{"id":21499,"date":"2021-07-28T11:38:38","date_gmt":"2021-07-28T11:38:38","guid":{"rendered":"https:\/\/www.skyatnightmagazine.com\/?p=94810"},"modified":"2021-07-27T12:32:52","modified_gmt":"2021-07-27T12:32:52","slug":"pictures-of-mars","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/pictures-of-mars\/","title":{"rendered":"Pictures of Mars"},"content":{"rendered":"

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By Lee Dyson\n \t\t<\/p>

Published: Tuesday, 27 July 2021 at 12:00 am<\/p>

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Mars is a cold and dead world, but it wasn\u2019t always this way. We know water once flowed on Mars. Orbital images reveal its valleys were formed by rivers, while surface experiments have found minerals that require liquid water to form.<\/p>\n

Today, however, Mars\u2019s rivers are no more.<\/p>\n

It\u2019s thought that the Red Planet\u2019s thin atmosphere is to blame as the low pressure caused most of the oceans to boil away, while temperatures mean any remaining water is frozen.<\/p>\n

What isn\u2019t known is how long there was water on the surface.<\/p>\n

\""The\"<\/div>\n

It could be that ancient Mars was warm enough to hold permanent oceans, but it could also be the case that the water spent most of its time frozen, and only thawed when a volcano eruption or meteor impact heated the planet enough to create a flash flood.<\/p>\n

Such eruptions were common in Mars\u2019s early history.<\/p>\n

With low gravity and air pressure, the volcanoes on Mars could grow to enormous size and the planet is home to the Solar System\u2019s largest known volcano: Olympus Mons, a huge shield volcano 624km wide and 22km high.<\/p>\n

However, the planet\u2019s interior solidified around a billion years after its formation, freezing the planet in this early stage of formation. Could Mars volcanoes still be active?<\/a><\/p>\n

\""A\"<\/div>
A section of Elysium Planitia on Mars, as seen by ESA\u2019s Mars Express spacecraft. Credit: ESA\/DLR\/FU Berlin (G. Neukum),\u00a0CC BY-SA 3.0 IGO<\/span><\/figcaption><\/div>\n

Facts about Mars<\/strong><\/h1>\n