Anew planet is discovered in a different solar system. The new planet is much like Earth. One difference is that the planet does not have tides. What does the planet lack that Earth has?

1 Answer
Jan 19, 2016

The main cause of tides on Earth is the moon.

Explanation:

Tides are the result of the differential gravitational pull of the moon an the Earth between the side nearest the moon, and the side farthest. So without a moon, we would not see the same tides.

HOWEVER

The sun's gravity also produces a tidal effect. Though less than that of the moon, it is not insignificant. So even without the moon, the Earth would still have tides about 40% of what they are now.

So if that planet indeed had no tides, it would have neither sun nor moon. Which wouldn't make it very Earth-like at all!