Vesta is a Planet !

CraigS · #1 13-12-2011, 08:02 AM

Is Vesta the 'smallest terrestrial planet?'

Quote:

"We're seeing enormous mountains, valleys, hills, cliffs, troughs, ridges, craters of all sizes, and plains," says Chris Russell, Dawn principal investigator from UCLA. "Vesta is not a simple ball of rock. This is a world with a rich geochemical history. It has quite a story to tell!"

In fact, the asteroid is so complex that Russell and members of his team are calling it the "smallest terrestrial planet."

Move over Pluto !

Cheers

spacezebra (Petra) · #2 13-12-2011, 08:09 AM

I'm a pluto supporter and sadly I accepted the IAU findings, however I thought that there were other criterion that had to be satisfied?

Not just geological. Have I missed something here?

Cheers Petra d.

CraigS · #3 13-12-2011, 10:21 AM

So Petra … which comes first .. the IAU (the chicken) … or reality (the egg)???

That is the question.

Cheers

Erg · #4 13-12-2011, 10:43 AM

The definition of planet set in 2006 by the International Astronomical Union (IAU) states that, in the Solar System, a planet is a celestial body which:

1.is in orbit around the Sun,

2.has sufficient mass to assume hydrostatic equilibrium (a nearly round shape), and

3.has "cleared the neighbourhood" around its orbit.

Dont need Dawn to establish any of those 3. IMO they are getting carried away with its beauty. It either fits the def or it doesnt. Doesnt matter how pretty or exciting it is.

Erg

Poita (Peter) · #5 13-12-2011, 10:52 AM

I don't know if I'd call it pretty.
http://upload.wikimedia.org/wikipedi...a_Rotation.gif

It may have been a planet under the draft proposal, but not under the current one.
The iron core and volcanic activity make it an interesting study, but it definitely isn't a planet by current definition. It is pretty tiny
http://upload.wikimedia.org/wikipedi.../Iau_dozen.jpg

renormalised (Carl) · #6 13-12-2011, 12:10 PM

If they're going to call Vesta a planet, then they might as well say the Moon really is made of green cheese (Swiss, at that!!

).

If you take the IAU's ridiculous pronouncement at its literal, strictest meaning, there are no planets in this solar system, except for Mercury and maybe Venus. Every other planet has "debris" in its orbit...think of all the Trojan asteroids floating around about, for a start. Then what about all the other asteroids....the Aten, Amor, Apollo, Centaur and other asteroid groups floating around....all busily orbiting about and near the planets. Cleared orbits???....hardly.

ballaratdragons (Ken) · #7 14-12-2011, 01:28 AM

I'm still waiting for them (IAU) to admit that Earth & Luna is a Double Planet system!

Instead they worry about how Geologically artistic a rock is to make it a planet.
Pretty does not a Planet make!

ZeroID (Brent) · #8 15-12-2011, 09:03 AM

Quote:

Originally Posted by ballaratdragons

I'm still waiting for them (IAU) to admit that Earth & Luna is a Double Planet system!

Instead they worry about how Geologically artistic a rock is to make it a planet.
Pretty does not a Planet make!

You are a closet 'Luneartharian' ......
From a old Sci Fi I read many moons ago...

The Luneartarians were a mythical people, the original habitants of Earth and the Moon, the only double planet system when space exploration was getting started. And they had powers beyond normal humans ...
Can't remember what the book was called or the author.

Might have been spelled Lunartharian, not sure. I'm off to google ...

higginsdj · #9 19-12-2011, 12:06 PM

Gee wiz - NASA's ignoring the rules and making up it's own names and titles - now there's something new.........

What better way to keep oneself at the forefront of pulicity than to make big, bold statements - who cares if they are true!

Cheers

renormalised (Carl) · #10 19-12-2011, 01:05 PM

Quote:

Originally Posted by higginsdj

Gee wiz - NASA's ignoring the rules and making up it's own names and titles - now there's something new.........

What better way to keep oneself at the forefront of pulicity than to make big, bold statements - who cares if they are true!

