|
Across
| 4 | | Any of the celestial bodies (other
than comets or satellites) that
revolve around the sun in the
solar system (6) |
| 5 | | One celestial body obscures another (7) |
| 6 | | Originally called black dwarfs,
these substellar objects were
first conceived of in the early
1960s as dark bodies floating
freely in space. Stellar models
had suggested that a true star
must have a m ass at least 80
times that of Jupiter to kindle
the stable fusion of hydrogen.
Objects with less than 80 Jupiter
masses were believed to exist, but
it was recognized that they would
be extremely difficult to find
because they would emit very
little light. Two words _ _ _ _ _
/ _ _ _ _ _ (5,5) |
| 8 | | Short-lived bursts of gamma-ray
photons, the most energetic form
of light. At least some of them
are associated with a special type
of supernovae, the explosions
marking the deaths of especially
massive stars. Three words _ _ _ _
_ / _ _ _ / _ _ _ _ _ (5,3,5) |
| 12 | | (astronomy) the luminous cloud of
particles surrounding the frozen
nucleus of a comet; forms as the
comet approaches the sun and is
warmed (4) |
| 13 | | active galactic nuclei
(abbreviation). A class of
galaxies which spew massive
amounts of energy from their
centers, far more than ordinary
galaxies. Many astronomers believe
supermassive black holes may lie
at the center of these galaxies
and power their explosive energy
output. (3) |
| 14 | | The (usually elliptical) path
described by one celestial body in
its revolution about another (5) |
| 15 | | The natural satellite of the Earth (4) |
| 16 | | Any celestial body visible (as a
point of light) from the Earth at
|
|
night (4)
| 17 | | Any star around which a planetary
system evolves (3) |
| 19 | | The closest of Jupiter's moons; has active volcanoes (2) |
| 20 | | A grouping of a number of similar
things (7) |
| 21 | | A starlike object that may send
out radio waves and other forms of
energy; large red shifts imply
enormous recession velocities (6) |
Down
| 1 | | A _ _ _ _ _/ _ _ _ _ _ is what
stars like our Sun become when
they have exhausted their nuclear
fuel. Near the end of its nuclear
burning stage, such a star expels
most of its outer material
(creating a planetary nebula),
until only the hot core remains,
which then settles down to become
a very hot (T > 100,000K) young
_ _ _ _ _/ _ _ _ _ _ (5,5) |
| 2 | | A diffuse mass of interstellar
dust or gas or both, visible as
luminous patches or areas of
darkness depending on the way the
mass absorbs or reflects incident
radiation. (7) |
|
| 3 | | The motion of a spinning body (as
a top) in which it wobbles so that
the axis of rotation sweeps out a
cone. The act of preceding in time
or order or rank (10) |
| 7 | | (astronomy) the precise date that
is the point of reference for
which information (as coordinates
of a celestial body) is referred (5) |
| 8 | | The largest of Jupiter's satellites (8) |
| 9 | | Stony or metallic object that is
the remains of a meteoroid that
has reached the earth's surface (9) |
| 10 | | A system of two stars that revolve
around each other under their
mutual gravitation. Two words _ _
_ _ _ _ / _ _ _ _ (6,4) |
| 11 | | A constellation on the equator
east of Taurus; contains
Betelgeuse and Rigel (5) |
| 17 | | The international scientific
organisation searching for extra
terrestrial life using radio
telescopes (4) |
| 18 | | The 4th planet from the sun.
(Roman mythology) Roman god of war
and agriculture; father of Romulus
and Remus; counterpart of Greek
Ares (4) |
|
|