﻿ Astronomy Picture of the Day [1]Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2023 September 20 [2]An artist's illustration pictures a cloudy red planet orbiting a distant red star. Near the exoplanet is a moon. Please see the explanation for more detailed information. Methane Discovered on Distant Exoplanet Illustration Credit: [3]Ahmad Jabakenji ([4]ASU Lebanon, [5]North Star Space Art); Data: [6]NASA, [7]ESA, [8]CSA, [9]JWST Explanation: Where else might life exist? One of humanity's [10]great outstanding questions, locating planets where extrasolar life might survive took a step forward in 2019 with the discovery of a significant amount of water vapor in the atmosphere of distant exoplanet [11]K2-18b. The planet and its parent star, [12]K2-18, lie about 124 light years away toward the constellation of the [13]Lion ([14]Leo). The [15]exoplanet is significantly larger and more massive than our Earth, but orbits in the [16]habitable zone of its home star. K2-18, although more red than our Sun, shines in [17]K2-18b's sky with a brightness similar to the [18]Sun in Earth's sky. The 2019 [19]discovery of atmospheric water was made in data from three space telescopes: [20]Hubble, [21]Spitzer, and [22]Kepler, by noting the absorption of water-vapor colors when the [23]planet moved in front of the star. Now in 2023, [24]further observations by the [25]Webb Space Telescope in [26]infrared light have uncovered evidence of other life-indicating molecules -- including [27]methane. The featured illustration imagines exoplanet [28]K2-18b on the far right orbited by a moon (center), which together orbit a [29]red dwarf star depicted on the lower left. Tomorrow's picture: space tag __________________________________________________________________ [30]< | [31]Archive | [32]Submissions | [33]Index | [34]Search | [35]Calendar | [36]RSS | [37]Education | [38]About APOD | [39]Discuss | [40]> __________________________________________________________________ Authors & editors: [41]Robert Nemiroff ([42]MTU) & [43]Jerry Bonnell ([44]UMCP) NASA Official: Phillip Newman [45]Specific rights apply. [46]NASA Web Privacy Policy and Important Notices A service of: [47]ASD at [48]NASA / [49]GSFC, [50]NASA Science Activation & [51]Michigan Tech. U. 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