This astroalert arrived yesterday:

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This Is SKY & TELESCOPE's AstroAlert for Minor Planets
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MYSTERY OBJECT

Since September 5th, the Minor Planet Mailing List (MPML)
has been abuzz with speculation about an unidentified 16th-
magnitude object. During the next 10 days the object will be
moving rapidly across Aries and then Taurus, passing between
the Pleiades and Hyades star clusters.

Bill Yeung discovered the object September 3rd in CCD images
taken with an 0.45-meter telescope in Benson, Arizona. The
fast-mover was "auto detected" when he analyzed his images
with DC-3 Dreams' PinPoint software. Yeung e-mailed the
positions to the Minor Planet Center (MPC) in Cambridge,
Massachusetts ( http://cfa-www.harvard.edu/iau/mpc.html ),
which quickly posted the object on its Near-Earth
Object Confirmation Page under the temporary designation
J002E3. But within a few days the MPC removed the object
from that listing; preliminary orbit calculations
suggested it was traveling in a large, 50-day orbit around
the Earth, not the Sun. It had all the earmarks of being a
spent rocket casing or other piece of "space junk" instead
of a true minor planet.

But what exactly is it? Efforts by Tony Beresford in Australia
and other satellite experts have failed to match this object
with any known artificial satellite. Photometric measurements
by Peter Kusnirak in the Czech Republic failed to show much
variation in brightness, as would be expected of a small
metallic object, especially if cylindrical. But the big
question is, if it is really in Earth orbit, why has it not
been detected before? In Yeung's words, 16th magnitude should
have made it "a piece of cake" for survey telescopes like
LINEAR and NEAT, or for CCD-equipped amateur instruments,
to locate long ago.

Finally, late on September 9th, Paul Chodas (Jet Propulsion
Laboratory) weighed in with this posting to the MPML:

"The unusual object J002E3, formerly on the Minor
Planet Center NEO confirmation page, has been loaded
into our Horizons system so that interested observers
can generate ephemerides.... Further observations of
the object are highly desirable to help characterize
the nature of the object: we will update our orbit
solution as they become available.

"Telnet and email users of Horizons can access this
object by typing 'J002E3'. Web users of Horizons can
access the object by going to the Major Body Menu,
selecting the Spacecraft list, and choosing the entry
'J002E3 Spacecraft (UNCONFIRMED)'. The available
time span is currently August 1 through December 1,
2002. The telnet address of Horizons
is ( telnet://ssd.jpl.nasa.gov:6775/ ), and the web
address is ( http://ssd.jpl.nasa.gov/cgi-bin/eph )."

For the full text, or to subscribe to the Minor Planet Mailing
List, please visit these URLs:

MPML Home page ( http://www.bitnik.com/mp )
MPML FAQ ( http://www.bitnik.com/mp/MPML-FAQ.html )
MPML's Yahoogroups page ( http://www.yahoogroups.com/group/mpml )

Amateurs who are experienced in astrometry should have no
trouble recording this mystery object with CCD-equipped 8-inch
and larger telescopes. Measurements should be sent both to
Chodas ( paul.chodas@jpl.nasa.gov ) and to the Minor Planet
Center ( mpc@cfa.harvard.edu ) using the standard reporting
format.

We don't provide an ephemeris in this AstroAlert because, like
2002 NY40 a few weeks ago, J002E3 has a very large topocentric
parallax. You'll need to enter your own observatory code,
or a latitude and longitude, into HORIZONS to obtain accurate
predictions for your location.


Roger W. Sinnott
Senior Editor
Sky & Telescope


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<font size=-1>[Shortened AstroAlert spacers, fixed urls, changed thread title from "Unusual Object J002E3, *formerly* on MPC NEO list"]</font>

<font size=-1>[ This Message was edited by: GrapesOfWrath on 2002-09-11 12:51 ]</font>

Any clue as to what the inclination is?

Aha, I found a Guardian article.They're calling it Earth's second moon. The article says it is inclined 21 degrees to the ecliptic.

That would be a clue, but the object goes way out past the moon's orbit, so maybe it's been perturbed considerably--if it is an old piece of space hardware.

<font size=-1>[Fixed url]</font>

<font size=-1>[ This Message was edited by: GrapesOfWrath on 2002-09-11 12:46 ]</font>

Souldn't that be earth's third moon; after cruithne ?
BBC article: http://news.bbc.co.uk/2/hi/science/nature/2251386.stm

Cruithne: http://burtleburtle.net/bob/physics/cruithne.html

Absolutely.

The NEO site has the message: J002E3 was not a minor planet (Sept. 6.68 UT)

So what's the inclination to the equator? The equator is 23 deg to the ecliptic so the new moon could be almost equatorial; or it could be 44 degrees to the equator; or so I think. Right?

Maybe it's Rama. Let's pay a visit.

__________________
Does earth plug a hole in Heaven or Heaven plug a hole in Earth? -Peter Gabriel

The Sky and Telescope online article has it moving northeasterwardly in Pisces.

Those clever folks at JPL think it's the Apollo 12 third stage, back from a sojourn in solar orbit.

