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I found the Geoff Marcy piece very interesting - optical SETI has been around for a while, and having a big name planet hunter associated with it will give it credibility.

But I'm wondering how that laser guide star (LGS) comment got in there... the LGS we use are rarely more than 20 W of optical emission, shining up through a turbulent (and therefore scattering) atmosphere, and even then that's ignoring diffraction effects over several parsecs which dilute the signal. Google tells me that the moon ranging experiments got almost no return from a dedicated projection telescope (not the 30cm ones LGS use).

SETI won't see our laser guide stars at all, and I'm a bit surprised that Geoff Marcy would say something that far off the mark. I'd believe Galacttic Internet Lasers before SETI looking for LGS.

The first stage of the Planetary Resources venture is to sell small inexpensive space telescopes -- that will be their near-term business. At the press conference, they suggested that universities could buy the telescope itself for somewhere between 1 and 10 million US dollars, and due to its small size, launch costs would also be low (ridesharing with a larger payload). There was also discussion of simply selling time on the scopes.

Midway down on the following page, there is an informative guided tour of the telescopes, and further down on the page, there is speculation about using them for extrasolar planet transit detection, and more.

(Since it is a discussion forum, there is plenty to ignore as well)

For a bit more on the telescopes, see first paragraphs of this article:

It would be interesting to hear what astronomers think.

Some of the comments about the "small space telescopes" in the forum you mention say "Hey, combining the observations from two small telescopes in space would be a cheap way to do interferometry." Those people clearly have no idea of the technical obstacles involved in optical interferometry.

Do they have any expertise in other areas?

By Michael Richmond (not verified) on 27 Apr 2012 #permalink

For whatever it is worth, the forum participants are talking about the Arkyd-200 (the 2nd generation of probes, which would have propulsion as well as a telescope). During the Planetary Resources press conference, an engineer discussed how multiple Arkyd-200 would use lasers to talk to each other in order to operate as a precisely controlled swarm.

As for me, I'm just excited about transits, and I was hoping the first generations scopes could be used for something like TESS.

Ha! I just noticed: it was pointed on later in the same forum discussion that one of the people Planetary Resources lists as an advisor is the TESS Project's Sara Seager.