The odds of Earth being hit by a large asteroid would be higher than previously assumed. This is confirmed by a new NASA study, as explained by James Garvin, chief scientist of the agency’s Goddard Space Flight Center, and first author of the research. The work was presented last week at the Lunar and Planetary Science Conference. Using a new catalog of high-resolution satellite images, Garvin and his colleagues have identified large rings around three impact craters.
Past impacts would be much more violent than assumed
For Garvin, the rings imply that the craters are tens of kilometers wider and record much more violent events than researchers had previously thought. If the chief scientist were correct, each impact would have resulted in an explosion about 10 times more violent than the largest nuclear bomb in history, powerful enough to blast part of the planet’s atmosphere into space. While not as destructive as the one that killed the dinosaurs, these impacts would have disrupted global climate and caused local extinctions. Garvin himself, however, wanted to underline: “We haven’t tried anything for sure yet”.
Bottke in Science says he is skeptical of the NASA study
Also maintaining a cautious attitude is Bill Bottke, an expert on planetary dynamics at the Southwest Research Institute in Boulder, Colorado, who heard from Science explained: “I’m skeptical. I want to see much more before I believe it”. Because water and wind rapidly obliterate most impact craters on Earth, researchers estimate asteroid impact frequency rates by calculating the size and age of craters on the Moon. They also study the size of near-Earth orbiting asteroids, which could lead to potential future impacts. Based on these two methods, the researchers estimate that an asteroid or comet a kilometer wide or more hits the planet every 600,000 to 700,000 years.
Researcher Osiak: ‘If the research were true it would be scary’
The new NASA study, however, suggests that in the last million years alone, four kilometer-long objects have impacted our continents and, given that two-thirds of the planet is covered by water, that could mean that up to a dozen asteroids of that size hit the Earth in total in the considered period. Anna Osiak, a crater researcher at the Polish Academy of Sciences, doubts that the rings identified by Garvin’s team are really crater rims. If somehow they were, she says, “that would be very scary because it would mean that we don’t really understand what’s going on and that there are a lot of space rocks that could come in and make a mess.”
NASA downsizes risk of asteroid impact in 2026
A more reassuring news has instead arrived regarding the asteroid 2023 DZ2, which has been talked about in the past few hours as a candidate for impact with the Earth for 2026. According to recent data collected by NASA, it would no longer be so scary . At the moment the space agency database – called Sentry: Earth Impact Monitoring of the Center for Near Earth Object Studies (CNEOS) of the Jet Propulsion Laboratory – reports the following data on the impact risk with 2023 DZ2 for March 27, 2026, the date in relation to which there was supposed to be some risk: 0.0000026% chance of collision with the Earth, or 1 in 38,000,000 chance of impact; 99.9999974% chance the asteroid will miss Earth. 2023 DZ2, about 60 meters wide, will pass relatively close to the Earth on March 25 at about 173,000 kilometers from us.
Source-tg24.sky.it