- Press Release
- Jan 28, 2023
UA Astronomers Discover that Earth’s Second Moon Wears Apollo Era Paint
Astronomers have the first direct evidence that a newly discovered object
orbiting Earth is debris from one of the Apollo moon launches over 30 years
Carl Hergenrother and Robert Whiteley, astronomers at the Lunar and
Planetary Laboratory at the University of Arizona, used the Steward
Observatory 61-inch telescope near Mount Bigelow in the Santa Catalina
Mountains north of Tucson for observations of J002E3.
The mysterious object named J002E3 was discovered in orbit around Earth on
Sept. 3 by amateur astronomer Bill Yeung, viewing from a site in southern
California. The discovery made news headlines as it might be the only
satellite, other than the moon, naturally captured by Earth to enter Earth
After studying the object’s past motion, Paul Chodas of the NASA Jet
Propulsion Laboratory (JPL) in Pasadena, Calif., concluded that the object
had been orbiting the sun until April of this year, when it was captured by
Earth. Researchers have believed that J002E3’s small size and unusual orbit
suggest the object is no asteroid or other natural object, but a piece of
man-made “space junk,” possibly a piece of one of the Saturn V rockets that
launched American astronauts to the moon during the Apollo program. The JPL
news release is on the web at http://neo.jpl.nasa.gov
Hergenrother and Whiteley measured reflected light from the object Sept. 12
and 13. The photometric measurements showed that the object spins once every
63.5 seconds or once every 127 seconds – more observations are needed to pin
down the exact time, Hergenrother said. “Such a rapid rate of rotation is
not unheard of either for an asteroid or a piece of man-made space junk, but
is very consistent with each,” he added.
The UA astronomers made their definitive observations with various filters
to sample the colors, or spectra, that J002E3 reflects.
“Rather than looking like a known asteroid, the colors were consistent with
the spectral properties of an object covered with white Titanium oxide (TiO)
paint,” Hergenrother said. “The Apollo Saturn S-IVB upper stages were
painted with TiO paint,” he noted.
Hergenrother and Whiteley checked their observations with some professional
colleagues, ” a kind of informal ‘peer review’ just in case we were way off
on things,” Hergenrother said.
Those key colleagues include Richard Binzel and Andrew Rivken of the
Massachusetts Institute of Technology. Binzel and Rivken took infrared
spectra on the unique object, and those spectra “confirm that J002E3 is a
dead ringer for white TiO paint,” Hergenrother added.
The object is most likely a S-IVB from either Apollo 8, 10, 11, or 12, with
Apollo 12 being most likely, the UA researchers conclude.
“As Bill Yeung said, this is the first recorded observation of any object
being captured into a geocentric orbit,” Hergenrother said.
“There is also a fairly good chance that J002E3 might crash into the moon at
some point. Scientifically, that isn’t too important, but it is interesting,
” he said.