Wirt writes:

>Bruce writes:
>
>> One of Dan Goldin's most arresting visions is a kindergarten classroom of
>>  2025 with pictures of blue and cloudy planets on the walls -- planets
>>  with strangely-shaped continents, circling other stars. Extrasolar
>>  planets as places, not just Doppler shifts.
>
>I'm sure that this is one of the reasons that people such as Nevill Woolf
>roll their eyes. This is an enormously tougher proposition to accomplish
>than
>this short sentence sounds like it ought to be.
>
>If we ever get [extrasolar planets] so that they can be resolved out of
>their central star's glare as simply a distinct point of light, that's
>going to have to be described as something close to a miracle.

While the task is daunting, I think that "miracle" may be going too far.
Unfortunately, the _Science_ article isn't yet part of the journal's free
content, but there's more (well-founded) hope than Wirt implies. The
steps to getting most of the way there -- and in particular, the steps to
getting to a point where spectroscopic observations of extrasolar planets
are possible -- are pretty clear, requiring in most cases incremental
improvements in existing technologies. The hardest challenges have to do
with maintaining a 6000 km baseline for an optical interferometer; if any
"miracles" are needed, it's in this area.

Dan Goldin's vision is for 25 to 30 years out. In the last 30 years,
sensor technology has improved dramatically. The most outstanding example
is in the angular resolution of X-ray images: almost eight orders of
magnitude from 1968 to 1999. A 50-million-fold improvement in angular
resolution would have seemed like a miracle in 1968, but it's here.

In the interest of not being too pollyanna, I'll point out that both of
the imaging projects now being worked on will use infrared rather than
visible light. This makes the task easier because planets are much
brighter in the infrared than they are at visible wavelengths. So
circa-2025 pictures of blue and cloudy worlds, if any, will have to be in
false color :-).

-- Bruce

PS. Besides, when you find a bureaucrat with vision, you don't want to do
anything to discourage them :-).

- B


--------------------------------------------------------------------------
Bruce Toback    Tel: (602) 996-8601| My candle burns at both ends;
OPT, Inc.            (800) 858-4507| It will not last the night;
11801 N. Tatum Blvd. Ste. 142      | But ah, my foes, and oh, my friends -
Phoenix AZ 85028                   | It gives a lovely light.
btoback AT optc.com                |     -- Edna St. Vincent Millay
Mail sent to [log in to unmask] will be inspected for a
fee of US$250. Mailing to said address constitutes agreement to
pay, including collection costs.

* To join/leave the list, search archives, change list settings, *
* etc., please visit http://raven.utc.edu/archives/hp3000-l.html *