[meteorite-list] Space Radar?

From: Richard A. Kowalski <kowalski_at_meteoritecentral.com>
Date: Thu, 14 Apr 2011 01:04:43 -0700
Message-ID: <4DA6AA9B.7000103_at_lpl.arizona.edu>

On 4/13/2011 11:41 PM, Meteorites USA wrote:
> How much is the Earth worth? ;)
>
> Eric

Hey Eric.
I know this was a bit of a rhetorical question, but I'll add a bit more to this
discussion for those who may not be familiar with the topic.

Unless I missed something, the United States is the only country funding NEO
surveys at this time, so apparently the "worth" of the earth, as ascribed by the
rest of the world is nothing, zip, nada. At least on this topic

I think you're point is probably better formed by the question "How much is our
civilization or species worth?"

About one month ago we had a meeting here in Tucson consisting of
representatives from all of the current major NEO surveys, professional follow
up observatories, other associated parties and Lindley Johnson and Don Yeomans.
Don may be familiar to some of you and he is the Manager of the NEO Program
Office at JPL and Lindley is the Program Officer at NASA HQ.

Lindley commented that as March 1st the estimated population of NEOs 1km in
diameter and larger was estimated at 940 to 1050 objects. with a total of 6938
known NEOs of all sizes. At that time we had discovered 909 1km and larger NEOs,
or approximately 87 - 97% of the population. Since we were tasked at finding 90%
of all NEOs in this size range, we have effectively completed the original goal
of the Spaceguard program, but he did stress that "we" aren't ready to make this
claim just yet. To prove the point that we aren't quite finished, I picked up
another 1km object on my very first run on a telescope after the meeting.

As you know the 1km diameter was chosen because it is the size object that will
end our civilization and anything much larger than that will make us go extinct.

The next phase has not yet started, despite the claims in the media last yet
that we are already failing behind in the task. Kinda confusing how anyone can
claim we are behind in accomplishing a task that we haven't been given the go
ahead to start, but we've recently seen you have to take the media with a grain
or two of salt...

Anyway, the new goal reduces the minimum size to 140 meters in diameter and this
was chosen for a number of reasons, not the least of which is objects this size
can cause substantial damage and death on national scales. If this next phase is
funded, something not certain at the moment, it should take 10 to 15 years to
complete as well. Of course again ground based surveys can do it with the lowest
monetary expense, but at a cost of taking longer to accomplish the task.

An important issue for issue for any ground based survey is that we are
literally blinded by the Sun. Because of this we can't see objects that forever
stay on the daylight side of our planet. To "see" in to this blind spot in our
coverage will require a space based system, but not one that uses radar. A
proposed IR telescope would the Sun not too far out from Venus, looking back
towards the earth. This proposed mission would be able to detect all of these
140 meter objects that threaten us, but it would still require the use of ground
based observatories for support and follow up observations, so it makes sense to
build ground based systems first.

It's been estimated that ground based systems would cost aa much as a 1/4
Gigabuck to build and operate for a decade or so, while the space based system
alone would be at least 1/2 Gigabuck. Combine the two and figure on a bit of
cost over-runs and $1,000,000,000 for all of Phase 2 spread over 10 or 15 years
is not unreasonable.

One final thing; A disclaimer.

As I mentioned in a previous post, I am using my work email to post only because
the list server barfed on my yahoo address earlier tonight.

Nothing posted here is in any way an official statement from NASA, the
University of Arizona, the Lunar and Planetary Laboratory or the Catalina Sky
Survey. This and other posts are my own somewhat informed opinion and should in
no way misconstrued as "official" in any way.

-- 
Richard Kowalski
Catalina Sky Survey
Lunar and Planetary Laboratory
University of Arizona
http://www.lpl.arizona.edu/css/

Received on Thu 14 Apr 2011 04:04:43 AM PDT