The sun's gravitational force is very strong. If it were not, a planet would move in a straight line out into space forever. The sun's gravity pulls the planet toward the sun, which changes the straight line of direction into a curve. This keeps the planet moving in an orbit around the sun. Because of the sun's gravitational pull, all the planets in our solar system orbit around it. The sun is a huge ball of super-hot gas. Deep inside the sun, the temperature is hotter than the hottest furnace.
The sun is so hot that it heats and lights all the planets in our solar system. Some planets orbit closer to the sun than others. And some are far away from the sun. The planets that are farthest from the sun are called the outer planets.
The planets that are closer to the sun are called the inner planets. The inner planets are close to each other as well as close to the sun. There are four inner planets:. The inner planets have a hard, rocky surface. It is possible to land a spacecraft on planets that have a hard surface.
The five outer planets are not only farther from the sun, but they are also far apart from one another. The last planet discovered in our solar system is farthest away from the sun. It is Pluto. We don't know much about Pluto yet except that it is very, very cold. Pluto is not like the other outer planets.
And it is not like the inner planets, either. Pluto is a mystery. Create a List. However, not everyone is aware of why the planets orbit around the sun and how they remain in their orbits. There are two forces that keep the planets in their orbits. Gravity is the primary force that controls the orbit of the planets around the sun.
While each planet has its own gravity based on the size of the planet and the speed at which it travels, orbit is based on the gravity of the sun. The sun's gravity is just strong enough to keep the planets pulled toward it to create an orbit pattern but not strong enough to pull the planets into the sun.
This is similar to the effect of the Earth on the orbit of the moon and satellites. The lesser gravity of the planets also helps to keep the planets from falling toward the sun. The m 1 and m 2 refer to the masses of the two objects involved in the interaction, G is the universal gravitational constant and r is the separation between the two objects.
This shows that gravity gets stronger for bigger objects, and weaker the farther away they are from each other. If planets were bigger, the force between them and the sun would be larger and it would alter their orbits.
Similarly, the equation shows that the distance of the planet from the sun is also a crucial factor in establishing an orbit. The physical law that states that objects in motion have a tendency to remain in motion also plays a role in keeping the planets in orbit. This set the planets into motion from their birth. Once the planets were in motion, the laws of physics keep them in motion by virtue of inertia.
When a molecular cloud grows to be massive enough, gravitationally bound and cool enough to contract-and-collapse under its own gravity, like the Pipe Nebula above, left , it will form dense enough regions where new star clusters will be born circles, above right.
Gravitation is unforgiving of imperfections, and because of the fact that gravity is an accelerative force that quadruples every time you halve the distance to a massive object, it takes even small differences in an initial shape and magnifies them tremendously in short order.
Inside the Orion Nebula, in visible light L and infrared light R , a star-forming nebula houses a But just as the nebula itself became very asymmetric, the individual stars that formed inside came from imperfect, overdense, asymmetric clumps inside that nebula. According to simulations, asymmetric clumps of matter contract all the way down in one dimension That "plane" is where the planets form, and many intermediate stages have been directly observed by observatories like Hubble.
But while much of the material gets funnelled inside, a substantial amount of it will wind up in a stable, spinning orbit in this disk.
Because of how angular momentum works overall, and how its shared pretty evenly between the different particles inside, this means that everything in the disk needs to move, roughly, in the same clockwise or counterclockwise direction overall.
Over time, that disk reaches a stable size and thickness, and then small gravitational instabilities begin to grow those instabilities into planets. Sure, there are small, subtle differences and gravitational effects occurring between interacting planets between different parts of the disk, as well as slight differences in initial conditions.
The star HL Tauri, as imaged in the optical in the upper-left , is brand new and contains a The young star in the upper left of the image above, on the outskirts of a nebular region — HL Tauri, about light years away — is surrounded by a protoplanetary disk. The star itself is only about one million years old. Thanks to ALMA, a long-baseline array that measures light of quite long millimeter wavelengths, or more than a thousand times longer than what our eyes can see, returned the following image.
The gaps in the While we'd observed young planets before, we've never seen this particular stage. From the early ones to the intermediate ones to the later stages of more-complete solar systems, they're all spectacular, and all consistent with the same story. Direct imaging of four planets orbiting the star HR light years away from Earth, a feat So why are all the planets in the same plane? It's a case where observations and simulations, based on theoretical calculations, agree remarkably with one another.
It's a remarkable story, and one that — thanks to not only simulations but now observations of the Universe itself — illustrates in incredible detail how rich and fascinating it is that all the planets orbit in the same plane no matter where in the Universe you go! This is a BETA experience.
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