http://www.eagle.ca/~harry/ba/eme/index.htm

Interesting piece for nostalgia's sake. I figure you can say that planetary science began with predictions of the planets' movements and the lunar phases, but the first moment when humans actively probed another world, in contrast to measuring light reflected from the Sun, was with these radar pings.

Fascinating. Thanks for posting this.

I had the chance to meet John DeWitt in the 1970s, while he was still an adjunct member of the Vanderbilt University physics department after having retired from WSM radio. In the 1960s, he had used the university's equipment at Dyer Observatory for some early experiments in astronomical TV imaging, and left the observatory with his homemade 12-inch Cassegrain reflector (as one might guess, on the high end of homebuilt telescopes). By 1976, he had a movable dish antenna in his yard and was the first person I knew to be picking up the network relay signals from various satellites. He had a hand-cranked motion to select satellites, along an axis tipped to provide the best great-circle approximation to the projected location of geostationary orbit. We sat enthralled at the weather forecast from Montreal. Oral history had it that he and Carl Seyfert arranged to climb one of WSM's high transmitting towers to spot Sputnik 1's booster stage soon after its launch, to get above a wet fog layer - after convincing themselves that they could safely leap from the ground to the first ladder rung without sustaining a really nasty shock.

As a matter of fact it had been done a couple of years earlier by the germans while experimenting with the "Würzburg Riese" radar, though nobody outside Germany may have known that in 1946. And if that seems unlikely, then remember that radio astronomy got started in several countries (including Sweden) by using surplus Würzburg antennas which were large and very high quality parabolics.

Come to think of it, there have been hints that the Moon was picked up when just above the horizon (and registered at some worrying, deeply aliased distance) by radar systems of several nations late in World War II. Anybody have more details?

IIRC, the Dutch group did their first detection of the 21-cm line using a receiver on one of the Würzburg antennas, at Kootwijk.