Comets | Universe Today

There are just so many ways the Universe is out to get us. Astronomers have already considered the threat from our Sun's orbit around the center of the Milky Way. When our Sun rises up out of flat plane of the Milky Way, it appears we might be less protected from intergalactic radiation and cosmic rays. Well, it looks like passing through the middle of the galactic plane might have its own share of risks: an increased number of comets might be hurled towards the Earth because of gravitational interaction with the densest parts of our galaxy.
Read more…

Filed under: Asteroids, Comets | 13 Comments »

Who can forget last October, when astronomers all over the world were astounded by the huge outburst of Comet Holmes? The eruption was the largest for more than a century. (Click on image to animate.) Fortunately for the world, a UK telescope was in the right place and the right time to capture the first images of this once-in-a-lifetime event. Read more…

Filed under: Comets | 20 Comments »

Just so it's clear in your mind: comets are dirty snowballs, asteroids are rocks. Got the difference? Wait… not so fast. Scientists studying the cometary dust picked up by NASA's Stardust spacecraft, and they're finding it's surprisingly asteroid like.
Read more…

Filed under: Asteroids, Comets | 5 Comments »

It seemed like such a shame. NASA built Deep Impact to see what happens when you smash a refrigerator-sized object into a comet. Mission accomplished, science gathered. But what about the flyby part of the spacecraft? It captured images of the collision with Comet Tempel 1, and then flew on without a target. Well, NASA announced this week that it has a new target: Comet Hartley 2.
Read more…

Filed under: Comets, Missions | 2 Comments »

For a little while there, Comet 17P/Holmes was the largest object in the Solar System, flaring up by a factor of over a million. Its cloud of gas and dust expanded outward to cover a diameter of 1.4 million km (870,000 miles) - bigger than the Sun. Well, the party's over. Comet Holmes is fading away again. But will it follow history and flare up again?
Read more…

Filed under: Comets | 22 Comments »

All right, here's the picture we've all been waiting for. Step aside ground-based observatories, papa Hubble's here with images of Comet Holmes, which is now larger than the Sun. But don't get fooled. That beautiful image on the left was taken by amateur astronomer Alan Dyer from Alberta, Canada. Hubble's version on the right. It's not as pretty, but it's got inner bigness.
Read more…

Filed under: Comets, Hubble | 3 Comments »

All right, that title is a little misleading. In fact, when I first read the original press release, my skepticism alarms went off. But it's true, the amazing Comet Holmes now has a halo that's larger than the Sun. Not bad for a comet that, until three weeks ago, was just a tiny dim dirty snowball orbiting near Jupiter.
Read more…

Filed under: Comets, Solar Astronomy | No Comments »

Mark your calendars for November 13th, 2007. That's the day ESA's Rosetta spacecraft will be making a close encounter with Earth on its way to Comet 67/P Churyumov-Gerasimenko. What's going on? The comet's out there guys, why is Rosetta back home? Well, it's all about speed.
Read more…

Filed under: Comets, Missions | No Comments »

Late last week, the normally dim Comet 17P/Holmes suddenly blazed into view, increasing in brightness by a factor of a million. Before the eruption you needed a large telescope to see it, and now you can make it out with the unaided eye - even in the light-polluted city skies.

There are now many amateur and professional astronomers turning their gaze towards the newly brightened comet.

Eric Allen has been capturing images for several days, and stitched them together into an animation that shows the expanding coma. Even cooler, he compares it to Jupiter visually, so you can see just how big and bright it has gotten.

UK astronomers tuned in with the powerful Isaac Newton Telescope in La Palma, showing the fuzzy coma. They also tucked in an image of the Earth in the bottom corner, for scale.

Astronomers from the University of Montreal captured this image that seems to show that the comet has an actual tail.

Probably the best image I've seen was captured by Mario Motta from the Amateur Telescope Makers in Boston. His image shows what clearly looks like a jet, blasting off one side of the comet.

Still want more images? Space Weather has this enormous photo gallery of images of Comet 17P/Holmes.

Over the next few days/weeks, I'm sure some even bigger telescopes will be joining the fray, so stay tuned.

Filed under: Comets | 2 Comments »

Astronomers from Europe and Asia are reporting that the normally dim Comet 17P/Holmes has had an eruption. Instead of being 17th magnitude - only visible to powerful telescopes - it's now 3rd magnitude. This makes it easy to spot with the unaided eye, even in cities with heavy light pollution.

To confirm this discovery, head outside after the skies are dark, and look to the Northeast. The comet is currently in the constellation Perseus, which is below the more familiar Cassiopeia. If you're familiar with the constellations at all, you'll now see a new, bright yellow star. A telescope reveals the fuzzy corona surrounding the comet.

