Anyone interested in science and outer space exploration knows that
today Huygens probe had just now successfully landed on Titan,
Saturn's largest moon. The probe began transmitting radio beacon
siginal at 11:25 CET, and the Green Bank radio telescope in West
Virginia, USA, picked up this faint but unmistakable radio signal (2040
MHz) from the probe.

My wondering is, considering the huge distance between Titan(Saturn)
and Earth, and the undirectionality of the beacon radio signal (not the
ones modulated with scientifically data that will be picked up by
Cassini and relays directionally to Earth), the telescope in WV must be
very very sensitive. Can anyone estimate what sensitivity it has, and
compare it with a regular radio receiver (say, 0.1uV)?