Was it a spent Apollo rocket stage from the ’60s? A scary space rock? Whatever it was, the mysterious object known as WT1190F zoomed in from deep space and went out in a largely unseen blaze of glory today.
Experts on orbital debris said WT1190F was probably a low-density object measuring just 6 feet (2 meters) long. Astronomers with the Catalina Sky Survey first observed the object in October. When they looked back at archived telescope data, they figured out that it had been tracing a highly eccentric orbit around Earth that swung out beyond the moon’s orbit.
Update: WT1190F caught on aerial video
The European Space Agency said the best match for an object with those characteristics was a “discarded rocket body.” Other observers suggested it could be debris cast off by a moon mission, perhaps going back to the Apollo era. No wonder the thing was nicknamed “WTF.”
Good candidates for WT1190F's identity are the TLI Stage for Lunar Prospector, and the final stage rocket for Japan's Nozomi probe
— Jonathan McDowell (@planet4589) November 13, 2015
WT1190F was unusual in that the course of its final, fiery plunge to Earth was extraordinarily well-known in advance. The experts said it was due to re-enter the atmosphere at 10:18 p.m. PT tonight (06:18 GMT Friday) at a velocity of 24,600 mph (11 kilometers per second).
Few if any pieces of the object were expected to survive the descent. If they did, they would have splashed into the Indian Ocean, about 60 miles (100 kilometers) off the southern coast of Sri Lanka. “Being local noon in the area, only the brightest part of the trajectory may become observable,” ESA’s Near-Earth Object Coordinating Center said in advance of the re-entry. “We would therefore expect observations to be possible from land only from the southern province of Sri Lanka.”
The initial reports on Twitter suggest that WT1190F was a no-show in Sri Lanka:
Where are you #wt1190f pic.twitter.com/nrOFyuRkjr
— Shalika Galawala (@shalikaa) November 13, 2015
Damn it. It's just not our lucky day. #fridaythe13th No one saw #spacejunk #wt1190f anywhere in Sri Lanka =
— Maahil? (@MaahilMohamed) November 13, 2015
. @Anuruddhawaru @isuranirmal If the loud noise was heard from widely separated locations at the same time, could be sonic boom from WT1190F
— Jonathan McDowell (@planet4589) November 13, 2015
Observer Peter Birtwhistle got some late observations from the UK 20 minutes before entry, which reportedly show interesting light curve
— Jonathan McDowell (@planet4589) November 13, 2015
Much ado about nothing?#WT1190F was like #lka #yahapalanaya:
Over-hyped, eagerly awaited – but turns out to be damp squib #අයියෝයහපාලනය— Nalaka Gunawardene (@NalakaG) November 13, 2015
Fake videos already started spreading #WT1190F
— Rovin Shanila (@Rovinovic) November 13, 2015
The people who had the best chance of spotting WT1190F on the way down were the researchers aboard a Gulfstream business jet that’s flying out of Abu Dhabi. Even if their observing campaign was a washout this time around, the exercise provided good practice for future aerial monitoring of incoming asteroids. Check for updates from the WTF-watchers on Impact.SETI.org.