Meteorites Archives

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.

April 29, 2020April 29, 2020 by Nancy Atkinson

Terrible Luck. The Only Person Ever Killed by a Meteorite – Back in 1888

The Chelyabinsk impactor vapor trail. — This image of a vapor trail was captured about 125 miles (200 kilometers) from the Chelyabinsk meteor event, about one minute after the house-sized asteroid entered Earth’s atmosphere. Credits: Alex Alishevskikh

What are your chances of getting smacked – and killed — by a meteorite? One astronomer put the odds of death by space rock at 1 in 700,000 in a lifetime, while others say it’s more like 1 in 1,600,000.

Computing the probability for such an untimely death is difficult because this type of event is so rare. In fact, even though thousands of meteorites are thought to hit the ground each year, in looking through the annals of meteorite history, there seemed to be no evidence that anyone had ever been killed by a meteorite. Until now.

January 13, 2020January 13, 2020 by Evan Gough

Almost 800,000 Years Ago, an Enormous Meteorite Struck Earth. Now We Know Where.

A map of the Australasian strewnfield, where tektites from a meteor impact are spread over the Earth's surface. Image Credit: By syncmedia - Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=19184380

20% of the surface of Earth’s Eastern Hemisphere is littered with a certain kind of rock. Black, glossy blobs called tektites are spread throughout Australasia. Scientists know they’re from a meteorite strike, but they’ve never been able to locate the crater where it struck Earth.

Now a team of scientists seems to have found it.

September 19, 2019September 19, 2019 by Evan Gough

A Distant Asteroid Collision Gave Earthly Biodiversity An Ancient Boost

An artist's illustration of the Ordovician Meteor Event. Image Credit: DON DAVIS, SOUTHWEST RESEARCH INSTITUTE

About 466 million years ago, there was an asteroid collision in the asteroid belt between Mars and Jupiter. The collision caused the breakup of a major asteroid, creating a shower of dust throughout the inner Solar System. That event is called the Ordovician Meteor Event, and its dust caused an ice age here on Earth.

That ice age contributed to an enormous boost in biodiversity on ancient Earth.

September 17, 2019September 17, 2019 by Evan Gough

Metallic Asteroids Might Have Had Volcanoes Erupting Molten Iron. That’s So Metal

This diagram depicts a theoretical phenomenon called ferrovolcanism, where metallic asteroids erupt molten iron in a class of asteroids called pallasites. The ferrovolcanism might result when pockets of melted alloy rise to the surface. An upcoming NASA space mission to the asteroid Psyche may allow scientists to confirm their theory. (Purdue University image/James Keane)

Remember the asteroid Psyche? It’s the largest known asteroid in the asteroid belt between Mars and Jupiter. It’s been in the news because of its unusual properties, and because NASA plans to launch a mission to Psyche in 2022.

Psyche, aka 16 Psyche, is unusual because it’s quite different from other asteroids. Psyche appears to be the remnant, exposed nickel-iron core of an early planet. Because of that, Psyche is a building block left over from the early Solar System, when planets were still forming. It’s like a planet without a crust.

August 4, 2019August 4, 2019 by Matt Williams

Bright Fireball Explodes Over Ontario, Meteorite Fragments Might Have Reached the Ground

. Credit: NASA’s All Sky Fireball Network

On Wednesday, July 24th, the people of the Great Lakes region were treated to a spectacular sight when a meteor streaked across the sky. The resulting fireball was observed by many onlookers, as well as the University of Western Ontario’s All-Sky Camera Network. This array runs across southern Ontario and Quebec and is maintained in collaboration with NASA’s Meteoroid Environment Office (MEO) at the Marshall Space Flight Center.

What is especially exciting about this event is the possibility that fragments of this meteorite fell to Earth and could be retrieved. This was the conclusion reached by Steven Ehlert at the MEO after he analyzed the video of the meteorite erupting like a fireball in the night sky. Examination of these fragments could tell astronomers a great deal about the formation and evolution of the Solar System.

July 29, 2019July 29, 2019 by Matt Williams

As Meteorites Slice Through the Atmosphere, They’re Sculpted Into Cones

Artist's concept of the meteorite entering Earth's atmosphere. Credit: University of Oxford

Since it first formed roughly 4.5 billion years ago, planet Earth has been subject to impacts by asteroids and plenty of meteors. These impacts have played a significant role in the geological history of our planet and even played a role in species evolution. And while meteors come in many shapes and sizes, scientists have found that many become cone-shaped once they enter our atmosphere.

The reason for this has remained a mystery for some time. But thanks to a recent study conducted by a team of researchers from New York University’s Applied Mathematics Lab have figured out the physics that leads to this transformation. In essence, the process involves melting and erosion that ultimately turns meteorities into the ideal shape as they hurl through the atmosphere.

July 26, 2019July 26, 2019 by Evan Gough

Fossilized Clams Had Evidence of a Meteorite Impact Inside Them

Some of the microtektites found by Mike Meyer inside fossilized clams in Florida. Image Credit: Photo by Meyer et al in Meteoritics and Planetary Science.

When an extraterrestrial object slams into the Earth, it sends molten rock high into the atmosphere. That debris cools and re-crystallizes and falls back down to Earth. Tiny glass beads that form in this process are called microtektites, and researchers in Florida have found microtektites inside fossilized clams.

April 17, 2019April 17, 2019 by Evan Gough

Astronomers Find a Chunk of a Comet Inside a Meteorite

A slice from the LaPaz 02342 meteorite which contains dust grains from an ancient comet. Image Credit: Carnegie Institution/Nittler et. al. 2019.

The early days of the Solar System are hard to piece together from our vantage point, billions of years after it happened. Now a team of scientists have found a tiny chunk of an ancient comet inside an ancient meteorite. They say it sheds light on the early days of the Solar System when planets were still forming.

November 9, 2018November 9, 2018 by Evan Gough

Not all the Earth’s Water Came From Comets

This view of Earth’s horizon was taken by an Expedition 7 crewmember onboard the International Space Station, using a wide-angle lens while the Station was over the Pacific Ocean. A new study suggests that Earth's water didn't all come from comets, but likely also came from water-rich planetesimals. Credit: NASA

We have comets and asteroids to thank for Earth’s water, according to the most widely-held theory among scientists. But it’s not that cut-and-dried. It’s still a bit of a mystery, and a new study suggests that not all of Earth’s water was delivered to our planet that way.

Continue reading “Not all the Earth’s Water Came From Comets”