Monday, 10 November 2014
Young Ice on Old Mercury: Dilemma for Long Ages
Finding water ice on Mercury, the solar system's innermost planet where temperatures can soar to over 430 degrees Celsius (800 degrees Fahrenheit), might be an enigma for long-agers. How could it possible survive there for millions of years?
Researchers first got to know about ice on Mercury some 20 years ago. In 2012, NASA’s MESSENGER spacecraft confirmed that there indeed was ice in “permanently shadowed craters” near the planet’s north pole.
Recently, researchers were able to study photos that MESSENGER sent. The images “suggest that the ice lurking within Mercury's polar craters was delivered recently, and may even be topped up by processes that continue today.”
This, of course, is an attempt to explain why there could be ice on the Sun’s next-door neighbour, a planet assumed to be billions of years old.
A more logical explanation is that Mercury is not that old at all. This view gets support from its weakening magnetic field, for instance.
There is no shortage of evidence for a young solar system. Saturn’s moons Titan, Mimas and Enceladus speak for a younger solar system, as do short-term comets.
Wall, Mike. 2014. First Photos of Water Ice on Mercury Captured by NASA Spacecraft. Space.com (October 15).