“This object came from outside our solar system.”
— Rob Weryk, postdoctoral researcher at University of Hawaii’s Institute for Astronomy
On October 14, 2017, what appears to be a comet (er, make that asteroid…read more below) sped past Earth at a distance of about 15 million miles after swinging around the Sun. It had come within 23.4 million miles of our home star over a month earlier on Sept. 9, and in fact wasn’t spotted by astronomers until Oct. 18—four days after its closest pass by us.
Further observations showed that the approximately 525-foot-wide object (an estimate based on its reflectivity) first approached traveling 16 miles a second from the direction of the constellation Lyra—quite a high angle from the plane of the rest of the Solar System—and is on a hyperbolic trajectory, moving quickly enough both in- and outbound along its course to permanently escape the Sun’s gravity unlike any other
comet asteroid ever observed.
See that big rock there? (It’s easy because there’s a big yellow arrow pointing to it.) That’s a 100-foot/30-meter wide boulder that was imaged sitting on the surface of Comet 67P/Churyumov-Gerasimenko by ESA’s Rosetta on May 2, 2015. Nine months later Rosetta captured another image of the same area in which that huge stone had clearly moved—find out below just how far!
Rosetta is down. I repeat: Rosetta is down.
This morning, Sept. 30, 2016, just after 10:39 UTC (6:39 a.m. EDT) ESA’s Rosetta spacecraft ended its mission with an impact onto the surface of the comet 67P/Churyumov-Gerasimenko. The descent, begun with a final burn of its thrusters about 14 hours earlier, was slow, stately, and deliberate, but even at a relative walking pace Rosetta was not designed to be a lander like its partner Philae and thus ceased operation upon contact with the comet.
With the comet 446 million miles (719 million km) from Earth at the time, the final signals from Rosetta were received 40 minutes after impact, officially confirming mission end.
This is an article, now updated, that I originally posted in 2009 during my first year of blogging. Since then more research has been done on the famous 1908 Tunguska Event and we even had a remarkably similar type of thing occur in February 2013 over the Chelyabinsk area, not too far from Tunguska, but even today, the 108th anniversary of the event, scientists aren’t in agreement over what it was that violently exploded over the boggy forests of Siberia—asteroid or comet.
Long the subject of debate, with various theories ranging from meteorite impact to a comet to a flying saucer’s sudden engine meltdown, there’s actually strong evidence that the 1908 “Tunguska Event” was likely caused by the explosion of a comet in the upper atmosphere.
This idea has been suggested before, and is supported by Cornell University engineering professor Michael Kelly’s study of – strangely enough – the space shuttle’s exhaust plumes and their effect on high-atmosphere cloud formation.
To those not familiar with the Tunguska Event, something exploded or impacted in the remote area of Russia on June 30, 1908, flattening the forest in an 830-square-mile area, but leaving no visible crater or other obvious sign of what caused the event. Nearby residents reported the sound of a massive explosion, but that’s about it. Whatever it was, the devastation it caused was extensive and undeniable.