{"id":25181,"date":"2021-10-21T00:00:00","date_gmt":"2021-10-21T00:00:00","guid":{"rendered":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/?post_type=purple_issue&p=25181"},"modified":"2021-10-21T12:30:17","modified_gmt":"2021-10-21T12:30:17","slug":"unveiling-venus","status":"publish","type":"post","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/2021\/10\/21\/unveiling-venus\/","title":{"rendered":"Unveiling Venus"},"content":{"rendered":"\n

With new scientific discoveries, recent flybys and future missions planned, are we about to finally unlock the secrets of the hellish planet? Planetary scientist Emily Lakdawalla investigates<\/p>\n\n

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A synthesised false colour image of Venus captured by Akatsuki. Blue and green show ultraviolet light, while red shows infrared<\/figcaption><\/figure><\/div>\n\n

Venus is in the hot seat this year: NASA and ESA recently announced three new missions to our nearest planetary neighbour, and another two have just flown past on their way to different destinations. Back in August, ESA\u2019s Solar Orbiter and the ESA-JAXA collaboration, BepiColombo, performed gravity-assist flybys, marking the first time since 1985 that three spacecraft have made in-situ scientific observations at Venus at the same time. (The third JAXA\u2019s Akatsuki, has been in orbit since December 2015.) <\/span><\/p>\n\n

Solar Orbiter is, obviously, a mission to study the Sun, not planets, so most of its cameras are useless at Venus. Most of BepiColombo\u2019s sensitive cameras can\u2019t see space during its long cruise to Mercury. But both spacecraft carry large suites of instruments designed to measure the intensity and direction of magnetic fields and other instruments that count the number and energy of charged particles (electrons, ions and larger particles). BepiColombo also carries an accelerometer that measures variations in the force of gravity as the spacecraft flies across a planet, giving clues to the composition of its mysterious interior.<\/span><\/p>\n\n

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BepiColombo snapped this image as it hurtled past Venus on its way to Mercury<\/figcaption><\/figure><\/div>\n\n
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Solar Orbiter captured a gleaming view of Venus during its flyby in August 2021<\/figcaption><\/figure><\/div>\n\n
Across the bow<\/strong><\/h5>\n\n

Venus doesn\u2019t have its own magnetic field, but the Sun induces one. As the solar wind streams outwards Venus\u2019s field cuts a bow shock into it, similar to the wake from a speedboat. Both BepiColombo and Solar Orbiter approached Venus from within Venus\u2019s \u2018wake\u2019, crossing over the bow shock near the time of closest<\/p>\n\n

approach. Solar Orbiter travelled the path 33 hours before BepiColombo. Having three different spacecraft travelling across large swaths of the magnetic field at the same time in different positions will have produced a rich set of science data and will help ESA plan its future EnVision mission to the planet (due to launch in the 2030s).<\/p>\n\n

The two spacecraft passed by Venus on different sides. The result was an acceleration of Solar Orbiter, speeding it on towards a November flyby of Earth and the beginning of its science mission. BepiColombo lost speed, dropping it closer to the Sun. It was due to meet Mercury in October this year, the first of six flybys before it gets captured on the seventh meeting in December 2025.<\/span><\/p>\n\n

Back on Earth, scientists are still publishing new results from ESA\u2019s Venus Express mission, which ended in January 2015, and are studying our neighbour with ground telescopes. In 2020, astronomers announced they\u2019d detected phosphine in Venus\u2019s atmosphere using the ALMA observatory. This could be a sign of life in the clouds, or could have spewed from volcanoes. Researchers at Portugal\u2019s Instituto de Astrof\u00edsica e Ci\u00eancias do Espa\u00e7o (IA) recently published a new General Circulation Model for Venus, a computer model of the atmosphere that\u2019s the necessary foundation for all predictions of weather and climate. The work focuses on a largely unexplored region of the atmosphere: a layer between the cloudy troposphere and the Sun-heated thermosphere. It explains some previously mysterious data from Venus Express, but more importantly, it generates new, detailed predictions for EnVision to test with observations.<\/span><\/p>\n\n

We\u2019re getting better at predicting the motions of Venus\u2019s winds and clouds, but there\u2019s a lot we don\u2019t understand. What drives its winds? What\u2019s happening below the clouds? Are there active volcanoes today? Why is its atmosphere so thick and choked with carbon dioxide? Did Venus once have liquid water and temperate surface conditions? And what can Venus\u2019s conditions today tell us about the future for Earth?<\/span><\/p>\n\n

<\/div>
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Action, Akatsuki!<\/h4>\n\n\n\n

