Galaxies and Solar Systems

SETI• In 1977 the National Aeronautics and Space

Administration (NASA) launched the last of its Mariner series , Voyager 1 and Voyager 2.

• Powered by a nuclear core of Plutonium-238 that will last until the year 2020.

• The first probes to explore the outer solar system starting with Jupiter and currently near Pluto.

• Each Voyager contains a 12inch gold plated disc with hundreds of pictures, music, mathematical formulas, and the genetic code of human DNA.

Voyager I & II

The Universe• The Universe is very simple to remember.• The Universe is everything: Time, space,

gravity, matter, energy, stars, dust, black holes, galaxies, and solar systems.

• From largest to smallest:Universe->Galaxies->Solar system->Planets->Atoms

Star Development • We learned that stars develop from Nebulas of

gas and dust.• We learned a star’s mass is important in

determining its life, brightness, temperature, and death.

• We have learned that stars in main sequence are producing energy through Nuclear fusion.

• But what becomes of Stars?

Path of a Star • Some stars are attracted to other stars. They

will collect and gather due to gravity. Stars will form patterns and paths (orbits).

• Some stars will attract smaller objects around themselves with gravity.

• A Galaxy is a group of stars gathered together by gravity.

• Three main types of galaxies are: elliptical, spiral and irregular.

Elliptical Galaxies• Elliptical galaxies look

like flattened balls; oval shape.

• Galaxies with billions of stars but little gas and dust.

• Because of the lack of gas and dust, new stars cannot form.

• Most elliptical galaxies contain only old stars.

• Egg shaped galaxy.

Spiral Galaxies

• A galaxy with rotating arms or bands of star clusters.

• Our galaxy is a spiral galaxy. Our sun is on an outer band/arm.

• Galaxy with dust and gas and middle aged stars.

• Fan or drain shaped galaxy.

Irregular Galaxies

• Galaxies with no definite shape or pattern.

• Contains dust, gas, and mostly young stars.

• A scattered galaxy shape.

Quasars Galaxies

• Quasar is a distant galaxy with a black hole at its center.

• As enormous amounts of gas revolve around such objects as a black hole, the gas heats up and shines brightly.

Solar Systems• A Solar systems is one star with planets, moons,

and asteroids orbiting it; all within a galaxy. • Like our sun surrounded by its orbiting planets.

Any Questions?

• Universe is space and everything in it.