“[If it hit Earth] it makes the bang of a very large nuclear weapon – a very large one.”
How big?
“It would have hit with over 30 times the energy of the atomic blast at Hiroshima,” says Swinburne University astronomer Associate Professor Alan Duffy.
I believe the bombs we dropped on Bikini atoll were about 1000 times as big as Hiroshima. Bikini might look a little messed up, but the rest of the world hardly knew it.
This estimate is way too low. The asteroid that exploded high above Chelyabinsk, Russia was much smaller; yet, delivered about 450 kt. at very high altitude. Try the full rated output of the Tsar Bomba as an appropriate match.