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."
It has a diameter of approximately 40 kilometers or 25 miles and an extensive gas coma. Hale-Bopp has three tails: one consisting of dust particles, one of charged particles, and a third of sodium particles.
Comet Hale-Bopp was discovered in July, 1995, by two amateur U.S. astronomers, Alan Hale and Thomas Bopp.
Messages are sent to and from the satellites via ground stations. Most communications satellites are in geostationary orbit, appearing to hang fixed over one point on the earth's surface.
A circle is formed by slicing the cone parallel to its base, an ellipse by slicing at any angle less than that of the side of the cone relative to the base, and a parabola by slicing parallel to the side of the cone.
A hyperbola is formed by cutting the cone at an angle steeper than that of the side. To a good approximation, all celestial bodies within the solar system follow orbits which can be represented by conic sections.
A superior planet, or other object, is in conjunction when it lies behind the sun.
An inferior planet, or other object, comes to inferior conjunction when it passes between the earth and the sun.
It is at superior conjunction when it passes behind the sun.
Planetary conjunction takes place when a planet is closely aligned with another celestial object; such as, the moon, a star, or another planet.
Superior conjunction occurs when a planet lies on the other side of the sun from the earth.
Inferior conjunction occurs when a planet lies on the line joining the sun and the earth, and is closer to the earth.
The first recorded constellation were arbitrary patterns of stars in which early civilizations visualized their gods, sacred creatures, and mythical heroes.
The constellations being presented now are derived from a list of 48 known to the ancient Greeks, who inherited some of them from the Babylonians.
The current list of 88 constellations was adopted in 1930 by the International Astronomical Union, astronomy's governing body.
The boundaries of the 88 accepted groups have been set by international convention; their positions are described in terms of right ascensions and declinations.
At a solar eclipse, first contact is when the advancing edge of the sun first appears to touch the moon; the second contact is when the advancing edge of the sun seems to touch the other side of the moon, beginning totality; the third contact is when the trailing edge of the sun "touches" the trailing edge of the moon, ending totality; and the fourth contact marks the end of the eclipse.
2. The transfer of heat through a fluid by the motion of the fluid itself.
Such motion is usually in the form of currents, in which the hotter, less dense material rises to be replaced below by cooler, denser material.
2. The innermost, central region of a planet, often comprising metallic substances that, through the dynamo effect, produce a magnetic field.
2. A faint halo of hot (estimated to be approximately 2,000,000°C or 3,600,000°F) and tenuous gas around the sun, which boils from the surface.
It is visible at solar eclipses or through a coronagraph, an instrument that blocks light from the sun's brilliant disk.
Gas flows away from the corona to form the solar wind.
2. Streams of ionizing radiations from space, largely of protons, alpha particles, and other atomic nuclei.
3. Very high energy nuclei moving at velocities close to that of light which are probably produced by supernova explosions.
On striking the earth's atmosphere, they produce cascades of other particles (by collision with nuclei in the atmosphere) called air showers.
2. The study of the creation of the universe.
Also check out the Index of other Scientific and Technological Topics.
