'Happy face' crater on Mars

April 10, 2006
'Happy face' crater on Mars

These images, taken by the High Resolution Stereo Camera (HRSC) on board ESA's Mars Express spacecraft, show the Galle Crater, an impact crater located on the eastern rim of the Argyre Planitia impact basin on Mars.

The HRSC obtained these images during orbits 445, 2383, 2438, 2460 and 2493 with a ground resolution ranging between 10-20 metres per pixel, depending on location within the image strip. The images show Crater Galle lying to the east of the Argyre Planitia impact basin and south west of the Wirtz and Helmholtz craters, at 51° South and 329° East.

The images of the 230 km diameter impact crater are mosaics created from five individual HRSC nadir and colour strips, each tens of kilometres wide.

A large stack of layered sediments forms an outcrop in the southern part of the crater. Several parallel gullies, possible evidence for liquid water on the Martian surface, originate at the inner crater walls of the southern rim.

Crater Galle, named after the German astronomer J.G. Galle (1812-1910), is informally known as the 'happy face' crater.

The 'face' was first pointed out in images taken during NASA's Viking Orbiter 1 mission.

Its interior shows a surface which is shaped by 'aeolian' (wind-caused) activity as seen in numerous dunes and dark dust devil tracks which removed the bright dusty surface coating.

The colour scenes, false-colour and near true-colour, have been derived from three HRSC colour and nadir channels gathered during five overlapping orbits. The perspective views have been calculated from a mosaic of digital terrain models derived from the stereo channels.

The black-and-white high-resolution image mosaic was derived from the nadir channel which provides the highest detail of all channels. The resolution has been decreased for use on the Internet, to around 50 m per pixel.

Source: ESA

Explore further: Chasms on Dione

Related Stories

Chasms on Dione

August 18, 2015

While not bursting with activity like its system sister Enceladus, the surface of Dione is definitely not boring. Some parts of the surface are covered by linear features, called chasmata, which provide dramatic contrast ...

The dwarf planet Ceres

August 12, 2015

The asteroid belt is a pretty interesting place. In addition to containing between 2.8 and 3.2 quintillion metric tons of matter, the region is also home to many minor planets. The largest of these, known as Ceres, is not ...

One decade after launch, Mars Orbiter still going strong

August 10, 2015

Ten years after launch, NASA's Mars Reconnaissance Orbiter (MRO) has revealed the Red Planet's diversity and activity, returning more data about Mars every week than all six other missions currently active there. And its ...

The planet Mercury

August 6, 2015

Mercury is the closest planet to our sun, the smallest of the eight planets, and one of the most extreme worlds in our solar systems. Named after the Roman messenger of the gods, the planet is one of a handful that can be ...

Video: Atlantis Chaos flyover

August 4, 2015

This colourful image is a topography map of a portion of the region known as Terra Sirenum, located in the southern hemisphere of Mars. The map is colour-coded, with reds and whites representing the highest topography and ...

Recommended for you

Secrets of a heat-loving microbe unlocked

September 4, 2015

Scientists studying how a heat-loving microbe transfers its DNA from one generation to the next say it could further our understanding of an extraordinary superbug.

Plants also suffer from stress

September 4, 2015

High salt in soil dramatically stresses plant biology and reduces the growth and yield of crops. Now researchers have found specific proteins that allow plants to grow better under salt stress, and may help breed future generations ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.