A tiny second moon may once have orbited Earth before catastrophically slamming into the other one, a titanic clash that could explain why the two sides of the surviving lunar satellite are so different from each other, a new study suggests.
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The second moon around Earth would have been about 750 miles (1,200 kilometers) wide and could have formed from the same collision between the planet and a Mars-sized object that scientists suspect helped create the moon we see in the sky today, astronomers said.
The gravitational tug of war between the Earth and moon slowed the rate at which it whirls, such that it now always shows just one side to Earth. The far side of the moon remained a mystery for centuries until 1959, when the Soviet Luna 3 spacecraft first snapped photos of it. (The far side is sometimes erroneously called the dark side, even though it has days and nights just like the near side.) [Video: How the Moon Was Made]
IN PICTURES: We love the moon
The moon has two faces
The moon's far side is very different than its near side.
http://www.csmonitor.com/Science/2011/0803/Did-the-Earth-once-have-two-moons
Comments
Your thread has reminded me of a great, and slightly bonkers film I watched:
http://www.bbc.co.uk/programmes/b00vfgcw
Have you seen the documentary 'In the Shadow of the Moon'? I shall quote from Edgar Mitchell who was speaking on the Apollo 14 Mission. The following has always struck me as being 'Buddhist', if I may express my feelings about the following comments he made in that way:
"Every two minutes I could see the Earth, the Moon, the Sun and a 360 panorama of the heavens and that was a powerful overwhelming experience, and suddenly I realised the molecules of my body and the molecules of the spacecraft and the molecules in the body of my partners were prototyped and manufactured in some ancient generation of stars. And, that was an overwhelming sense of oneness, of connectedness. It wasn't 'them and us', it was 'that's me. That's all of it. It's one thing.' It was accompanied by an extasy. A sense of 'Oh my God, wow, yes, an insight, an epiphany".
It is one of the most beautiful documentaries i've ever watched!
I shall indulge in your link Leon - the moon fascinates me, thanks!
Dandelion
I did a couple of courses in planetary science as an undergraduate at university, and found it really interesting, I was tempted to go down the exoplanet researcher route after my degree, but ended up down another path. Still find it fascinating stuff tough.
http://www.nature.com/news/2011/110803/full/news.2011.456.html
http://en.wikipedia.org/wiki/Formation_and_evolution_of_the_Solar_System
http://en.wikipedia.org/wiki/Planetesimals
Thanks!
http://www.universetoday.com/15019/how-many-moons-does-earth-have/
http://wiki.answers.com/Q/How_many_moons_does_the_Earth_have
It is entirely plausible to suggest that earth has had more than one satellite in its history. read the summaries in the links I gave and it will show you this.
People care because they enjoy scientific inquiry. Better they enjoy learning than spending time breaking the precepts, gambling, or ... um ... spending hours on internet forums?? Oh well. Never mind. :-/
Conventionally speaking.
But 'satellite' is different to 'moon'.
Because it's called history people!
History is important.
That is like saying, Hitler existed, so who cares?
What if there is another Hitler?...!!!
People are one thing.
"moons" are another.
It takes a slightly different structure to argue the resurgence of a human being's existence, to that of a planetary body.
Well I care for one, plus if everyone had the attitude of, "who cares" about anything, then we would still be in the stone age. I mean if no one cares, then why invent anything, why have laws etc etc, its human curiosity that has propelled civilization from the stone age to advances in societies such as cures and treatments for the countless ailments that exist in our world. Moreover, imagine if Siddhattha Gotama had a "who cares" attitude, imagine if he was happy to stay in his life of luxury and not want to find the meaning of his life; it is thanks to this attitude of caring, of being inquisitive, curious, of wanting to know the answers to what, why, when, where, how, that we have the Dharma, that we have cures to diseases, that we landed on the moon, that we have computers, the list goes on and on. In my opinion its good to be inquisitive, its good to ask questions, its good to care.
The earth has more than one satellite, but has only one moon.
This - is irrelevant.
I mean, explain to me how this enhances your own practice and improve it, specifically?
As I have said in my opinion no matter if it is scientific, Buddhists or any other subject; its good to be inquisitive, its good to ask questions, its good to care. Its the only way we can learn and evolve our knowledge and understanding.
With regard to other stuff, it pays to know what is relevant to practice and supportive of progress, and what is just inquisitiveness on a simply personal basis.
I'm not suggesting you're either right or wrong. I am suggesting you discern what is fruitful, and what is a waste of time.
Discussing the possibility of there once having been more than one moon - is a waste of time.
In my opinion.
Age of the earth? Who cares?
Dinosaurs? Who cares?
Evolution? Who cares?
Stars and interplanetary objects? Who cares?
Psssh, silly scientists.
Science asks fundamental questions about the nature of the universe, why things are the way they are, and tries to explain this. By understanding little bits of the jigsaw, such as how the earth evolved, allows us to put these jigsaw pieces together and hence allows us to see the bigger picture, and answer the bigger questions such as how we got here and how things will evolve in the future. To play ignorant to these questions, and hide from the answers, citing who cares, or it has nothing to do with practice, in my opinion would be a terrible waste of the opportunity that humans have to be able to answer these fundamental questions and unlock the secrets of the universe. Therefore, I am glad that not everyone thinks like you; no offense intended.