NASA’s orbiter discovers frost on Moon’s South Pole
Scientists have identified bright areas in craters near the Moon’s South Pole that are cold enough to have frozen water present on the surface.
The researchers were able to discover frost by using data from the National Aeronautics and Space Administration’s (NASA) lunar orbiter.
Important features of the study
- The scientists came to the conclusion by analysing combined surface temperatures with information about how much light is reflected off the Moon’s surface.
- The icy deposits appear to be patchy and thin, and it is possible that they are mixed in with the surface layer of soil, dust and small rocks called the regolith.
- The researchers said they did not see expanses of ice similar to a frozen pond or skating rink. Instead, they saw signs of surface frost
What is cold trap?
Cold traps are permanently dark areas — located either on the floor of a deep crater or along a section of crater wall that does not receive direct sunlight — where temperatures remain below minus 163 degrees Celsius. Under these conditions, water ice can persist for millions or billions of years.
Driving goal of LRO
- Understanding the nature of these deposits has been one of the driving goals of Lunar Reconnaissance Orbiter, or LRO, which has been orbiting the Moon since 2009.
- Researchers found evidence of lunar frost by comparing temperature readings from LROs Diviner instrument with brightness measurements from the spacecrafts Lunar Orbiter Laser Altimeter, or LOLA.
- In these comparisons, the coldest areas near the South Pole also were very bright, indicating the presence of ice or other highly reflective materials.
- The researchers looked at the peak surface temperatures, because water ice won’t last if the temperature creeps above the crucial threshold.
- The study strengthens the case that there is frost in cold traps near the Moon’s South Pole. So far, however, researchers have not seen the same signs near the Moon’s North Pole.