Listen to today's episode of StarDate on the web the same day it airs in high-quality streaming audio without any extra ads or announcements. Choose a $8 one-month pass, or listen every day for a year for just $30.
You are here
Mars of the Atlantic
A tiny island half way between Africa and South America is sometimes called the Mars of the Atlantic. That’s not just because its landscape looks like an alien world. A 19th-century expedition to the island studied Mars to help refine the scale of the solar system. And since the 1960s, space agencies have built facilities there to watch missions to Earth orbit and beyond.
Ascension Island is a little south of the equator, and covers about 36 square miles.
In 1877, British astronomer David Gill and his wife, Isobel, spent six months there. Mars was lining up opposite the Sun, and was especially close to Earth. By measuring angles between Mars and the Sun, Gill estimated the distance between Earth and the Sun — the key to mapping the entire solar system. His number was just one-tenth of one percent off the present-day value. Today, the site of their observations is known as Mars Bay.
Because Ascension is in the middle of a large expanse of open ocean, it’s a good place for monitoring spacecraft. NASA built a tracking station for its Apollo missions there in the 1960s, and operated it for a quarter of a century. An Air Force runway later served as a backup landing site for space shuttles. And NASA placed a telescope on the island for tracking space debris.
Ascension also hosts stations for tracking GPS satellites and rockets launched from South America — keeping many eyes on space from the Mars of the Atlantic.
Script by Damond Benningfield