Q:

How was the moon formed?

A:

The most popular theory regarding lunar formation is that a Mars-sized planetoid slammed into the Earth and flung molten debris into orbit around 40 million years after the solar system was created, according to scientists at the National Aeronautics and Space Administration (NASA). This is called the giant impact theory.

Debris from the collision was bound together by gravity, and these ejected particles coalesced to form the moon. Initially, both the Earth and moon spun very fast on their axes, but they have since slowed down. The giant impact hypothesis explains why the moon is made of lighter elements without a heavy core. This mathematical model also explains why the moon's orbit became tidally locked with the same face towards the Earth at all times.

There are two other theories regarding how the Earth's moon formed. One is that the moon was created at the same time as the Earth because particles were coming together during the solar system's formation. If this is true, then scientists believe the moon would be much denser.

Another theory of lunar formation involves the Earth's gravity capturing a moon passing by the planet. This is how Mars got its two moons. Scientists think that if this how the moon came into Earth's orbit, the celestial body wouldn't be spherical nor would the moon line up with the Earth's ecliptic orbit.


Is this answer helpful?

Similar Questions

  • Q:

    Why is the moon important?

    A:

    Most people know that the moon's gravitational influence has an effect on the tides on Earth, but some scientists also believe that the presence of the moon played an important role in making Earth habitable to begin with. The interplay between the Earth and the moon mirrors events that occurred throughout the early solar system, as a Mars-sized object may have hit the Earth, sending some of the mantle into orbit that soon cooled into the moon. Over time, the relationship between the Earth and the moon may well have assisted the advent of life.

    Full Answer >
    Filed Under:
  • Q:

    Why do we only see one side of the moon?

    A:

    The moon completes one full rotation about its axis in the same time it takes Earth to complete a full revolution, resulting in one side always turning to face the parent planet in sync with its orbit. This phenomenon is known as tidal locking.

    Full Answer >
    Filed Under:
  • Q:

    How long does it take the moon to orbit the Earth?

    A:

    The Earth's moon takes 27 Earth days to completely orbit the Earth. A day on the moon is also equal to a little over 27 days on Earth.

    Full Answer >
    Filed Under:
  • Q:

    Why do we always see the same face of the moon?

    A:

    The moon is tidally locked with Earth, which has the effect of synchronizing its rotation period with the period of its orbit. Completing one "day" per orbit of the Earth, the moon has shown the same face to the Earth for billions of years.

    Full Answer >
    Filed Under:

Explore