REAL LIFE NEWS: PHOBOS IS CRACKING UP
by Hazed
NASA scientists have announced that Phobos, Mars’ larger moon, is showing signs of structural failure that mean it will one day fall apart.
The moon is very close to Mars – it orbits just 6,000km away from the planet – and that means it is subject to huge tidal forces.
It was the Viking spacecraft in the mid-1970s that first showed us that Phobos had grooves running across it, and scientists thought then that they were caused by tidal stresses. However, at the time it was thought that the moon was solid, so these forces wouldn’t be sufficient to break it up.
Now, however, the view of Phobos’ interior has changed. Experts now think that it has an interior of rubble surrounded by powdery regolith about 100 metres thick. That means the structure is elastic enough to distort, causing the stress fractures on the surface. The second link below shows those grooves.
Over time the stresses will get worse because the moon is losing altitude at a rate of 2 metres every 100 years.
Let’s hope the moon holds together long enough to be colonized, so Tracey and the scientists on the Phobos base in Fed DataSpace still have somewhere to live!
Source: http://www.theregister.co.uk/2015/11/11/feeble_phoebus_flaking_as_it_falls_to_mars/
http://apod.nasa.gov/apod/ap151122.html
