The risk of giant asteroids hitting Earth could be much higher than we think

A study presented last weekend at the Lunar and Planetary Science Conference 2023held in Woodlands, Texas, USA, carries an important caveat: our estimates of the risks of giant asteroids hitting Earth are likely to fall far short of reality, sadly.

The lead researcher who reached this conclusion is James Garvin, chief scientist at NASA’s Goddard Space Flight Center, who believes we may have misunderstood the tracks of some of the most severe asteroid strikes in the last million years.

If he’s right, our planet is seeing its chances of being hit by something brutal grow much more than forecasts suggest.

The best-known of all meteorite impacts (as the chunks of space rock that pass through Earth’s atmosphere are called), blew a huge hole in the crust of what is now Mexico’s Yucatán Peninsula, about 66 million Years ago. exterminate dinosaurs and devastate life on Earth in general.

Called Chicxulub Crater, this hole has a diameter of over 180 km, and is the result of the impact of an asteroid about 15 km in diameter – considering the average between the various calculated estimates.

As highlighted on the website Scientific alarmeven much smaller rocks can still wreak havoc on our planet and this, one thought, could happen every 600,000 years or so.

It turns out that these calculations can be compromised and their results turn out to be erroneous because the Earth’s ‘scars’ are constantly changing, for example due to the dynamics of the planet’s winds, water and tectonic plates.

And such a record gets harder to read the further you look back, thanks to the wear and tear these agents cause on the earth’s surface. According to Garvin, even more recent events can be difficult to interpret through an accumulation of dust and microorganisms.

Using a new catalog of high-resolution satellite images to take a closer look at the eroded remains of some of the largest impact craters to have formed in the last million years, the scientist and his team aimed to better assess the true size of these scars.

They found that many of these craters have faint rings beyond what has generally been thought to be their outer edges, effectively making them larger than previously thought.

An approximately 13 km wide depression in Kazakhstan called Zhaminshin, for example, is believed to have been created by a meteorite with a diameter of 200 to 400 meters that struck the Earth about 90,000 years ago.

However, based on the new analysis, this event could have been even more catastrophic, leaving a crater closer to 30 km wide.

The sizes of three other large craters were also recalculated, all doubled or tripled. That could mean miles of rock fall every 10,000 years, a time span 600 times shorter than previously thought.

It’s important to remember that NASA researchers and other scientists around the world regularly scan the skies for asteroids that could one day pose a risk of impacting Earth. Space rocks larger than 140 m, with orbits passing within 7.4 million km of our planet, are considered potentially dangerous objects.

The post Risk of Giant Asteroids Hitting Earth Could Be Much Higher Than You Think first appeared in Olhar Digital.

Source: Olhar Digital