Vesta Is a Baby Planet, Not an Asteroid

astroengine writes "Vesta, the second largest object in the main asteroid belt, has an iron core, a varied surface, layers of rock and possibly a magnetic field — all signs of a planet in the making, not an asteroid (abstract). This is the conclusion of an international team of scientists treated to a virtual front row seat at Vesta for the past 10 months, courtesy of NASA's Dawn robotic probe. Their findings were presented during a NASA press conference on Thursday. As to why Vesta never made it to full planethood, scientists point to Jupiter. When the giant gas planet formed, nearby bodies such as Vesta found their orbits perturbed. 'Jupiter started to act like a spoon in a pot, stirring up the asteroid belt and the asteroids started bumping into one another,' said Dawn lead scientist Christopher Russell. 'If they're just out there gently orbiting and everything is going smoothly, then without Jupiter in the picture, they would gather mass and get bigger and bigger and bigger. But with Jupiter there, stirring the pot, then the asteroids start bumping into one another and breaking apart, so nothing grew in that region, but started to shrink.'"

Comments

Pluto?

[sunderland56]

So Pluto was deemed just another large chunk of space debris orbiting the earth, and hence not a planet. Vesta *is* just a large asteroid amongst a whole bunch of others, but it is a planet?

I'm confused now.

Re:Pluto?

[Xtifr]

The abstract specifically says that Vesta is not an asteroid. When Ceres was reclassified as a dwarf planet, there was some question about Vesta, because it's not a proper spheroid. The question is: was it deformed by external forces or was it just never able to form a proper spheroid?

Since "baby planet" is not a proper IAU category, I think this means either A) it's a dwarf planet, like Pluto or Ceres, or B) the question is still open, but we've learned something new about its origin--a completely separate matter.

I think the IAU definitions are extremely silly, but I also think it's extremely silly think that Pluto is special, or any more deserving of planet status than Ceres, which was not considered a planet for many, many years. Personally, I'd rather see a definition of planet that includes Ceres and excludes Pluto than the reverse. (Though I'm also open to a definition that includes Ceres, Pluto, Luna, Ganymede, Titan, and more.)

Re:Pluto?

[osu-neko]

...space debris orbiting the earth...

Wait, Pluto orbits the Earth now?

Everything orbits the Earth. Heliocentrism is a fraud, brought to use by the same "scientists" as evolution, global warming, and that dubious round-earth theory. :p

Re:Pluto?

[harperska]

No, what they have found, and what makes this newsworthy, is that Vesta's composition is much more like the terrestrials (Mercury, Venus, Earth, Luna, Mars) than what they believe Ceres' composition is. They now believe that Vesta belongs to the terrestrial family, having a silicate rock crust/mantle surrounding an iron core. Ceres, on the other hand, is probably made primarily of an ice crust/mantle with a rock core, putting it in the same family as the moons of the gas giants, and the Kuiper Belt objects like Pluto. So while Ceres and Vesta live in the same castle, they are adopted from different families.

They will know more when Dawn leaves Vesta and visits Ceres, though.

Re:Pluto?

[Red Flayer]

Since "baby planet" is not a proper IAU category, I think this means either A) it's a dwarf planet, like Pluto or Ceres, or B) the question is still open, but we've learned something new about its origin--a completely separate matter.

It's not a baby planet, it's not a dwarf planet. It's a proto-planet stuck in proto- state due to Jupiter.

I like to think of it as an aborted planet.

Obviously we need to outlaw Jupiter to prevent further proto-planet abortions.. Furthermore, we need full funding of a federal agency to ensure Jupiter isn't available to all wanton sinners who would otherwise bring a planet to full term.

Well, folks, seems to me like we finally figured out how to ensure NASA's budget isn't axed.

And it's a Good Thing (tm)

[Barbara, not Barbie]

... because otherwise, Vesta would have sucked up all the material there, including a lot that went into Jupiter, and become the equivalent of Jupiter, but closer.

That would have turned Mars into an asteroid belt ... and Earth into an undersized Mars.

And since Venus is just too darn close to the sun to support life ... another lifeless solar system.

Re:And it's a Good Thing (tm)

[chebucto]

Are you sure about that?

My astronomy is rusty, but I seem to recall that the inner planets are rocky because their proximity to the sun meant they were unable to build up the kind of atmosphere the gas giants did: their atmospheres boiled off before they could grow to the mammoth proportions of the gas giants.

Given the distance from the sun to Cerers, would Ceres ever have been able to form into a gas giant?

Anyway, who's to say Jupiter (or at least its moons) are lifeless? :|]

Re:And it's a Good Thing (tm)

[Solandri]

That was the old theory. The problem with studying the cosmology of star systems is that until recently we only had a sample of one. When they started finding planets orbiting other stars, they tended to be gas giants because of the methods used (orbit perturbations, light falloff due to occultations). But a surprising number of these gas giants orbit closely around their parent star. IIRC one has an orbit whose period is a few Earth-weeks. At this point, I think you can say all bets are off.