That's only relevant at relativistic speed, an Asteroid isn't going to come in at 10% of the speed of light. An Asteroid is going at most about 70 km/s: https

That's only relevant at relativistic speed, an Asteroid isn't going to come in at 10% of the speed of light. An Asteroid is going at most about 70 km/s: https://astronomy.stackexchange.com/questions/20805/what-are-the-maximum-and-minimum-impact-speeds-for-an-asteroid-that-would-strike https://astronomy.stackexchange.com/questions/20805/what-are... That's 0.02% of the speed of light (300 000 km/s).