Japan\u2019s probe is exploring Venus\u2019s atmosphere and producing valuable images along the way<\/strong><\/p>\n\n\n\n

\"\"<\/figure><\/div>\n\n\n\n

Akatsuki\u2019s (see inset) infrared camera IR2 could see the warmth emanating from the clear air under Venus\u2019s clouds at night. In this image, Venus\u2019s nightside is at left (the dayside was too bright and has been masked). Brighter areas show where the lowest cloud decks are thick; in darker regions, the camera can \u2018see\u2019 more clear air, but not all the way to the surface.<\/p>\n\n\n\n

Akatsuki\u2019s Ultraviolet Imager (UVI) sees Venus\u2019s uppermost clouds, made of drops of sulphuric acid. The dark streaks betray the presence of an unknown chemical that scientists call an \u2018ultraviolet absorber\u2019.<\/p>\n\n\n\n

Perhaps EnVision will identify it. At the altitude of the clouds seen here, Venus\u2019s atmosphere rotates around the planet once every four days.<\/p>\n<\/div><\/section>\n\n

Peering beneath the clouds<\/h4>\n\n

How Venus\u2019s atmosphere compares to Earth\u2019s<\/strong><\/p>\n\n

\"\"<\/figure><\/div>\n\n

Venus\u2019s atmosphere is much taller than Earth\u2019s, and various exploratory spacecraft that have visited the planet have used scientific instruments to peer through the atmosphere to different depths, giving us detailed information about Venus\u2019s sky and thick cloud decks. However, we have much yet to learn. What might future missions reveal about the ground underneath?<\/p>\n\n

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<\/p>\n\n\n\n

Emily Lakdawalla is a planetary scientist, writer and science communicator<\/p>\n<\/div>\n<\/div>\n\n

<\/p>\n\n

Photos: JAXA, ESA\/NASA\/NRL\/SOLOHI\/PHILLIP HESS, ATMOSPHERES ILLUSTRATION BY PAUL WOOTTON<\/p>\n","protected":false},"excerpt":{"rendered":"

With a host of missions planned, are we any closer to unlocking the secrets of the hellish planet?<\/p>\n","protected":false},"author":24,"featured_media":25174,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ub_ctt_via":"","purple_page_number":"34","purple_custom_meta_purple_page_number":"34","purple_seq_number":"1","purple_custom_meta_purple_seq_number":"1","purple_source_article":"article_34-1.xml","purple_custom_meta_purple_source_article":"article_34-1.xml","purple_source_issue":"November-2021","purple_custom_meta_purple_source_issue":"November-2021","purple_external_id":"November-2021-34-1","purple_custom_meta_purple_external_id":"November-2021-34-1","purple_issue_code":"|0000086546||","purple_custom_meta_purple_issue_code":"|0000086546||","purple_android_product":"com.im.skyatnight.198","purple_custom_meta_purple_android_product":"com.im.skyatnight.198","purple_ios_product":"com.im.skyatnight.198","purple_custom_meta_purple_ios_product":"com.im.skyatnight.198","purple_web_product":"","purple_custom_meta_purple_web_product":"","purple_publication_id":"075fab74-0a21-4201-866a-899d6c41c40c","purple_migrated":"","kt_blocks_editor_width":""},"categories":[21],"tags":[14],"featured_image_src":"https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/10\/22b670fe-167f-4c6f-bfb9-aad7d51b9c3d.jpg","author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"acf":{"readingTimeMinutes":"5","apple_news_title":""},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/10\/22b670fe-167f-4c6f-bfb9-aad7d51b9c3d.jpg",2048,1248,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/10\/22b670fe-167f-4c6f-bfb9-aad7d51b9c3d-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/10\/22b670fe-167f-4c6f-bfb9-aad7d51b9c3d-300x183.jpg",300,183,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/10\/22b670fe-167f-4c6f-bfb9-aad7d51b9c3d-768x468.jpg",768,468,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/10\/22b670fe-167f-4c6f-bfb9-aad7d51b9c3d-1024x624.jpg",800,488,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/10\/22b670fe-167f-4c6f-bfb9-aad7d51b9c3d-1536x936.jpg",1536,936,true],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/10\/22b670fe-167f-4c6f-bfb9-aad7d51b9c3d.jpg",2048,1248,false]},"uagb_author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"uagb_comment_info":0,"uagb_excerpt":"With a host of missions planned, are we any closer to unlocking the secrets of the hellish planet?","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/25181"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/users\/24"}],"replies":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/comments?post=25181"}],"version-history":[{"count":7,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/25181\/revisions"}],"predecessor-version":[{"id":26795,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/25181\/revisions\/26795"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/25174"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=25181"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=25181"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/tags?post=25181"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}