# What would happen to a world with three moons?

The world I’m building is approximately 1/3 of the size of earth and it has 3 moons orbiting it. The orbits are all different but occasionally they have either a full moon or a new moon on the same day. I have a couple of questions. First, if all these moons were small (totaling to about 1/3 the size of earth’s moon) and slightly different sizes with different orbits, would the planet still be able to support life? If the answer to the first question is yes, then what would happen to tides and earthquakes and volcanoes? Would it be possible for a three mooned planet to function pretty similarly to Earth?

• Arrrr, matey, The sea tides with three weenie moons be a complex beast, but of little ferocity. You can safely leave port without a spare copy of the tide tables. Commented Jul 30, 2020 at 22:11
• To support @user535733's observation, 1/3 the moon, 1/3 the gravity, and the further the moon the less impact it has. Consequently, even when all three moons are lined up, the total gravimetric influence is less than Luna has on Earth.
– JBH
Commented Jul 31, 2020 at 4:50
• So the size of the moons relative to the size of the planet doesn’t matter for it’s gravitational effect? I just want to make sure I’m understanding correctly. Commented Jul 31, 2020 at 15:11
• What will happen to that world? Eventually its star will become a red giant and overheat the planet, destroying all life, and maybe swallow the planet entirely. The same thing that happens to all planets eventually. Commented Jul 31, 2020 at 15:33
• “Size” is an ambiguous term. When you say “totalling to about 1/3 the size of the Earth’s moon”, do you mean that their total volume is 1/3 of our moon’s volume, that their total visible area in the sky is 1/3 of our moon’s visible area, that their total surface area is 1/3 of our moon’s surface area or that the sum off their radii is 1/3 of our moon’s radius? These will give four very different results. Commented Aug 1, 2020 at 9:28