As reported by Larry Kellogg, the recent attempt to pick up a signal from Pioneer 10 may have come up short, although the team working on the project is processing the data in the attempt to pin down anything that isn’t noise. Says Kellogg:

Distance makes a difference… The 8 watt transmitter wouldn’t be putting out a full 8 watts (a night light of power) and the signals seen at Earth were buried down in the noise you get from just pointing an antenna out into space. It is like looking for a needle in the front lawn down in the grass.

One spike looks a lot like the one next to it.

If you see something you think is your needle you can narrow the band pass filter and magnify what you are looking at. You don’t see anything next to it though and so you have to look back and fourth and hope you recognize your needle.

We haven’t had any signals from Pioneer since 23 January 2003; the last telemetry data were received on 27 April 2002. With no real-time detection of the spacecraft’s carrier signal, the suspicion grows that we have lost Pioneer 10 forever (although the ongoing data analysis could still prove this wrong). If so, we can thank the probe for its extraordinary journey, and say thanks as well to the team that sent it on its way. A comprehensive book on the Pioneer program is Mark Wolverton’s The Depths of Space (Washington DC: Joseph Henry Press, 2004). The Pioneer 10 and 11 home page is here.