A menacing asteroid about six miles wide triggered Earth’s last mass extinction. Now, scientists have discovered its origin.
Unlike most of the space rocks impacting our planet today, this behemoth comes from beyond the gas giant Jupiter. It is a “C-type asteroid” – a dark, carbon-rich remnant of the outer solar system – and an impact about 66 million years ago scattered the deadly body’s remains across the planet.
Mario Fischer-Gödde, who studies asteroids and planetary origins at the University of Cologne in Germany, told Mashable that it was “a projectile from the outer reaches of the solar system that sealed the fate of the dinosaurs.”
NASA scientists view the first Voyager images. What he saw made him shudder.
Fischer-Gödde led the new study, which was published in a peer-reviewed journal science.
Asteroids leave considerable traces. Today, the impact zone is known as Chicxulub Crater and is mostly buried beneath the Yucatan Peninsula. The massive object struck shallow water, blowing large amounts of debris into the sky and causing a dramatic cooling of the climate. A long, brutal winter followed. Photosynthesis stops. The food chain collapsed and about 70% of the species on earth died. Although some dinosaurs survived.
Mix and match speed of light
A thin layer of sediment from this event, called the K-Pg boundary, is found around our planet. One of these elements, ruthenium, is relatively rare in the Earth’s crust, meaning nearly 100 percent of the ruthenium in this widespread sheet of sediment came from the infamous asteroid. Importantly, the researchers found that the ruthenium isotopes (different types of ruthenium) in this leaky layer were similar to carbon-rich meteorites found across Earth. What’s more, the ruthenium sample didn’t match the remnants of other major asteroid impacts, which are from objects that formed in the inner solar system.
“We found that the asteroid that struck Chicxulub had the same composition as carbonaceous meteorites, which are carbonaceous (type C) asteroids that originally formed outside the orbit of Jupiter,” Fisher-Gold said. fragments.
Previous research also suspected a C-type asteroid as the culprit, but did not use ruthenium in the analysis. Fisher-Gold explains that this is because making these ruthenium measurements is very difficult, and advances in technology have made the latest observations possible. There are only three or so laboratories in the world, including the University of Cologne, that can carry out this ultra-specialized research.
The C-type asteroid Mathilde was captured by the NEAR spacecraft on June 27, 1997.
Image credit: NASA/JPL/JHUAPL
Depicts an asteroid collision 66 million years ago that may have sent a mountain-sized rock hurtling toward Earth.
Image credit: NASA/JPL-Caltech
As the solar system formed, many C-type asteroids began populating the outer reaches of the main asteroid belt, a ring containing millions of rocky objects located between Mars and Jupiter. It’s here that the six-mile-wide Chicxulub impactor may have been pushed toward Earth. Fisher-Gold explained that this could have been triggered by a collision between two asteroids. Or exposure to sunlight causes an area on the space rock to heat up and release energy, which may push the asteroid (this result is called the “Yarkovsky effect”).
However, such a massive collision with Earth is extremely rare. A “dinosaur-killing” impact on rocks that could be half a mile or more in diameter would have occurred on a time scale of 100 million years. Astronomers have discovered more than 90% of “planet-killer” asteroids that sometimes pass near the Earth. These boulders do not pose any known threat of collision in the next century; the likelihood of an impact in the next thousand years is extremely low. (Meanwhile, an impact from an object about 460 feet in diameter would occur every 10,000 to 20,000 years, an event that would have devastating effects on a regional scale.)
Luckily, NASA has successfully tested the first-ever attempt to intentionally move an asteroid should astronomers discover a large asteroid that threatens our humble world. Of course, this skill needs further refinement, but it could prove useful in protecting our civilization from future destruction.
NASA has never even had to issue a warning about incoming space rocks, big or small. But if an event like this happens, you’ll hear from the White House and many others — not just the titillating tabloids.
