{"id":241117,"date":"2016-05-20T04:00:00","date_gmt":"2016-05-20T08:00:00","guid":{"rendered":"http:\/\/spaceweekly.com\/?guid=1112141de30f7773092abac585bde80e"},"modified":"2016-05-20T04:00:00","modified_gmt":"2016-05-20T08:00:00","slug":"rub-al-khali","status":"publish","type":"post","link":"https:\/\/spaceweekly.com\/?p=241117","title":{"rendered":"Rub al Khali"},"content":{"rendered":"<p>\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/www.esa.int\/var\/esa\/storage\/images\/esa_multimedia\/images\/2016\/05\/rub_al_khali\/15992289-1-eng-GB\/Rub_al_Khali_small.jpg\" width=\"170\" height=\"96\" align=\"left\" hspace=\"8\" \/><\/p>\n<p>\nRolling sand dunes in the expansive Rub\u2019 al Khali desert on the southern Arabian Peninsula are pictured in this image from the Sentinel-2A satellite.\n<\/p>\n<p>\nAlso known at the \u2018Empty Quarter\u2019, the Rub\u2019 al Khali is the largest <i>contiguous sand desert<\/i> in the world. Precipitation rarely exceeds 35 mm a year and regular high temperatures are around 50\u00b0C.\n<\/p>\n<p>\nThe yellow lines and dots in this false-colour image are sand dunes. Looking closer at the dunes in the lower right, many have three or more \u2018arms\u2019 shaped by changing wind directions and are known as \u2018star dunes\u2019. They tend to \u2018grow\u2019 upwards rather than laterally, and reach up to 250 m in height in some parts of the &nbsp;Rub\u2019 al Khali.\n<\/p>\n<p>\nThe dunes are interspersed with hardened flat plains \u2013 remnants of shallow lakes that existed thousands of years ago, formed by monsoon-like rains and runoff. The multispectral instrument on Sentinel-2 uses parts of the infrared spectrum to detect subtle changes in vegetation cover, but can also see changes in mineral composition where vegetation is sparse. In this image, shades of brown to bright purple show the mineral composition, possibly including salt or gypsum.\n<\/p>\n<p>\nThis image \u2013 also featured on the <a href=\"http:\/\/www.esa.int\/ESA_Multimedia\/Videos\/2016\/05\/Earth_from_Space_Rub_al_Khali_Desert\">Earth from Space video programme<\/a> \u2013 was captured by Sentinel-2A on 22 December 2015. The satellite is the first in the two-satellite Sentinel-2 mission for Europe\u2019s Copernicus programme, and carries a wide-swath high-resolution multispectral imager with 13 spectral bands for a new perspective of our land and vegetation.<\/p>\n","protected":false},"excerpt":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/www.esa.int\/var\/esa\/storage\/images\/esa_multimedia\/images\/2016\/05\/rub_al_khali\/15992289-1-eng-GB\/Rub_al_Khali_small.jpg\" width=\"170\" height=\"96\" align=\"left\" hspace=\"8\"><\/p>\n<p>\nRolling sand dunes in the expansive Rub&rsquo; al Khali desert on the southern Arabian Peninsula are pictured in this image from the Sentinel-2A satellite.\n<\/p>\n<p>\nAlso known at the &lsquo;Empty Quarter&rsquo;, the Rub&rsquo; al Khali is the largest <i>contiguous sand desert<\/i> in the world. Precipitation rarely exceeds 35 mm a year and regular high temperatures are around 50&deg;C.\n<\/p>\n<p>\nThe yellow lines and dots in this false-colour image are sand dunes. Looking closer at the dunes in the lower right, many have three or more &lsquo;arms&rsquo; shaped by changing wind directions and are known as &lsquo;star dunes&rsquo;. They tend to &lsquo;grow&rsquo; upwards rather than laterally, and reach up to 250 m in height in some parts of the &nbsp;Rub&rsquo; al Khali.\n<\/p>\n<p>\nThe dunes are interspersed with hardened flat plains &ndash; remnants of shallow lakes that existed thousands of years ago, formed by monsoon-like rains and runoff. The multispectral instrument on Sentinel-2 uses parts of the infrared spectrum to detect subtle changes in vegetation cover, but can also see changes in mineral composition where vegetation is sparse. In this image, shades of brown to bright purple show the mineral composition, possibly including salt or gypsum.\n<\/p>\n<p>\nThis image &ndash; also featured on the <a href=\"http:\/\/www.esa.int\/ESA_Multimedia\/Videos\/2016\/05\/Earth_from_Space_Rub_al_Khali_Desert\">Earth from Space video programme<\/a> &ndash; was captured by Sentinel-2A on 22 December 2015. The satellite is the first in the two-satellite Sentinel-2 mission for Europe&rsquo;s Copernicus programme, and carries a wide-swath high-resolution multispectral imager with 13 spectral bands for a new perspective of our land and vegetation.<\/p>\n","protected":false},"author":5,"featured_media":615444,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[27],"tags":[],"class_list":["post-241117","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-multimedia"],"_links":{"self":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts\/241117","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=241117"}],"version-history":[{"count":1,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts\/241117\/revisions"}],"predecessor-version":[{"id":241118,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts\/241117\/revisions\/241118"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/media\/615444"}],"wp:attachment":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=241117"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=241117"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=241117"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}