{"id":401105,"date":"2025-09-05T22:41:18","date_gmt":"2025-09-05T22:41:18","guid":{"rendered":"https:\/\/www.europesays.com\/uk\/401105\/"},"modified":"2025-09-05T22:41:18","modified_gmt":"2025-09-05T22:41:18","slug":"interstellar-comet-is-about-to-make-extremely-close-passes-of-earth-mars-and-the-sun","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/uk\/401105\/","title":{"rendered":"Interstellar comet is about to make extremely close passes of Earth, Mars and the Sun"},"content":{"rendered":"<p>Comet 3I\/ATLAS will soon disappear behind the Sun, from our perspective on Earth, but before it does so, it will have a close encounter with the planet Mars, then with our own planet.<\/p>\n<p>In fact, the comet will come so close to the Sun, it will actually pass within Mars&#8217;s orbit \u2013 i.e. between Mars and the Sun \u2013 on its journey through our Solar System.<\/p>\n<p>So what are the chances that <a href=\"https:\/\/www.skyatnightmagazine.com\/news\/comet-3i-atlas-c-2025-n1\" target=\"_blank\" rel=\"noopener\">3I\/ATLAS<\/a> might hit Mars? Or we might even ask: will this strange rock from interstellar space hit Earth?<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"827\" height=\"827\" src=\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2025\/09\/comet-3i-atlas.gif\" alt=\"A series of images showing the movement of comet 3I\/ATLAS across the sky. Credit: ATLAS, University of Hawaii, NASA\" class=\"wp-image-175397\"\/>A series of images showing the movement of comet 3I\/ATLAS across the sky. Credit: ATLAS, University of Hawaii, NASA<br \/>\n<strong>The story so far<\/strong><\/p>\n<p>Comet 3I\/ATLAS was discovered on 1 July 2025 by astronomers using the ATLAS\u00a0(Asteroid Terrestrial-impact Last Alert System) survey telescope in Rio Hurtado, Chile.<\/p>\n<p>It&#8217;s an interstellar visitor, which distinguishes it from the vast majority of known <a href=\"https:\/\/www.skyatnightmagazine.com\/space-science\/a-guide-to-comets\" target=\"_blank\" rel=\"noopener\">comets<\/a> that originate from within our Solar System and orbit the Sun.<\/p>\n<p>3I\/ATLAS originated from deep space, around a distant star, and is simply passing through our Solar System.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"800\" src=\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2025\/09\/3i-atlas-vlt.jpg\" alt=\"Composite showing comet 3I\/ATLAS's movement across the sky, captured by ESO\u2019s Very Large Telescope. Images were captured over the course of 13 minutes on the night of 3 July 2025. Credit: ESO\/O. Hainaut\" class=\"wp-image-175098\"\/>Composite showing comet 3I\/ATLAS&#8217;s movement across the sky, captured by ESO\u2019s Very Large Telescope. Images were captured over the course of 13 minutes on the night of 3 July 2025. Credit: ESO\/O. Hainaut<\/p>\n<p>It won&#8217;t go into orbit around our Sun; it has entered our Solar System and will eventually leave.<\/p>\n<p>Since its discovery, some of the most powerful telescopes on Earth \u2013 and in space \u2013 have captured images of 3I\/ATLAS, including the <a href=\"https:\/\/www.skyatnightmagazine.com\/news\/comet-3i-atlas-very-large-telescope\" target=\"_blank\" rel=\"noopener\">Very Large Telescope<\/a>, the <a href=\"https:\/\/www.skyatnightmagazine.com\/news\/comet-3i-atlas-gemini-north\" target=\"_blank\" rel=\"noopener\">Gemini North telescope<\/a>, <a href=\"https:\/\/www.skyatnightmagazine.com\/news\/3i-atlas-spherex-webb\" target=\"_blank\" rel=\"noopener\">SPHEREx and Webb<\/a>, and the <a href=\"https:\/\/www.skyatnightmagazine.com\/news\/hubble-3i-atlas-july-2025\" target=\"_blank\" rel=\"noopener\">Hubble Space Telescope<\/a>.<\/p>\n<p>These observations have enabled scientists to pin down more detail about its size, its shape and what it&#8217;s made of.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"885\" src=\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2025\/09\/3i-atlas-hubble.jpg\" alt=\"Image of interstellar comet 3I\/ATLAS captured by the Hubble Space Telescope\u2019s Wide Field Camera on 21 July 2025. Credit: NASA, ESA, D. Jewitt (UCLA); Image Processing: J. DePasquale (STScI)\" class=\"wp-image-174229\"\/>Image of interstellar comet 3I\/ATLAS captured by the Hubble Space Telescope\u2019s Wide Field Camera on 21 July 2025. Credit: NASA, ESA, D. Jewitt (UCLA); Image Processing: J. DePasquale (STScI)<\/p>\n<p>They&#8217;ve even been able to detect CO2 and water ice at the comet.