Create an account
a model of the universe in which earth is at the center of the revolving planets and stars
a model of the solar system in which Earth and the other planets revolve around the sun
system made up of the nine unique planets, including earth, and many smaller objects, that orbit the sun.
an object that orbits a star is large enough to have become rounded by its own gravity and has cleared the area of its orbit
a large round object that revolves around the sun but has not cleared the region around its orbit
the process in which two atomic nuclei combine to form a larger nucleus, forming a heavier element and releasing huge amounts of energy
a region of very tightly packed gas in the sun's interior where energy is transferred mainly in the form of light
the blocking of gas from the sunlight to the earth that occurs when the moon is directly between the sun and earth
A huge, reddish loop of gas that protrudes from the sun's surface, linking parts of sunspot regions
an eruption of gas from the sun's surface that occurs when the loops in sunspot regions suddenly connect
the trapping of the heat near a planets surface by certain gases in the planets atmosphere
The name often given to the first four outer planets: Jupiter, Saturn, Uranus, and Neptune.
the region of the solar system between the orbits of Mars and Jupiter, where many asteroids are found
a region of the solar system that is just beyond the orbit of neptune and that contains small bodies made mostly of ice
loose collections of ice, dust, and small particles whose orbits are usually very long, narrow ellipses
the center of the atom which contains the protons and neutrons; in cells, structure that contains the cell's genetic material (DNA) and controls the cell's activities
Objects revolving around the sun that are too small and too numerous to be considered planets
Please allow access to your computer’s microphone to use Voice Recording.
Having trouble? Click here for help.
We can’t access your microphone!
Click the icon above to update your browser permissions and try again
Reload the page to try again!Reload
Press Cmd-0 to reset your zoom
Press Ctrl-0 to reset your zoom
It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.
Please upgrade Flash or install Chrome
to use Voice Recording.
For more help, see our troubleshooting page.
Your microphone is muted
For help fixing this issue, see this FAQ.
Star this term
You can study starred terms together