A University of Colorado study, using data from the Mars Global Surveyor and Mars Odyssey orbiters, has concluded that the area surrounding the rover Opportunity's landing site once contained a huge body of water -- up to 330,000 square kilometers. That makes this Martian sea comparable to the Baltic or, as investigator Brian Hynek of the Laboratory for Atmospheric and Space Physics puts it, 'all of the Great Lakes combined.' Hynek's paper on the Martian sea ("Implications for hydrologic processes on Mars from extensive bedrock outcrops throughout Terra Meridiani") appears in the September 9 issue of Nature, and you can find CU's press release on his work here. The physicist used the thermal emission imaging system on-board Mars Odyssey to infer the size of rocks, studying how larger and smaller particles change temperature at different rates in daylight and at night. His thermal maps show wide areas of bedrock, and tell him that water once extended far beyond the landing area. To...

The BBC talked to SETI@Home researchers and others this morning re the possible SETI reception discussed below. The verdict: "It's all hype and noise," said its chief scientist, Dr Dan Wertheimer. "We have nothing that is unusual. It's all out of proportion." And Dr Paul Horowitz, of Harvard University, who specialises in hunting for possible alien contacts added: "It's not much of anything at all. We're not investigating it further." What will bear investigating is what caused what seems to have been a spurious signal. Should be a good chance to sort out a possible bug in the Arecibo receiving equipment. Check here for more.

New Scientist is carrying the news of a singular find by SETI@Home, the distributed computing project that uses data from the Arecibo radio telescope to look for extraterrestrial radio signals. What is being described as 'the best candidate yet for a contact by intelligent aliens in the nearly six-year history of the SETI@home project' has been detected, emmanating from a source that may or may not be located somewhere between the constellations Pisces and Aries. Dubbed SHGb02+14a, the signal is weak and may in fact be the result of either an unknown natural phenomenon or an artifact in or near the Arecibo dish itself. Centauri Dreams' take: the odd drift in the 1420 MHz signal argues for a local anomaly at Arecibo. Yes, it could be a transmitter on a rapidly spinning planet, but what confounds researchers is that each observation starts at exactly 1420 MHz and then sees the signal begin to drift. What we need are independent observations from other dishes to confirm whether...