Technology & Science

Satellite captures images of vast clouds on Mars

A European satellite in orbit around Mars since 2003 has captured images of large water-ice and dust clouds across Mars.

More than 21,000 images have been taken since 2007, but have just been released

A sequence of images taken by the Mars Express as a cloud came into view on March 7, 2013. (NASA)

A European satellite in orbit around Mars since 2003 has captured images of large water-ice and dust clouds across the Red Planet.

The newly released images of Martian limb clouds — clouds over the edge of the planet — were taken by the European Space Agency's (ESA) Mars Express.

The spacecraft delivered Beagle-2, a lander that was to have reached the Martian surface on Christmas 2003. However, after attempts were made to contact the lander for a month, it was deemed lost. NASA's Mars Reconnaissance Orbiter (MRO) located it on the surface of the planet in 2015.

Mars Express still made use of the camera designed to confirm the landing of Beagle-2. It was switched back on in 2007 when it was used for outreach and citizen science. 

But in 2016, scientists using new software went through images taken using the webcam — more than 21,000 — and identified clouds extending across the planet.

Dust clouds can be seen over the Utopia region of Mars in November 2007. Arrows indicate the dust front in each image. (NASA)

While clouds have been seen on Mars, the spacecraft provides the unique view of capturing the expanse of these limb clouds.

On average, the altitudes of the clouds are between 50 and 80 kilometres and extend across Mars from about 400 to 1,500 kilometres.

Together with the images from the webcam, researchers also consulted weather data collected by the MRO. 

They found that some of the clouds contained water, but usually at sunrise or in the early afternoon. This occurs as the water ice condenses. As sunlight increases, the ice evaporates, forming the clouds.

If you'd like to see images taken by Mars Express for yourself, check out this Flickr page where photographs are uploaded daily.

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