Argyre Planitia and Hooke Crater
Science & Exploration

Ice-coated beauty in Mars’ Silver Island

04/10/2012 4989 views 24 likes
ESA / Science & Exploration / Space Science / Mars Express

On 8 June, the high-resolution stereo camera on Mars Express captured a region within the 1800 km-wide and 5 km-deep Argyre basin, which was created by a gigantic impact in the planet’s early history.

After Hellas, the Argyre impact basin is the second largest on the Red Planet.

Argyre and Hooke Crater perspective view
Argyre and Hooke Crater perspective view

The name stems from the Greek word ‘argyros’ (silver) and Argyre was an ‘island of silver’ in Greek and Roman mythology. Giovanni Schiaparelli, the famed Italian astronomer, gave the name to this bright region on Mars in his detailed 1877 map.

At the centre of the larger impact basin is a flat region known as Argyre Planitia. The Mars Express images in this release all show a portion of the northern part of this plain, with a large portion of each image dominated by the western half of the 138 km-wide Hooke Crater, named after the British physicist and astronomer Robert Hooke.

Argyre and Hooke Crater in context
Argyre and Hooke Crater in context

Most of Argyre Planitia has been shaped by wind, glacial and lacustrine (lake-based) processes, creating the smoother appearance of the landscape surrounding Hooke Crater.

Inside Hooke Crater itself, prevailing wind activity has formed dunes and helped to create linear erosion features, clearly seen in the following topographic image.

Topographical view Argyre Planitia
Topographical view Argyre Planitia

The most striking feature of this image release, shown clearly in the first image at the top of the page, is the icing sugar-like covering of the surface to the south (left) of the image. This is frost, but made of carbon dioxide, not water.

Carbon dioxide ice is commonly seen on the surface of Mars, and has long been thought to form only at ground level, freezing out of the atmosphere as frost, which is most likely the case here.

3D anaglyph view Hooke Crater
3D anaglyph view Hooke Crater

The lowlands to the south (left in the first image) of Hooke and regions within the crater are covered by a thin ice layer. However, it is lacking on the inner north-facing crater wall. It was probably melted there by the Sun, as indicated by the timing of the image.

Taken at around 4:30 in the local afternoon and during the southern hemisphere’s mid-winter, the Sun would have been just over 20 degrees above the horizon. It should then have been able to melt ice on the steeper north-facing slopes, but would probably not have had enough time to warm and melt any on low-lying horizontal surfaces.

Schiaparelli would doubtless have marvelled at the exquisite images coming back from Mars Express, which continues to provide today’s scientists with a bounty of wonderful data.

Related Links

Argyre Planitia and Hooke Crater
Science & Exploration

Ice-coated beauty in Mars’ Silver Island

04/10/2012 4989 views 24 likes
Read
Hadley Crater
Science & Exploration

Hadley Crater provides deep insight into martian geology

06/09/2012 4105 views 6 likes
Read
Ladon basin in full colour
Science & Exploration

The fractured features of Ladon basin

02/08/2012 2423 views 4 likes
Read
Melas Dorsa in full colour
Science & Exploration

Melas Dorsa reveals a complex geological history on Mars

05/07/2012 3504 views 8 likes
Read
Danielson and Kalocsa craters
Science & Exploration

Mars crater shows evidence for climate evolution

07/06/2012 2779 views 3 likes
Read
Acidalia Planitia and Tempe Terra transition
Science & Exploration

Signs of ancient flowing water on Mars

04/05/2012 2546 views 4 likes
Read
Science & Exploration

First Mars Express gravity results plot volcanic history

26/04/2012 3170 views 9 likes
Read
Pit-chains in Tharsis
Science & Exploration

The pit-chains of Mars – a possible place for life?

05/04/2012 3878 views 13 likes
Read
Ancient northern ocean on Mars
Science & Exploration

ESA's Mars Express radar gives strong evidence for former M…

06/02/2012 6497 views 7 likes
Read
Part of Syrtis Major
Science & Exploration

Mars Express reveals wind-blown deposits on Mars

03/02/2012 1928 views 2 likes
Read
Phlegra Montes on Mars
Science & Exploration

Mountains and buried ice on Mars

02/12/2011 3068 views 7 likes
Read
Battered volcano Tharsis Tholus
Science & Exploration

Battered Tharsis Tholus volcano on Mars

08/11/2011 3081 views 2 likes
Read
Oraibi crater in Ares Vallis
Science & Exploration

Mars Express observes clusters of recent craters in Ares Va…

07/10/2011 1769 views 3 likes
Read
Holden and Eberswalde craters
Science & Exploration

Rare martian lake delta spotted by Mars Express

02/09/2011 4308 views 17 likes
Read
Mars’ northern polar regions
Science & Exploration

Mars’ northern polar regions in transition

05/08/2011 3665 views 4 likes
Read
Science & Exploration

Phobos slips past Jupiter

17/06/2011 4523 views 13 likes
Read
Springtime at Mars’ south pole
Science & Exploration

Springtime at Mars’ south pole

07/06/2011 3306 views 5 likes
Read
Deep fractures on Mars
Science & Exploration

Mars Express sees deep fractures on Mars

06/05/2011 2642 views 2 likes
Read

Related Links