![Far Side of the Moon](https://www.astronomy.com/wp-content/uploads/sites/2/2023/02/asy-20010319-00717-orig-lg.jpg)
Earth’s Moon.
JPL/NASA
If we had such a moon, its lower mass likely would not affect our planet much other than to annoy astronomers yearning for moonless nights. Only a massive extra moon would affect Earth’s tides and therefore influence the long-term stability of the planet’s spin axis. There are a number of reasons not to expect earthlike planets to have more than one large moon.