3200 Phaethon - another asteroid that is like a comet

... or a comet that is like an asteroid? The EU crowd will have a field day with this.

"Rock Comet" 3200 Phaethon has sprouted a tail, proving that the mysterious object is the source of the annual Geminid meteor shower.

Article: science.nasa.gov...

Meteor showers originate from comets' tails, but the Geminids meteor shower has been traced to what until recently appeared like a rocky asteroid, 3200 Phaethon. It was an enigma to astronomers, until they've recently observed that at perihelion (the closest approach to the Sun), this asteroid grows a tail, like a comet. It is a dusty tail, and astronomers think that it occurs due to the intense heat of the Sun fracturing the rocky surface of this asteroid.

Even the asteroid's orbit around the Sun resembles that of a comet. en.wikipedia.org...

I always thought of asteroids as very inert bodies, but more and more of them are seen to exhibit activity like shedding dust. Turns out they can be quite a dynamic bunch.

reply to post by wildespace


thanx for the reminder , will be waiting for it next month 13 - 14 December which is not so far away

wildespace
... or a comet that is like an asteroid? The EU crowd will have a field day with this.

"Rock Comet" 3200 Phaethon has sprouted a tail, proving that the mysterious object is the source of the annual Geminid meteor shower.

Article: science.nasa.gov...

Meteor showers originate from comets' tails, but the Geminids meteor shower has been traced to what until recently appeared like a rocky asteroid, 3200 Phaethon. It was an enigma to astronomers, until they've recently observed that at perihelion (the closest approach to the Sun), this asteroid grows a tail, like a comet. It is a dusty tail, and astronomers think that it occurs due to the intense heat of the Sun fracturing the rocky surface of this asteroid.

Even the asteroid's orbit around the Sun resembles that of a comet. en.wikipedia.org...

I always thought of asteroids as very inert bodies, but more and more of them are seen to exhibit activity like shedding dust. Turns out they can be quite a dynamic bunch.

edit on 28-11-2013 by wildespace because: (no reason given)

A rock comet is a Rocket right? lol

We still have so much to learn about our neck of the woods too bad we don't spend more time and money doing just that!

reply to post by wildespace


Brings up an interesting question.

Is a comet defined by it's make-up/composition or by its orbit or both?

If it has to be "icy" how much ice does it have to have to be considered a comet vs. an asteroid?

Seems things are being somewhat redefined as we speak the more we learn. I think that's a good thing.

Riffrafter
reply to post by wildespace

 

Brings up an interesting question.

Is a comet defined by it's make-up/composition or by its orbit or both?

If it has to be "icy" how much ice does it have to have to be considered a comet vs. an asteroid?

Seems things are being somewhat redefined as we speak the more we learn. I think that's a good thing.

Good questions. The International Astronomical Union describes a comet as "a body made of rock and ice, typically a few kilometres in diameter, which orbits the Sun. Comets may pass by the Sun only once or go through the Solar System periodically. A comet’s tail is formed when the Sun’s heat warms the coma or nucleus, which releases vapours into space." www.iau.org...

Dunno if it's the official definition, so I emailed them asking if they have an official one. But so far, the idea seems to be (and I agree with it) that a comet is an icy body that develops a tail and a coma when it gets close to the Sun in its orbit. They are also characterised by very elliptical orbits that take them fairly far and fairly close to the Sun. Asteroids, on the other hand, tend to have more circulat orbits. Main-belt comets aren't really comets but asteroids that develop a comet-like appearance by shedding dust. But the asteroid in question isn't even a main-belt asteroid; it goes out beyond Mars and comes back closer than Mercury. It could be a chunk that broke off a larger asteroid in the main belt and got flung towards the Sun, giving it such elliptical orbit.