Is Comet Holmes bigger than the Sun? (Yes!)

New Scientist ^ | November 16, 2007 | David Shiga

[NYer]

The notion that Comet Holmes is bigger than the Sun has been making the rounds on space-related websites of late. But is it true?

According to a statement on astronomer Dave Jewitt's website, it is. "Formerly, the Sun was the largest object in the Solar System," the statement reads. "Now, comet 17P/Holmes holds that distinction."

Jewitt works at the University of Hawaii, and is certainly an authority on icy denizens of the solar system, having co-discovered the first Kuiper Belt object.

But what the statement is referring to is not the "body" of the comet, called the nucleus, which is only 3.6 kilometres across, but the extended cloud of dust around the nucleus called the coma.

Comet Holmes's coma has been expanding rapidly ever since a remarkable outburst of dust and ice from its surface on 24 October that suddenly increased the comet's brightness and brought it to the world's attention. (The image above, taken by Alan Dyer, shows Comet Holmes' coma and part of its tail.)

Measurements by University of Hawaii astronomers showed the coma was 1.4 million kilometres across as of 9 November. That's slightly larger than the diameter of the Sun, which is about 1.39 million kilometres.

That's large for a comet coma, but it's not the biggest ever. Comet Hale-Bopp's coma peaked at a diameter of between 2 and 3 million kilometres in 1997.

And comet tails can get even larger. Comet Hyakutake's was measured to be more than 500 million kilometres long in 1996 by the Ulysses spacecraft and may have been longer.

Jupiter's magnetotail, a long stream of charged particles extending from the solar system's largest planet, is larger than this. It's exact size is unknown, but is at least 650 million kilometres long.

[NYer]

[HuntsvilleTxVeteran]

The sky is falling, we must elect a democrat or a RINO to save the earth. /S

[rightinthemiddle]

"Outstanding."

[darkwing104]

Wow!

[frogjerk]

Fire and Ice.

[frogjerk]

The sky is falling, we must elect a democrat or a RINO to save the earth. /S

Chortle...snicker...gefaw...TGIF

[null and void]

[wastedyears]

Crazy stuff

The space stuff scares me because we have absolutely no control over it. Like gamma ray blasts.

[Arkinsaw]

Not really impressed. If you are going to count the size of the comet’s coma, you might as well count the size of the sun’s heliosphere...which is much bigger.

http://en.wikipedia.org/wiki/Heliosphere

[darkwing104]

The man who never blinked!

[Eyes Unclouded]

Mankind keeps forgetting his place in the grand scheme of things.

[reagan_fanatic]

Wonder if he and Nancy Pelosi used the same plastic surgeon.

[ShadowAce]

The space stuff scares me because we have absolutely no control over it.

That's precisely why it doesn't scare me. Why worry about something over which you have no control?

[Moonman62]

Good point.

[RightWhale]

That’s one small place for Man, one giant place for Mankind.

[HuntsvilleTxVeteran]

Where is Algore when we need him, whine, sob, cry, I am afraid?/S

[Swordmaker]

The misbehaving Comet is now bigger than the Sun... PING!

I like how they have added a false color blue to the comet picture to imply the presence of water...

If you want on or off the Electric Universe Ping List, Freepmail me.

[jonrick46]

It time to make that walk down the Santa Monica Pier. Ding! Ding! All aboard!

[2 Kool 2 Be 4-Gotten]

If we want to understand “Mankind” we have to break it down into it’s component words - “Mank” and “ind”. These don’t make any sense which is probably why “Mankind” doesn’t either. /Jack Handy

[RightWhale]

Those who habitually go outdoors at night to watch the stars and planets, etc. find these events interesting. Some things such as glare from light pollution are annoying when they wash out these events so we have to go to the Internet to find out what is right there visible to normal eyesight in a decent night sky. Who here has seen this comet for themselves?