Space
A Formula For SETI
1960 AD
GREEN BANK, WEST VIRGINIA
Frank Drake, the man who conducted the first modern search for radio signals from other civilizations, developed a way of thinking about how many civilizations there could be in our galaxy. It’s now known as the Drake Equation: N = R x Fs x Fp x Ne x Fl x Fi [...]
"We've Had a Problem Here"
April 11, 1970 AD
LUNAR ORBIT
"Houston, we’ve had a problem here," astronaut John Swigert radioed Mission Control.
Indeed Apollo 13 did have a problem. Two days after the April 11, 1970 liftoff the mission was 300,000 kilometers (about 200,000 miles) from home and hurtling towards the Moon. Suddenly there was a bang.
Comets: Beyond the Atmosphere
1572 AD
HVEN ISLAND, DENMARK
Just how far away are comets? The Greek philosopher Aristotle said they were disturbances in the atmosphere, but the great Danish astronomer Tycho (pronounced "TY-koh") Brahe proved him wrong.
Copernicus had recently begun the revolution that would let us understand the universe, by showing that the Earth was not the center of the [...]