x Abu Dhabi, UAEFriday 19 January 2018

Dynamic moon

We can predict to the second when a celestial event will occur, but yesterday's "supermoon" reminds us that Earth's rocky satellite can still capture our imagination.

Moon myths are as old as time. The Mayans built temples in its honour, Egyptians crafted calenders to track its movements. Few celestial bodies have been as mythologised - and misunderstood - as our moon.

Which makes yesterday's "supermoon" showcase all the more remarkable. Astronomers know, with astonishing precision, when the moon turned full and that no less than 25 minutes after that, it arrived at its perigee. At a mere 356,955 kilometres away from Earth the moon's approach was as close as it had been in a year. It won't be as close or as bright again until 2014.

With such accuracy it might seem that we know all there is to know about our rocky satellite. But scientists themselves are still discovering.

Last week brought word that NASA has found evidence the moon is actually a dynamic hunk of rock, not the dead geologic mass previously assumed. A lunar orbiter found fault-like ridges and corresponding valleys on the moon's surface which, taken together, suggest the moon is shrinking in some places, and growing in others.

Of course it's also possible that giant subterranean moon-rock eating worms have been doing their worst on the moon's surface, gnawing away while we sleep.

Either way, the moon still manages to capture our imagination.