It’s a common theme in science fiction: The Moon is destroyed or suddenly pulled from the Earth’s orbit. What would happen to the Earth?
It occurs to me that while discussion of the Moon being destroyed usually focuses on things like tides and debris raining down on earth, a more serious possibility would be throwing the earth out of its current orbit.
The Moon doesn’t actually orbit the Earth. Actually, the Earth and the Moon orbit around a common point known as the epicenter.
Given that the Moon is so large that the Moon and Earth represent a virtual double planet, the sudden destruction of the moon could very well send the Earth into an orbit further from, or closer to, the Sun, depending on where the Earth was in relation to its orbit around that epicenter. Since it would move tangentially away from that point, the end result is unknowable … but it would be bad.
Imagine a cue ball suddenly caroming around a pool table… But not to worry. We’d all be dead by the time it hit anything even without the impact of any debris from a shattered Moon, since it would probably be like a case of cosmic whiplash as the Earth suddenly took off in a whole new direction while none of us were belted in.
The result would be a VERY short science fiction story, but a great disaster movie.
Business is humming if you’re in the business of extra-solar planets, exobiology or exoenvironmental studies.
Recently, it was announced that scientists had determined that liquid water and hydrocarbons were present on Saturn’s moon Enceladus. They made this determination using Cassini’s plasma spectrometer, which had found specific ions characteristic of water in motion. (It never ceases to amaze me how scientists can tease information out of data using the most obscure scientific facts.)
That makes at least 4 worlds (Earth, Mars, Enceladus, and Europa) in our solar system where liquid water and other ingredients necessary for life have been found to be present now or in the past, or probably so. Continue reading →