Interplanetary flight is the next giant leap for humans in space. Yet consensus on even the smallest steps forward has proven elusive. In June, a US National Research Council report1 illuminated many options but offered no recommendations. Return to the Moon? Head straight to Mars? Pluck a boulder off an asteroid and tug it to lunar orbit, just so that idle astronauts have somewhere to go and something to do? NASA must decide which path to follow before President Barack Obama’s budget announcement in January 2015. Some options are better than others. The cost and complexity of human space exploration demands that each element be measured by its value towards the ultimate goal: Mars.
The first images from NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft show a planet in the process of losing parts of itself. Streams of hydrogen atoms drift away from the red planet, into the depths of space. The pictures are the first clear look at how crucial elements erode away from the Martian atmosphere, says Bruce Jakosky, a planetary scientist at the University of Colorado Boulder and the mission’s principal investigator. MAVEN’s goal is to measure how the solar wind and other factors nibble away at Mars’s atmosphere, so that scientists can better extrapolate how the once-thick atmosphere has thinned over billions of years. That process transformed Mars from a relatively warm, wet planet into a mostly dry, mostly frozen wasteland.
Spectacular flyover of Mars Nature
A new video lets viewers experience the sensation of flying over the Martian surface based on actual topographical data taken by a European satellite orbiting the red planet.
The mountains, craters, ancient river beds and lava flows that mark the Martian landscape are visible in images from a stereographic camera aboard ESA’s Mars Express probe.
A series of Martian craters assumed to have been formed by meteorites may actually be extinct volcanoes so massive that, when they were active billions of years ago, they could have buried Mars in ash.
The craters pepper the surface of Arabia Terra, a geologically ancient region of northern Mars. They appear as several huge circular pits that resemble Earth’s calderas, in which magma beneath a volcano drains after a volcanic eruption, causing the ground above the magma chamber to collapse. The best example on Mars is a feature called Eden patera, a depression about 85 kilometres long, 55 kilometres wide and 1.8 kilometres deep, says Joseph Michalski, a researcher jointly at the Planetary Science Institute in Tucson, Arizona, and at the Natural History Museum in London.
A meteorite that fell to Earth last July in Morocco has proven to be a rare chunk of Mars. Only a handful of Martian meteorites are known, and only five (counting the new find) come from meteorites whose fall was witnessed. That’s important because it tells scientists how long it has been lying on the ground, and therefore how much contamination it might have picked up. In this case, about a dozen pieces (such as the one shown, right), totalling several kilograms, were recovered from Morocco in late December.
“Because it’s only been on the ground for six months or less, it hasn’t been exposed to much contamination,” says Chris Herd, a planetary geologist specializing in meteorites at the University of Alberta, Edmonton, Canada. Herd chairs an international meteoritics committee that yesterday certified the rocks as coming from Mars and approved their name – Tissint – in honour of the village near which they were found.
When water gushed on Mars Nature
Were the northern plains of Mars submerged in a vast flood as recently as 20,000 years ago? Geologists claim to have found evidence of a recent volcanic eruption under the ice cap that could have created a wall of water 200 metres high and 35 kilometres wide.
Signs of volcanic activity and flowing meltwater have been found before, but the new study links the two together with strong geological evidence, bolstering theories that water was the chief sculptor of the huge chasms in the northern martian ice cap. The flood, the researchers say, could have occurred within the past 10 million years and maybe as recently as 20,000 years ago — more evidence that Mars has not been a geological corpse since its wet and warm period billions of years ago.
The methane in Mars’s atmosphere could easily be produced by mineral chemistry, rather than life. That’s the claim from a pair of geologists whose calculations suggest that some experts have been too quick to assume a bacterial source for the gas.
The radar stowed on board the European Space Agency’s Mars Express orbiter will finally be unfolded in early May. The Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) will look for traces of water ice beneath the martian surface, and could potentially detect reservoirs up to five kilometres underground.
Next time you go for a stroll on Mars, be sure you don’t leave any litter behind. A plan to keep parts of the red planet in their pristine state could see seven areas turned into ‘planetary parks’, regulated just like national parks here on Earth. The scheme has been proposed by Charles Cockell, a microbiologist for the British Antarctic Survey in Cambridge, and Gerda Horneck, an astrobiologist from the German Aerospace Centre in Cologne, Germany.
The Mars Express spacecraft has returned stunning images of mountains and valleys that show signs of past volcanic activity, and suggest that glaciers once shaped the red planet’s surface. The pictures from Mars Express show the western end of the Valles Marineris canyon system, which stretches for about 4,000 kilometres close to the martian equator. In places, the main canyon is 10 kilometres deep, more than six times as deep as the Grand Canyon in Arizona. Mars Express’s High Resolution Stereo Camera (HRSC) has now photographed this area in more detail than ever before, picking out features as small as 50 metres across