Earth may once have had two moons

[dipsydoodle]

A new theory suggests the Earth once had a small second moon that perished in a slow motion collision with its "big sister".

Researchers suggest the collision may explain the mysterious mountains on the far side of our Moon.

The scientists say the relatively slow speed of the crash was crucial in adding material to the rarely-seen lunar hemisphere.

Details have been published in the journal Nature.

http://www.bbc.co.uk/news/science-environment-14391929

[Sherman A1]

1. Interesting

Thanks for posting.

[Ter]

2. If it perished in a crash...

...Wouldn't we have rings around our planet, like Saturn?

[laconicsax]

4. There were probably rings a long time ago.

Gravity sucks, so the bits making up rings wound up rainng down here or on the moon.

Also, the slow impact wouldn't have released as much debris as if it were a high-speed impact.

[Ter]

5. The Earth would have been beautiful with rings

Check this out:

http://www.youtube.com/watch?v=wxPVfzH-z_Q&feature=player_embedded

[struggle4progress]

6. I once heard an astronomer discuss long-term simulations of Saturn's rings: apparently,

they are not stable over an extended period -- we happen to have evolved at about the right time to see them, and something like a few million years might make a huge difference

If the earth ever had rings, anywhere near the lunar orbit, the moon might rapidly perturb the orbits of the ring debris, capturing some of the particles, launching other particles into the earth, and throwing still others into wildly erratic paths past the earth and into far space

[PetrusMonsFormicarum]

3. Muad'Dib

The sleeper must awaken.