Meteorite flux has changed in deep time – First experimental results published in Nature Astronomy

In February 2017 we published the article Rare Meteorites Common in the Ordovician Period in Nature Astronomy.  This the first empirical reconstruction of variations in the meteorite flux to Earth in deep time. We show that the meteorites falling  on Earth in the Ordovician period one million years before the L-chondrite parent body breakup were very different from todays meteorites.  We show that primitive achondrites that are extremely rare in today’s flux were one of the most common types of Ordovician meteorites. The article was accompanied by a News and Views item “Meteorites: A shift in shooting stars” by Francesca DeMeo at the Massachusetts Institute of Technology, US. Our article received much media attention,  reaching an altmetric value in the top 99th percentile.

The article in Nature Astronomy can be found here 2017-Nature Astronomy.pdf, and the accompanying News and Views item here: DeMeo.pdf.

Doing astronomy by “looking down, instead of up”. Fredrik Terfelt collects some of the 270 kg of Ordovician rock from which the micrometeoritic spinels grains for the Nature Astronomy paper were recovered. The Lynna River section in the St. Petersburg region of Russia.

First reconstruction of Mesozoic meteorite flux published in Geology – no signs of a Baptistina asteroid breakup event

We just published completed another of our first “windows” into the meteorite flux to Earth in deep time. We extracted and analyzed 108 extraterrestrial spinels from 1652 kg of pelagic limestone from  the Lower Cretaceous Maiolica Formation in the Apennines of Italy.  You find the paper here: 9-2017Schmitz-Geology

The crew that did the first pilot sampling in July 2014, Jan Smit, Walter Alvarez, and Birger, Laura and Nelly Schmitz, in front of the micrometeorite-rich bed MMA 36 of the Maiolica Formation. The pilot samples showed that the Maiolica limestone is perfect for our type of work, being extremely pure and very easy to dissolve.
The crew that did the first pilot sampling in July 2014, Jan Smit, Walter Alvarez, and Birger, Laura and Nelly Schmitz, in front of the micrometeorite-rich bed MMA 36 of the Maiolica Formation. The pilot samples showed that the Maiolica limestone is perfect for our type of work, being extremely pure and very easy to dissolve.
Karl Terfelt collects 300 kg of Maiolica limestone bed MMA 335.
Karl Terfelt collects 300 kg of Maiolica limestone bed MMA 335.

Discover Magazine ranks our “extinct” meteorite as one of the 100 most important discoveries in 2016

In June 2016 we published the paper “A new type of solar-system research recovered from Ordovician limestone” in Nature Communications. This led to an unexpected reaction: Almost every leading daily news paper around the world highlighted the discovery of the world’s first “extinct” meteorite.

According to altmetrics value the article is now ranked as number 181 of the 271,861 tracked articles of a similar age in all journals (Sept. 18, 2017). Among the 759 tracked articles of a similar age published in Nature Communications it is ranked as number 7.

The media frenzy started after BBC wrote about our discovery. Then Nature.com highlighted our discovery at their prime space slot for a couple of days. Discover Magazine ranked our finding among the 100 most important during 2016.

You can find the article in Nature Communications here.

The fossil meteorite Österplana 065 from Ordovician limestone at Kinnekulle. The chromium- and oxygen-isotopic composition of relict spinel grains from the meteorite show that it is a kind of meteorite that is not known among the documented 50,000 meteorites that have fallen on Earth in recent times. Probably the parent-body of Österplana 065 has been consumed in collisions in space, thus there will never fall such a meteorite on Earth again. Hence it is an “extinct” type of meteorite.

 

Here are some of the media highlights:

New York Times:

New ‘Extinct’ Meteorite Hints at Violent Cosmic Collision

Washington Post:

https://www.washingtonpost.com/news/speaking-of-science/wp/2016/06/15/ancient-swedish-space-rock-may-be-a-whole-new-kind-of-meteorite/?utm_term=.1f8adda9e967

BBC:

http://www.bbc.com/news/science-environment-36532174#

The Hindu:

http://www.thehindu.com/todays-paper/tp-in-school/unknown-alien-rock-found/article14424213.ece1