1900

The number of known NEOs has surpassed 1900 (c.f., http://cfa-www.harvard.edu/iau/lists/Unusual.html):
* 150 Atens
* 894 Apollos
* 861 Amors

Does anyone care to guess the exact date when the number will reach 2000?
See attached notes for earlier level-crossing dates.

Ron Menich

rmenich@...
03/14/2002 01:49 AM

The number of known NEOs has hit the 1800 mark for the first time (c.f., http://cfa-www.harvard.edu/iau/lists/Unusual.html):
* 138 Atens
* 837 Apollos
* 825 Amors

We passed
* 1500 on 20010926
* 1600 on 20011121
* 1700 on 20020111
* 1800 on 20020313

More NEOs have been discovered since September than were discovered from
the dawn of time until Gerard K. O'Neill's death.

Ron

rmenich@...
01/11/2002 07:31 PM

The number of known NEOS has first surpassed the 1700 mark (c.f., http://cfa-www.harvard.edu/iau/lists/Unusual.html):
* 130 Atens
* 782 Apollos
* 792 Amors

Sometimes a 'known' NEO is rescinded, and thus the count is not always
monotonically increasing. That's why I use the terminology "first
surpassed".

But clearly the trend is up and up. I attach my previous messages from
dates at which the count first passed the 1500 and 1600 marks. We passed

1500 less than 4 months ago! And all of these discoveries were on what,
compared to the Shuttle and ISS, are miniscule budgets.

Ron

rmenich@...
11/21/01 01:36 PM

As of this morning, the number of NEOs first surpassed the 1600 mark
(c.f., http://cfa-www.harvard.edu/iau/lists/Unusual.html):
* 122 Atens
* 728 Apollos
* 754 Amors

I attach below my note from 9/26, the date at which the number of NEOs
first passed the 1500 mark.

Happy Thanksgiving. We should all give thanks for the LINEAR telescope,
which accounts for 70% of new minor planet discoveries.

Ron
rmenich@...
09/26/2001 08:40 AM AST

Yes, I agree that this group should be large and diverse enough to discuss

both Lunar and NEO options. And the points you make are fair. You may be

right that lunar resource utilization scenarios are better, at least in
the near term.

I guess one of my major points is that SSI and the folks who contribute to

this list are quite familiar with the ideas of O'Neill, and O'Neill's
major thrust was the lunar mass driver and utilization of Lunar resources.

In part because of O'Neill's charisma and his book, and in part because
of historical lack of knowledge regarding NEOs, lunar resource utilization

studies are pretty well advanced relative to NEO utilization studies.
Researchers have done analyses on lunar missions, oxygen production via
various means, etc. NASA summer studies in the late '70s built on the
O'Neill's lunar resource utilization ideas.

But there are now well over 30 times as many known NEOs as when O'Neill
first formulated his space colony ideas, and there are over six and a half

times as many known NEOs as when O'Neill died in 1992. And the number of

known NEOs grows almost daily. AS OF THIS MORNING, the number of known
NEOs surpassed the 1500 mark. There are now 1503 known NEOs, comprising
115 Atens, 684 Apollos, and
704 Amors ( c.f., http://cfa-www.harvard.edu/iau/lists/Unusual.html ). I think that, were O'Neill alive today, he would be more balanced in
comparing lunar and asteroidal resource utilization scenarios, and so
would the downstream research that would stem from his charisma.

I do not oppose lunar resource utilization. I see the merits of proximity

to Earth in terms of travel time and the time value of money, ability to
use teleoperation, and the like. It's just terribly exciting to me that a

new avenue for extraterrestrial resource utilization --- NEOs, the avenue
that O'Neill only saw dimly because little was known about them in 1977
--- becomes more apparent every day.