Many asteroids might be remnants of 5 destroyed worlds, scientists say

[Judi Lynn]

- click for image -

http://www.trbimg.com/img-5b3bacc0/turbine/ct-asteroids-destroyed-planetesimals-20180703-001/400/400x400

A handout photo made available by the Japan Aerospace
Exploration Agency (JAXA) on June 25, 2018, shows the
Ryugu Asteroid photographed with the ONC-T
(Optical Navigation Camera - Telescopic).
 (Jaxa/University of Tokyo/Kochi U / EPA)


Sarah Kaplan Washington Post

July 3, 2018 11:55 AM


In the beginning, the solar system was little more than a cloud of dust and gas. Then cold temperatures caused the center of the cloud to collapse, forming the sun. The newborn star lit up with nuclear fusion, sending light and heat out into the spinning circumstellar disk. Soon that material coalesced into gas planets, ice giants and rocky worlds, creating the solar system we know today.

For years, asteroids were thought of as the leftovers of planet formation - chunks of material that never quite made it to planet size and that were drawn into the crowded belt of rocky remnants that circles the sun between Mars and Jupiter.

But according to a study published Monday in the journal Nature Astronomy, these were once pieces of worlds, too. A vast majority of the half-million bodies in the inner asteroid belt may in fact be shrapnel from as few as five parent bodies called "planetesimals," scientists say. But the tangled orbits of those lost worlds meant they were doomed to collide, producing fragments that also collided, producing still more fragments in a cataclysmic cascade that's been going on for more than 4 billion years.

The finding doesn't only illuminate a "mystery" of the asteroid belt, said Katherine Kretke, a planetary scientist at the Southwest Research Institute who was not involved in the study. It could also help resolve a debate about the formation of the eight planets - including Earth.

More:
http://www.chicagotribune.com/news/nationworld/science/ct-asteroids-destroyed-planetesimals-20180703-story.html

[byronius]

1. Great visual.

I'd love to have the hi-def 3D history of the solar system. Scroll around looking for cool stuff. Some of those planetary collisions must have been spectacular.

Judi Lynn? Can you whip that up? You seem real smart.

[Judi Lynn]

2. Didn't see anything like that, yet, but I did find something interesting, a moment ago:

[Judi Lynn]

3. Uh, oh. Haven't seen this, yet, just discovered it:Blow your Mind History of the Universe in 2 Hours

You never know!

[Judi Lynn]

4. Asteroid belt may be remains of half a dozen ancient planets

Michael Irving
2 hours ago

They might seem like boring old rocks, but asteroids and meteorites have some fascinating stories to tell about the history of the solar system. New research from the University of Florida has now traced back the origins of almost all asteroids in the inner belt to just five or six ancient minor planets.

They might seem like boring old rocks, but asteroids and meteorites have some fascinating stories to tell about the history of the solar system. New research from the University of Florida has now traced back the origins of almost all asteroids in the inner belt to just five or six ancient minor planets.

The solar system was far rougher in its youth than it is today. As the huge disc of dust and gas surrounding the Sun started clumping together, planets and moons were born and torn apart as they smashed into each other. The eight planets we know today are the survivors of this time, but other protoplanets were likely jostling for space before or during their reign.

Some of these lost worlds came to an explosive end when they collided with Earth, Mars and Uranus, but they live on in the form of moons of those planets. Meteorites, meanwhile, tell tales of ancient ocean planets and Mercury-sized planetoids that lived long enough for diamonds to form deep below their surface – and died explosively enough for the gems to be cast out into space.

More:
https://newatlas.com/meteorites-asteroids-ancient-planets/55299/