A drifting SpaceX rocket is on a collision course with the moon, slated to slam into the lunar surface this week, packing the equivalent energy of three tons of TNT. Fernando anticipates an impact crater nearly 90 feet across and 16 feet deep, too small to see from Earth but visible to spacecraft. It will be the second dead rocket known to crash into the moon accidentally. With meteoroids and other natural objects offering little if any warning before walloping the moon, scientists said there’s much to learn by observing well-tracked strikes by human-made objects like the one coming up. NASA hurled rocket sections and lunar modules into the moon during the Apollo era for seismic measurements.