HiRISE Images: Landslides in Valles Marineris

Valles Marineris is the largest canyon in the Solar System: if superposed on a map of the United States, it would stretch all the way from Los Angeles to Washington, D.C., possibly even up to New England!

So this image is just a very small portion of the system.

This observation shows us gully-like landslides (called "mass wasting") on the interior layered deposits of Valles Marineris.

These include alcoves and channels, which are also visible in PSP_004396_1675.

However, that image quality was very poor due to a dust storm, so a re-image can give us fine-scale shapes and sizes.

Light Pollution, Canyonland and the Milky Way

Celestial scenes like this one of the Milky Way are getting rarer by the day.

Light pollution overwhelms views of our galaxy for two-thirds of the population of the US and the majority of Europeans.

But some "optically clean" oases where we can look at the stars unhindered do remain, called "Dark Sky Parks".

This site in Canyonlands National Park in Utah is near one of them.

The sky here appears much as it would have done 4000 years ago, when artists in the so-called Archaic civilisation are thought to have painted the ghost-like figures on the canyon walls.

No other cultural artefacts have been found, suggesting the site, known as the Great Gallery, was not used for everyday living but for special religious ceremonies.

(Image: Bret Webster)