Planetary scientists looking for water ice on Mars have employed a number of tactics to great success in their search. The Phoenix lander dug it up; orbiting radar measurements have seen it under insulating blankets of debris. (Frozen water sublimates to vapor in Mars's climate and so is not stable when exposed at the surface.)

Now a team of researchers has let meteorite impacts do the digging for them—a paper in this week's Science presents observations of fresh impacts and what they turn up from below the surface.

Using instruments on NASA's Mars Reconnaissance Orbiter (MRO), a group led by Shane Byrne, a planetary scientist at the University of Arizona's Lunar and Planetary Laboratory, found five recent impact craters in the Martian mid-latitudes, near the boundary where subsurface ice is thought to be no longer tenable. All were relatively small, ranging in size from about four to 12 meters across.

The Lunar Reconnaissance Orbiter (LRO), launched in June to survey the moon with an eye toward a human return there, is already hard at work. At a news conference from the Goddard Space Flight Center in Greenbelt, Md., NASA presented preliminary results from the spacecraft's instruments, which have just finished a transition from the commissioning to operational phases.

In its one-year primary mission, LRO will seek to map the moon in great detail, measure the radiation that human tissue would be subjected to during a lengthy lunar stay, and search for traces of water ice on the lunar surface. Water would be an invaluable resource for future lunar explorers—astronauts could save enormous amounts of launch weight if they did not have to carry their own water supply.

Meteorites can reveal a lot about the composition and formation of their parent bodies, but such postcards from beyond come with no return address, making their provenance difficult to establish. Often, astronomers must observe the object's inbound trajectory and then trace its orbit backward through time to nail down the region of space or the specific parent body that a meteorite sprang from. (In one unprecedented case announced in March, a group of researchers had the added advantage of having spotted the object in space before its atmospheric entry.)

In 2007 a sky-watching program known as the Desert Fireball Network tracked a streak of light over Australia that led researchers to meteorite fragments on the ground. Through an analysis of its composition and orbital characteristics, the meteorite, known as Bunburra Rockhole, has revealed itself to be out of the ordinary, one of a small family of its kind to not originate from a large asteroid known as Vesta. The research, led by meteoritic and planetary scientist Philip Bland of Imperial College London, appears in this week's Science.

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 middle of the 20th century was an eventful time in terms of Earth's geopolitics. In the spring of 1949, the North Atlantic Treaty Organization (NATO) was taking shape, and simmering tensions in Korea hinted at the war that would begin there the following year. Twelve years later, in the summer of 1961, President John F. Kennedy was in his first year of office and had already committed the U.S. to reaching the moon before the decade was out.

A few hundred million miles away, during that same interval of years, Jupiter had its own share of the action. The gas giant passed the time by borrowing a comet called 147P/Kushida-Muramatsu to form a temporary satellite, holding onto it for two orbits. That's the conclusion, anyway, of a study presented yesterday (pdf) at the European Planetary Science Congress in Potsdam, Germany, by a team of researchers from Japan and the U.K.

One of NASA's moon probes, the Lunar Crater Observation and Sensing Satellite (LCROSS), will complete a relatively simple mission next month: releasing a spent rocket stage toward a shadowy crater, then following it to see what the impact stirs up before crashing the mother ship itself into the crater. All the while, Earth-based and orbiting telescopes will be watching, looking for any evidence of water ice that might be hidden in the crater's depths.

Today, NASA unveiled its target of choice for LCROSS's double impact on October 9: a south-polar crater known as Cabeus A. The 48-kilometer-wide crater is named for 17th-century Italian astronomer Niccolo Cabeo. According to NASA, Cabeus A was chosen both for its potential for harboring water ice and for its location, which will allow Earth observers to track the plumes thrown up by the LCROSS impacts. For a fuller description of the LCROSS mission, see our coverage from June, just before the spacecraft launched.

Back in May, the White House announced that it was convening a 10-member independent panel to take a long, hard look at NASA's plans for human spaceflight. The committee delivered a summary of its report (pdf) to the president's Office of Science and Technology Policy this week, solidifying many of the sober warnings that the panel had aired in a series of public meetings earlier this summer.

The nation's current program for human spaceflight appears to be "on an unsustainable trajectory," the report of the Review of U.S. Human Space Flight Plans Committee declares. "It is perpetuating the perilous practice of pursuing goals that do not match allocated resources."

Gardeners, take note: the secret to growing hearty tomatoes is remarkably close at hand. Look no further than your fireplace and, er, your bladder.

According to a study from a group of environmental scientists at the University of Kuopio in Finland, human urine and wood ash make a reasonably potent tomato fertilizer, boosting plant growth and fruit yield dramatically over untreated plants and nearly keeping pace with conventional fertilizer. The research appears in the August 26 Journal of Agricultural and Food Chemistry.

The idea did not come completely out of left field—urine and ash have individually found use in helping plants grow, and their beneficial aspects appear complementary on paper. A commonly used nitrogenous fertilizer called urea is prevalent in urine, and wood ash (the Finnish group used birch) is rich in nutrients, such as potassium and calcium, that urine lacks.

The so-called Station Fire, which now covers more than 120,000 southern California acres and is burning largely uncontained, continues to threaten the century-old Mount Wilson Observatory, home to astronomer Edwin Hubble at the time he made his landmark observations of the universe's expansion.

The observatory is currently unmanned due to the fire threat and the attending smoke, but a webcam atop Mount Wilson's 150-foot solar tower has provided observatory managers and concerned observers with a view from the scene. At 12:55 P.M. (Eastern Daylight Time) the camera showed a great deal of smoke but no flames.

At one point, the Station Fire also threatened NASA's Jet Propulsion Laboratory in Pasadena, which now appears to be out of harm's way. The lab resumed normal operations today after a partial closure yesterday due to smoky conditions.

The Indian space program joined an elite group last year when its first lunar probe entered orbit around the moon and began taking detailed observations. But the Indian Space Research Organization (ISRO) lost radio contact this weekend with the probe, Chandrayaan 1, and the mission came to an abrupt end after communications could not be reestablished.

"Our efforts to establish contact have failed. The mission has been terminated," ISRO spokesperson S. Satish told Reuters. "There was no point continuing with the mission."