rubble pile Archives

October 30, 2024October 30, 2024 by Evan Gough

Tiny Fragments of a 4-Billion Year Old Asteroid Reveal Its History

Asteroid Ryugu contains organic molecules called polycyclic aromatic hydrocarbons, thought to be chemical building blocks for life. Courtesy ISAS/JAXA — Asteroid Ryugu as seen by Japan's Hayabusa 2 spacecraft, which returned a sample of the ancient asteroid to Earth in 2020. Image Courtesy ISAS/JAXA

In June 2018, Japan’s Hayabusa 2 mission reached asteroid 162173 Ryugu. It studied the asteroid for about 15 months, deploying small rovers and a lander, before gathering a sample and returning it to Earth in December 2020.

The Ryugu sample contains some of the Solar System’s most ancient, primitive, and unaltered material, opening a window into its earliest days about 4.6 billion years ago.

January 31, 2023January 31, 2023 by Evan Gough

Don’t Bother Trying to Destroy Rubble Pile Asteroids

Detailed view of the rubble-pile asteroid 25143 Itokawa visited by the Japanese spacecraft Hayabusa in 2005. Credit: JAXA

The asteroids in our Solar System are survivors. They’ve withstood billions of years of collisions. The surviving asteroids are divided into two groups: monolithic asteroids, which are intact chunks of planetesimals, and rubble piles, which are made of up fragments of shattered primordial asteroids.

It turns out there are far more rubble pile asteroids than we thought, and that raises the difficulty of protecting Earth from asteroid strikes.

July 29, 2020July 29, 2020 by Evan Gough

A Group of Meteorites All Came From a Destroyed Planetesimal With a Magnetic Core

Samples from a rare meteorite family, including the one shown here, reveal that their parent planetesimal, formed in the earliest stages of the solar system, was a complex, layered object, with a molten core and solid crust similar to Earth. Photo credit: Carl Agee, Institute of Meteoritics, University of New Mexico. Background edited by MIT News.

Before our Solar System had planets, it had planetesimals. Scientists think that most of the meteorites that have struck Earth are fragments of these planetesimals. Scientists also think that these planetesimals either melted completely, very early in their history, or that they remained as little more than collections of rocks, or “rubble piles.”

But one family of meteorites, that have been found spread around the world, appear to come from a planetesimal that bucked that trend.