When Moons Collide They Form One

[thiosk]

To the folks saying old theory is old, there has been no formal theory that explains why the so-called "dark side of the moon" has such a dramatically different topography than the sexual-chocolate side of the moon. The Cosmic Splat theory, as I've taken to calling it, is among the first credible, and testable, answers to that question.

 

[Aeshi]

Really? I thought that the Moon was supposedly formed by debris blasted into space when a small planet crashed into Earth billions of years ago.

Off topic: How is the article picture relevant in any way,shape or form?

 

[Kimarous]

Anyone else get this in their head when they saw the topic title?


On the actual topic, I'm not putting any real stock in it.

 

[Illithidae]

ok, if the earth was once a moon, what was it orbiting? Earth orbits the sun becuase its a planet, but a moon needs to orbit something that isn't a sun. What were these moons orbiting?

They're theorizing that Earth once had two moons, not that Earth was a moon.

And a moon doesn't need a planet to revolve around, it's still a bunch of rock like a planet. See: Asteroid belts.

Really? I thought that the Moon was supposedly formed by debris blasted into space when a small planet crashed into Earth billions of years ago.

There's nothing here to say that it didn't - both moons easily could've been formed from the impact in different areas, only to collide later on.

OT: Quite interested with seeing how this gets on!

 

[Kashrlyyk]

Reading the article myself I marvelled at how astronomers view the world - those two moons supposedly crashed into each other at a "very slow" speed of 25 kilometers per second, or a good 5000 miles per hour.

Judging by the wording that wouldn't be enough for a planetary speeding ticket.

1) 1 km/sec = 3600 km/h = around 2400 miles per hour.
2) You forgot to multiply with 25.

It actually is: 90000 km/h or around 60000 miles per hour. Still around 3 hours to the moon.

 

[Kargathia]

Reading the article myself I marvelled at how astronomers view the world - those two moons supposedly crashed into each other at a "very slow" speed of 25 kilometers per second, or a good 5000 miles per hour.

Judging by the wording that wouldn't be enough for a planetary speeding ticket.

1) 1 km/sec = 3600 km/h = around 2400 miles per hour.
2) You forgot to multiply with 25.

It actually is: 90000 km/h or around 60000 miles per hour. Still around 3 hours to the moon.

Pulled out my calculator now instead of throwing a rough guess at it as I did earlier, and it comes out 56250 miles per hour. At which point I don't call the 50000+ a bad estimate, even if I made a typo and forgot a 0.

Not entirely too sure though where going to the moon comes into play here, as if I recall correctly this was the speed during impact.

 

[General Vagueness]

Anyone else get this in their head when they saw the topic title?


On the actual topic, I'm not putting any real stock in it.

I did, I was going to put "apparently they were wrong" but I checked and sure enough you beat me

 

[GrizzlerBorno]

God I wish we had two moons. Like Mars. Mars has it good!

 

[GamemasterAnthony]

I kinda wonder what things would have been like if we still had two moons...especailly the tidal patterns and such.

CAPTCHA: Magarian disini

Yeah, barkeep? I'll have the Magarian disini, and my friends here will have the Romulan Ale and the Pan-Galactic Gargle Blaster.

 

[manaman]

AND NOW SOME SCIENCE!

According to QI the Earth still has two moons.
And i consider everything Stephen Fry says to be true regardless of context or likelihood

There's actually more (which they also mentioned on later shows).

While none of them are on the same scale, both physically and scientifically as the Moon, they are in fact large bodies that orbit Earth, by definition a satellite, which the Moon is also.

There full names are:

- 3753 Cruithne
- 2002 AA
- 2003 YN
- 2004 GU
- 2010 SO16

http://en.wikipedia.org/wiki/Earth#Moon
http://en.wikipedia.org/wiki/Quasi-satellite

Of course that doesn't sound very poetic. "When the 2010 SO16 hits my eye like a big pizza pie, that's... erm... complex astronomy."

Only you know, those objects are all earth Trojans, or in orbital resonance. Not orbit.

The more I hear and the more I see of that show the more it reminds me of Cracked.com. There is a kernel of truth, but it often gets buried in bullshit and selectively picked sources and wordings for the sake of comedy.

 

[Sansha]

"...relatively slowly - 4,500 to 6,700 miles per hour..."

I like that line, gives one some scale of the vastness and power of celestial bodies.

 

[stvncpr236]

Oh come on, we all know the second moon was a giant space station destroyed by the Rebels to protect us from the Empire

 

[minimacker]

While it explains one theory, I can't help to think there are some difficulties in this new theory.

Why did the two moons have an almost identical orbital circle to the point where they "slowly collided". They must have been smaller, if they merged together, thus would not have a gravitational pull strong enough to pull each other unless they were at near identical distances from Earth.

Just why exactly would the Giant Impact create two moons?

 

[Squilookle]

"modern man walking upon its surface still evokes patriotic feelings."

Only to the sort of people who squeal in terror at the thought of the Apollo landing planting a flag on the moon that was anything but the Star Spangled Banner. Like maybe... a flag representing Earth itself for example...

 

[Somebloke]

EDIT: The below was in response to: "If it was gravity, wouldn't the mountains be facing earth? I would have thought the dark side would be flat, and the earth facing side mountainous."


I suppose the idea could be that gravity caused the wrinkling, but then centripetal force caused the new elevated and top-heavy plates to drift outwards - dunno. :7

Break a mirror array, face the peer dismay.

 

[Neverhoodian]

Hmmm, I wonder if Calvin and Hobbes provided some inspiration for this theory: