{"id":191,"date":"2020-09-13T12:49:13","date_gmt":"2020-09-13T12:49:13","guid":{"rendered":"https:\/\/blogs.ua.es\/cienciasplanetariasua\/?page_id=191"},"modified":"2024-11-13T15:11:30","modified_gmt":"2024-11-13T15:11:30","slug":"neas-forecast","status":"publish","type":"page","link":"https:\/\/blogs.ua.es\/cienciasplanetariasua\/neas-forecast\/","title":{"rendered":"NEAs forecast"},"content":{"rendered":"<p><strong>Asteroids Near Earth: Should We Be Alarmed?<\/strong><\/p>\n<p>News about objects passing near Earth frequently makes headlines. However, this should not generally cause alarm. The increasing sensitivity of NEA (Near-Earth Asteroid) surveys inevitably leads to the discovery of more and more objects of various sizes.<\/p>\n<h3>Understanding NEA Approaches<\/h3>\n<p>Take this example:<\/p>\n<ul>\n<li><strong>Future Approaches:<\/strong> Between March 20, 2021, and the same date in 2022, only <strong>2 NEAs larger than 20 meters (magnitude 26)<\/strong> were predicted to pass within 5 Earth-Moon distances (5 D_TL).<\/li>\n<li><strong>Past Approaches:<\/strong> In contrast, <strong>78 NEAs<\/strong> of similar size were observed to have come within this distance in the previous year.<\/li>\n<\/ul>\n<p>This highlights a key point: detecting small objects when they are far from Earth is very difficult. The sunlight reflected from an asteroid just a few tens of meters wide is nearly undetectable from Earth until the object is close enough.<\/p>\n<h3>Small Asteroids and Undetected Approaches<\/h3>\n<p>As a result, it is likely that objects the size of a bus may enter and explode in the upper atmosphere without being detected beforehand.<\/p>\n<p>For larger NEAs, the situation improves:<\/p>\n<ul>\n<li><strong>For NEAs larger than 50 meters (magnitude 24):<\/strong>\n<ul>\n<li>Only <strong>1 approach<\/strong> is predicted in the next year.<\/li>\n<li><strong>6 such objects<\/strong> were observed in the past year.<\/li>\n<\/ul>\n<\/li>\n<li><strong>For NEAs larger than 100 meters:<\/strong>\n<ul>\n<li><strong>193 approaches<\/strong> are expected in the next 140 years.<\/li>\n<li><strong>151 approaches<\/strong> have been observed since the early 20th century.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>Are We Prepared?<\/h3>\n<p>While current searches are effective (though not yet sufficient) for potentially hazardous objects, they remain limited for smaller bodies. These smaller objects pose a lesser\u2014though not negligible\u2014threat. The effects of atmospheric explosions from objects several tens of meters wide could range from the <strong>Chelyabinsk event in 2013<\/strong> to the <strong>Tunguska event in 1908<\/strong>, which destroyed 2,000 km\u00b2 of Siberian forest.<\/p>\n<h3>Upcoming NEA Updates<\/h3>\n<p>We will periodically share a list of NEAs with estimated sizes larger than 40 meters that are predicted to approach within 10 Earth-Moon distances (1 D_TL \u2248 3.85 million km) in the next 365 days, based on data from CNEOS-JPL.<\/p>\n<h3>Current Outlook<\/h3>\n<p>At this time, <strong>no object<\/strong> has a probability of impact greater than the background risk (the probability of a previously undiscovered object suddenly appearing on a collision course with Earth) for the next 140 years.<\/p>\n<p>The closest predicted encounter is <strong>99942 Apophis<\/strong>, which will pass at <strong>0.10 D_TL (38,500 km)<\/strong> on <strong>April 13, 2029<\/strong>.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-281\" src=\"https:\/\/blogs.ua.es\/cienciasplanetariasua\/files\/2021\/02\/Captura-de-pantalla-2021-02-15-a-las-18.32.29.png\" alt=\"\" width=\"2442\" height=\"658\" \/><\/p>\n<p>Source: CNEOS (JPL)<\/p>\n<p>05\/02\/2021<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Asteroids Near Earth: Should We Be Alarmed? News about objects passing near Earth frequently makes headlines. However, this should not generally cause alarm. The increasing sensitivity of NEA (Near-Earth Asteroid) surveys inevitably leads to the discovery of more and more &hellip; <a href=\"https:\/\/blogs.ua.es\/cienciasplanetariasua\/neas-forecast\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":4446,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-191","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/blogs.ua.es\/cienciasplanetariasua\/wp-json\/wp\/v2\/pages\/191","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.ua.es\/cienciasplanetariasua\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/blogs.ua.es\/cienciasplanetariasua\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.ua.es\/cienciasplanetariasua\/wp-json\/wp\/v2\/users\/4446"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.ua.es\/cienciasplanetariasua\/wp-json\/wp\/v2\/comments?post=191"}],"version-history":[{"count":30,"href":"https:\/\/blogs.ua.es\/cienciasplanetariasua\/wp-json\/wp\/v2\/pages\/191\/revisions"}],"predecessor-version":[{"id":495,"href":"https:\/\/blogs.ua.es\/cienciasplanetariasua\/wp-json\/wp\/v2\/pages\/191\/revisions\/495"}],"wp:attachment":[{"href":"https:\/\/blogs.ua.es\/cienciasplanetariasua\/wp-json\/wp\/v2\/media?parent=191"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}