The nebular hypothesis says that the Solar System ..
the solar nebula hypothesis, ..
Venus and Uranus are exceptions—they rotate on
their axes in that same direction.
According to the solar nebula hypothesis, Earth and the other planets of the solar system formed billions of years ago as the sun condensed from the interstellar medium.
How Was the Solar System Formed? - The Nebular Hypothesis
The important point is that Nichols has developed a tool for testing ideas for formation of the Solar System, which will help us understand star and planet formation in general.
Building Blocks of Life Found in Comet's Atmosphere
Scientists believe that the solar system was formed when a cloud of gas and dust in space was disturbed, maybe by the explosion of a nearby star (called a ). This explosion made waves in space which squeezed the cloud of gas and dust. Squeezing made the cloud start to collapse, as gravity pulled the gas and dust together, forming a solar nebula. Just like a dancer that spins faster as she pulls in her arms, the cloud began to as it collapsed. Eventually, the cloud grew hotter and denser in the center, with a disk of gas and dust surrounding it that was hot in the center but cool at the edges. As the disk got thinner and thinner, particles began to stick together and form clumps. Some clumps got bigger, as particles and small clumps stuck to them, eventually forming or . Near the center of the cloud, where planets like formed, only rocky material could stand the great heat. Icy matter settled in the outer regions of the disk along with rocky material, where the giant planets like formed. As the cloud continued to fall in, the center eventually got so hot that it became a star, the Sun, and blew most of the gas and dust of the new solar system with a strong . By studying meteorites, which are thought to be left over from this early phase of the solar system, scientists have found that the solar system is about 4600 million years old!
How Good are those Young-Earth Arguments: Hovind's …
Several radiometric systems can be used on CAIs, including:Both systems indicate that CAIs began forming roughly two million years prior to chondrules (at roughly 4.571 ga). But note: The uniformity of these ages implies that they formed through the same underlying process. The only reasonable hypothesis is that they condensed from the Solar Nebula.