Earth Could Sustain Life Even Without the Moon

According to the conclusions of a new scientific study, it would appear that our planet would still be able to support life even if the Moon was not there. This result goes up against decades of scientific thinking which holds that without the stabilizing effects of the Moon, Earth would be uninhabitable.

What the planet's natural satellite does is prevent Earth's rotational axis from shifting too much over time. Since the Moon formed, our planet has always had sunlight coming perpendicularly on the Equator. Without the satellite, this would change, experts proposed years ago.

In fact, Earth's axis may shift by such an extent that the Sun could shine nearly directly above the poles. Needless to say, such as scenario would cause massive and abrupt bouts of climate change, which would make it extremely difficult for complex organisms to evolve.

What the new study shows is that our planet's obliquity – its axial tilt – would in fact vary by only 10 degrees if the Moon were to be removed from the equation. As such, life may have developed here in its current form even without the natural satellite.

The University of Idaho research team that conducted the new investigation was led by astronomer Jason Barnes. The findings were presented at an American Astronomical Society meeting earlier this year, Space reports.

If this is confirmed, than it means that astronomers looking for complex life on exoplanets could eliminate this condition from their studies as well. What this implies is that alien life may develop on Earth-like planets even if a large moon is not present.

Previously, astronomers though that this was next to impossible. The Moon was believed to be important to Earth in this sense because of its large size compared to its parent planet's. Mars' largest moon Phobos, for example, is 60 million times smaller than the Red Planet.

According to theoretical predictions made by the latest cosmological models, only about 1 percent of all Earth-like planets in the Universe have large moons around them. The new research shows that life is not unlikely to develop on the remaining 99 percent of planets.

Back on Earth, lacking a stabilizing moon would only allow our planet a change in obliquity of 10-20 percent over 500-million-year intervals. The climate changes associated with this process would not be significant enough to halt the development of complex life.

The shifts “would have effects, but not preclude the development of large scale, intelligent life,” the research team says. “A moon can be stabilizing or destabilizing, depending on what's going on in the rest of the system,” Barnes concludes.