Answer: Total Solar Eclipses

When it comes to life in our Solar System there are a lot of things the different planets share. Earth isn’t the only planet that experiences tidal forces. It isn’t the only planet with an atmosphere. Other planets have shooting stars (if anyone were there to observe the objects entering their atmospheres and burning up that is), and we’re certainly not the only planet with a natural satellite (our Moon): other planets often have many, many, more than us.

There is one astronomical phenomenon we have here on Earth that no one anywhere else in the solar system will ever get to experience: total solar eclipses. Why on Earth and nowhere else? By pure chance the Sun just happens to be 400 times larger than the moon and roughly 400 times farther away. Because of the simple geometry of things we end up in a situation where, when everything is aligned just right, the moon slides perfectly over the sun turning it into a dark and mysterious-looking hole in the sky.

There may be other planets out there in the universe that experience total solar eclipses, but to date astronomers have yet to locate another planet like Earth where the host sun, the planet, and the planet’s moon are all sized and aligned in such a fashion that a total solar eclipse could occur.