Cheers

FY2012 is coming up, and NASA looks like it's possibly loosing a few billion in funds. So, you know what this is being done for

Kal (Andrew) · #11 19-12-2011, 01:42 PM

I take issue with them using the term 'terrestrial'.

Doesn't that imply that it is from earth?

renormalised (Carl) · #12 19-12-2011, 01:47 PM

Strictly speaking, yes. However when used in this context it refers to rocky planets....as you'd already know.

TrevorW · #13 19-12-2011, 05:32 PM

What gives the IAU the right to detemine that Pluto isn't a planet yet some small chunk of rock is

as far as I'm concerned Pluto is a planet as well as Mickey, Donald and Dopey

N1CK06 (Nick) · #14 20-12-2011, 12:40 AM

They are suggesting that Vesta should be categorised as a "dwarf planet", which puts it in the same class as what Pluto has been demoted to. Among these is the dwarf planet Ceres which the Dawn probe will be passing sometime in 2015 which is also located in the asteroid belt.

I suppose there could be many more dwarf planets in our solar system that fit in with IAU's classifications which haven't been accepted as dwarf planets yet.

Cheers,
Nick

snas (Stuart) · #15 20-12-2011, 11:38 PM

My question is, what is the origin of the lines that seem to run around Vesta's "equator" on Peter's .gif http://upload.wikimedia.org/wikipedi...a_Rotation.gif

Stuart

N1CK06 (Nick) · #16 21-12-2011, 12:48 AM

Quote:

Originally Posted by snas

My question is, what is the origin of the lines that seem to run around Vesta's "equator" on Peter's .gif http://upload.wikimedia.org/wikipedi...a_Rotation.gif

Stuart

Good question! I was curious myself and found this interesting article which mentions them: http://planetary.org/blog/article/00003233/

It seems they relate to the large impact basins at Vesta's south pole which indicates they may have formed as a result of a large collision with an asteroid. I'm not too sure exactly how they came to be though..

My guess is that the impact has caused the surface to deform as a response to the force of the collision. This also agrees with the article in the original post which mentions tectonic features.

renormalised (Carl) · #17 21-12-2011, 01:15 AM

You've pretty much hit the nail on the head there, Nick. They're ripples caused by the impact of large bodies on the surface of the asteroid. Actually, they're akin to ripples in water when you drop a rock into it, only in this case it's deformation occurring in the rocks, that were formed by powerful shockwaves. In very large earthquakes here on Earth, you can occasionally see these waves pass through the surface layers of the crust...as a rippling effect. You'll also see them formed in major asteroid impacts on the terrestrial planets as well.

Ric · #18 21-12-2011, 12:19 PM

Quote:

Originally Posted by renormalised

You've pretty much hit the nail on the head there, Nick. They're ripples caused by the impact of large bodies on the surface of the asteroid. Actually, they're akin to ripples in water when you drop a rock into it, only in this case it's deformation occurring in the rocks, that were formed by powerful shockwaves. In very large earthquakes here on Earth, you can occasionally see these waves pass through the surface layers of the crust...as a rippling effect. You'll also see them formed in major asteroid impacts on the terrestrial planets as well.

Hi Carl

Would they be the same as a Love or Rayleigh wave here on Earth?

renormalised (Carl) · #19 21-12-2011, 12:34 PM

Similar, but far more energy and faster. Normally Love/Rayleigh waves don't physically deform the rocks (unless they're generated by a big quake) . The shockwaves from a major impact visibly deform the surrounding rocks. In terms of water waves, they'd be more akin to tsunamis than wind driven surface waves.

N1CK06 (Nick) · #20 21-12-2011, 01:48 PM

So these ripples would have to suggest that Vesta has a crust. And if the size and force of the collision that caused the ripples can be determined from analysing the impact basin then the crustal thickness, density and maybe even the rock type could also be determined. They could tell a lot about this "planet". Although I'm sure the Dawn probe has equipment that can determine this in a much easier way.