Halloween ‘Great Pumpkin’ asteroid will narrowly miss Earth

A simulation by NASA of an asteroid passing close by Earth
A simulation by NASA of an asteroid passing close by Earth

While ghosts, ghouls and other horrible creatures will stalk the streets of Derry at Halloween, we’ve been spared an even bigger fright - by an asteroid nicknamed The Great Pumpkin.

NASA is tracking the Halloween flyby of asteroid 2015 TB145, which was discovered only weeks ago and which will, in astronomical terms, narrowly miss Earth.

Discovered on October 10, the 400 metres object is travelling at 22 miles per second and will pass at the closest distance that any asteroid will come to earth until 2027. Its closest approach will come at 5pm on October 31.

However, it will still be so faint that a small telescope will be needed to see it.

Scientists have highlighted that the fact they did not know the asteroid was meant to come so close until just three weeks ago showed how important it was to be vigilant against objects hurtling in our direction through space.

“That such a large object, capable of doing significant damage if it were to strike our planet, was discovered only 21 days before closest approach demonstrates the necessity for keeping daily watch of the night sky,” Detlef Koschny, an astronomer with the European Space Agency, said in a statement.

NASA is working to map potentially dangerous asteroids and comets that pass within 30 million miles (48 million km) of Earth.

A 65-foot-wide (20 m) asteroid broke apart over Chelyabinsk, Russia, in February 2013, shattering windows and damaging buildings. More than 1,000 people were injured by flying debris. Although the Great Pumpkin may produce meteors that pass through the Earth’s atmosphere, it poses no danger.

“The trajectory of 2015 TB145 is well understood,” said Paul Chodas, manager of the Center for Near Earth Object Studies at NASA’s Jet Propulsion Laboratory, Pasadena, California.

“At the point of closest approach, it will be no closer than about 300,000 miles - 480,000 kilometers or 1.3 lunar distances. Even though that is relatively close by celestial standards, it is expected to be fairly faint, so night-sky Earth observers would need at least a small telescope to view it.”

“The close approach of 2015 TB145 at about 1.3 times the distance of the moon’s orbit, coupled with its size, suggests it will be one of the best asteroids for radar imaging we’ll see for several years,” said Lance Benner, who leads NASA’s asteroid radar research program.

“The asteroid’s orbit is very oblong with a high inclination to below the plane of the solar system. Such a unique orbit, along with its high encounter velocity -about 35 kilometers or 22 miles per second - raises the question of whether it may be some type of comet. If so, then this would be the first time that the Goldstone radar has imaged a comet from such a close distance.”