WASHINGTON, May 8 \u2014 Astronomers have gotten their clearest look yet at the surface of an exoplanet \u2014 a planet beyond our solar system \u2014 thanks to Nasa\u2019s James Webb Space Telescope.<\/p>\n
Webb gathered data on a rocky exoplanet with a diameter about 30 per cent larger than Earth that indicates it is a desolate and airless world whose surface may resemble that of Mercury, our solar system\u2019s innermost planet. Its lack of a discernible atmosphere and its extreme temperatures \u2014 fiercely hot on one side and frigid on the other \u2014 seem to render it uninhabitable.<\/p>\n
The planet is called LHS 3844 b, or Kua\u2019kua, the word for butterfly in an indigenous language spoken in Costa Rica. It orbits a star smaller and less luminous than the sun, located about 49 light-years from Earth. A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km).<\/p>\n
\u201cThis planet is not a nice place,\u201d said astronomer Laura Kreidberg, managing director of the Max Planck Institute for Astronomy in Germany and senior author of the study published this week in the journal Nature Astronomy.<\/p>\n
\u201cIt\u2019s a hellish, barren rock \u2014 much more similar to Mercury than it is to the Earth. There is no trace of an atmosphere. Instead we\u2019re seeing a dark surface, likely old. Picture a bare rock hurtling through space for billions of years. You wouldn\u2019t want to go there,\u201d Kreidberg said.<\/p>\n
The observations suggest an ancient planetary surface covered by darkened regolith \u2014 loose, fragmented rocky material that covers solid bedrock, born of eons of continuous bombardment by stellar radiation and micrometeorite impacts.<\/p>\n
Webb, which was launched in 2021 and became operational in 2022, has enabled revolutionary advances in the understanding of exoplanets. Its robust infrared observational capabilities have helped discern the chemical composition and internal dynamics of exoplanet atmospheres, even showing what kind of clouds are present.<\/p>\n
Webb is now letting astronomers directly study the geology and surface composition of exoplanets, said astronomer and study lead author Sebastian Zieba of the Center for Astrophysics, Harvard & Smithsonian in Massachusetts.<\/p>\n
\u201cThat was very challenging before the James Webb Space Telescope. This, therefore, also puts the Earth and the solar system as a whole into greater context, allowing us to check if processes or surface compositions familiar within the solar system are common around other stars, too,\u201d Zieba said.<\/p>\n
\u201cIt\u2019s like we suddenly cleaned our glasses and can see the planets clearly for the first time,\u201d Kreidberg added.<\/p>\n
The star that Kua\u2019kua orbits is a common type called a red dwarf. Its mass is about 15 per cent that of the sun and its luminosity about 0.3 per cent. Kua\u2019kua is located extremely close to the star, orbiting it once every 11 hours. It also is \u201ctidally locked,\u201d meaning one side always faces the star and the other side always faces away, as the moon does with Earth.<\/p>\n
The planet\u2019s \u201cdayside\u201d surface \u2014 perpetually broiled by the star \u2014 is about 1,340\u00b0Fahrenheit (725\u00b0Celsius). There was no detectable heat on the planet\u2019s \u201cnightside.\u201d<\/p>\n
Webb enabled the researchers to detect light \u2014 specifically the infrared region of the electromagnetic spectrum \u2014 coming directly from the planet\u2019s surface.<\/p>\n
\u201cDifferent rocks have different spectral fingerprints, just like atmospheres do. Dark volcanic rocks like basalt matched our observations much better than brighter, silica-rich rocks like granite,\u201d Zieba said.<\/p>\n
The surfaces of Mercury and the moon are basalt-dominated.<\/p>\n
\u201cOn Earth, widespread granite formation is linked to water and plate tectonics,\u201d Zieba said, referring to the geological process on our planet involving the gradual movement of the immense plates that make up Earth\u2019s surface. \u201cSo if you ever robustly identified granite-like surfaces on an exoplanet, that would not (automatically) mean life, but it would suggest a much more Earth-like geological history compared to other surfaces.\u201d<\/p>\n
Another possibility matching the observations was a solid surface of relatively recent volcanic rock, but the researchers searched for volcanism-related gases like sulphur dioxide and found none.<\/p>\n
Without an atmosphere, there is scant protection from stellar radiation or charged particles from the star and no chance for liquid water, considered fundamental for life.<\/p>\n
\u201cSo overall, this is almost certainly not a habitable world,\u201d Zieba said. \u2014 Reuters\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"WASHINGTON, May 8 \u2014 Astronomers have gotten their clearest look yet at the surface of an exoplanet \u2014…\n","protected":false},"author":2,"featured_media":476128,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[270],"tags":[18,19,17,5923,208573,208574,208575,62918,51059,133,451],"class_list":["post-476127","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-eire","tag-ie","tag-ireland","tag-james-webb-space-telescope","tag-lhs-3844-b","tag-max-planck-institute-for-astronomy","tag-mercury-like-surface","tag-nature-astronomy","tag-red-dwarf","tag-science","tag-space"],"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@ie\/116543835757837156","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/476127","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/comments?post=476127"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/476127\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media\/476128"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media?parent=476127"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/categories?post=476127"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/tags?post=476127"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}