Search results
Results from the WOW.Com Content Network
Although denser than the space surrounding them, most nebulae are far less dense than any vacuum created on Earth (10 5 to 10 7 molecules per cubic centimeter) – a nebular cloud the size of the Earth would have a total mass of only a few kilograms.
The nebular hypothesis is the most widely accepted model in the field of cosmogony to explain the formation and evolution of the Solar System (as well as other planetary systems). It suggests the Solar System is formed from gas and dust orbiting the Sun which clumped up together to form the planets.
The nebular hypothesis says that the Solar System formed from the gravitational collapse of a fragment of a giant molecular cloud, [9] most likely at the edge of a Wolf-Rayet bubble. [10] The cloud was about 20 parsecs (65 light years) across, [9] while the fragments were roughly 1 parsec (three and a quarter light-years) across. [11]
The first planetary nebula discovered (though not yet termed as such) was the Dumbbell Nebula in the constellation of Vulpecula.It was observed by Charles Messier on July 12, 1764 and listed as M27 in his catalogue of nebulous objects. [10]
Cat's Eye Nebula (NGC 6543) Cat's Eye Nebula (NGC 6543) Nebulium was a proposed element found in astronomical observation of a nebula by William Huggins in 1864. The strong green emission lines of the Cat's Eye Nebula, discovered using spectroscopy, led to the postulation that an as yet unknown element was responsible for this emission.
The history of scientific thought about the formation and evolution of the Solar System began with the Copernican Revolution. The first recorded use of the term " Solar System " dates from 1704. [ 1 ] [ 2 ] Since the seventeenth century, philosophers and scientists have been forming hypotheses concerning the origins of the Solar System and the ...
It was proposed as a replacement for the Laplacian version of the nebular hypothesis that had prevailed since the 19th century. The hypothesis was based on the idea that a star passed close enough to the sun early in its life to cause tidal bulges to form on its surface, which along with the internal process that leads to solar prominences ...
1602-1608 – Galileo Galilei experiments with pendulum motion and inclined planes; deduces his law of free fall; and discovers that projectiles travel along parabolic trajectories. [3] 1609 – Johannes Kepler announces his first two laws of planetary motion. [4] 1610 – Johannes Kepler states the dark night paradox. [5]