What Is the Penumbra

August 12, 2018 pluto 0

If you are standing in the Moon’s penumbra and look at the Sun, you will witness a partial solar eclipse. During some eclipses, the Sun, the […]

Human Homes for Alien Planets

July 3, 2018 pluto 0

The first humans to set foot on Mars will be greeted by an unfamiliar and unfriendly climate: dust storms, freezing temperatures, and intense radiation will […]