Meteorite find may be 'missing half' of interstellar collision

Jul 01, 2014 by Bob Yirka report
The Thorsberg quarry and the Mysterious Object. (A) Thorsberg quarry on June 15, 2013. The Österplana church is seen in the back. (B) The Mysterious Object from the Glaskarten 3 bed. The meteorite is 8 × 6.5 × 2 cm in size. It was found in the youngest quarried bed of the Thorsberg quarry, at the top of the section. Credit: Earth and Planetary Science Letters, Volume 400, 15 August 2014, Pages 145–152.

(Phys.org) —A team of researchers with members from the U.S., Sweden and Switzerland studying a meteorite found in a Swedish quarry is reporting that the rock is unlike anything else ever found. In their paper published in Earth and Planetary Science Letters, they suggest the meteorite might just be evidence of a collision between two asteroids millions of years ago.

For several years scientists have debated the reason behind a lull, then sudden resurgence of biodiversity on planet Earth a little over 500 million years ago—some suggest the resurgence was due to a sudden major increase in the number of . The increase, theorists suggest, came about due to an impact between two asteroids, likely somewhere between Jupiter and Mars. Debris from the remains of one of those objects is believed to be the source of L , which have been found in many places around the globe. But, until now, no evidence of the other asteroid has been found on Earth, putting a damper on the theory—some have suggested the second asteroid simply vaporized on impact. The meteorite found in Sweden has reignited interest, however, because it's possible it is a piece of that second asteroid (because it appears to have been part of the same as the L chondrites), which if true, will add a lot of credence to the entire theory that seeks to explain the sudden resurgence of life during the early part of the Ordovician period.

The meteorite was found by quarry workers three years ago—other meteorites have been found in the same quarry before, but all of them were L chondrites. It was different from the other's, the researchers noted, after studying its crystals, but was in the same rock layer and dating in the lab, suggesting it arrived during the same time period as part of a wider meteor shower. While still in the same class of primitive achondrites as L chondrites, it's not exactly the same because of small differences in its elemental composition. The team is hopeful that the finding suggests that others will be found, hopefully some that can offer more evidence of their origin.

The unique has not been given an official name yet—for now it's simply being referred to as the "mysterious object."

Explore further: Research shows collision created Chelyabinsk asteroid

More information: A fossil winonaite-like meteorite in Ordovician limestone: A piece of the impactor that broke up the L-chondrite parent body? Earth and Planetary Science Letters, Volume 400, 15 August 2014, Pages 145–152. www.sciencedirect.com/science/… ii/S0012821X14003367

Abstract
About a quarter of all meteorites falling on Earth today originate from the breakup of the L-chondrite parent body ∼470 Ma ago, the largest documented breakup in the asteroid belt in the past ∼3 Ga. A window into the flux of meteorites to Earth shortly after this event comes from the recovery of about 100 fossil L chondrites (1–21 cm in diameter) in a quarry of mid-Ordovician limestone in southern Sweden. Here we report on the first non-L-chondritic meteorite from the quarry, an 8 cm large winonaite-related meteorite of a type not known among present-day meteorite falls and finds. The noble gas data for relict spinels recovered from the meteorite show that it may be a remnant of the body that hit and broke up the L-chondrite parent body, creating one of the major asteroid families in the asteroid belt. After two decades of systematic recovery of fossil meteorites and relict extraterrestrial spinel grains from marine limestone, it appears that the meteorite flux to Earth in the mid-Ordovician was very different from that of today.

add to favorites email to friend print save as pdf

Related Stories

Research shows collision created Chelyabinsk asteroid

May 23, 2014

(Phys.org) —On February 15 2013, an asteroid exploded about 30 kilometers above Chelyabinsk, Russia. The explosion, shared on video around the world, was the Earth's second largest recorded airburst. By ...

Mercury meteorite among world's rarest rocks

Nov 26, 2013

(Phys.org) —Talk about a precious stone—the largest piece of the only known meteorite from the planet Mercury has found its way to Yale, where it is now on display at the Peabody Museum of Natural History.

Recommended for you

SDO captures images of two mid-level flares

Dec 19, 2014

The sun emitted a mid-level flare on Dec. 18, 2014, at 4:58 p.m. EST. NASA's Solar Dynamics Observatory, which watches the sun constantly, captured an image of the event. Solar flares are powerful bursts ...

Why is Venus so horrible?

Dec 19, 2014

Venus sucks. Seriously, it's the worst. The global temperature is as hot as an oven, the atmospheric pressure is 90 times Earth, and it rains sulfuric acid. Every part of the surface of Venus would kill you ...

Image: Christmas wrapping the Sentinel-3A antenna

Dec 19, 2014

The moment a team of technicians, gowned like hospital surgeons, wraps the Sentinel-3A radar altimeter in multilayer insulation to protect it from the temperature extremes found in Earth orbit.

Video: Flying over Becquerel

Dec 19, 2014

This latest release from the camera on ESA's Mars Express is a simulated flight over the Becquerel crater, showing large-scale deposits of sedimentary material.

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

Birger
4.8 / 5 (4) Jul 01, 2014
Not "interstellar"*. Should be "interplanetary".

*However, some cosmic dust that enter the Earth's atmosphere and burns as meteors have hyperbolic paths** and are truly interstellar objects. These objects are just dust motes and pose no threats.
**Radar can follow the trail of ions the meteors leave in the atmosphere and recostruct their paths.
hemitite
5 / 5 (1) Jul 01, 2014
Sometimes it's the editor that "crafts" the headlines for these stories... Wouldn't it be great to find a "fossil" meteorite?
Torbjorn_Larsson_OM
5 / 5 (4) Jul 01, 2014
I dunno. It's a Yirka article, which means its anybodies guess as to how closely it follows the press material. :-/

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.