One report from Japan says, "Perseus does not look 'Perseus' familiar to us due to the bright stellar object now."

Spaceweather and Bad Astronomy have more details.

Thanks to BAUT member Keith G for the photograph. Here's a link to the forum where people are discussing it.

Filed under: Comets | No Comments »

Comets are known as dirty snowballs. As they approach the Sun, the constant solar wind picks away at their snowy exterior, creating the beautiful tail we see trailing behind. But sometimes the solar wind is replaced with a solar hurricane, and in the case of Comet Encke, its graceful tail was completely torn off.
Read more…

Filed under: Comets | 1 Comment »

When Deep Impact smashed into Comet Tempel 1, it did its job well… too well. Yes, it did carve out a crater on the surface of the comet, releasing a plume of debris visible from here on Earth. But there was a problem. The impact released so much debris into space that the spacecraft couldn't see the surface of the comet before it sped by. No problem, there's another handy spacecraft out there, with all the right equipment and nothing to do: Stardust.
Read more…

Filed under: Comets, Missions | No Comments »

The most successful comet hunter is not some dedicated amateur who sacrifices night after night searching for icy bodies from the outer Solar System. It's not a robotic telescope surveying the heavens. Nope, it's SOHO - a space telescope staring at the Sun; and it discovers comets as a happy side benefit. But recently it turned up something new, one of Halley's cousins; a periodic comet.
Read more…

Filed under: Comets | No Comments »

The traditional thinking is that life on Earth began… on Earth. At some point in our distant past, some mixture of amino acids made the jump from a pool of organic molecules to something more lifelike. But maybe the source of life on Earth came from space, hitching a ride aboard balls of ice and dust: comets.
Read more…

Filed under: Astrobiology, Comets | No Comments »

Scientists think they might have the solution to a mystery that's been haunting paleontologists for years: what caused an abrupt period of cooling 13,000 years ago and an extinction of the large mammals. The conventional theory is that when human hunters arrived in North America, they killed off all the tasty large mammals. But there's evidence that a comet exploded over North America at approximately the same time. This could also cause cooling, and wipe out the animals.
Read more…

Filed under: Comets | 4 Comments »

Comet McNaught, one of the brightest comets in last few decades recently swept past the Sun, providing a beautiful show. Unfortunately, the comet was so low to the horizon that only viewers in the Southern hemisphere were able to see its brightest point.
Read more…

Filed under: Comets | No Comments »

A small dwarf planet out past the orbit of Neptune could eventually become one of the brightest comets ever seen. Caltech professor Mike Brown - the discoverer of Eris - presented his calculations during the annual meeting of the American Astronomical Society held in Seattle in early January.
Read more…

Filed under: Asteroids, Comets | No Comments »

Although it's viewed more than 1,000 comets, NASA and ESA's Solar and Heliospheric Observatory has never seen anything like Comet McNaught.
Read more…

Filed under: Comets | No Comments »

The sudden brightening of Comet McNaught has reminded us what a treat it can be to see a comet with the unaided eye. A diffuse ball with a long tail stretching across the sky. There's nothing else in the night sky that can compare to a bright comet. But what are these objects, where do they come from, and what can they tell us about the formation of the Solar System?
Read more…

Filed under: Comets, Podcasts | No Comments »

Okay, this is unprecedented. The really bright Comet McNaught that I mentioned a few days ago is now so bright that you can see it in the daytime. It's extremely close to the Sun, so you need a way that you can block the glare of the Sun, but still see the sky.
Read more…

Filed under: Comets | 1 Comment »

Bad Astronomer Phil Plait is raving about it, our forum is buzzing about it, and there seem to be stories and photographs and popping up everywhere. One of the brightest comets we've seen in decades is blazing across the night sky, but you've got to move fast if you want to see it.
Read more…

Filed under: Comets | No Comments »

NASA announced today that it will be extending Deep Impact's mission, giving it a chance to visit another comet. The mission made big news when it slammed an impactor spacecraft into Comet Tempel 1 in July, 2005. NASA had hoped they could steer the spacecraft past another comet, to continue its scientific discoveries. Mission planners chose Comet Boethin as the spacecraft's next target, which it should be able to reach in December, 2008.
Read more…

Filed under: Comets, Missions | No Comments »

If you've got keen eyes, a computer connection, and a little spare time, you could help discover particles of interstellar dust. Poring over the samples returned by NASA's Stardust probe is a big job, so the scientists have opened up the task to volunteers through the Internet. Using a virtual microscope, volunteers can download images and search for the telltale track of a interstellar dust particles that were captured in aerogel. Discoverers will get a chance to name the particles they discover.
Read more…

Filed under: Comets, Missions | No Comments »