A friend reminds me of cosmologist Paul Davies'
essay, "Is Anybody Out There?" (April 10, 2010), which provides some interesting information on funding patterns for
SETI, the Search for Extra-Terrestrial Intelligence:
Most of the funding today comes from private donations through the SETI Institute, a private nonprofit founded in 1984 in Mountain View, Calif. The jewel in its crown is the Allen Telescope Array, a $35 million dedicated network of 42 small dishes in northern California, with about $30 million of the funding contributed by Microsoft co-founder Paul Allen. The goal is to ultimately increase the network to 350 dishes. Donors on other projects have included David Packard and Bill Hewlett (co-founders of Hewlett-Packard) and Gordon Moore (co-founder of Intel).
The US government hasn't funded SETI since 1993. Davies offers imaginative ways for the super-rich to look for aliens:
On purely statistical grounds any visitation is likely to have been a very long time ago. To pluck a figure out of midair, imagine that an alien expedition passed our way 100 million years ago. Would any traces remain?
Not many. However, some remnants might still persist. Buried nuclear waste could be detectable even after billions of years. Large-scale mineral exploitation such as quarrying leaves distinctive scars that, in the case of Earth, would eventually become obscured by overlying strata but would still show up in geological surveys. Space probes parked in orbit round the sun might lie dormant yet intact for an immense period of time. Scientists could look for such hallmarks of alien technology on Earth and the moon, in near space, on Mars and among the asteroids.
Davies' (not entirely serious, I suspect) suggestions, intriguing as they are, still remind me - I must admit - of a woman doing Internet searches on an ex-boyfriend and turning up accidentally at gatherings and restaurants he has sometimes frequented. And the reality is that, if he had died in the meantime, she might not even be one of the people that anyone would think to notify. So she could be haunting a ghost, to say nothing of haunting her own real life.