_________________
"... to strive, to seek, to find, and not to yield." - Tennyson, Ulysses

<font size=-1>[ This Message was edited by: ToSeek on 2002-09-11 22:58 ]</font>

That is a really cool animation they have. I wonder if it is possible to predict the future of the orbit? I wonder how long before it gets ejected from the earth-moon system?

So, if I'm reading it right, the Apollo 12 SBIV was actually left in orbit around the Earth in the '70s. But they think it escaped into solar orbit, floated around for a few decades, and then got recaptured by the Earth, and in much the same orbit as it had before. That's quite a surprising trip. [img]/phpBB/images/smiles/icon_eek.gif[/img]

But they also say it could be from one of the other pre-landing missions as well. I wonder what info makes them suspect A-12 the most? And of course, it's possible that it's just an asteroid, and not Earth hardware at all.

They also say it has a 20% chance of hitting the Moon next year, and a 3% chance of hitting the Earth in the next decade. I actually kind of hope it strikes the Moon, as long as it hits on the near side. That would be an interesting event to observe. [img]/phpBB/images/smiles/icon_smile.gif[/img]

Of course, if it manages to stay in orbit for a long time, we might eventually be able to send out a small probe and get a good look at it. Whether asteroid or old hardware, that would make for a great mission, IMO.

__________________
...And that, my liege, is how we know the Earth to be banana-shaped. --Sir Bedevere

Squink posted:
Souldn't that be earth's third moon; after cruithne ?
BBC article: http://news.bbc.co.uk/2/hi/science/nature/2251386.stm

Cruithne: http://burtleburtle.net/bob/physics/cruithne.html

Not really. 3753 Cruithne is an *asteroid* of the Aten class (period 0.997 years,
semi-major axis 0.998 A.U., and an inclination 19.8 degrees to the ecliptic). It is not in orbit around the Earth in the same way a satellite or the Earth's moon is. Its orbit takes the asteroid from just outside the orbit of Mercury to just outside the orbit of Mars, so it spends most of its time well away from the Earth. It currently has an encounter "resonance" with the Earth's (it currently comes by us every year at roughly the same time), but it doesn't come particularly close (about 31 million miles this November). However, it is clearly in a solar orbit and thus is *not* a moon of the Earth, despite what some rather exagerated press releases might be saying (I'm a little surprised that the BBC didn't get this right). Clear skies to you.

One of its discovers, Paul Wiegert, has described it as Earth's "companion asteroid." He mentions that they've found a couple more.

The original article in Nature was titled "An Asteroidal Companion to Earth." His webpage about the asteroid (I got the addresses from the BA's page about Cruithne) said "The near-Earth asteroid 3753 Cruithne is in an unusual orbit about that of the Earth," so it's not hard to see how the BBC might interpret that that way.

<font size=-1>[Add pdf article link, and reference to 1998 UP1 and 2000 PH5]</font>

<font size=-1>[ This Message was edited by: GrapesOfWrath on 2002-09-13 10:10 ]</font>

The object was captured when it passed in the L1 point? Isn't that where SOHO is? Of course, the chance that they would have hit one another is still small.

__________________
Isn't the fact that they don't visit us proof that intelligent life is out there?

The Confused Philosopher - RCAF

The L1 is more a volume than a "point". Also, SOHO is not at the "point" but more of a loose orbit in the general vicinity.

__________________
Any day you wake up on "the right side of the dirt" is a good day.

T. Anderson

Ah.

I was just saying that, if NASA's theory is correct, the 2 spacecraft might have still be pretty close to one another, at least by astronomical standards. But like I said, the chance of a collision would have been very small.

__________________
Isn't the fact that they don't visit us proof that intelligent life is out there?

The Confused Philosopher - RCAF

Well, there's been a lot of discussion about the object. as for apollo boosters, a reverse run of all the data from the orbits shows it may have left a geocentric orbit in 1971... timewise, that would narrow it down to only one possible S-IVb rocket... My confusion is that NASA and JPL have tried to use this same explanation for two other weird objects, 1991VG and 2000SG344.
Whatever, look for it on Sept 28th... it's going to be magnitude 42. Should be pretty easy to track, if you use JPL's data. Hopefully someone paints it with some radar and gets a good image.

http://www.cnn.com/2002/TECH/space/0...oon/index.html
Ohhhh, noooo, I have the sinking sensation that he probably should NOT have said that. Nobody would have worried about it destroying the world--until somebody SAID, "There's no danger of it destroying the world."

Great. Now we can all look forward to two weeks of It's-The-End-Of-The-World / No-It's-Not-The-End-Of-The-World /How-Can-We-Know-For-Sure-Whether-It's-The-End-Of-The-World-Or-Not-I'm-Packing-Anyway hysteria...

On 2002-09-13 15:35, Chip wrote:
Object J002E3: Amateur astronomers who feel up to the challenge of spotting this object, believed to be a booster from Apollo 12, will need a telescope of 8-inches or larger.

This website offers information on where to report observations.

Wouldn't it be beautifully ironic if the Appolo 12 booster did impact earth, and landed on Bart Sibrel?