Our Home.

• The solar system is where we reside. Our only home – earth, is but a small speck among the myriad objects that make up the solar system

• Our curiosity has taken us far into the reaches of the solar system, but only remotely.

• Though it is infinitely tiny compared to our galaxy, and especially the universe, we continue to explore and discover new things about our solar system every day.

• The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it.

• Formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. (protostar formation)

• Edge of the solar system sometimes defined as where the solar wind stops. (Heliopause) This is about 100 A.U. from the sun

• Furthest known objects may extend to 50,000 A.U. (1 light-year) from the sun.

• Estimated boundary of the suns gravitational dominance is about 2 light-years.

• Remember, the closest star, Alpha Centauri, is 4.3 light years away.

• Inner solar system

• From the sun to the Asteroid Belt

• 0 – 5 A.U.

• Asteroid Belt

• ~5 A.U. Contains 25,000,000+ asteroids

• Outer solar system

• From Jupiter to Neptune

• 5 – 30 A.U.

• Kuiper Belt

• Beyond Neptune, includes Pluto

• 30 – 50 A.U. from the sun

• Oort cloud

• Beyond the Kuiper Belt

• 2000 – 50,000 A.U. ( 1 light-year)

• (Greek "wandering star") A celestial body orbiting a star or stellar remnant

• Massive enough to be rounded by its own gravity,

• Not massive enough to cause thermonuclear fusion.

• Has cleared its neighboring region of planetesimals.

• A celestial body that orbits a planet or smaller body, which is called its primary.

• A moon can orbit a Planet, minor planet, or dwarf planet.

Between the meteorites and the moons.

• A celestial body orbiting the Sun

• Massive enough to be spherical as a result of its own gravity

• Has not cleared its neighboring region of planetesimals

• Is not a satellite (does not orbit another planet).

• 5 currently recognized by the IAU: Ceres, Pluto, Haumea, Makemake, and Eris.

• 50 – 200 other current candidates.

• No true formal definition

• Tends to refer to minor planets within the inner solar system, larger than 10 km diameter.

• Can also be referred to as Planetoid or “Small Solar System Object”

• ANY object that is part of the solar system and beyond the orbit of Neptune.

• Kuiper Belt:

• Objects from 30 – 50 A.U. (KBO = Kuiper Belt Object)

• Primarily Icy, with frozen volatiles (methane, ammonia, etc.)

• Scattered Disc:

• Sparse collection of larger TNOs, beyond the Kuiper Belt

• Similar in composition to Kuiper Belt Objects

• It is now believed that most comets originated from this region.

• Oort Cloud:

• Farthest reaches of the solar system

• Spherical in structure, instead of flat, disc shaped regions

Boulders to Dust

• Highly eccentric orbits

• Believed to originate from the scattered disc

• Many come from the Kuiper Belt or Oort Cloud as well.

• Can range from “Icy mudball” to “dirty snowball” in composition.

• sand to boulder-sized particle of debris in the solar system

• Ranges from icy to rocky to metallic

• When it enters the earth’s atmosphere it becomes a METEOR

• Once it lands on the surface of the earth, it becomes a METEORITE