earth asteroid tc4

The giant asteroid TC4, first spotted in October 2012, will fly past Earth once more this year. Experts predict that it will graze past the planet on October 12, at a distance of 56 million kilometers.

“We know for sure that there is no possibility for this object to hit the Earth,” said Detlef Koschny of the European Space Agency (ESA) Near Earth Objects research team. “There is no danger whatsoever.”

Space impact

During its first recorded “close encounter” with Earth, it flew past the planet at a harmless distance of about 88,000 km (54,600 mi)— about a fourth of the distance between our planet and the Moon.

Its size ranged from 15 to 30 m (48-98 ft) long, and was travelling at roughly 14 km/s. To put things into perspective, imagine something as large as a blue whale moving at speeds faster than a rocket escaping our atmosphere.

Scientists at the time predicted that the asteroid would return this year, but couldn’t figure out its proximity. However, experts now have the technology to do so, in the form of the Very Large Telescope of the European Southern Observatory (ESO) in Chile. 

The asteroid will be reentering our field of view at half the distance away. This means it will still be safely away from our planet and the geostationary satellites that orbit around it.

“It’s damn close,” said Rolf Densing, who heads the European Space Operations Centre in Darmstadt, Germany. “The farthest satellites are 36,000 kilometres out, so this is indeed a close miss.”

Asteroid watch

Researchers can use the data gathered from this rare event to move beyond early warning to active deflection. In other words, they can use the information to develop a planetary defense system of sorts.

The ESA stated that observing TC4’s movements can be a great opportunity for testing our capability to track near-Earth objects, as well as how we would respond in the event of an imminent collision from space.

An asteroid slightly larger than TC4 exploded over Tunguska, Siberia, in 1908 — the biggest recorded collision in recent history.

In 2013, a much smaller space rock (20 m in size) exploded over the city of Chelyabinsk in central Russia. Its explosive power was comparable to that of about 30 atom bombs, shattering the windows of almost 5,00 buildings and injuring more than 1,200 people. The ESA believes that a TC4-sized object entering Earth’s atmosphere is likely to produce the same results

Luck from above

However, researchers are confident that TC4 will not harm Earth during its flyby.

“The Chelyabinsk meteoroid was a piece of comet and they are usually made of icy material,” said Densing. “Due to [its] icy nature[,] it probably dissipated in the atmosphere. When we’re talking about asteroids, this is solid material. They are mostly made up of iron, so will not so easily dissipate their energy in the atmosphere.”

While it may behave differently from the Chelyabinsk object, TC4 is unlikely to rain debris down into the atmosphere. Even if it did, Koschny claims that it will do relatively minimal damage. Koschny’s advice? Stay away from windows and any other fragile objects that may shatter from the resulting shockwave.

Meanwhile, Densing, who has warned humanity about its ill-preparedness for Earth-bound objects, says there’s nothing to worry about this one.

“However, it makes you wonder what will happen next time,” he continued, “I would have felt a bit more comfortable if we… had a longer pre-warning time.” –MF

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Author: Tomas Pedrosa

A graduate of Information Design, a versatile writer, and an avid gamer, Tomas prides himself in his willingness to gain new experiences and perspectives, and to apply what he learns in his other pursuits. Curiosity, interest, and obsession—these are the mile markers that keep him going down his road.