NASA's much publicized crash of two spacecraft into the frozen depths of lunar crater last week may have been a visual bust, but a spacecraft flying overhead 90 seconds after the impact found a huge temperature spike.
"We have a bunch of people sitting around here trying to figure out what it means," said David Paige, the lead investigator of a radiometer instrument on NASA's Lunar Reconnaissance Orbiter.
LRO was launched in June along with a piggyback satellite known as LCROSS, which crashed a 2.5-ton spent rocket stage, along with itself, into a permanently shaded part of crater on the moon's south pole.
The point of the operation was to kick up plumes of dust and debris so instruments on spacecraft and ground-based telescopes could scan the ejected material for signs of water.
LRO flew over the targeted crater 90 seconds after LCROSS's empty Centaur rocket body smashed into the moon.
"We pointed our instruments at the location of the impact and lo and behold we could actually detect it," Paige told Discovery News.
"The fact that we could detect it at all means it must be pretty hot, but there are some subtleties we're trying to understand," Paige said.
Based on the strength of the signal picked up by the LRO instrument, the crash site "must have gotten way above room temperature," he added.
The targeted crater has high walls which effectively shield part of its basin from sunlight at all times, producing temperatures as low as about minus-370 degrees Fahrenheit.
Scientists theorize that the lunar deep freeze may hold a cache of frozen water that possibly dates back several billions of years.
NASA launched LRO and LCROSS to assess what natural resources the moon may have as it prepares for a new wave of space exploration that will put people beyond the 225-mile high orbit of the International Space Station and the space shuttle.
The United States is the only country that has landed astronauts on the moon. Six crews landed on the moon between 1969 and 1972 as part of the Apollo program.
Paige said the heat footprint from the crash site was still detectable two hours later when LRO flew by a second time. NASA on Tuesday released LRO temperature maps of the crater over eight successive orbits.
Scientists analyzing scans of the initial impact relayed by LCROSS during a four-minute interval before it too crashed into the crater are combing through their data and expect to make an announcement soon.
"I am preparing a public release that I hope to get out in the next couple of days," lead scientist Anthony Colaprete wrote in an email to Discovery News.