Tag Archives: stardust

Ancient Comet May Have Turned Chilean Desert Into Glass

Clods of glass in the Atacama Desert, site of an ancient fireball airburst.
Photo: R. Scott Harris

Nearly 50 miles (80 kilometers) of the Chilean coast are covered with oblong fragments of desert glass that researchers who recently studied them say came from a comet’s explosion over the Atacama Desert about 12,000 years ago.

The explosion was what’s called an airburst, which can happen when an object like a meteor or comet falls to Earth. These objects heat up due to friction with our planet’s atmosphere. While some burn up entirely in the atmosphere, other objects explode when they come in contact with thicker parts of the atmosphere. They can cause ground temperatures to be as hot as the Sun, with beyond-hurricane-force winds.

Such was the case for a comet that fell to Earth during the late Pleistocene, according to the team of researchers who studied the composition of the silicate glasses littered about Chile’s Atacama. They found the fireball’s explosion caused bits of space rock to fuse with the molten soils below, forming glasses. Their results were published this week in Geology.

“The Atacama is perfect for preserving the record,” Peter Schultz, a planetary geologist at Brown University, told Gizmodo in an email. “The difference between other glasses across the Atacama and these glasses is that our glasses are really large and indicate complex interactions between the airburst, heating, and winds.

“In other words, it teaches us about the details of the event for the first time,” Schultz added. “We actually have more glasses in Argentina of much older ages but can show that these were produced by actual collisions.”

Previously, a different team thought that the glasses came from ancient grass fires, long before the area became desert, that burned hot enough to transform the soil. But the recent team suspects an extraterrestrial object is the source of the geological oddity because of the unique mineral constitution and structure of the glasses, which showed evidence of being bent and transformed while still liquid. Those details have been observed in other airburst remnants and wouldn’t look so violent in grassfire glasses.

Furthermore, the team found minerals that come from other space rocks, like troilite and cubanite. Such inclusions are similar to those collected by NASA during the Stardust mission, from dust of the Wild-2 comet in 2004.

​​“Those minerals are what tell us that this object has all the markings of a comet,” said Scott Harris, a planetary geologist at the Fernbank Science Center and a co-author of the study, in a Brown University release. “To have the same mineralogy we saw in the Stardust samples entrained in these glasses is really powerful evidence that what we’re seeing is the result of a cometary airburst.”

The current age estimate of the airburst remains a work in progress on the testing front. The youngest date estimate, made by another co-author, was about 11,500 years ago. “There’s also a chance that this was actually witnessed by early inhabitants, who had just arrived in the region,” Schultz said in the same release. “It would have been quite a show.”

If not for humans, depending on the timing, one has to pity the doomed giant ground sloths and other megafauna in the area. They would’ve been burned to a crisp in an instant.

More: Here’s What Would Happen If a Giant Asteroid Struck the Ocean

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Need some space? You can now buy 7 billion-year-old stardust and pieces of the moon and Mars

If you’re looking for an out-of-this-world gift this Valentine’s Day, an auction house is offering up rare meteorite chunks from the moon, Mars and beyond — for as little as $250.

In an online sale beginning Tuesday, February 9, Christie’s auction house is auctioning off 72 meteorites — solid pieces of debris from celestial objects like comets and asteroids that arrive on Earth as shooting stars, somehow managing to survive their journey through our atmosphere to land on the surface.  

“The weight of every known meteorite is less than the world’s annual output of gold, and this sale offers spectacular examples for every collector, available at estimates ranging from hundreds to hundreds of thousands of dollars,” the auction house wrote on its website. 

Included in the collection is a meteorite containing 7 billion-year-old stardust, space gems encased in iron and the fourth-largest slice of the moon. A large chunk of Martian rock, worth an estimated $30,000 to $50,000, holds bubbles of the planet’s atmosphere trapped inside.

“The Most Beautiful Extraterrestrial Substance Known — End piece of the Fukang Meteorite.” Estimate: $3,500 – 4,500.

Christie’s


According to Christie’s, there are a dozen samples from the moon and Mars, and another dozen previously housed by famous museums around the world. 

“Everyone has an image in mind of how a meteorite ‘should look’ – an extraterrestrial body frictionally heated while punching through Earth’s atmosphere,” James Hyslop, head of science and natural history for Christie’s, said in a statement. “Rarely do the objects survive this fiery descent look like that shared ideal seen in this meteorite. It is a wonder to behold and an honor to have been entrusted with its sale.”

One object in the collection never hit the ground — a young boy in Morocco found the meteorite in the branches of a tree a day after a meteor shower — it’s worth an estimated $15,000 to $25,000. Yet another hailed from the U.S.’ largest meteorite shower in Odessa, Texas, expecting to fetch $40,000 to $60,000. 

“If there was ever a time to be awed by the infiniteness of the night sky, we’re living in it, but if you want to inspire and see eyes widen — touch a meteorite,” said curator Darryl Pitt.

“Gibeon Meteorite — Natural exotic sculpture from outer space.” Estimate: $15,000 – $25,000.

Christie’s


The auction house said that one of the highlights of the sale is a 16-pound “highly aesthetic oriented stone meteorite,” estimated to sell for $50,000 to $80,000.

“Unlike 99% of all other meteorites, this meteorite did not tumble or invert as it plunged to Earth but maintained a stable orientation throughout its descent,” the auction house said. “The surface that faced Earth showcases elongated flight marks that radiate outwards in this compelling, extraterrestrial aerodynamic form.” 

The meteorites have been found all over the world, from the Sahara Desert to Chile to Russia. 

The “Deep Impact: Martian, Lunar and Other Rare Meteorites” auction runs until February 23, and interested buyers located in New York can see them in person, by appointment. 

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