<\/p>\n<p>There&#8217;s also evidence that it might be the <a href=\"https:\/\/www.skyatnightmagazine.com\/news\/interstellar-visitor-3i-atlas-oldest-comet-ever-seen\" target=\"_blank\" rel=\"noopener\">oldest comet we&#8217;ve ever seen<\/a>.<\/p>\n<p>And astronomers have been able to calculate 3I\/ATLAS&#8217;s orbit, indicating its predicted path through our Solar System with remarkable accuracy.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"886\" src=\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2025\/09\/comet-3i-atlas-orbit.jpg\" alt=\"Diagram showing the orbit of comet 3I\/ATLAS. Credit: NASA\/JPL-Caltech\" class=\"wp-image-175399\"\/>Diagram showing the orbit of comet 3I\/ATLAS. Credit: NASA\/JPL-Caltech<br \/>\n<strong>3I\/ATLAS and its close encounter with the planets<\/strong><\/p>\n<p>As you can see from the NASA diagram above, 3I\/ATLAS will pass pretty close to the Sun, Earth, Mars and Jupiter on its way across our Solar System.<\/p>\n<p>It will get pass by close to Earth, at least on a cosmic scale. Scientists estimate the closest it will get to our planet is about \u00a0270 million km (170 million miles).<\/p>\n<p>That&#8217;s about 1.8 <a href=\"https:\/\/www.skyatnightmagazine.com\/space-science\/astronomical-unit\" target=\"_blank\" rel=\"noopener\">astronomical units<\/a> (AU), where 1 AU is the average distance between Earth and the Sun.<\/p>\n<p>Considering the comet originated in deep space and could have been flung in any direction across the Universe, that&#8217;s pretty close.<\/p>\n<p>According to NOIRLab, operated by the U.S. National Science Foundation, 3I\/ATLAS&#8217;s close approach to Earth is due on 19 December 2025.<\/p>\n<p>But before that, it will make its closest approach to the Sun around 30 October 2025, getting as close as 210 million km (130 million miles).<\/p>\n<p>Again, given the vastness of the Universe, that&#8217;s very close indeed.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"800\" src=\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2025\/09\/comet-3i-atlas-gemini-north-closeup.jpg\" alt=\"Interstellar comet 3I\/ATLAS as seen by the Gemini North Telescope. Credit: International Gemini Observatory\/NOIRLab\/NSF\/AURA\/K. Meech (IfA\/U. Hawaii). Image Processing: Jen Miller &amp; Mahdi Zamani (NSF NOIRLab)\" class=\"wp-image-173402\"\/>Interstellar comet 3I\/ATLAS as seen by the Gemini North Telescope. Credit: International Gemini Observatory\/NOIRLab\/NSF\/AURA\/K. Meech (IfA\/U. Hawaii). Image Processing: Jen Miller &amp; Mahdi Zamani (NSF NOIRLab)<\/p>\n<p>At this point, it will be located between Mars&#8217;s orbit and the Sun and travelling at 25,000 km (15,500 miles) per hour.<\/p>\n<p>But even before that happens, 3I\/ATLAS will make its closest approach to Mars on 3 October 2025, reaching a distance of just 28 million km (18 million miles) from the Red Planet.<\/p>\n<p>That&#8217;s about 0.19 AU, just a fifth of the distance between Earth and the Sun.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"1200\" src=\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2025\/09\/comet-3i-atlas-gemini-north.jpg\" alt=\"Interstellar comet 3I\/ATLAS as seen by the Gemini North Telescope. Credit: International Gemini Observatory\/NOIRLab\/NSF\/AURA\/K. Meech (IfA\/U. Hawaii). Image Processing: Jen Miller &amp; Mahdi Zamani (NSF NOIRLab)\" class=\"wp-image-173405\"\/>Interstellar comet 3I\/ATLAS as seen by the Gemini North Telescope. Credit: International Gemini Observatory\/NOIRLab\/NSF\/AURA\/K. Meech (IfA\/U. Hawaii). Image Processing: Jen Miller &amp; Mahdi Zamani (NSF NOIRLab)<br \/>\n<strong>Will the comet hit Earth, Mars or Jupiter?<\/strong><\/p>\n<p>The short answer as to whether 3I\/ATLAS will hit Earth, Mars or Jupiter is &#8216;no&#8217;.<\/p>\n<p>Scientists are able to pinpoint the orbits of celestial objects with remarkable accuracy by observing how these objects move through space.<\/p>\n<p>Remember <a href=\"https:\/\/www.skyatnightmagazine.com\/space-science\/asteroid-2024-yr4\" target=\"_blank\" rel=\"noopener\">asteroid 2024 YR4<\/a>, which was discovered in December 2024, and which made headlines because of the minuscule chance it might hit Earth or our Moon?