Russia's Phobos-Grunt probe, which had been slated to head off this year on a sample-return mission to Phobos, the larger of Mars's two moons, will not launch until at least 2011, according to the Russian Interfax news agency.

Citing "a source in Russia's space industry," the news agency reported that the Russian Federal Space Agency and the Russian Academy of Sciences would make the postponement official in the next few days. As noted in a recent feature article about the Phobos-Grunt mission on ScientificAmerican.com, the delay has been rumored for months.

As was the case with NASA's mammoth rover, the Mars Science Laboratory, pushing a mission start date back from late 2009 requires a lengthy delay. The launch window to the Red Planet and its environs, based on the relative positions of Earth and Mars, only comes about every 26 months or so.

The rapidly ascending Chinese space program is setting its sights on a new target: Mars.

China plans to send an orbiter to the Red Planet on a Russian launch vehicle later this year, according to the Xinhua News Agency. The nation's first Mars probe, Yinghuo 1, will piggyback on the ambitious Phobos–Grunt mission, a Russian spacecraft that will seek to return soil samples from Phobos, the larger of Mars's two tiny moons.

Details on the orbiter's cost and scientific goals are scarce, with a Shanghai Aeronautic Bureau official telling the news agency: "(The major task) is to orbit and explore Mars and test data of Mars' atmosphere and surrounding environment. This is to create a better platform for future space exploration." A 2007 Xinhua report described a small probe: just 2.5 feet (75 centimeters) long and weighing 240 pounds (110 kilograms).

The Mars rover Spirit has suffered through many hardships in its five years on the forbidding planet, outliving the scope of its original mission by more than 20 times in the process.

But now Spirit faces a new and tricky challenge—its wheels have partly sunk into a patch of soft soil. The rover's controllers have put a halt to driving operations while they try to figure out how to get it unstuck.

"Spirit is in a very difficult situation," John Callas, project manager for the rovers at the NASA Jet Propulsion Laboratory (JPL) in Pasadena, Calif., said in a statement yesterday. "We are proceeding methodically and cautiously. It may be weeks before we try moving Spirit again." A JPL spokesperson said today that the rover's condition had not changed.

Titan, Saturn's largest moon, has a curious abundance of methane, both in its atmosphere and in massive liquid pools on the surface. As with Mars, the presence of the relatively short-lived compound on Titan raises questions about its origin. (Methane comes largely from biological processes on Earth, but other celestial bodies might have different primary sources for the hydrocarbon, such as subsurface geologic activity—Titan appears to be something of a long shot for sustaining life.)

Satellite data from NASA's Cassini mission continue to provide clues as to the workings of Titan's methane cycle. A new paper in Geophysical Research Letters details the latest findings from Cassini, including a vast system of hydrocarbon (methane and ethane) lakes near the poles that appear to be replenished by seasonal precipitation from storm clouds. One of the lakes, whose discovery was announced last summer, is comparable in surface area to Lake Ontario.