https://www.theguardian.com/science/201 ... e-altitude
A house-size asteroid will give Earth a near-miss on Thursday, giving experts a rare chance to rehearse for a real-life strike threat as it passes inside the moon’s orbit.
Dubbed 2012 TC4, the space rock will shave past at an altitude of less than 44,000km (27,300 miles) – just above the 36,000km plane at which hundreds of geosynchronous satellites orbit the Earth.
That represents about an eighth of the distance between the Earth and the moon.
Nasa’s Mike Kelley, who leads the exercise to spot, track and intimately probe the transient visitor, insisted there was “no danger. Not even for satellites”.
“We’ve now been observing TC4 for two months, so we have very accurate position information on it, which in turn allows very precise calculations of its orbit,” which will not cross that of Earth nor its satellites, he told AFP.
