\n
![\"EarthSnap\"\/](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2025\/09\/earthsnap-banner-news.webp.webp\")
\n<\/a><\/p>\n
What makes 3I\/ATLAS especially intriguing is that the comet might be three billion years older than our entire Solar System.<\/p>\n
Caught on camera from Mars<\/p>\n
When 3I\/ATLAS passed about 18.6 million miles from Mars on October 3, two orbiting spacecraft were ready. <\/p>\n
ESA\u2019s ExoMars Trace Gas Orbiter (TGO) and Mars Express<\/a> pointed their cameras at the comet, hoping to get a rare view. It was the closest look any ESA spacecraft could get.<\/p>\n The challenge? These cameras were made for imaging Mars: bright, nearby, and relatively easy to photograph. <\/p>\n 3I\/ATLAS, by contrast, was much dimmer. It was somewhere between 10,000 and 100,000 times fainter than Mars, according to the team operating the CaSSIS camera on TGO<\/a> (Trace Gas Orbiter).<\/p>\n \u201cThis was a very challenging observation for the instrument,\u201d said Nick Thomas, principal investigator of the CaSSIS camera.<\/p>\n Capturing the interstellar visitor<\/p>\n Despite the challenge, the TGO managed to capture a sequence of images showing a faint, blurry white speck moving across the sky. <\/p>\n The tiny dot marked the comet\u2019s center \u2013 its rocky, icy core known as the nucleus \u2013 surrounded by a glowing halo of gas and dust called the coma.<\/p>\n The camera couldn\u2019t distinguish the small nucleus itself. That would\u2019ve been like trying to spot a cellphone sitting on the Moon from Earth.<\/p>\n The coma was a different story. It\u2019s a cloud of gas and dust released by the comet as it gets heated by the Sun. It can stretch thousands of miles wide. But even that glow faded quickly with distance, so the full size wasn\u2019t clear in the pictures.<\/p>\n Comets typically develop a tail as they approach the Sun. The tail may reach millions of miles in length through space, blown back by solar wind. In the case of 3I\/ATLAS, the tail was still too faint to be detected by CaSSIS.<\/p>\n The Mars Express orbiter also attempted to capture the comet. With only half a second of exposure time per image, however, its shots did not reveal anything apparent yet. <\/p>\n The team used instruments on both spacecraft<\/a> to study the light from the comet. By breaking down that light into its spectrum, scientists might be able to figure out what the comet is made of. But there\u2019s no guarantee the coma or tail were bright enough to give clear results.<\/p>\n \u201cThough our Mars orbiters continue to make impressive contributions to Mars science, it\u2019s always extra exciting to see them responding to unexpected situations like this one. I look forward to seeing what the data reveals following further analysis,\u201d said Colin Wilson, Mars Express and ExoMars project scientist at ESA<\/a>.<\/p>\n Where did 3I\/ATLAS come from?<\/p>\n The million-dollar question is, where did 3I\/ATLAS come from? The comet didn\u2019t form anywhere near the planets we know. It came from another star system entirely. Hence, its name starts with \u201c3I,\u201d the third known interstellar object.<\/p>\n The comet was first spotted on July 1, 2025, by the ATLAS telescope in R\u00edo Hurtado, Chile. Since then, scientists have tracked it using telescopes on Earth and in space.<\/p>\n Everything in our Solar System<\/a> was born from the same swirling cloud of gas and dust. This includes planets, moons, comets, and even humans. But interstellar comets like 3I\/ATLAS didn\u2019t come from that cloud.<\/p>\n These deep space comets hold clues about alien solar systems \u2013 the kind we\u2019ve only seen as tiny dots of light around distant stars.<\/p>\n Soon, another ESA spacecraft will have a closer look. The Jupiter Icy Moons Explorer<\/a>, or Juice, will observe the comet from farther away. That will happen shortly after the comet reaches its closest point to the Sun.<\/p>\n At that stage, it should be more active, meaning more gas and dust, and hopefully, a bigger tail. However, the data from Juice won\u2019t arrive until February 2026.<\/p>\n ESA is also working on a mission called Comet Interceptor, scheduled to launch in 2029. The goal of the mission is to wait in space for a fresh comet from the outer edges of the Solar System, or maybe even another interstellar object.<\/p>\n \u201cWhen Comet Interceptor was selected in 2019, we only knew of one interstellar object \u2013 1I\/\u02bbOumuamua, discovered in 2017,\u201d said Michael Kueppers, Comet Interceptor project scientist. <\/p>\n \u201cSince then, two more such objects have been discovered, showing large diversity in their appearance. Visiting one could provide a breakthrough in understanding their nature.\u201d<\/p>\n Unfortunately, 3I\/ATLAS will not be here for long. It\u2019s currently passing the Sun<\/a> and will leave our Solar System for good. But with every passing visitor, we learn just a little more about what\u2019s out there.<\/p>\n \u2014\u2013<\/p>\n Like what you read? Subscribe to our newsletter<\/a> for engaging articles, exclusive content, and the latest updates.\u00a0<\/p>\n Check us out on EarthSnap<\/a>, a free app brought to you by Eric Ralls<\/a> and Earth.com.<\/p>\n \u2014\u2013<\/p>\n","protected":false},"excerpt":{"rendered":"In early October, astronomers spotted something ancient and mysterious gliding past Mars. It was not a spacecraft or…\n","protected":false},"author":2,"featured_media":211191,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[64,63,128,285],"class_list":{"0":"post-211190","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-space","8":"tag-au","9":"tag-australia","10":"tag-science","11":"tag-space"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/211190","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=211190"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/211190\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/211191"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=211190"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=211190"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=211190"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"On](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2025\/10\/comet_3I_ATLAS_ExoMars_Trace_Gas_Orbiter_observes_1s.webp.webp\")
<\/a>On October 3, 2025, ESA\u2019s ExoMars Trace Gas Orbiter (TGO) turned its eyes towards interstellar comet 3I\/ATLAS as it passed close to Mars. Together with Mars Express, ExoMars TGO had the closest view of the comet of all ESA spacecraft. Click image to enlarge. Credit: ESALooking deeper with Mars orbiters<\/p>\n![\"ESA\u2019s](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2025\/10\/comet_3I-ATLAS_ESA-missions_1s.webp.webp\")
<\/a>ESA\u2019s Mars and Jupiter missions observe comet 3I\/ATLAS. Earth has been moving away from 3I\/ATLAS as it approaches the Sun. The comet is now on the other side of the Sun, making it impossible to observe from Earth. Click image to enlarge. Credit: ESAGetting closer to Comet 3I\/ATLAS<\/p>\n