Moon and Aldebaran

You won’t find a much quieter place in the solar system than the far side of the Moon. The Moon doesn’t produce any radio noise, and it blocks radio signals from Earth. That could make it a good site for radio telescopes. But it’ll take a lot of work to build them — and to keep the farside nice and quiet.

Radio telescopes are needed to study the Dark Ages — the period in the early universe when the first stars and galaxies were taking shape. The energy from that era is visible mainly at radio wavelengths. But Earth produces huge amounts of interference — from cell phones to orbiting satellites to microwave ovens. That overwhelms the whispers of the universe.

So astronomers are drafting plans for radio telescopes on the Moon. But the farside is about to get a lot louder. New orbiters and landers will broadcast from there, making it much less favorable for astronomy.

Scientists are trying to get international treaties to limit farside broadcasts. They want to set up a “quiet zone” where no signals at scientifically interesting wavelengths would be allowed. No one knows yet if they’ll succeed at keeping the far side of the Moon quiet.

The Moon is just a couple of days past full tonight, so it’s nice and bright. The star Aldebaran, the eye of the bull, rises close to its lower right, and will be to the lower left of the Moon at dawn.

More about the Moon, Aldebaran, and another bright companion tomorrow.

Script by Damond Benningfield