Planet formation and star formation

In summary, the star that the Earth is located around would have started to fuse atoms and as a result, a "shockwave" would have pushed most of the remaining gas and dust in the disk outward. This would have created the asteroid belt and the planets around the sun would have shifted their orbits. The early Earth would not have had any water or atmosphere and would have been very different from what it is today.
  • #1
TShock
12
0
When our star the Sun finally accumulated enough matter for fusion to start what would that have done to the planets around it? Afterward what would have happened to the Earth for it to get from when the sun started fusion and blasted the Earth and now, with water and atmosphere?
 
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  • #2
I think it would have caused a huge solar wind or "shockwave" if you will. Pushing most of the remaining gas & dust in the what was left of the initial dust/gas cloud. Keep in mind, when this was happening, there was no water or atmosphere to speak of on earth.. really, Earth wasn't even earth, it was more of a proto-planet. I'm not sure how much of an impact it would have on the planets at that point in there evolution. My guess is it would probably shift their orbits outward {relative to their distance from the sun} and shower the planets with radiation..

.. is that what you're looking for...?
 
  • #3
I might be mistaken but I always thought that the fact we have 3 rocky inner planets, the asteroid belt and then gas giants is a result of the protosun igniting, blowing off any excess gas from the 3 inner planets and driving loose debris outwards forming the asteroid belt (but more or less leaving the gas giants alone which gathered up the relegated gas). From what I've read, astronomers are puzzled when they find a massive gas giant exoplanet orbiting so close to a host star as they imply this wouldn't form naturally and would expect to find rocky planets so close, the only explanation being that the gas giant was captured after the sun had formed, meaning it wasn't around for the initial fusion ignition.

The arrangement of our solar system (rocky inner planets, astroid belt, gas giants) might have more to do with orbital mechanics but the idea that this is the result of some 'ignition' within the Sun seems initially plausible.
 
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  • #4
As others have mentioned the inner region of the protoplanetary disk would have been very hot. It would have been too hot for gases to exist and so you get the rocky and metallic elements forming planitesimals in this region. These would eventually become the terrestrial planets and the asteroids from the asteroid belt. At this time The terrestrial planets may have had a hydrogen and helium atmosphere which will have been blasted away. A secondary atmosphere is believed to have been accumulated later once everything had settled down through a combination of gases trapped in the material they formed from and comets.

The important thing here any way is that the early Earth was nothing like it is today during the turbulent times at the birth of the sun.
 
  • #5
Recent developments in the evolution of the early solar system indicate that the Earth didn't even exist at the time of the birth of the Sun. Stars form quickly; planets are a lot slower to form. We have now observed many young stars that remain surrounded by a dust/gas nebula. Infant stars do not shine all that brightly; it takes several million years for a young star to clear out the gas and tens of millions to clear out the dust. This gives the planets time to form from planetesimals. Jupiter was most likely the first planet to form and aided in the formation of the other planets.

A recent Scientific American article on planetary formation is at http://www.sciam.com/article.cfm?id=the-genesis-of-planets".
 
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  • #6
Kurdt said:
...and the asteroids form the asteroid belt...
A side question, how did the asteroid belt get there? a failed terrestrial planet maybe? I remember being told as a child that another planet/asteroid smashed into what "was" a planet, leaving its shattered remains as the belt we currently see... Anybody know? {or atleast have a better idea?}

stevebd1 said:
... astronomers are puzzled when they find a massive gas giant exoplanet orbiting so close to a host star as they imply this wouldn't form naturally and would expect to find rocky planets so close...
My instructor called them, "Hot Jupiters" {http://exoplanets.org/massradiiframe.html" [Broken]}.. I was looking for the nice little animation he showed in class, but I can't seem to find it. Anyway, he stated that some think that these HJ's started out farther and have migrated inwards.
 
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  • #7
The most likely answer IMHO is that the asteroid belt formed in that region because it was the very edge of the terrestrial planet forming region and was under the influence of the larger gas giant planets. This prevented the earlier terrestrial planetesimals from accreting the material.
 

1. How do planets form?

Planets form from the leftover materials of a star's formation, known as a protoplanetary disk. These materials clump together due to gravity and eventually become large enough to form planets.

2. What is the role of gravity in planet formation?

Gravity plays a crucial role in planet formation by pulling together materials in a protoplanetary disk and causing them to collide and merge. Without gravity, planets would not be able to form.

3. How do stars form?

Stars form from dense regions of gas and dust in space, known as molecular clouds. These clouds collapse under their own gravity, causing the gas and dust particles to heat up and form a dense core, which eventually becomes a star.

4. What is the difference between a protostar and a main sequence star?

A protostar is a young, developing star that is still in the process of accumulating mass and undergoing nuclear fusion. A main sequence star, on the other hand, is a stable, mature star that is in a state of equilibrium, with its energy output balancing its gravitational collapse.

5. How long does it take for a star and its planets to form?

The time it takes for a star and its planets to form varies depending on the size and type of the star. Generally, it can take anywhere from a few million to billions of years for a star and its planets to form.

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