{"id":17796,"date":"2020-02-13T19:07:48","date_gmt":"2020-02-13T11:07:48","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/how-a-space-snowman-called-arrokoth-is-shedding-new-light-on-planetary-origins\/"},"modified":"2020-02-13T19:07:48","modified_gmt":"2020-02-13T11:07:48","slug":"how-a-space-snowman-called-arrokoth-is-shedding-new-light-on-planetary-origins","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/how-a-space-snowman-called-arrokoth-is-shedding-new-light-on-planetary-origins\/","title":{"rendered":"How a space snowman called Arrokoth is shedding new light on planetary origins"},"content":{"rendered":"
\"Arrokoth
A computer-generated reconstruction of Arrokoth\u2019s shape makes it look like a squashed snowman, but slightly less squashed than originally thought. (NASA \/ JHUAPL \/ SwRI Image \/ Roman Tkachenko)<\/figcaption><\/figure>\n

The space snowman that was the focus of a close encounter with NASA\u2019s New Horizons probe last year is helping scientists answer a cosmic question: How did the building blocks of the solar system get their start?<\/p>\n

\u201cThis is a game-changer,\u201d said Alan Stern, a planetary scientist at the Southwest Research Institute and principal investigator for the New Horizons mission.<\/p>\n

Stern and other members of the New Horizons science team shared their latest findings about the snowman-shaped object now known as Arrokoth today at the American Association for the Advancement of Science\u2019s annual meeting in Seattle. Those findings are detailed in a trio of studies published by the journal Science.<\/p>\n

The biggest revelation has to do with Arrokoth\u2019s ancient origins.<\/p>\n

A detailed analysis of the object\u2019s double-lobed, snowman-like structure supports the view that Arrokoth came into existence when a localized cloud of primordial material collapsed into two nearby clumps that gently fused together.<\/p>\n

That\u2019s in contrast to an alternate view, known as hierarchical accretion, which proposes that objects from different parts of the early solar system smashed together to form planetesimals like Arrokoth.<\/p>\n

The studies released today follow up on first-look reports that were published in Science last May. The updated view presented by the scientists today is based on an analysis of 10 times as much data as they had available back then.<\/p>\n

\"Arrokoth
This animated view of Arrokoth is based on images that were captured at slightly different viewing angles by NASA\u2019s New Horizons probe as it flew past. The 3-D effect helps scientists get a better sense of the Kuiper Belt object\u2019s shape and structure. (NASA \/ JHUAPL \/ SwRI Image \/ Roman Tkachenko)<\/figcaption><\/figure>\n

New Horizons was launched back in 2006 and got an unprecedented look at Pluto as it flew past in 2015. Arrokoth, which is a billion miles beyond Pluto, was chosen as the piano-sized probe\u2019s next target for observation. It\u2019s thought to be representative of the small mini-planets that took shape during the collapse of the solar nebula, the vast cloud of gas and dust that surrounded our infant sun.<\/p>\n

With New Horizons\u2019 encounter with Arrokoth on New Year\u2019s Day of 2019, the space snowman became the farthest-out celestial object to be observed close up. The science team was wowed by the data that trickled back in the first months after the encounter, but they still had some mysteries to sort out.<\/p>\n

Scientists now say several new clues have led them to the conclusion that Arrokoth\u2019s two constituent pieces formed in the same neighborhood of the primordial solar system and came together gently.<\/p>\n

First of all, the two lobes have closely aligned poles and equators, and there\u2019s no evidence of a high-speed smash-up. \u201cOnly at much lower collision velocities, substantially less than the mutual escape speed, and at an oblique angle, do the outcomes of our simulations begin to resemble Arrokoth,\u201d the New Horizon scientists wrote in one of their research papers.<\/p>\n

The simulations suggest that Arrokoth\u2019s two halves came together at a speed of 7 mph or less. \u201cThey\u2019re just kissing,\u201d William McKinnon, a planetary scientist at Washington University of St. Louis, explained at today\u2019s briefing. \u201cIf they were spacecraft, they\u2019d be docking.\u201d<\/p>\n

Another clue came from the uniformity of the object\u2019s spectral signature. Both lobes are unusually red in color, and spectral analysis suggests the strong presence of methanol ice. The fact that the two lobes are chemically homogeneous serves as further evidence that they formed in close proximity.<\/p>\n

\u201cIt\u2019s drawing basically from locally sourced materials all at once,\u201d Lowell Observatory\u2019s Will Grundy said.<\/p>\n

McKinnon said the cloud-collapse scenario would explain how the solar system got such a fast start 4.5 billion years ago. \u201cIt jump-starts planet formation,\u201d he said.<\/p>\n

Planetesimals like Arrokoth almost certainly served as the seeds for growing bigger worlds, including terrestrial planets like Earth and gas giants like Jupiter, the scientists said.<\/p>\n

A 3-D reconstruction of Arrokoth\u2019s shape indicates that the larger lobe measures 12.8 by 12.3 wide and 5.8 miles thick, while the smaller lobe is 9.6 by 8.6 miles wide and 6.1 miles thick. Those dimensions make the snowman look more like a squashed bug \u2014 but overall, it\u2019s not as squashed as scientists assumed it was last year. Arrokoth\u2019s volume is now estimated to be 30% larger than previously thought.<\/p>\n

Today New Horizons is more than 315 million miles beyond Arrokoth and zooming outward through the Kuiper Belt, the icy ring of material on the solar system\u2019s edge. It\u2019s expected to keep sending back scientific data about Arrokoth for another year.<\/p>\n

In the meantime, New Horizons\u2019 scientists will be using time on ground-based telescopes to search for more distant Kuiper Belt objects that could be candidates for a future flyby. Within the next year or two, they hope to identify a third way-out world that\u2019s ready for its close-up.<\/p>\n

The three Science studies are \u201cThe Geology and Geophysics of Kuiper Belt Object (486958) Arrokoth,\u201d with John Spencer of the Southwest Research Institute as first author; \u201cThe Solar Nebula Origin of (486958) Arrokoth, a Primordial Contact Binary in the Kuiper Belt,\u201d with William McKinnon of Washington University in St. Louis as first author; and \u201cColor, Composition and Thermal Environment of Kuiper Belt Object (486958) Arrokoth,\u201d with Will Grundy of the Lowell Observatory as first author.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

A computer-generated reconstruction of Arrokoth\u2019s shape makes it look like a squashed snowman, but slightly less squashed than originally thought. (NASA \/ JHUAPL \/ SwRI Image \/ Roman Tkachenko) The space snowman that was the focus of a close encounter with NASA\u2019s New Horizons probe last year is helping scientists answer a cosmic question: How […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[2337,2338,2173,4809,2174,4810,2937],"class_list":["post-17796","post","type-post","status-publish","format-standard","hentry","category-news","tag-2014-mu69","tag-arrokoth","tag-kuiper-belt","tag-nasa-new-horizons","tag-new-horizons","tag-new-horizons-probe","tag-ultima-thule"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/17796"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=17796"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/17796\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=17796"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=17796"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=17796"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}