| WORD |
MEANING |
| A.S.I. |
Agenzia
Spaziele Italiana - The Italian Space Agency. |
| Accretion |
The
build-up and accumlation of matter (dust and gas) which results in the
formation of stars, planets, moons and other objects in solar systems. |
| Adams,
John Couch |
When
he was 24, English astronomer and mathematician John Adams was the first
to predict the location of an object beyond the orbit of Uranus. This
object was later found by German astronomer Johann Gottfried Galle in 1646
and became known as Neptune. Galle used predictions of its location by
French astronomer Urbain Jean Joseph Le Verrier since Adams didn't publish
his findings! Adams lived from 1819 to 1892. |
| Adrastea |
Moon of Jupiter,
discovered in 1979 by Voyager, 2nd closest moon to Jupiter, diameter 40 km (25 miles) |
| Aegir |
moon of saturn |
| Aitne |
Moon
of Jupiter, discovered in 2003 by a group of astronomers at the University
of Hawaii. It is irregularly shapes with a diameter of about 4 km (2 and a
half miles). It orbits the planet at a distance of 23,981,000 km
(14,901,100 miles). |
| Albiorix |
moon of saturn |
| Aldrin, Edwin "Buzz" |
Apollo 11 astronaut. Second man to walk on the
Moon's
surface. |
| Alpha
Centauri |
The
3rd nearest star to Earth, after the Sun and Proximus Centauri. 4.4 light
years away. Also the fourth brightest star in the sky, after the Sun,
Sirius and Canopus, with a magnitude of -0.3. |
| Aoede |
moon of jupiter |
| Aphelion |
The
greatest distance of a planet or comet in its orbit around the Sun.
Opposite to perihelion. |
| Apoapsis |
The
greatest distance of a body (a moon or an artificial satellite) in its
orbit around bodies other than the Sun or Earth (for example, a moon around
Jupiter). |
| Apogee |
The
greatest distance of a body (the Moon or an artificial satellite) in its
orbit around Earth. |
| Apollo |
Name given to missions
in the 1960s and 1970s designed to land man on the Moon and return
him home. Three astronauts testing Apollo 1 died in a fire in the capsule.
Apollo 4 - 6 were unmanned launches. Apollo 7 was a manned launch but
didn't go to the Moon. Apollo 8 - 10 were manned launches to
the Moon (but were not designed to land). Apollo 11 - 17 were manned missions to
land on the Moon. No moon landing took place during Apollo 13 due to an
explosion onboard. |
| Amalthea |
Moon of Jupiter,
discovered in 1892 by Edward Emerson Barnard. 200 km (150 miles) in
diameter. |
| Ananke |
moon of jupiter |
| Anthe |
Moon of Saturn |
| Arago,
Dominique François Jean |
French
astronomer and physicist. He discovered the production of magnetism by
rotation. He was also director of the Paris Observatory and lived from
1786 to 1853. |
| Arcturus |
Fifth brightest star in the sky, 36 light years from Earth,
magnitude 0.0 |
| Arche |
moon of jupiter |
| Ariel |
moon of uranus |
| Armstrong, Neil |
Apollo
11 astronaut. First man to walk on the Moon's surface. |
| d'Arrest,
Heinrich Louis |
Danish
astronomer involved in the first observation of the planet Neptune. He was
assisting German astronomer Galle who was using information provided by
French mathematician Le Verrier about the position of an object beyond
Uranus. While Galle observed the sky, d'Arrest read from a star chart.
Galle spotted an object which wasn't listed on d'Arrest's chart, and the
first observation of Neptune was made! D'Arrest lived from 1822 to 1875. |
| Asteroid |
Medium-sized
rock fragments left over from the formation of the Solar System left to
float around space. Smaller than planets but larger than meteoroids.
Also known as "Planetoids" |
| Asteroid
Belt |
Region
in between the orbits of Mars and Jupiter where a large number of
asteroids orbit the Sun. |
| Asteroid
Number |
Each
asteroid discovered is given a number based on the order that it was
discovered. 1 Ceres means that Ceres was the first asteroid to be
discovered. 4 Vesta means that Vesta was the fourth asteroid to be
discovered. |
| Astronaut |
A
person who travels into space. Russia/Soviet equivalent is Cosmonaut. |
| Astronomical
Unit |
A
unit of measurement used for measuring distances in space. 1 A.U. is equal
to the approximate distance from the Earth to the Sun (150 million
kilometres). |
| Astronomy |
The
study of the objects in the sky, eg: stars, planets, moons, galaxies,
comets, asteroids, etc. |
| Astrology |
The
belief that the positions of the Sun, Moon, stars and planets can affect a
person's destiny. |
| Atlas |
Moon of Saturn |
| Atmosphere |
The
layer of gas surrounding the surface of a planet, moon or star. |
| Atom |
A
tiny particle of matter, itself made up of many particles of matter. |
| Aurora |
Glowing lights in the sky
caused by the interaction between the Solar Wind (charged particles from
the Sun) and a planet's magnetic field. |
| Aurora
Australis |
An
aurora which can be seen in the Southern Hemisphere. The glowing lights
are caused by the interaction of charged particles from the Sun and
Earth's magnetic field in the upper atmosphere (or ionopshere). Also known
as the "Southern Lights" |
| Aurora
Borealis |
An
aurora which can be seen in the Northern Hemisphere. The glowing lights
are caused by the interaction of charged particles from the Sun and
Earth's magnetic field in the upper atmosphere. Also known as the
"Northern Lights" |
| Autonoe |
moon of jupiter |
| Axis |
The
imaginary line around which a planet, moon, star spins. |
