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. |
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