Hi All

The ESO's Working Group on Exoplanets has released an interesting report. The report is really interesting because it seems that the OWL super-telescope project will be able to directly detect (via some neat optics) exo-Earths out to ~ 10 pc, and exo-Jovians even further out. The OverWhelming Large telescope will have a 80-100 metre diameter main mirror, which is just phenomenal. Coupled with adaptive optics and some new tricks it will have a vast reach into the depths of space.

Even better would be an interferometer based on multiple OWLs on the Farside of the Moon... but that's a dream for the planners of another decade or two away. Such a system would be able to directly image (~ 100 pixel wide) exo-Earths out to ~ 100 pc. And it would be able to detect them maybe 1000 pc or more away.

So what if OWL, or more near term giants, detected an exo-Earth at Alpha Centauri? Searches for Jovians around A, B or Proxima have come up empty so far, but Neptunians or terrestrials are an open question.

If a bright spark was found around A or B there'd be a race to get a spectrogram and see if it had an oxygen atmosphere.

If so, then the optical interferometers would be trying to image it in ever greater resolution.

Would it spur an interstellar effort? Jordin Clare's laser-bomblet driven starship is a "near-term" system (assuming SPS) able to accelerate a vehicle to ~ 0.1 c or so. I'd say the push would be for ~ 0.2 c at least and maybe ~ 0.4. Say a fly-by imager at 0.4 c and a heavier orbiter/lander-bus at ~ 0.2 c. Thus first results ~ 15 years after launch and detailed study 12 years after that.

Would any one nation dare to bridge the stars at 0.1-0.3 c to follow the probes if the report was favourable? A manned mission at 0.3 c would take ~ 14 years to cross the gulf with ~ 1 year to deccelerate and approach. An orbiter/lander would be logical since we're talking one-way flight. And preferably a "fleet" of vehicles, armed with sensor webs and lasers/nukes powerful enough to vaporise interstellar debris encountered during the trek. The lone-starship of stereotypical Trekiverse fiction is stupid. Debris could wipe you out and no one would ever know the details.

Personally I'm not keen on Gary's World-Ship approach - making 200 years/light-year seems excessively slow. There is debris, but is there so much that ships have to "crawl" through deep-space? Personally I think the active sensors/weapons approach makes more sense, perhaps combined with a cloud of "dusty plasma" as a precursor shield. If plasma-dust sails can be developed (they're being researched) they'd make ideal interstellar shields, vaporising any debris nuggets long before they strike. A carbon erosion shield can then easily handle the plasma/vapour.

But this will all be pissing in the wind if we never get serious about space colonisation. For example, the super-volcano in Yosemite could blow tomorrow and would proceed to wipe out human life. It either erupts or blows-up every ~ 600 Kyr and last blew ~ 635 Kya so it's overdue. Unless we get off this rock and/or build self-contained habitats we will never avoid planetary hazards like that. Some rock will get us if planet Earth doesn't first - it almost took us out when Mount Toba blew ~ 71,000 years ago. That's the human genetic bottle-neck, when we were reduced to a few bands, one of which led to all non-Africans.

What if they never made it?

Adam