Astronomy for Beginners
Here’s where you’ll find observing guides, how-to articles and great astronomy hints and tips. Don’t forget to also check out our comprehensive astronomy dictionary.
The point in the orbit of an object that takes it closest to the Sun.
These are huge ‘bubbles’ (some the size of Jupiter) under the surface of the Sun, caused by the rising and sinking of super-hot gas in the Sun’s interior. Smaller convection cells cause ‘granules’ on the surface. These can be observed with a specially filtered H-alpha telescope.
The solid, central part of a comet, composed of rock, dust and frozen gases.