When the moon goes splat

IF YOU ARE A space fan, the last week or so has offered plenty to keep your brain cells tingling, including meteor showers and possible liquid on Mars. But did you hear the one about the moon going splat? Earth may have once had two moons which collided and merged, resulting in the farside highlands of the single moon that orbits our planet now.

That’s a scenario outlined in a letter to the journal Nature, which describes how simulations of that slow collision result in the smaller moon forming an “accretionary pile” rather than a crater.

And if moon-splatting theories weren’t enough to be getting on with, how about liquid water on Mars? Analysis of images from the surface of the red planet taken by the Mars Reconnaissance Orbiter describes intriguing features: dark streaks or tendrils that appear on some steep slopes in warmer periods and fade in winter.

There is already evidence of water on Mars in the form of ice, but this finding hints at a more fluid variety: “Liquid brines near the surface might explain this activity, but the exact mechanism and source of water are not understood,” write the study authors in Science.

Meanwhile, also on Mars, the rover Opportunity has been inching towards the Endeavour crater and has beamed back images from close to the rim.

At around 14 miles (22 km) in diameter, Endeavour is no meagre pothole, and is more than 25 times wider than Victoria crater, an earlier stop that Opportunity examined for two years. Closer to home, keep your eyes peeled at night for the annual Perseid meteor shower, which should peak this week.

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Eight years and 34 million miles on, Mars rover nears end of road

It travelled at an average speed of 60cm an hour and it has arrived a year late. But the Mars rover Opportunity is finally approaching its destination, the rim of the vast Endeavour crater.

Nasa hailed the six-wheel Opportunity's approach to the 22.5km-wide crater last night as a "tremendous scientific success".

The ageing robotic field geologist has logged more than 32km since it was first parachuted on to the planet's surface in 2003, along with its twin rover Spirit, for a planned three-month mission after their 34 million-mile journey from Earth. Spirit emitted its last signal a year ago after becoming trapped in sand. Opportunity crawled out from a crater in 2008 and headed south to the Endeavour, a two-year journey in theory, which has taken longer because Opportunity had to drive backwards to prevent its front wheel from wearing out.

At the crater, Opportunity will travel south across the rim to perform a geological assessment of the location, examining the clay minerals formed under wet conditions at the oldest of the four craters it has visited.

The finishing point was nicknamed Spirit Point in honour of Opportunity's fallen twin. Scott Maxwell, leader of the Mars Rover driving team, tweeted: "The drive we uplink today will actually take us physically on to Cape York. So. *Freaking*. Excited."

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Forget Two Moons, Earth Would not Have Needed a Moon at all

A recent study suggested that Earth might have lost one of its two moons following a collision between the two. But a new study concludes that Earth's orbit would have been stable even without a moon.

Moon stabilizes the tilt of Earth that in turn ensures stable climatic conditions for the evolution of complex life. However, according to the latest study, "the influence of other planets in the solar system could have kept a moonless Earth stable."

"The stabilizing effect that our large moon has on Earth's rotation may not be as crucial for life as previously believed," lead researcher Jason Barnes of the University of Idaho said in his report published in Astrobiology magazine.

Barnes and his collaborators concluded that the pull of other planets in the solar system orbiting the Sun would keep Earth’s rotation on its axis steady. They insist that Jupiter, being the most massive planet of the solar system, would restore stability of a moonless Earth.

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ISRO mulls delaying moon mission, may opt for foreign tie-up

The Indian space programme appears to have shifted to the 'go slow' mode as far as its plan to send a manned mission to space is concerned. The Indian Space Research Organisation (ISRO) had earlier fixed an unofficial target of 2016 for the first human space flight from the Indian soil.

Now, ISRO chairman Dr K. Radhakrishnan says the agency is open to different options, including foreign tie-ups, for India's manned mission.

One of the key requirements for such a mission is a launch vehicle with high reliability - one with a risk factor as less as one in 100. The crew escape factor should be even better and the tolerable risk factor must be one in 1000. An upgraded version of the Geosynchronous Satellite Launch Vehicle - GSLV Mark II - could take a two-member crew to space.

But the two failures of GSLV last year have come as a blow to the Indian space agency. "GSLV will now have to first go on unmanned missions," Radhakrishnan said. Other technologies, too, need to be perfected.

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Plans to build budget trip to Mars

NASA is working with private industry to go well beyond simply supplying ferry flights to the International Space Station, but to Mars on the cheap.

Space Exploration Technologies, or SpaceX, is preparing to launch its second test Dragon capsule on 30 November with the intention of docking it at the space station.

In addition to carrying cargo to and from the station, SpaceX plans to upgrade the Dragon to fly people into space and to one day land it on Mars.

"We figured out that for a pretty low cost, a Dragon capsule on a Falcon Heavy (rocket) could go to Mars for hundreds of millions of dollars, not billions," says Pete Worden, director of NASA's Ames Research Center, speaking at the NewSpace 2011 commercial space conference last weekend.

The mission, informally known as Red Dragon, would follow NASA's upcoming US$2.5 billion (AU$2.3 billion) Mars Science Laboratory, which is due to launch in November and arrive on Mars next August. Its goal is to determine if the red planet is, or ever was, suitable for microbial life.

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Driving on the moon: the 40-year legacy of NASA's first lunar car

When NASA's Apollo 15 astronauts David Scott and James Irwin touched down on the moon 40 years ago, they had an extra special tool packed away on their lunar lander: a dune buggy-size rover that enabled them to become the first humans to drive on the surface of a world beyond Earth.
Rover technology has made great strides since Scott and Irwin landed on the moon on July 30, 1971, but the lessons learned from NASA's first Lunar Roving Vehicles (LRVs) are still applicable today. While technology has evolved since the Apollo era, NASA's first rovers are influencing manned and robotic vehicles for exploration on Mars and beyond.

The "LRV on Apollo fulfilled a very important need, which was to be able to cover large traverses, carry more samples, and get more scientific exploration done," Mike Neufeld, a curator in the space history division at the Smithsonian National Air and Space Museum in Washington, D.C. told SPACE.com. "It was a really important part of why Apollo 15, 16 and 17 were so much more scientifically advanced and productive."

Apollo 15 was the fourth mission to land men on the moon, and it was the first of three missions to use the LRVs. The rover had a mass of about 460 pounds (208 kilograms) and was designed to fold up so it could fit inside a compartment of the Lunar Module.

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