Complex sentence: Its mass can be found by using the formula about the annihilation of an antimatter meteor and simple calculations show that it was around a picogram, well within the size of most meteors that may enter in the atmosphere.
Split into simpler sentences: Its mass can be found by using the formula about the annihilation of an antimatter meteor. Simple calculations show that it was around a picogram, well within the size of most meteors that may enter in the atmosphere.