Are celestial objects made of ice and dust
that revolve around the sun in long, elliptical
an English astronomer, was on of the first
men to recognize that comets are definitely
members of the solar sysytem.
1. It may make one loop around the sun and
return to the outer shell.
2. It can fall into a new, eccentric orbit around
3. It may approach so close to the sun that it
*Several distinct parts:
Nucleous- A head has a solid core, surrounded by
Coma- The head of a comet, believed to be composed
of frozen gases and ice mixed with smaller quantities
of meteoric materials.
Hydrogen cloud- huge (million of km in diameter) but
very sparse envelope of neutral hydrogen.
Dust tail- up to 100 million km long, composed of
smoke and dust particles driven off the nucleus by
escaping gases; the most prominent part of a comet.
Plasma tail- up to 100 million km long, composed of
plasma and laced with rays and steamers caused by
interactions with the solar winds.
Or planetoids are small bodies observed to range in
diameter from a kilometre to a thousand kilometres.
*Ceres- largest asteriod.
The first to be discovered.
Hermes- A small asteroid, barely more that a mile
in diameter, has come within 485,000 miles of the
Origin of Asteroid
1. Some astronomer believe that they are fragments
of a planet which was shattered by gravitational
forces when it passed too close to the giant Jupiter.
2. Other suggest that the asteroids may be the pieces
of two planets which collided and were both
blasted into fragments.
3. A completely different into theory is that they are
fragments of the solar system which never grew
large enough to form an ordinary planet.
*Meteoroid-Small solid particles from a comet or
*Meteorites- The remains of the meteoroids found on
the surface of the Earth.
*Meteors- When these particles become visible in the
Given to these small visitors, comes from a Greek
word meaning “something in the air”.
Shooting Stars- Streaks of light that last few seconds
in the sky.
The meteors that reach the Earth seem to come from
two different sources:
1. Small fragments like those in the belt of asteroids
between Mars and Jupiter.
2. Appears to be the tails of comets.
“Twinkle, twinkle little star, how I wonder what
you are, Up above the world so high, like a
diamond in the sky”…
Star- gigantic balls of flaming gases.
*Blue or White star- The hottest star.
*Yellow star- The sun, the hotter star.
*Red stars- coolers or least hot.
groups of star.
When the sun moves against the background of constellations it is
called zodiac constellations.
13 Zodiac constellations
*Galaxies- are huge systems of billions of stars
and other celestial bodies.
*Milky way- the Galaxy which our sun belong.