Astronomy and related astronomical terms
(the science of the celestial bodies: the sun, the moon, and the planets; the stars and galaxies; and all of the other objects in the universe)
As he raised his cup,
"Thank heavens my business
Is looking up."
According to the Department of Energy, homes incorporating solar heating designs can save as much as 50 percent on heating bills.
The negative aspects of solar energy is that it depends heavily on a range of factors including location, time of year, and the weather.
An extensive list of related words and definitions may be seen at this photovoltaic terms page.
The constellation contains the vernal equinox, the point at which the Sun's path around the sky (the ecliptic) crosses the celestial equator.
The Sun reaches this point about March 21 each year as it passes through Pisces from mid-March to late April.
A planet's own gravity pulls itself into its most stable shape, a slightly flattened sphere.
It includes the studies of objects ranging in size from micrometeoroids to gas giants, with the objectives of determining their compositions, dynamics, formations, interrelations, and histories.
It includes the study of Kuiper belt objects, dwarf planets, Titan, other icy satellites, extra-solar planetary systems (from brown dwarfs to stellar disks), and the occasional inner solar system body.
Its height is variable and ranges from 100 to 3,000 meters.
2. A shell of gas thrown off by a star at the end of its life.
Planetary nebulae have nothing to do with planets. They were named by William Herschel, who thought their rounded shape resembled the disk of a planet.
After a star; such as, the sun has expanded to become a red giant, its outer layers are ejected into space to form a planetary nebula, leaving the core as a white dwarf at the center.
The nine planets in the solar system are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto.
The inner four, called the "terrestrial planets" are small and rocky, and include the planet earth.
The outer planets, with the exception of Pluto, are called the major planets, and consist of large balls of rock, liquid, and gas; the largest is Jupiter, which contains a mass equivalent to 70% of all the other planets combined.
Planets do not produce light, but reflect the light of their parent star.

The planets are illustrated at the sight indicated below and links are available for more details about their Greek and Latin myths, symbolisms (system of symbols), and scientific information.
Click on this link for significant images and more detailed information about planets.
2. The modern equivalent of the astrolabe, but more convenient to use.
2. The so-called "fourth state of matter", consisting of ions and electrons in equilibrium.
Such a state can be arrived at in regions of very high temperatures; such as, those which exist within stars.
Its brightest stars (highly luminous, blue-white giants only a few million years old) are visible without the need of a telescope, but there are many fainter ones.
Also check out the Index of other Scientific and Technological Topics.