Small asteroid misses Earth by only four thousand miles

Small asteroid misses Earth by only four thousand miles


http://www.newscientist.com/news/news.jsp?id=ns99996307


Jim Oberg asks -- were there any other possibile sensors
thatr might have detected (but not identified) this bogie?
Visual? Radar? IR?


Asteroid shaves past Earth's atmosphere

13:59 23 August 04

NewScientist.com news service

The closest observed asteroid yet to skim past the Earth without hitting the
atmosphere, was reported by astronomers on Sunday.

The previously unknown object, spanning five to 10 metres across, has been
named 2004 FU162. It streaked across the sky just 6500 kilometres - roughly
the radius of the Earth - above the ground on 31 March, although details
have only now emerged.

"Jim Oberg" wrote in message ...

Small asteroid misses Earth by only four thousand miles


http://www.newscientist.com/news/news.jsp?id=ns99996307


Jim Oberg asks -- were there any other possibile sensors
thatr might have detected (but not identified) this bogie?
Visual? Radar? IR?

Depends where it's coming from. Earthbound visual detectors
are useless for objects approaching from the daylight side of
Earth, since no reflected sunlight is visible. Radar and IR are
better, but not many have enough resolving power to detect a
5-10m object.

Something that size didn't/doesn't pose anything but a very
localized risk anyway.

Rick

Asteroid shaves past Earth's atmosphere

13:59 23 August 04

NewScientist.com news service

The closest observed asteroid yet to skim past the Earth without hitting the
atmosphere, was reported by astronomers on Sunday.

The previously unknown object, spanning five to 10 metres across, has been
named 2004 FU162. It streaked across the sky just 6500 kilometres - roughly
the radius of the Earth - above the ground on 31 March, although details
have only now emerged.

"Rick" wrote in message
...
"Jim Oberg" wrote in message
...

Small asteroid misses Earth by only four thousand miles


http://www.newscientist.com/news/news.jsp?id=ns99996307


Jim Oberg asks -- were there any other possibile sensors
thatr might have detected (but not identified) this bogie?
Visual? Radar? IR?

Depends where it's coming from. Earthbound visual detectors
are useless for objects approaching from the daylight side of
Earth, since no reflected sunlight is visible. Radar and IR are
better, but not many have enough resolving power to detect a
5-10m object.

Something that size didn't/doesn't pose anything but a very
localized risk anyway.

Rick

Sounds like an ideal type body for asteroid material return.
300-1,000 tons of material if you can figure a capture
to orbit method.

"redneckj" wrote in message news:bNsWc.44518
snip
Sounds like an ideal type body for asteroid material return.
300-1,000 tons of material if you can figure a capture
to orbit method.
snip

Totally, what a great way to do some research then to have an asteroid
orbiting the earth, up close and personal. I wonder what sized body it would
take before it had an effect on the earth, much like the moon does?

BV.

"Benign Vanilla" wrote in message ...
"redneckj" wrote in message news:bNsWc.44518
snip
Sounds like an ideal type body for asteroid material return.
300-1,000 tons of material if you can figure a capture
to orbit method.
snip

Totally, what a great way to do some research then to have an asteroid
orbiting the earth, up close and personal. I wonder what sized body it would
take before it had an effect on the earth, much like the moon does?

BV.

Capture to reentry might be easier. But any capture for research and
analysis is no more useful than all the meteorite analysis already
done.

Capture for semi commercial exploitation would be a MASSIVE
breakthrough.

In sci.space.policy Benign Vanilla wrote:

"redneckj" wrote in message news:bNsWc.44518
snip
Sounds like an ideal type body for asteroid material return.
300-1,000 tons of material if you can figure a capture
to orbit method.
snip

Totally, what a great way to do some research then to have an asteroid
orbiting the earth, up close and personal. I wonder what sized body it would
take before it had an effect on the earth, much like the moon does?

Approximately moon sized ;-) Well, ok, it might be small moon sized but
not a "pebble" sized.


BV.



--
Sander

+++ Out of cheese error +++

"redneckj" wrote in message
...

Sounds like an ideal type body for asteroid material return.
300-1,000 tons of material if you can figure a capture
to orbit method.

Oh, God, yes. I'd rather see something like that before I die than men on
Mars. Men on Mars may not necessarily lead on to anything else, in the same
manner as Apollo. But retrieval of space resources to HEO would to me mean
that we were starting the process of being in space to stay.

