On August 23 the Pan-STARRS comet and asteroid survey nabbed a speedy new object circling around planet Earth – not the sun. Excuse me. Don’t all asteroids orbit the sun? That’s why this one stuck out like a sore thumb. Provisionally named 2013 QW1, the discoverers wondered whether it might instead be an artificial object. If you’re thinking alien spaceship, probably not, but maybe a human-built one.
Soon the European Space Agency’s Near Earth Object (NEO) Coordination Center sent out an alert requesting more observations of 2013 QW1 to nail down its identity. Italian and French astronomers took up the challenge. Using the large Italian Telescopio Nazionale Galileo on the island of La Palma, the teams focused a spectrograph on the fast-moving object and “fingerprinted” the light it reflected from the sun. What they found didn’t resemble a rock at all but bore the signature of previously observed space junk. We’re talking discarded rocket stages, abandoned boosters and defunct satellites.
2013 QW1 turned out to be man-made, most likely a booster stage that helped launch a satellite or space probe into orbit. It was quickly stripped of its asteroid designation, renamed 2010-050B and entered into the Distant Artificial Satellite Observations list. Expert satellite observers can go HERE to get positions and brightnesses of a number of the objects on the list including 2010-50B.
In case you’re wondering about the current whereabouts of our former asteroid, it’s cruising along near Antares in Scorpius and very faint at 17th magnitude.
2013 QW1 wasn’t the first piece of orbital debris to be confused with an asteroid. NASA typically sent the upper stages of the Saturn V rockets – the ones that shot the Apollo craft to the moon – crashing into the moon’s surface to create artificial moonquakes. Seismographs brought there by the astronauts picked up vibrations from the impacts that were used to study the moon’s interior structure.
The 3rd stage (S-IVB upper stage) of Apollo 12 failed to crash and instead took up an orbit alternately dominated by the sun and Earth. On September 3, 2002 an object with the temporary name of J002E3 was discovered rapidly circling the Earth at twice the distance of the moon. Light reflected from its surface revealed telltale signs of titanium-enriched white paint used at that time for the Apollo rockets. It didn’t take long for astronomers to realize they’d finally found Apollo 12′s long-lost upper stage.
Like trick or treats on Halloween, you never know what you might find in the bottom of your bag when you go asteroid hunting.