Unseen dark comets 'could pose deadly threat to earth'

Telegraph ^ | Thursday, February 12, 2009 | Kate Devlin

[SunkenCiv]

The comets, of which there could be thousands, are not currently monitored by observatories and space agencies.

Most comets and asteroids are monitored in case they start to travel towards earth.

But Bill Napier, from Cardiff University, said that many could be going by unnoticed.

"There is a case to be made that dark, dormant comets are a significant but largely unseen hazard," he said

Scientists estimate that there should be around 3,000 comets in the solar system, but only 25 have so far been identified.

"Dark" comets happen when the water on their surface has evaporated, causing them to reflect less light.

Astronomers have previously spotted comets heading towards earth just days before they passed.

In 1983 a comet called IRAS-Araki-Alcock passed at a distance of just 5 million kilometres, the closest of any comet for 200 years, but it was noticed just a fortnight beforehand.

Tests on another comet, called Comet Borrelly, in 2001 revealed it to have large dark patches across much of its surface.

Steve Larson of the University of Arizona's Catalina Sky Survey in Tucson, which monitors comets, said the idea of an unknown number of "dark" comets circling earth had "merit".

But Clark Chapman from the Southwest Research Institute in Boulder, Colorado, said that such comets "would absorb sunlight very well" and so could be detected by the heat they emit, reports New Scientist magazine.

[bigheadfred]

Hey...

This could be our big chance at that grant money. We could start by looking in the Hubble Archive. I think it was you that told me they had just found an extra-solar planet there. Probably plenty of dark comets too, just waiting to be discovered.

We could conduct this research in the safety of our own homes, within easy walking distance of the refrigerator. Some ACDC playing softly in the background, ya know, to help you focus. And even when you were staring off into space with a blank expression I’m thinking that still counts as research. Win-Win.

[SunkenCiv]

· join list or digest · view topics · view or post blog · bookmark · post a topic ·
	Gods Graves Glyphs	To all -- please ping me to other topics which are appropriate for the GGG list. GGG managers are SunkenCiv, StayAt HomeMother, and Ernest_at_the_Beach
·Dogpile · Archaeologica · ArchaeoBlog · Archaeology · Biblical Archaeology Society · · Discover · Nat Geographic · Texas AM Anthro News · Yahoo Anthro & Archaeo · Google · · The Archaeology Channel · Excerpt, or Link only? · cgk's list of ping lists ·

[SunkenCiv]

Some ACDC playing softly in the background, ya know, to help you focus.

Wow, never tried that. Always crank it.

[Dustbunny]

Just goes to prove how slang changes over the years. When we were young, many, many years ago, AC/DC had a totally different meaning.

[bigheadfred]

Always crank it.

Yeah, so do I. But we're supposed to be WORKING

[djf]

Stupid title.

All comets are dark.
We don’t see the comet, we see the gas.

(not yur fault, though!!)

[Recon Dad]

It's not worth worrying about some dark comet when we have a dark disaster already in running around Washington, DC right now.

[wildbill]

Just enough truth in the story to scare the bejesuz out of people—and sell newspapers.

[dforest]

Zer0 will send Hillary on this mission. She can use some of that “smart diplomacy” with these dark comets.

Plus, she has been rendered invisible lately.

[wolfcreek]

Here's a real one and it should be visable this month. I give you, Comet Lulin http://www.skyandtelescope.com/observing/highlights/35992534.html

[SunkenCiv]

It’s a long way to the top when you wanna crank AC/DC and can’t.

[SunkenCiv]

‘Forensic evidence’ of undiscovered planets
Telegraph | February 19, 2008 | Nic Fleming
Posted on 02/13/2009 7:54:10 PM PST by SunkenCiv
http://www.freerepublic.com/focus/chat/2185379/posts