Galle Crater aka 'Happy Face' - Mars Express HRSC images

Aug 29, 2026

Uploaded by Cipher

Galle Crater on Mars, informally called the “Happy Face” crater, is shown through High Resolution Stereo Camera (HRSC) imagery from ESA’s Mars Express spacecraft. The images cover multiple orbits and provide perspective views, close-ups, and false-colour mosaics at resolutions roughly between 10–20 m per pixel (and ~50 m per pixel for internet display). The 230 km-diameter impact crater lies east of Argyre Planitia, with layered southern outcrops and gullies that may indicate past liquid water. The document also summarizes imaging composition and HRSC processing, plus contact details for enquiries.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages5

Reading Time13 min

AccessFree to download

Galle Crater overview

“Happy Face” naming and observational history

Imaging details and resolution

Geological features and possible water evidence

HRSC mission, processing, and contacts

| News Archive until 2007
Galle Crater aka 'Happy
10 April 2006 | Face' | | --- | --- | |
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Crater Galle, false-colour close-up mosaic | | | | | |
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Southern aspect of Crater Galle, perspective view | | | | | Galle Crater aka 'Happy Face' 1 / 5 Crater Galle, perspective view Crater Galle, close-up view Crater Galle, false-colour mosaic Crater Galle, 'Happy Face' crater, on Mars These images, taken by the DLR-operated High Resolution Stereo Camera (HRSC) onboard 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. Crater Galle is informally known as 'Happy Face' crater. 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. Galle Crater aka 'Happy Face' 3 / 5 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 latitude and 329° East longitude. The images of the 230 km-diameter impact crater are mosaics created from five individual HRSC nadirand 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'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. Crater Galle, black-and-white mosaic 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. Map showing Crater Galle and surrounding features The HRSC on Mars Express was developed by DLR and built in cooperation with industrial partners (EADS Astrium, Lewicki Microelectronic GmbH and Jena-Optronik GmbH) . The HRSC experiment on Mars Express is led by the Principal Investigator (PI) Prof. Dr Gerhard Neukum. The science team of the experiment consists of 45 Co-Investigators from 32 institutions and 10 nations. This camera on Mars Express is operated by DLR's Institute of Planetary Research. The systematic processing of the HRSC image data is carried out at DLR and scene processing is carried out by the PIgroup at the Institute for Geosciences of the Freie Universität Berlin in cooperation with DLR's Institute of Planetary Research, Berlin. Contact Elke Heinemann German Aerospace Center (DLR) Corporate Communications, Online Communication-DLR Web Portal Tel: +49 2203 601-2867 Fax: +49 2203 601-3249 E-Mail: [elke.heinemann@dlr.de](elke.heinemann@dlr.de) Prof. Dr. Ralf Jaumann German Aerospace Center Institute of Planetary Research, Planetary Geology Tel: +49 30 67055-400 Fax: +49 30 67055-402 E-Mail: [Ralf.Jaumann@dlr.de](Ralf.Jaumann@dlr.de) Contact details for image and video enquiries as well as information regarding DLR's terms of use can be found on the DLR portal imprint. Galle Crater aka 'Happy Face' 5 / 5

FAQs

What is Galle Crater and why is it called “Happy Face”?

Galle Crater is an impact crater on Mars. It is informally known as the “Happy Face” crater because the “face” was first identified in images from NASA’s Viking Orbiter 1 mission.

Which spacecraft and instrument captured the images?

The images were taken by the DLR-operated High Resolution Stereo Camera (HRSC) onboard ESA’s Mars Express spacecraft.

What geological features are highlighted in the crater?

The images show layered sediment outcrops in the southern part of the crater and several parallel gullies on the inner crater walls, which may be evidence of liquid water on Mars.

Aug 29, 2026

Uploaded by Cipher