Solar System

• Asteroids are rocky objects in space that are too small and numerous to be considered real planets. Most of these revolve around the sun between the orbits of Mars and Jupiter. This region of the solar system is called the asteroid belt.
• Comets are seen as a streak of light in the atmosphere just like the other minor members of the solar system.
• Nucleus is described as the frozen center of a comet.It is believed to be solid containing the chunk of dust, ice or frozen gases, water vapor and other materials. It is relatively small only 10 km or less across, but it contains majority of the comet's mass.
• Coma is described as a roughly round gaseous blob

  surrounding the nucleus.

  It is composed of water vapor, carbon dioxide, gas, ammonia, dust and neutral gases that have sublimed from the solid nucleus.

  Sublimation is the change from solid to gas.

  The gases emitted from the nucleus are due to its warming by the sun.

  At a distance between 1 to 2 AU (astronomical units), the heat from the sun is sufficient to evaporate amount of materials.
• An Astronomical Unit is the average distance between the Earth and the Sun.
• One AU is equal to 149,597,870 km
• Tail is described as usually long, curved with

  diffused appearance.

  When the comet travels close to the sun , the tail

  gets longer. Due to the solar wind, the gases (cyanogen, carbon, methane, water and other compounds containing hydrogen, oxygen, nitrogen and carbon) and dust particles are blown away from

  the sun’s direction.
• The ion tail or plasma tail is composed of ionized gas.
• Ions are charged particles.
• When a gas is made up of ions , it is in

  the plasma state.
• Plasma is different from a gas,

  because it is made up of groups of

  positively and negatively charged

  particles.
• The dust tail is a long, wide tail composed of

  microscopic dust particles that have evaporated from

  the comets nucleus and are pushed away photons from

  the sun.
• Photons are particles of light that carry energy.
• Particles of light hit the dust particles. Photons push the

  stream of dust into a very long tail.
• Hydrogen Envelope are gases surrounding the coma.
• The hydrogen envelop is about 10

  million km across at the nucleus of the

  comet and about 100 million km long.