Lunar freeze

Our solar system's coldest climes found on the moon

Leading astronomers have found the coldest spot in our solar system, and it’s in Earth’s backyard – the moon.

Launched on June 18th, Nasa’s new Lunar Reconnaissance Orbiter (LRO) is making the first complete temperature map of the moon. It has revealed that its south pole has colder conditions than the banished planet Pluto.

There, 239,000 miles away in the permanently shadowed crater floors, "daytime" temperatures never rise above minus 396.67 degrees Fahrenheit, according to the LRO. That's just 35 degrees higher than the lowest temperature possible. Pluto is at least a degree warmer, despite being about 40 times farther away from the sun.

The discovery has significant implications for the advancement of human exploration and scientific benefit. Ice made from water, methane or ammonia from ancient comet collisions would be well-preserved at the bottom of these lunar freezers.

Such ices could be valuable resources that human lunar explorers could use, and they would help answer questions about the arrival of such "volatiles" to the Earth-moon system – evidence that Earth's geological processes have largely erased from its own surface.

“That ultra-cold temperature is important because it can trap volatile chemicals, such as water and methane,” said NASA probe project scientist Richard Vondrak.

“Trapped volatiles would give any future astronauts resources to mine and could help scientists understand more about the origin of the early solar system,” he said.

The moon probe, only a week into its science mission, has also found lots of indications of hydrogen, which could indicate trapped ice below the moon's surface.

If enough of these resources exist to make mining practical, future long-term human missions to the moon potentially could save the considerable expense of hauling water from Earth.