A nebula ais one of the most beautiful deep-sky objects in the night sky. But what is a nebula? And how do these space clouds form?
Sixteen asteroids have diameters of 240 kilometers or larger, the largest of which is Ceres, which has a diameter of about 1,000 kilometers. Are all asteroids in our solar system in the main belt, or are there other bodies that share the space between Mars and Jupiter? And what about ...
How are planetary nebula formed? How are comets in the Kuiper belt formed? How are asteroids formed in space? Did Jovian or terrestrial planets form first? Why do Jovian planets and terrestrial planets differ in mass? How did the solar system form?
According to the solar nebula theory, the sun formed around 4.5 billion years ago from a massive cloud of gas and dust in space [source: NASA]. Imagine a huge cloud in space that shrinks and spins because of outside forces. This cloud becomes a flat, spinning disk, called a solar nebul...
The protostar is basically a baby star, and grows into a star through its life cycle in the same way as we are born and grow.The main process of all stars' birth is called Nuclear Fusion. Nuclear Fusion happens in very large clouds on gas called nebula. When nuclear fusion starts in ...
The crust along a divergent boundary is some of the newest crust on earth. Explain why. Mountain roads are curved and not straight up the slope, why? What caused the collapse of the solar nebula? What evidence convinced Wegener and peers that in the past, land was one supercontinent and ...
Solar atmosphere, which afterwards contracted into a solid terraqueous sphere, from which the Moon was thrown off by the same process... [Under such a view] the Moon must necessarily have carried off water and air from the watery and aerial parts of the Earth and must have an atmosphere."...
Define the terms:Galaxy,nebula,black hole,supernova,comet,asteroid,meteorite(这题必须用英文答)How and when is earth thought to have formed?Do the magnetic poles of the earth change?How do we know?What is "space weather',and how are we on earth protected from it?How are insolation and ...
Scientists are continuing to study planets in and out of the solar system in an effort to better understand which of these methods is most accurate. The core accretion model Approximately 4.6 billion years ago, the solar system was a cloud of dust and gas known as a solar nebula. Gravity ...
Scientists believe our solar system began forming as a huge cloud of dust that collapsed to form a sun surrounded by a flat disk of particles rotating around it, This disk-the solar nebula, as it is called-was denser in the center than it was in its outer reaches. It was also hotter ...