{"id":899889,"date":"2026-10-30T12:30:16","date_gmt":"2026-10-30T12:30:16","guid":{"rendered":"https:\/\/www.newsbeep.com\/us\/899889\/"},"modified":"2026-10-30T12:30:16","modified_gmt":"2026-10-30T12:30:16","slug":"comets-probably-didnt-bring-lifes-building-blocks-to-earth","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us\/899889\/","title":{"rendered":"Comets Probably Didn\u2019t Bring Life\u2019s Building Blocks to Earth"},"content":{"rendered":"

As NASA says, comets are \u201ccosmic snowballs<\/a>\u201d of frozen gases, rock, and dust that include<\/a> a good amount of organic materials. Accordingly, scientists have long suggested<\/a> that a comet brought these molecules to Earth and that they became the building blocks for life here. But a new study explains how that scenario might actually be impossible.<\/p>\n

It\u2019s very likely that comets carrying organic materials have crashed into Earth at some points in our distant past. The issue, however, has to do with whether these fragile molecules survived its vessel\u2019s violent entry\u2014and the odds are very slim, as researchers explained in a study<\/a> published today in Scientific Reports. According to the paper, modeling simulations strongly suggest that comets travel too fast and at too sharp an angle to Earth\u2019s atmosphere for the molecules to escape vaporization.<\/p>\n

\u201cHistorically, scientists thought that comets were important for the origin of life on Earth, because they carried carbon- and nitrogen-bearing molecules,\u201d Richard Anslow, the study\u2019s lead author and an astronomer at Cambridge University in the U.K., said in a statement<\/a>. \u201cSo these giant space snowballs were almost like a \u2018get out of jail free card\u2019 that brought all the molecules a planet would need to seed life. It\u2019s kind of a romantic idea, but our results suggest it\u2019s highly unlikely.\u201d<\/p>\n

A bumpy ride <\/p>\n

In 2023, Anslow and colleagues explored<\/a> an idea that was arguably favorable to this \u201cget out of jail free card,\u201d as he puts it. Specifically, they explored whether comets could deposit similar organic materials on other planets in the galaxy, with the understanding that such systems would be promising candidates in the search for extraterrestrial life.<\/p>\n

One important takeaway from this study, however, was that a comet would have to travel at speeds below roughly 9 miles (15 kilometers) per second. Any faster than that, the precious molecules would break apart from the speed and temperature of impact. Ideally, a comet could travel at the right speed in systems where groups of planets orbit closely together, such that a comet would essentially \u201cbounce<\/a>\u201d between their orbits.<\/p>\n

Wait a second\u2026 <\/p>\n

Then, perhaps naturally, the team shifted its focus back to the solar system. Was it possible that something like that unfolded in our neighborhood? To find out, the team ran simulations of hydrogen cyanide, a compound that\u2019s frequently found on solar system comets. The models incorporated the latest advancements in comet impact simulations, comet-atmosphere interactions, and comet evolution. And the numbers didn\u2019t look too promising.<\/p>\n

\u201cIt would really have to be a one-in-a-million occurrence,\u201d Anslow said. \u201c[N]ot only would you need an impact at just the right speed and just the right angle, you would also need everything to happen after that point, in terms of the concentration and the speed at which the chemical origins of life got going.\u201d<\/p>\n

It would take a miracle <\/p>\n

It\u2019s possible that all these factors miraculously aligned to make it work, but that would \u201cbe a really rare occurrence\u2014at best, a one-off fluke,\u201d Anslow said. And in the larger flow of things, the organic compounds that did survive would only be an \u201cinsignificant source of the concentrated feedstock molecules required for prebiotic chemistry [the synthesis of key molecular building blocks],\u201d according to the paper.<\/p>\n

According to the study, scientists have proposed two main sources for prebiotic chemistry. One, an exogenous (originating outside of Earth) delivery via comets, asteroids, and interplanetary dust particles. Two, endogenous (originating here on Earth) synthesis within the Earth\u2019s own atmosphere. To be clear, as the team explained in the paper, there\u2019s still some conflicting evidence that made scientists hesitant to fully subscribe to the latter view.<\/p>\n

Unfinished business <\/p>\n

But on a global scale, the \u201cintact delivery\u201d of hydrogen cyanide via comets is \u201corders of magnitude\u201d below what the atmosphere can produce, even in the most unfavorable of conditions, the team explained in the paper. That said, the study only (mostly) rules out comets, and the exogenous delivery camp includes asteroids, which slammed into Earth much more often than comets. And for what it\u2019s worth, scientists have used meteorites to follow some promising leads on the solar system\u2019s past<\/a>.<\/p>\n

On another note, Anslow noted in the statement that the cometary delivery scenario for prebiotic chemistry could be more likely on Mars, since it\u2019s smaller and has a much thinner atmosphere than Earth. But that\u2019s just a maybe, he added, the point being that, if something like this truly happened on Earth, it\u2019d be odd if it didn\u2019t happen on Mars.<\/p>\n

\u201cOr the other, perhaps more likely, alternative, is that it didn\u2019t happen on either planet,\u201d he said.<\/p>\n","protected":false},"excerpt":{"rendered":"As NASA says, comets are \u201ccosmic snowballs\u201d of frozen gases, rock, and dust that include a good amount…\n","protected":false},"author":2,"featured_media":899890,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[32],"tags":[32021,16492,79],"class_list":["post-899889","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-comets","tag-planetary-science","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/899889","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=899889"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/899889\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/899890"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=899889"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=899889"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=899889"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}