astronomers anyway, but as the days have gone by it has slowly climbed higher — meaning it is now visible in the southern part of the sky during the late evening around midnight.

This past weekend I managed to observe and take a few pictures of the comet from a reasonably dark sky site. On Friday and Saturday night it was easily visible, against the background stars, as a slightly teardrop shaped grey smudge (with a hint of the dusty anti-tail) through a pair of 10×50 binoculars; during periods of good transparency I believe I glimpsed it with the naked eye too.

Tonight Comet Lulin appears close to Saturn in the sky and tomorrow it makes its close approach to Earth, at a distance of some 61 million km (38 million miles). On the 28th February it will be very close to the bright star Regulus in Leo. Interestingly, NASA observations made with the Swift spacecraft suggest that in late January Lulin was ejecting around 3000 litres of water every second! The Society for Popular Astronomy, here in the UK, have a webpage (scroll down to links for detailed charts) showing the location of the comet over the next few days. So if you are interested, don’t miss this opportunity to see a visitor from the outer Solar System as it gracefully passes us by.

Comet Holmes

If you haven’t tried to observe outbursting Comet Holmes (17P) yet, you really should! This comet is putting on an unusual show in the northern hemisphere’s night sky. Northern hemisphere observers will be able to spot it as a bright fuzzy star (now growing to almost half the apparent diameter of the Full Moon) in Perseus. A good pair of binoculars will show its bright round fuzzy nucleus best.

To locate it, scour along a line between the bright star Capella in Auriga and Mirfak in Perseus. Through a pair of 10×50 binoculars it is quite possible to find the fuzzy white orb of Holmes amongst the background stars.

Over the past few weeks the comet has dramatically risen to naked eye visibility with a million fold increase in brightness. What’s odd about this comet though is that it is brightening as it moves away from the Sun. Normally comets brighten as they approach it! Astronomers are not sure what might have caused the incredible outburst. It may have been caused by a collision with a small rocky object (a meteoroid) or a sudden collapse and subsequent exposure of parts of the comet’s icy surface.

Current estimates have the comet at roughly magnitude 2.5, well within naked-eye visibility. So weather permitting you will be able catch a glimpse of this intriguing celestial visitor as it heads away from the Sun.