[meteorite-list] Mystery Object Orbits Earth (J002E3)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:08:29 2004
Message-ID: <200209202031.NAA16649_at_zagami.jpl.nasa.gov>

http://science.nasa.gov/headlines/y2002/20sep_mysteryobject.htm

Mystery Object Orbits Earth
NASA Science News

A puzzling object just discovered in orbit around Earth might be an Apollo
rocket on a fantastic journey through the solar system.

Sept. 20, 2002: Something odd is circling our planet. It's small, perhaps
only 60-ft long, and rotates once every minute or so. Bill Yeung, an amateur
astronomer in California, first spotted the 16th magnitude speck of light on
Sept. 3rd in the constellation Pisces. He named it J002E3.

Automated asteroid surveys scan the skies every few weeks, yet there was no
sign of Yeung's object earlier this year. "It must have entered Earth orbit
recently," says Paul Chodas of NASA's Near-Earth Object Program at JPL. "But
it doesn't match any recently-launched spacecraft."

In other words, it's a mystery.

Could it be an alien spaceship? "If it is," says Chodas, "the aliens aren't
good pilots. J002E3 is in a chaotic orbit. It loops around Earth once every
48 days or so, coming as close to our planet as the Moon and ranging as far
away as two lunar distances." There's no evidence that the speck is moving
under its own power. The orbit is constantly changing because of
gravitational perturbations by the Sun and Moon.

At first Yeung and others thought J002E3 might be a small asteroid--a
reasonable guess. The object is as bright as a 30m-wide space rock and it's
moving about as fast as an asteroid should move. Mars and Jupiter have
captured asteroid moons before; perhaps Earth had done the same.

It was a good idea, except for the paint.

That's what University of Arizona astronomers found on Sept. 12th when they
measured the spectrum of sunlight reflected from J002E3. "The colors were
consistent with ... white titanium dioxide paint," says Carl Hergenrother,
who conducted the study (with colleague Robert Whiteley). That's the type of
paint NASA used on Apollo moon rockets 30 years ago.

So, J002E3 might be a spacecraft after all--an old one from Earth. Where has
it been all these years?

"Orbiting the Sun," answers Chodas. "I've traced the motion of J002E3
backwards in time to find out where it's been," he explains. Apparently,
J002E3 left Earth in 1971, went around the Sun 30 or so times, and came back
again. Chodas, a expert in planetary motion who has seen plenty of
complicated orbits, says "I've never seen anything like this."

At first glance, J002E3 would seem to be from Apollo 14. That mission began
in January of 1971, and according to Chodas' calculations J002E3 broke out
of Earth orbit in March of the same year. There's a problem, though: NASA
has accounted for all the big pieces of the Apollo 14 spacecraft. None are
missing.

Chodas inventories the mission: On Jan. 31, 1971, a Saturn V rocket blasted
off from Florida with Al Shepard, Ed Mitchell and Stuart Roosa inside. Two
stages of the rocket fell back to Earth when they exhausted their fuel. A
third stage, the S-IVB fuel tank and rocket engine, which propelled the crew
from Earth-orbit toward the Moon, was likewise discarded. The S-IVB,
however, did not fall back to Earth; it hit the Moon. Ground controllers
guided it there on purpose to provide an impact for lunar seismic monitoring
stations. The lunar module Antares was also deliberately crashed--more data
for the seismic network. The command module Kitty Hawk returned the crew to
Earth.

J002E3 couldn't be any of those things. "There is an outside chance that it
might be one of the Spacecraft-Lunar Module Adapter (SLA) panels," adds
Chodas, "although J002E3 appears to be too bright for one of those."

Another possibility is that J002E3 is an S-IVB from Apollo 12. Unlike Apollo
14, Apollo 12's S-IVB did not crash into the Moon. The crew jettisoned it on
Nov. 15, 1969, when it was nearly out of fuel. Once the astronauts were
safely away, ground controllers ignited the S-IVB's engine. They meant to
send the 60-ft-long tank into a Sun-centered orbit, but something went
wrong; the burn lasted too long. Instead of circling the Sun, the S-IVB
entered a barely-stable orbit around the Earth and Moon "much like the
current orbit of J002E3," notes Chodas.

Eventually, the Apollo 12 S-IVB vanished--no one knows when. Perhaps
gravitational tugs from the Sun and Moon accumulated until they nudged the
engine away from Earth in 1971. In this scenario, it would have circled the
Sun for 31 years until it was re-captured by Earth's gravity in 2002.

"It's plausible," says Chodas, "but still speculative."

Whatever J002E3 is, it's taking a fantastic journey through the solar
system--and it's not done yet. Chodas' calculations indicate that J002E3
will leave Earth again in June 2003 to resume its orbit around the Sun.
"Thirty years from now," he notes, "it might come back again."

If it does, perhaps it will be greeted by human explorers on regular "milk
runs" between the Earth and Moon. They might detour briefly and discover,
once and for all, what J002E3 really is: a historical attraction, maybe, or
something wholly unexpected....

For now the best we can do is watch J002E3 from afar--an unresolved speck of
light easily detected by 8" to 10" telescopes with CCD cameras. This week
J002E3 is gliding through the constellation Taurus. Where will it go next?
Find out by visiting JPL's Near-Earth Object Program web site
(http://neo.jpl.nasa.gov, which offers a helpful ephemeris for observers.
J002E3 won't be here long, so catch it while you can!
Received on Fri 20 Sep 2002 04:31:15 PM PDT