An Alien’s Perspective of Earth?

While NASA’s Galileo spacecraft had the primary mission of studying Jupiter and its surrounding satellites, the orbiter was able to tell us much about Earth on its way there. 

Because the spacecraft did not have enough fuel to take it to Jupiter, scientists devised a VEEGA (Venus-Earth-Earth Gravity Assist) to slingshot Galileo in Jupiter’s direction. As a result, the spacecraft had to fly past Earth twice. This particular photo was taken on December 16th, 1992, about 6.3 million km away from Earth, 8 days after the orbiter’s second encounter with the Earth.

However, the first encounter proved especially groundbreaking. The great astronomer Carl Sagan had a rather profound question: what would aliens think of Earth if they came to our Solar System? Sagan then came up with a set of experiments intended to provide humans with that unique perspective. Using the assumption that aliens would simply fly by Earth instead of making contact, scientists on the Galileo project used the orbiter’s sensing instruments to acquire data that one would look for when attempting to determine the existence of (carbon-based) life on a planet.

The findings proved to be incredible. Using technology that would surely be primitive to any alien civilization that managed to make it to Earth, whttps://fbcdn-sphotos-g-a.akamaihd.net/hphotos-ak-xap1/v/t1.0-9/10686809_794920303902349_4755300207495758525_n.jpg?oh=6d73a64dd5914934767a53b84c60f227&oe=550E9BF5&__gda__=1426775593_688773b057dc6d45ef4ec25c4ff6fbc7e were still able to deduce water, clouds, oceans, an oxygen atmosphere, life, and even intelligence.

While the Galileo mission taught us much about Jupiter and its surroundings (and Venus and asteroids), perhaps the greatest consequence of the mission was learning about ourselves from a new light.

-CS

Image Credit: NASA