THE SKY THIS OCTOBER: STUDIES INTO RADIO ASTRONOMY AND COLD FEET

Radio astronomy is perhaps the second biggest subfield in astronomy. No, it's not about listening to the radio while you watch the stars (that's called a cheap date where I come from).

All objects radiate electromagnetic radiation unless they are at absolute zero, which is theoretically impossible unless you are talking about your spouse's feet! The type of radiation we emit depends on our temperature.

The Sun's surface is nearly 5,000 degrees and so it radiates most of its energy in the visible part of the spectrum. Human bodies which are near 100 degrees, radiate most of their energy in the infrared part of the spectrum, unless you are my spouse's feet. Distant dust clouds in outer space are nearly 200 degrees and they radiate in the radio part of the spectrum.

The interesting thing about radio waves is that they penetrate dust and gas much better than visible light does. For example, we cannot see the center of our galaxy in the visible part of the spectrum because there is too much gas and dust in the way. On the other hand, radio signals easily pass through the gas and dust allowing us to not only see the center of our galaxy but all the way through the galaxy to the other side!

Current cosmological theory says that the Big Bang occurred over 12 billion years ago at a temperature of hundreds of millions of degrees. As the galaxy expanded, the radiation from the Big Bang cooled In fact, it has cooled down to just three degrees above absolute zero.

Now here comes the cool part (pun intended).

Turn your television to a channel with no signal on it. Look at the screen and notice all those snow-flake like noise patterns on the screen. This is what TV was like when I was young! No wonder we had to read books and look at the stars.Any given screen has, on average, about three of those speckles which came from the Big Bang itself! Those photons have traveled for 12 billion years dodging stars, planets, dust and gas, and presidential elections, only to slam into your TV antenna and show up as a flash on your screen.

You have just performed your first radio astronomy experiment.

You can actually climb up on your roof, dismount your TV antenna and point it around the sky and keep track of how much noise you see on the screen You will find that it easily increases when you point at the Sun, the planet Jupiter, or the galactic center.

You could map out the sky and produce your first radio image of the universe! Please ask your parents before you actually perform this experiment.

You cannot deny Venus her glory this month as she claims her vantage point in the southwest at sundown She is the brightest thing in the sky. The fainter Mercury is between Venus and the Sun. The next great sight, beside the beautiful Milky Way overhead, occurs near midnight as mighty Jupiter and Saturn appear.

Next month in combination with their westward motion and converting off of daylight savings time, they will appear around 8:00 pm.

The best views this month are actually in the early mornings Just before sunrise, go out, look nearly straight up, and gaze at the planets Jupiter and Saturn, near the bright star Aldebaran, and the winter constellations of Taurus (the "V"), and Orion the mighty hunter, and the star cluster Pleiades.

It doesn't get much better than this (till next month). It may be cold out so wear a jacket, but it's nothing compared to those cold feet when you get back to bed!

Dr. Michael Cobb is chairman of the physics department at Southeast Missouri State University. He can be reached at 651-2172.