KFL@MIT-MC.ARPA (08/08/85)
From: Keith F. Lynch <KFL@MIT-MC.ARPA> The Earth is much brighter in the microwave region of the spectrum than the Sun is. The Sun gives off small amounts of radio waves and microwaves because of its heat. Jupiter gives off very small amounts of radio waves for that reason. Jupiter's main radio emissions are in the 10 meter and the 0.1 meter bands, and are NOT thermal, but are caused either by giant lighning storms on the planet or, more likely, by ions from Io spiralling in Jupiter's magnetic field. Jupiter does NOT radiate hardly any microwaves. Earth is always brighter than the Sun in the microwave region due mainly to high power military radar. But if a large, highly directional antenna such as the one at Aricebo is used, the Earth is, in one direction only, on one frequency only, one of the brightest microwave sources in the whole galaxy, and can communicate with a similar station 1000 light years away. ...Keith
demillo@uwmacc.UUCP (Rob DeMillo) (08/09/85)
> From: Keith F. Lynch <KFL@MIT-MC.ARPA> > > Earth is always brighter than the Sun in the microwave region due > mainly to high power military radar. But if a large, highly directional > antenna such as the one at Aricebo is used, the Earth is, in one direction > only, on one frequency only, one of the brightest microwave sources in the > whole galaxy, and can communicate with a similar station 1000 light years > away. > ...Keith The latter statement is true, but not relavent to the conversation, since the original posting involved "the earth sticking out like a sore thumb." And, unless you happen to be looking from the right direction at the right time on the right frequency, we aren't. -- --- Rob DeMillo Madison Academic Computer Center ...seismo!uwvax!uwmacc!demillo "...That's enough, that's enough! Television's takin' its toll. Turn it off, turn it off! Give me the remote control! I've been nice! I've been good! Please don't do this to me! I've been nice, turn it off, I don't wanna hav'ta see... ...'The Brady Bunch!'"