|09-27-2002, 11:49 AM||#1|
Rocket Scientists Find a Rocket
Rocket Scientists Find a Rocket
By Michelle Delio
2:00 a.m. Sep. 25, 2002 PDT
Sometimes, astronomers really do need to use rocket science when they observe unidentified objects in the sky. Especially if they wind up identifying, well, a rocket.
NASA scientists used a combination of high technology and backyard astronomers' observations to confirm the identity of an object that's been circling the earth since early September.
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Since its first sighting on Sept. 3, scientists had suspected that the 60-foot-long object, named JOO2E3, was a small asteroid. But further observations have proven that JOO2E3 was manufactured by humans, and is probably the long-lost third stage of the Apollo 12 rocket that took astronauts to the moon in 1969.
Although JOO2E3 can be seen by amateur astronomers using 8- to 10-inch telescopes, high-tech scopes like NASA's Hubble Space Telescope couldn't conclusively identify it. The Hubble's 2.4-meter diameter mirror is limited to capturing images of objects no smaller than 80 meters across. J002E3 is, at best, about 30 meters across.
JOO2E3 was identified partly through reports from amateur astronomers who tracked the object's position over a two-week period and supplied scientists with enough data to extrapolate JOO2E3's past and present orbit.
Analysis by a high-power telescope provided the final clues: JOO2E3's surface is covered in white paint.
University of Arizona astronomers measured the spectrum of sunlight reflected from J002E3 and found the colors were consistent with white Titanium oxide (TiO) paint. That's the same type of paint NASA used on Apollo moon rockets 30 years ago, according to Carl Hergenrother, who conducted the study with colleague Robert Whiteley.
Hergenrother and Whiteley used the Steward Observatory's 61-inch telescope for their observations of J002E3, using various filters to sample the colors, or spectra, that J002E3 reflects.
Hergenrother and Whiteley checked their observations with Richard Binzel and Andy Rivken of the Massachusetts Institute of Technology. Binzel and Rivken took infrared spectra readings on J002E3, and agreed that its surface is coated with something that's "a dead ringer for white TiO paint," Hergenrother said.
Using two weeks' worth of data primarily supplied from amateur astronomers on J002E3's current orbit, scientists can also predict the path that JOO2E3 will travel for years into the future.
They can also figure out what JOO2E3 has been doing over the past few decades.
JOO2E3, in its probable previous incarnation as Apollo 12's S-IVB, escaped from Earth's orbit in March 1971.
The Apollo 12 crew jettisoned the S-IVB on Nov. 15, 1969, when it was nearly out of fuel. Ground controllers then ignited the S-IVB's engine, intending to send the object into a sun-centered orbit.
But something went wrong and S-IVB ended up racing Earth in an orbit around the sun. (S-IVB won, completing 33 solar orbits in the time it took Earth to complete 31 laps.)
The last time S-IVB was seen was back in 1971, when scientists figure it flew a little too close to the sun and got snagged into a solar orbit though a special "portal" located at the L1 Lagrangian point, where the gravitational pulls of the sun and Earth are approximately equal.
NASA's Genesis spacecraft, currently collecting samples of solar-wind material near the L1 point, will use a similar tactic for its return to Earth in 2004.
In 1986, S-IVB lapped Earth again, but was too far away to be snagged by Earth's gravity. This year, S-IVB passed too close to the L1 portal and Earth's gravity grabbed it.
Scientists said that if JOO2E3 isn't S-IVB, it could be one of the four 22-foot-long panels that enclosed the lunar modules from six Apollo missions or a rocket stage from Soviet or U.S. unmanned lunar missions.
Additional observations in coming weeks are expected to pin down the identification.
Whatever JOO2E3 turns out to be, the object will likely end its travels by heading into the moon or the Earth in several thousand years.
It's expected to disintegrate "as a beautiful infra-red fireball," according to NASA scientists, well before impact.
"It was once written "To thine own self be true". But how do we know who we really are? Every man must confront the monster within himself, if he is ever to find peace without. .." Outer Limits(Monster)