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"For centuries, astronomers and philosophers wondered how our solar system and its planets came to be. As telescopes advanced and space probes were sent out to explore, we learned more and more about our solar system, which gave us clues to how it might have taken shape.
But were our ideas right?
We could only see the end result of planet formation, not the process itself. And we had no other examples to study. Even with the knowledge gained about our solar system, we were left to wonder, are there other planetary systems out there, and did they form like ours? Discoveries made by the Hubble Space Telescope are helping us fill in key pieces to the puzzle of how planets form.
A cloud collapses to form a star and disk. Planets form from this disk.
According to our current understanding, a star and its planets form out of a collapsing cloud of dust and gas within a larger cloud called a nebula. As gravity pulls material in the collapsing cloud closer together, the center of the cloud gets more and more compressed and, in turn, gets hotter. This dense, hot core becomes the kernel of a new star.
Meanwhile, inherent motions within the collapsing cloud cause it to churn. As the cloud gets exceedingly compressed, much of the cloud begins rotating in the same direction. The rotating cloud eventually flattens into a disk that gets thinner as it spins, kind of like a spinning clump of dough flattening into the shape of a Pizza. These "circumstellar" or "protoplanetary" disks, as astronomers call them, are the birthplaces of planets."
Source: http://hubblesite.org/hubble_discoveries/discovering_planets_beyond/how-do-planets-form
What else can I help you with?
Were stars formed before the planets?
Yes. Planets orbit around the stars, so the stars must have preceded the planets. Additionally, our concept of the "big bang" implies that the early universe was composed of 98% or more hydrogen, a percent and a bit as helium, and "everything else" as about 1%. All of the heavier solid elements were created in supernova explosions in the cores of massive stars.
What are star planets called?
That doesn't make sense. There are stars, and there are planets. If you mean "planets around stars, other than the Sun", those are usually called "extrasolar planets" or "exoplanets".
What are the similarities between exoplanets and the planets in your solar system?
In both systems, the Moon goes around the Earth.
When does 2012 Dancing with the Stars begin?
March 19, 2012
What was different about planets and stars in ancient times?
Almost nothing was different, except our understanding of things. The stars have been shining for millions or billions of years; all the planets have been pretty much just where they are for about 4 billion years or more. "Ancient" times in our human history is anything more than 2000 years ago.
What is the name for the nebula planets from out of?
Nebulae are the birth places for stars, not planets. However, once stars begin to form, planets can come about through gravitational 'clumping' in the stellar accretion disc.
How large are stars compared with planets?
Almost all stars are significantly larger than almost all planets.
Are all-stars round?
Yes. All the stars are round and all the planets are round.
Are all stars round?
Yes. All the stars are round and all the planets are round.
Why do planets seem brighter than stars?
Some planets seem brighter - not all of them. Planets are quite near to us, as compared to the stars.
Are all stars and planets are about the same age?
All of the planets are in the same atmosphere. All of the planets are unique. All of the planets are considered planets. All of the planets have moons. All of the planets are named after a mythical person or thing.
How does the distance of planets compare to the distance of stars?
Stars are all over Hollywood, planets are above us in the sky.
Do stars orbit planets or planets orbit stars?
Planets orbit stars.
What planets has the most stars around it?
Because the stars are relatively so far away, all planets of this solar system have the same number of stars near them.
Do dwarf stars begin their life as planets?
No, but planets or planet dust could be pulled together to make a star, resulting in a dwarf star. (in theory)
Where do all-stars begin there life?
Stars begin their lives as clouds of gas and space dust.
How many stars with planets?
There are more than 300 known stars with known planets, and the list gets longer all the time.
