Yesterday, I wrote:

> Tomorrow at 1pm EDT, NASA has scheduled a space science update. This one
> touts a major new extrasolar discovery. What this almost certainly means is
> not that life has been detected outside our own solar system. Much more
> likely -- but otherwise I have no idea what they're going to say -- is that
> they've improved their experimental resolutions to the point that they can
> possibly sense planets that may be only a few times larger than Earth. If
> that's true, then the second expected announcement would also be that
they've
> just increased the number of extrasolar planets found by several times,
given
> that Earth-size planets ought to at least equal in number the size of the
gas
> giants, especially among those planets that are close in to their
respective
> stars.
>
>  But all of that is a guess on my part. While the conference won't be
> broadcast on NASA TV (meaning that it can't be of all that important),
these
> conferences are almost always to be found on the web somewhere (space.com
is
> a good place to look) and I find them very interesting.
>
>  Nonetheless, whatever they say, you'll almost certainly hear a very
> condensed version of it on the nightly news tomorrow evening. I've enclosed
> NASA's announcement below:

Early this morning, quite a few hours ago, I received the following note from
from Jean Schneider of the Paris Observatory, which in a blatant break with
netiquette, I'll repeat here:

=======================================

Subj:    nasa announcement: wrong guess
Date:   6/13/02 12:35:39 AM Mountain Daylight Time
From:   [log in to unmask]
To: [log in to unmask]

You wrote "Much more
likely -- but otherwise I have no idea what they're going to say -- is
that
they've improved their experimental resolutions to the point that they can
possibly sense planets that may be only a few times larger than Earth"

They will announce:
- about 15 planets
- one with 30 Earth masses
- one "true Jupiter" at 5 AU from the star (mass=4 Jup)
- one system with 3 planets

That is at least what they have in their data, may by they will not
announce everything today.
To have accurate updates, look at www.obspm.fr/planets

You may also know that Geoff Marcy and Paul Butler are not those who have
discovered the first planet.

J. Schneider

=======================================

As it's still an hour before the NASA webcast, it's good to know what they
are going to announce. Virtually all of the extrasolar planets that have been
discovered thus far have been accomplished by observing the doppler shift in
the spectral light of their host stars (however, there are a few transiting
planet discoveries to boot).

While planets orbit around their stars, the stars also orbit around their
planets. Of course, the stars' motion isn't all that much, just a few
meters/second back and forth due to the motion of Jupiter/Saturn-like planets
and just centimeters/second for Earth-sized planets. Right at the moment, the
last I heard, the best that the experimental setups can measure is
back-and-forth motion in the 3-5 meters/second range, but there is no
theoretical reason why cm/sec measurements can't eventually be accomplished,
thus allowing us to see planets equivalent to earth masses at earth distances
from their stars.

That was my hope that today's announcement, that it would say that
instrumentation of this quality had been built. Of course, this comes from
someone who pays only very minor attention to the field. Nonetheless, once
accomplished, the number of planets that will be found is expected to rise
dramatically, essentially by an exponential power law.

But Jean Schneider is different from me. Jean maintains a constantly updated
extrasolar planet encyclopedia at:

     http://www.obspm.fr/encycl/encycl.html

Just to introduce us all to Jean, it's important to know that none of us are
planetary astronomers. We're just a bunch of computer geeks who occasionally
take an interest in other things outside our well-lit, well-refridgerated
computer rooms.

And as to the comment regarding the history of extrasolar planetary
discovery, there's a very concise history at:

     http://www.public.asu.edu/~sciref/exoplnt.htm

...if you're interested.

Wirt Atmar

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