Travelers In The Night

A partnership of humans and computers will help to minimize the damage when asteroid hunters find a space rock with our number on it.

Looking into the sky at night with radio eyes you would not see the points of starlight forming the constellations instead you would see a very bright, colorful and wildly changing scene. In a desert valley near the Great Basin National Park Caltech is building the world’s largest radio telescope called the Deep Synoptic Array or DSA for short.

Although no comet nucleus impact on the Earth has been conclusively identified, there is some evidence that suggests the 1908 Tunguska event in Russia, which knocked down trees over a 770 square mile area, could have been caused by a fragment of Comet Encke. However there is no doubt that the Earth's collision with dust and small debris left trailing from comets produces some of the meteor showers we enjoy so much.

Bill Gray is an astronomer who specializes in tracking objects in space which come near the Earth. In addition to natural objects like asteroids and comets Bill also tracks rocket boosters and space junk that humans have discarded. On several occasions he has helped asteroid hunters to not waste time following a piece of space junk which initially appeared to be a threatening Earth approaching asteroid. Recently Bill used observations by very well equipped and talented amateur observers in Utah, England, China, and Mississippi to predict that the upper stage of a SpaceX Falcon 9 rocket will hit the Moon at 5,400 mph on August 5 of 2026.

In 2017 observers in 50 countries at 440 different observatories made nearly 19 million observations of asteroids and comets which enable scientists to calculate where about 800,000 objects will be in the future.