What was Descates's theory of the origin of the solar system?
The universe spun, and stars and planets formed from this spinning material.
What was Kant's theory of the origin of the solar system?
Gravity would cause a spinning cloud of gas and dust to flatten into a disk.
What was Laplace's theory of the origin of the solar system?
A spinning cloud of gas and dust would cool and shrink, leaving material behind to form planets.
What was Buffon's theory of the origin of the solar system?
A comet hit the sun; the pieces flew off to form planets.
What was Moulton and Chamberlin's theory of the origin of the solar system?
A large star passed near the sun; its gravity pulled off blobs of material that formed planets.
What does the Bible say about the origin of the solar system?
God made it!
What is the modern theory of the origin of the solar system?
Nebula hypothesis
What is the nebula hypothesis?
1. A large cloud of gas (hydrogen) and dust, a nebula, begins to collapse under its own gravity or some gravitational perturbationwfor example, a nearby star or supernova.
2. The collapsing cloud begins to spin.
3. The spinning, collapsing cloud flattens
What evidence is there to support the nebula hypothesis?
n the 1980s, astronomers used a radio telescope and detected a disk of gas and dust around the star Beta Pictoris. Since then, the Hubble space telescope has peered into the M33, a large cloud of gas and dust in the constellation Orion (Orion nebula) wher
What happens to the protostar next?
It continues to grow and accumulate material (as it spins). Eventually it gets massive enough, dense enough and hot enought for nuclear fusion.
What causes all stars to glow and produce energy?
Nuclear fusion.
What happens once nuclear fusion begins in the young star?
The nuclear fusion creates a solar wind that drives remaining gas and dust to the other parts of the disk. The young star stops accumulating material.
What are planetesimals?
Small bodies orbiting the sun, thought to have formed when the solar system formed and which may have formed the planets.
What happens to planetesimals orbiting around a star?
They collide with each other and eventually grow to form planets that orbit the star.
Where would rocky planets form?
In the inner portions of the disk.
What are some examples of rocky planets?
Mercury, Venus, Earth and Mars.
Where would gas planets form?
In the outer portions of the disk.
What are some examples of gas planets?
Jupiter, Saturn, Uranus, and Neptune.
Why would rocky planets form in the inner portion of the disk?
The inner portion is warmer, so only heavy elements (rocks, metals) remain there.
Why would gas planets form in the outer portion of the disk?
the outer portion is much colder so gases (hydrogen), ice and dust can clump together.
What is needed for the planets to orbit around the sun?
Just the right amount of mass and spin.
Could the "just right" amount of mass and spin have happened by accident?
No, probably not.
What happened to the leftover particles that did not become planets?
The solar winds blew them to the outer reaches of the solar system.
What did the leftovers form?
The Oort Cloud and The Kuiper Belt.
What comes from the Oort Cloud and the Kuiper Belt?
Comets the regularly visit the inner solar system
Why was Pluto demoted from a planet?
Pluto was recently demoted from a planet because it more closely resembles a Kuiper Belt object than other planets. It is small, rocky, far away, and does not orbit in the plane of the solar system.