We cannot predict, with any certainty, the impact on human thought, of seeing the Earth from Mars, but we can make some educated guesses.

To begin with, we have, in a way, already seen the Earth from the Martian surface, through the eyes of the Curiosity Rover. On January 31, 2014, our robot explorer took a photo of the Earth and the moon just after sunset. Without enhancement, you really can’t see the moon, but the Earth from Mars looks a lot like Mars from the Earth. It resembles a bright star that doesn’t blink the way that stars do.

In the context of the Overview Effect, it is worth noting that all the distinguishing features of our home planet, such as oceans, continents, and ice caps, disappear when seen from that great a distance. This is relevant because seeing the Earth from orbit or the moon still provides the viewer with those features. However, what is more striking is coming to understand that these features are parts of a whole system, the Earth itself.

That is the essence of the Overview Effect.

At some point, however, the Mars mission astronauts will move out beyond the moon and begin to see the Earth shrink in size until, closer to Mars, it looks like that unblinking star. At this singular moment, if not sooner, they will experience an enhancement of the Overview Effect that I have called “the Copernican Perspective.”

The Copernican Perspective is a realization that the Earth is not only a whole, but is also a part, in this case of the solar system. While the Earth is relatively large as seen from orbit, and still quite an impressive sight when viewed from the moon, it will be rather easy to miss, or even ignore, when seen from Mars.

Early Earthlings on the red planet may respond to this situation with homesickness. When we travel on the surface of the Earth, we often long for the familiar sights and sounds of our home country, which we can no longer see or hear.

They may also react with a form of denial. After all, anyone who has volunteered to leave their home planet and establish a new civilization on an alien world must have settled accounts with themselves and their families, making the case that the adventure would be worth the sacrifices it entails.

As they settle in and begin to create a new civilization, another sentiment may begin to develop: frustration.

(To be continued)