Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation: Please wait while one of the largest mobile machines in the world crosses the road. The machine pictured above is a bucket-wheel excavator used in modern surface mining. Machines like this have given humanity the ability to mine minerals and change the face of planet Earth in new and dramatic ways. Some open pit mines, for example, are visible from orbit. The largest excavators are over 200 metres long and 100 metres high, now dwarfing the huge NASA Crawler that transports space shuttles to the launch pads. Bucket-wheel excavators can dig a hole the length of a football field to over 25 metres deep in a single day. They may take a while to cross a road, though, with a top speed under one kilometre per hour.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell (USRA)
NASA Web Site Statements, Warnings, and
Disclaimers
NASA Official: Phil Newman;
Specific rights apply.
A service of:
ASD at
NASA /
GSFC
& Michigan Tech. U.