What causes planets to form in the first place?

Question

In other words, just because gas and dust floats around in space, they spontaneously begin to form a planet? What initiates the process?

Ok and if gravity does, what causes it to start? I thoguht that phsyics follows laws, like Newtons laws in this instance. So gravity can't just on it's own accord start to bring particles together can it? the forces in space are in balance, even dow nto dust and gas, so what causes the forces to go out of balance and begin to accumulate to a planetoid and then a planet? What starts it?

Answer 1

Planet formation is still somewhat of a mystery, but astronomers believe they understand the basic process. The best explanation to be accepted by most astronomers is known as the solar nebula hypothesis. Stars are formed from giant clouds of gas and dust known as nebulae. Gravity causes the matter in the nebula to coalesce. Gravity soon causes the central part of the nebula to collapse and form a star. The rest of the gas and dust forms a flat, rotating ring around the new star. Eventually the gravity of the new star begins to pull matter towards it. Small whirlpools of spinning matter form within this disk. Gravity causes these whirlpools to aggregate into small masses known as planetesimals. These planetesimals continue growing, pulling in the matter around them. Gravity soon pulls them into a spherical shape. These small spheres may collide and merge with others as they grow in size and become what is known as a protoplanet. Sometimes, a smaller sphere of matter may become captured by a larger one and enter into an orbit, creating a moon. Over time, gravity causes the heavier elements in the protoplanets to separate from the lighter ones in a process called uniformitarianism. This forms the planet's metal core, rocky crust, and usually an atmosphere composed of gas. As the star and planets continue to grow, the dust and gas of the nebula begins to thin. Smaller chunks of condensed matter is left over in the outer regions of the disk. These form the Kuiper belt of planetoids and the Oort cloud of comets. Eventually the solar wind from the star will blow away the excess gas and dust. A new solar system has been born. The process is slow and takes millions of years. Many stars have been observed to have flat disks of matter around them. These could very well be new solar systems in the making.

Answer 2

THE ORIGIN OF THE SOLAR SYSTEM

What makes the Earth rotate on its axis?

Mike: The solar system formed about 5 billion years ago. When a star forms, material collapses into the centre to form a star. Around it, it forms a planetary disc. That disc fragments due to gravity. Bits coalesce which have more gravity, and you get planets and planetessimals forming. When the bits collapse to form the Earth, the Earth rotates because the disc was rotating already. If you have ever seen an ice skater with arms out, she spins quite slowly. When her arms are drawn in, she spin much faster. This is called conservation of angular momentum. Even though this disc was rotating, it began to spin in a similar way to when an ice skater draws her arms in.

Why do they all rotate in the same direction?

----------Because the disc was spinning around the sun in a particular direction, the rotation of the planets follow the direction of the disc. Uranus is different because it's on its side. It's thought that some interactions after the formation of Uranus moved it on its side - perhaps a big collision.

The solar system is surprisingly flat. Why?

-------------- A good picture of the solar system as its being form is like a fried egg with the yolk being the sun. The flat disc rotating around the sun fragmented and formed our planets.

Is the Milky Way - our galaxy - rotating as well?

------------ Rotation is ubiquitous in astrophysics, and the reason is conservation of angular momentum. You have large clouds of gas that collapse under gravity to form either galaxies on very large scales or, within galaxies, stars or even planets. As the material falls in, there's no reason for its angular momentum to change because there is nothing to change its direction (called 'torque').


Note: some words considered are more gravity,flat disc,dust,axis,spin,angular momemtum,torque,direction etc..,

Answer 3

hello jae,well that is a really good question,
as people before me have pointed out(well some of them)that gravity pulls the dust and other particles that have flown out in incredibly fast proportions in high quantities when a star breaks down this process occurs when the star when it is old and is atleast 2times bigger than the sun it kind of magnifies so to speak and gets bigger and then after a long time(a billion years) breaks of then the outer body of the star is thrown out these particles are highly charged and is heated to the extent of melting the planet jupiter.These super heated particles due to the high pressure that the heat creates and because of the heat gases form accidentaly if not gravitationaly collide and merge as an object sticks to another object due to intent heat because of them colliding by accident or by gravity they get naturally bigger resulting in the heat spreading over a wider area and they eventually cooling off or more objects falling into them say the asteroids making them bigger.After many million years when the colliding of objects have done and when they eventually cool of the minerals especially iron which may have been in liquid state due to intense heat as it melts at 4000degree celcius this intense heat must have cooled of and let iron and other minerals to solidify as a result the planets get more weight as previously these were in the form of liquid lava.due to intense pressure some iron or many would have been magnetically charged and we know that all things contain some amount of iron in them and due to the large amount of iron and stuff gradually becomes a planet and that's where newton's laws come into effect.

Answer 4

Forces in space are NOT in balance. They are continuously trying to balance. So the motion exists. Any mass has an attraction to the other masses. So they get accumulating in a period of time and from planets asteroids etc.

Answer 5

God created the planets on the second day.According to Genesis ,Chapter One, verse 14-19.God created Heavenly Bodies on the fourth day.

Answer 6

Gravity does. It pulls those bits and pieces together to form larger bodies. More debris equals more (bigger) planet, get enough space junk together you get a star.

Answer 7

accretion driven by gravity

Answer 8

http://www.sciencedaily.com/releases/1999/12/991208153928.htm

hope it'll help