--


Regards,
Mike Combs
----------------------------------------------------------------------
Member of the National Non-sequitur Society. We may not make
much sense, but we do like pizza.

redneckj wrote:
"Rick" wrote in message
...

"Jim Oberg" wrote in message

...

Small asteroid misses Earth by only four thousand miles


http://www.newscientist.com/news/news.jsp?id=ns99996307


Jim Oberg asks -- were there any other possibile sensors
thatr might have detected (but not identified) this bogie?
Visual? Radar? IR?

Depends where it's coming from. Earthbound visual detectors
are useless for objects approaching from the daylight side of
Earth, since no reflected sunlight is visible. Radar and IR are
better, but not many have enough resolving power to detect a
5-10m object.

Something that size didn't/doesn't pose anything but a very
localized risk anyway.

Rick


Sounds like an ideal type body for asteroid material return.
300-1,000 tons of material if you can figure a capture
to orbit method.




Went by kind of quickly: V inf was 10.84 km/sec and V perigee 13.39 km/sec
V circular orbit at that altitude is 5.57 and escape 7.87 km/sec. You
would need 5.23 km/sec delta vee or more to capture it.

http://neo.jpl.nasa.gov/cgi-bin/neo_...how=1&from=120

There are much nicer asteroids in terms of delta vee. The above website
allows you to sort close approaches by relative velocity, distance, etc.


--
Hop David
http://clowder.net/hop/index.html

"Hop David" wrote in message
...


redneckj wrote:

Sounds like an ideal type body for asteroid material return.
300-1,000 tons of material if you can figure a capture
to orbit method.




Went by kind of quickly: V inf was 10.84 km/sec and V perigee 13.39 km/sec
V circular orbit at that altitude is 5.57 and escape 7.87 km/sec. You
would need 5.23 km/sec delta vee or more to capture it.


http://neo.jpl.nasa.gov/cgi-bin/neo_...how=1&from=120

There are much nicer asteroids in terms of delta vee. The above website
allows you to sort close approaches by relative velocity, distance, etc.

That vee is most inconvenient for the purpose. My mental picture was
of an object with about 1 km/sec at infinity. Perhaps 200 m/sec over
escape at perigee. I was thinking of capture to high eliptical orbit.
Still a lot of vee to rendezvous each time, and too much Van Allen
exposure, but doable. Maybe another body at another time.

--
Hop David
http://clowder.net/hop/index.html

redneckj wrote:

Went by kind of quickly: V inf was 10.84 km/sec and V perigee 13.39 km/sec
V circular orbit at that altitude is 5.57 and escape 7.87 km/sec. You
would need 5.23 km/sec delta vee or more to capture it.



http://neo.jpl.nasa.gov/cgi-bin/neo_...how=1&from=120

There are much nicer asteroids in terms of delta vee. The above website
allows you to sort close approaches by relative velocity, distance, etc.


That vee is most inconvenient for the purpose. My mental picture was
of an object with about 1 km/sec at infinity. Perhaps 200 m/sec over
escape at perigee. I was thinking of capture to high eliptical orbit.

My mental picture as well, with a slight alteration: The perigee would
more likely be between 1 and 3 lunar distances (More than 3 LD and it's
very easy to perturb it out of earth's Sphere Of Influence). At higher
altitudes it might be easier to come up with the delta vee to nudge it
into an elliptical orbit.

Still a lot of vee to rendezvous each time, and too much Van Allen
exposure, but doable. Maybe another body at another time.

Using the same site I cited earlier:
http://neo.jpl.nasa.gov/cgi-bin/neo_...Table& show=1

To get above page I chose

Sort by relative velocity H=24
Future only Ascendng Sort
20 rows per page max Nominal dist. = .1 AU

There are some asteroids the size of a basketball,
which aren't worth the effort.
The H=24 makes it likely the asteroid has a diameter
exceeding 50 meters

For these the minimum V inf is around 1.5 km/sec.

You can get much lower V inf if you expand Nominal dist.= .2 AU but
then it would take some delta vee to bring it within Earth's Sphere Of
Influence.

(I chose 20 rows per page because "show full table" takes awhile to
download even with DSL)

The best resource on NEOs is the jpl website in my opinion. Yeoman,
Baalke et al deserve some Kudos.


Using MADMEN you can use fission or solar energy and asteroid material
as reaction mass
http://www.space.com/businesstechnol...ed_040519.html
So it doesn't have to be hugely expensive to change an asteroid's velocity.

--
Hop David
http://clowder.net/hop/index.html