<\/p>\n<p>Astronomers were able to refine that object&#8217;s orbit with each passing day, the small chance of it hitting our planet diminishing even further by the time it reached a distance where it could no longer be observed.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"783\" src=\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2025\/09\/asteroid-2024-YR4-orbit.jpg\" alt=\"Predicted orbit of asteroid 2024 YR4, which could have a near miss with Earth in 2032. Credit: NASA\/JPL\" class=\"wp-image-166831\"\/>Predicted orbit of asteroid 2024 YR4. Credit: NASA\/JPL<\/p>\n<p>All evidence points to comet 3I\/ATLAS passing through our Solar System without hitting any of the planets, including our own.<\/p>\n<p>What&#8217;s really interesting, however, is the prospect of some of the many robotic rovers and other spacecraft currently in our Solar System capturing a glimpse of 3I\/ATLAS.<\/p>\n<p>That would mean image showing the oldest comet we know of, which originated around a distant star, as seen from the perspective of another planet.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1600\" height=\"1200\" src=\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2025\/09\/Feb2014_1600x1200.jpg\" alt=\"A view of Earth from Mars, appearing like the brightest star in the Martian sky. This image was captured by NASA's Curiosity rover on 31 January 2024. Credit: NASA Jet Propulsion Laboratory-Caltech\/Malin Space Science Systems\/Texas A&amp;M University. Source: NASA Jet Propulsion Laboratory.\" class=\"wp-image-147660\"\/>Mars rovers have seen Earth from Mars. Imagine a Mars orbiter seeing comet 3I\/ATLAS from Mars. Credit: NASA Jet Propulsion Laboratory-Caltech\/Malin Space Science Systems\/Texas A&amp;M University. Source: NASA Jet Propulsion Laboratory.<\/p>\n<p>There&#8217;s already talk of Mars missions like the European Space Agency&#8217;s Mars Express and ExoMars Trace Gas Orbiter spacecraft carrying out observations of the comet, as reported by <a href=\"https:\/\/www.space.com\/astronomy\/comets\/interstellar-comet-3i-atlas-will-fly-by-mars-1-month-from-now-and-europes-red-planet-orbiters-will-be-ready\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Space.com<\/a>.<\/p>\n<p>Or the HiRISE camera on NASA&#8217;s Mars Reconnaissance Orbiter could be used to spy the comet, too.<\/p>\n<p>And a <a href=\"https:\/\/arxiv.org\/abs\/2508.15768\" target=\"_blank\" rel=\"noreferrer noopener\">paper submitted to Cornell University<\/a> suggests that other spacecraft like &#8220;the <a href=\"https:\/\/www.skyatnightmagazine.com\/news\/nasa-europa-clipper-search-life-at-jupiter-icy-moon\" target=\"_blank\" rel=\"noopener\">Europa Clipper<\/a>, <a href=\"https:\/\/www.skyatnightmagazine.com\/space-missions\/hera-europes-asteroid-mission-to-defend-earth\" target=\"_blank\" rel=\"noopener\">Hera<\/a> and even the more distant <a href=\"https:\/\/www.skyatnightmagazine.com\/space-missions\/lucy-mission-trojan-asteroids\" target=\"_blank\" rel=\"noopener\">Lucy spacecraft<\/a> may pass through 3I&#8217;s cometary tail in the period after its perihelion passage, potentially directly observing the conditions and composition there.&#8221;<\/p>\n<p>It seems, then, that our best views of 3I\/ATLAS, our best chances of gathering data on this interstellar visitor, may come not from telescopes on Earth or even in Earth orbit, but instead from telescopes and spacecraft we&#8217;ve put on other planets.<\/p>\n","protected":false},"excerpt":{"rendered":"Comet 3I\/ATLAS will soon disappear behind the Sun, from our perspective on Earth, but before it does so,&hellip;\n","protected":false},"author":2,"featured_media":401106,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[70,16,15],"class_list":{"0":"post-401105","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-science","9":"tag-uk","10":"tag-united-kingdom"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/115154104497564236","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/401105","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=401105"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/401105\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/401106"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=401105"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=401105"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=401105"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}