![\"An](\"https:\/\/th-thumbnailer.cdn-si-edu.com\/f-Hhyk0ostVv14reI1KQ0WPJ1gA=\/1000x750\/filters:no_upscale():focal(960x544:961x545)\/https:\/\/tf-cmsv2-smithsonianmag-media.s3.amazonaws.com\/filer_public\/74\/a8\/74a80d30-bbfd-411e-bc0d-651ab6871582\/artistic_rendering_asteroid.jpg\")
An artist’s impression of a generic asteroid. NASA has identified an asteroid with a more than 1 percent chance of striking Earth in December 2032, per a statement<\/a> released by the agency this week. While the identification has triggered international planetary defense measures, experts say that further observations of the asteroid might drop the impact probability down to zero.<\/p>\n \u201cMost likely this one will pass by harmlessly,\u201d Colin Snodgrass<\/a>, an astronomer at the University of Edinburgh in Scotland, tells the Guardian<\/em><\/a>\u2019s Ian Sample. \u201cIt just deserves a little more attention with telescopes until we can confirm that. The longer we follow its orbit, the more accurate our future predictions of its trajectory become.\u201d<\/p>\n The NASA-funded\u00a0Asteroid Terrestrial-impact Last Alert System<\/a> (ATLAS) station in Chile first reported the asteroid, called 2024 YR4, on December 27, 2024. Within a few days it had risen to the top of NASA\u2019s Sentry risk table<\/a> and the European Space Agency\u2019s near-Earth object Risk List<\/a>, where it currently has a 1.6 percent chance, or 1-in-63 odds, of impacting Earth in about eight years. That also means it has a 98.4 percent chance of zooming by without causing any damage.<\/p>\n Should you be worried about 2024 YR4? Short answer = no. But I do advise you wear your seat belt when driving! More in this article by The Planetary Society (@exploreplanets<\/a>). https:\/\/t.co\/hCUAMFmH2k<\/a><\/p>\n \u2014 Dr Heidi B. Hammel (@hbhammel) January 30, 2025<\/a><\/p><\/blockquote>\n <\/center><\/p>\n Asteroid 2024 YR4 is estimated to have a diameter of around 130 to 300 feet, which is not remotely large enough to be civilization-ending, like the space rock that nearly wiped out the dinosaurs<\/a>. It\u2019s more comparable to the 1908 Tunguska impactor<\/a>, which flattened an 830-square-mile area of forest<\/a> in Siberia. An asteroid of this size still has the potential to destroy a major city or cause a massive tsunami, but in the unlikely case of a predicted collision, authorities would have time to plan necessary evacuations.<\/p>\n However, scientists infer the size of asteroids from the amount of light they reflect, which also depends on their composition. That means astronomers have some inherent uncertainty in their measurement of this asteroid\u2019s diameter.<\/p>\n \u201cIf the asteroid has a darker surface, that number is too small; if it has a more reflective surface, that number is too high,\u201d David Rankin<\/a>, an engineer at the Catalina Sky Survey, tells Space.com<\/a><\/em>\u2019s Robert Lea. Scientists will be able to more accurately study all aspects of the asteroid, and thus refine their predictions, during its next flyby in 2028.<\/p>\n \u201cThe first step in the planetary defense response is to trigger further observations,\u201d explains Snodgrass to the Guardian<\/em>. \u201cIf these observations don\u2019t rule out an impact, the next steps will be more detailed characterization measurements using telescopes and discussion of what space agencies could do in terms of more detailed reconnaissance and eventually mitigation missions. This asteroid is of the scale that a mission like DART could be effective, if required, so we have the technology, and it has been tested.\u201d<\/p>\n NASA\u2019s Double Asteroid Redirection Test, or DART, successfully changed the course of an asteroid<\/a> by slamming a spacecraft into it in 2022, demonstrating the methodology\u2019s potential to redirect future Earth-threatening objects.<\/p>\n \u201cThe international systems we\u2019re putting in place to find, track and characterize\u2014and, if it comes to it, mitigate the impacts of\u2014hazardous asteroids and comets are working as intended,\u201d Andy Rivkin<\/a>, an astronomer and planetary defense researcher at the Johns Hopkins Applied Physics Laboratory, tells the New York Tim<\/em>es<\/em><\/a>\u2019 Robin George Andrews.<\/p>\n Asteroid 2024 YR4 is currently ranked at level three on NASA\u2019s Torino Impact Hazard Scale<\/a>, meaning it merits attention by astronomers. The highest ranking an asteroid has ever reached on the scale is four, briefly achieved by asteroid Apophis<\/a> in 2004 before further observations downgraded it back to zero. It seems likely that this will also happen with asteroid 2024 YR4.<\/p>\n \u201cWe expect the impact probability to go to zero rather than 100 percent,\u201d Rivkin says to the New York T<\/em>imes<\/em>. \u201cBut it may take a few years before we get the data to show that.\u201d<\/p>\n
\n ESA-Science Office, ESA Standard Licence<\/span>
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