London, December 17 (ANI): NASA's Lunar Reconnaissance Orbiter has used its Diviner instrument to find the coldest place in the solar system at the Moon, where night-time surface temperatures can dip as low as minus 249 degree Celsius.
According to a report by BBC News, the Diviner instrument probed the insides of permanently shadowed craters on the Moon.
It found that mid-winter, night-time surface temperatures inside the coldest craters in the northern polar region can dip as low as minus 249 degree C (26 Kelvin).
"The Moon has one of the most extreme thermal environments of any body in the Solar System," said Professor David Paige, the Diviner principal investigator at the University of California, Los Angeles.
"During the middle of the day, temperatures can get up to about 400K (127C) at the equator; and at the poles at night, they can get very cold," he added.
The tilt of the lunar axis is 1.54 degrees.
For most places, this makes no difference, but as Prof Paige explained, at the poles, this gives rise to a small, three-degree change in the elevation of the Sun on the horizon through the course of a year.This results in a significant variation in the extent of shadows and temperatures," he said.
Diviner observed the lowest summer temperatures in the darkest craters at the southern pole to be about 35K (-238C); but in the north, close to the winter solstice the instrument recorded a temperature of just 26K on the south-western edge of the floor of Hermite Crater.
There were also areas on the southern edges of the floors of Peary and Bosch Craters that got almost as cold.
"The way you can make something cold is to eliminate all possible other heat sources, and in these craters at the lunar poles they receive no direct sunlight and the coldest places don't even receive any indirect sunlight," Prof Paige said.
"In other words, only what little radiation may be scattered from some distant cliff gets down into these areas; and they just cool off. Finally, they reach an equilibrium temperature down at those low values," he added.
The discovery adds further weight to the idea that some craters on the Moon could harbour water-ices for extended periods, and also more volatile substances that require even colder storage temperatures. (ANI)