CAMBRIDGE, Mass. – Astronomers at MIT played a key role this week in
identifying a near-Earth object as most likely the third stage of an
Apollo-era moon rocket.

Based on an analysis of the orbital trajectory of the object, it
appears that the object is the S-IVB stage from the Apollo 12 mission,
launched to the moon on Nov. 14, 1969. Further analysis by NASA’s Jet
Propulsion Laboratory scientists indicates that the object is likely to
complete six orbits of the Earth and then return to an orbit around the
Sun sometime next summer.

Professor Richard P. Binzel and research scientist Andrew Rivkin from
MIT’s Department of Earth, Atmospheric and Planetary Sciences became
aware of the discovery of the unusual object in Earth orbit earlier
this month.

Amateur astronomer Bill Yeung discovered the object, known as J002E3,
on Sept. 3. Paul Chodas of the Jet Propulsion Laboratory analyzed the
object’s orbit and determined that it entered an Earth-centric orbit in
April after being in a heliocentric orbit.

“We had read about J002E3 and the question of whether it was an
asteroid or Apollo Saturn stage, and realized that we had the chance to
take an infrared spectrum and possibly help identify it,” Rivkin said.

Binzel and Rivkin used NASA’s Infrared Telescope Facility in Hawaii to
conduct a spectral analysis of the object in infrared wavelengths of
light between 0.8 microns and 2.5 microns. The telescope was operated
remotely from a computer facility in the Green Building on the MIT
campus.

Rivkin and Binzel analyzed the data to obtain a spectrum, and found it
looked unlike any asteroids they had previously seen. While puzzling
over the first night’s data, they received an e-mail from Carl
Hergenrother and Rob Whiteley, astronomers at the Lunar and Planetary
Laboratory at the University of Arizona, who had also observed J002E3
in visible light using the Steward Observatory in the Santa Catalina
Mountains.

“We were able to combine our two data sets and produce a single
spectrum spanning the visible and infrared, which is of a shape that
looks a lot like titanium oxide paint,” Rivkin said. The third stage of
the Saturn V moon rocket was painted with white titanium oxide paint.

Binzel and Rivkin were able to correlate the spectral analysis observed
using the telescope with known measurements of titanium oxide paint.
“We now have available titanium oxide paint measurements at
near-infrared wavelengths that are an excellent match to the telescopic
measurements using NASA’s Infrared Telescope Facility,” said Professor
Binzel, whose work is partially funded by the National Science
Foundation.

The Saturn V’s third stage, called the S-IVB, was used in the Apollo
program to perform the Trans Lunar Injection burn, which increased the
Apollo spacecraft’s velocity to 25,000 miles per hour on a trajectory
to the moon. On the first four lunar missions (Apollo 8, 10, 11 and
12), the S-IVB was left in a heliocentric orbit. Beginning with Apollo
13 in 1970, the spent third stages were targeted at the moon so that
scientists could measure the lunar impact with seismometers that were
deployed as part of the Apollo lunar surface experiments package.