Why We Should Go Back to the Moon
For the Sake of the Science There
What recent scientific discovery suggests that we ought to resume space flights to the Moon for purposes of scientific research?
Why, that would be the discovery of traces of the isotope iron-60 in deep-sea rocks and meteorites. The reason that discovering this isotope, which has a half-life of 2,600,000 years, is so important is that it can’t be made in detectable quantities by any process that happens on the Earth. It can only be found in material expelled by a supernova. So how did it get to the Earth?
There is only one possible explanation: At some time within the past 2.6 million years the Earth must have been close enough to supernovae for them to deposit traces of their emissions in our planet. That is to say, within about 100 light years.
But our stellar neighborhood has been studied thoroughly enough for scientists to be pretty sure that there was no supernova within that distance over that period of time.
The only explanation is that at some point our solar system must have been in a different galactic neighborhood … as, in fact, we know that it was, because our sun has been shown to circle the core of the galaxy every 60 million years, in an orbit with a constant radius of about 30 thousand light years. So that trace of iron-60 is nothing but an heirloom left by some long-ago brush with a neighborhood in the heavens where supernovae are or were common, as, for example, the light from the neighborhood of the Orion Nebula shows that it was at one time.
Now the astrophysicists begin to prick up their ears. If some ancient supernova left traces of itself in the rocks of the Earth it must have left similar traces in the rocks of Earth’s constant companion, the Moon. For Earth, those traces would have been eroded away long ago by the actions of wind and wet, but not on the Moon, which possesses neither.
So, if you want to learn the secrets of or galaxy, don’t bother with big telescopes. With your shovel on your shoulder, just head for the Moon and dig, dig, dig!