— NASA's Hubble confirms that galaxies are the ultimate recyclers — New observations by NASA's Hubble Space Telescope are expanding astronomers' understanding of the ways in which galaxies continuously recycle immense volumes of hydrogen gas and heavy…
— Frozen comet had a watery past, University of Arizona scientists find — For the first time, scientists have found convincing evidence for the presence of liquid water in a comet, shattering the current paradigm that comets never get warm enough to melt…
— Sugar-grain sized meteorites rocked the climates of early Earth and Mars — Bombardments of 'micro-meteorites' on Earth and Mars four billion years ago may have caused the planets' climates to cool dramatically, hampering their ability to support life, according…
— Astrophysicist: White dwarfs could be fertile ground for other Earths — Planet hunters have found hundreds of planets outside the solar system in the last decade, though it is unclear whether even one might be habitable. But it could be that the best place…
— Integral spots matter a millisecond from doom — ESA's Integral gamma-ray observatory has spotted extremely hot matter just a millisecond before it plunges into the oblivion of a black hole. But is it really doomed? These unique observations…
— MESSENGER spacecraft to swing into orbit around Mercury — At 8:45 p.m. EDT on March 17, the MESSENGER spacecraft will execute a 15-minute manoeuvre that will place it into orbit around Mercury, making it the first craft ever to do so, and…
— Baby stars born to 'napping' parents — Cardiff University astronomers believe that a young star's long 'napping' could trigger the formation of a second generation of smaller stars and planets orbiting around it…
— Oldest objects in solar system indicate a turbulent beginning — Scientists have found that calcium, aluminium-rich inclusions (CAIs), some of the oldest objects in the solar system, formed far away from our sun and then later fell back into the…
— Oxygen isotope analysis tells of the wandering life of a dust grain 4.5 billion years ago — Scientists have performed a micro-probe analysis of the core and outer layers of a pea-sized piece of a meteorite some 4.57 billion years old to reconstruct the history of its formation,…
Volcanic ash in Meridiani Planum
Deposits of volcanic ash colour this view of the Meridiani Planum, as seen by the Mars Express High Resolution Stereo Camera. They also give clues to the prevailing wind direction in this region of Mars.
Meridiani Planum, a plain at the northern edge of the southern highlands of Mars, is half way between the volcanic Tharsis Region to the west and the low-lying Hellas Planitia impact basin to the south-east. Through a telescope, Meridiani Planum is a striking, dark feature, close to the Martian equator.
Meridiani Planum extends 127 km by 63 km and covers an area of roughly 8000 sq km, which is about the size of Cyprus. It was chosen as a central reference point for Mars' geographical coordinate system. So the Martian prime meridian, the equivalent of the Greenwich, UK, prime meridian on Earth, has been set to run through this region.
The High-Resolution Stereo Camera (HRSC) took this image. It was obtained on 1 September 2005, during orbit 2097, at a resolution of about 13 m per pixel.
In the centre of the image, the floor of an impact crater almost 50 km wide is covered in dark material. This resembles volcanic ash, which is predominantly composed of minerals such as pyroxene and olivine. Poking through the dark covering are small mounds, probably made of more resistant material. The softer material around them has been eroded and blown out of the crater by north-easterly winds and now forms dark streaks on the surroundings.
An impact crater just 15 km wide, to the upper left, exhibits the same dark material on its south-western edge. It is likely that this material was blown into the smaller crater from the larger one. The nearly black structures are almost certainly dunes made of volcanic ash-rich sediments. In contrast, the 34-km-wide impact crater to the lower right of the image is largely filled with light material.
The southern area, to the left of the image below the smaller crater, exhibits dark features. Located on the lee side of ridges, these are probably similar deposits of ash-rich material, again blown out of the crater.
Or subscribe for our Newsletter, a free e-mail publication. It is published practically every day.
Third red spot appears on Jupiter
New observations indicate interior of Mars Is colder
Worldwide Telescope brings space exploration to your computer
The Antennae Galaxies move closer