No, NASA Is Not Bombing the Moon

There seems to be a little lunacy making the rounds that NASA is going to "bomb" the Moon on Friday morning, or "hurt the Moon," or "split the Moon in half," or change its orbit. This is all just nonsense and scare-mongering, and those worried about our Moon can rest assured our lunar companion will remain in the sky relatively unchanged after this experiment to search for water ice on the Moon's south pole. Let's take a look at the physics involved and what might happen to the Moon.

First of all, there are no explosives involved. The LCROSS mission is going sending a upper stage of a Centaur rocket and a smaller spacecraft to impact the Moon. The two objects will create a crater — The 5,000-pound (2,270-kilogram) Centaur is expected to slam into Cabeus Crater on the Moon's south pole at a sharp angle at a speed of 5,600 mph (9,000 kilometers per hour). The Centaur's collision is expected to create a crater roughly 60 or 70 feet wide (20 meters wide) and perhaps as much as 16 feet (5 meters) deep, ejecting approximately 385 tons of lunar dust and soil — and hopefully some ice.

The LCROSS spacecraft itself, weighing in at 1,500-pounds (700-kilograms), will follow the Centaur by about four minutes and fly through the regolith plume thrown up by the collision, just before it too slams into the lunar surface, kicking up its own smaller plume of debris, all the while using its sensors to look for telltale signs of water, beaming the information back to Earth.

So, yes, it will make a rather big crater on the Moon. But one close-up look at the lunar surface will reveal that the Moon is full of craters, and still regularly receives hits by meteorites and larger space rocks – not as much as in the past, as most of the craters on the Moon are from an earlier period in our history when there was more debris left over from the formation of the solar system. The Moon was not "hurt" in the past, and it will not get hurt by this impact.