Where is the Solar System in the Universe?

What is the solar system?

• The solar system consists of:

– The sun (which is the name of our star)– Planets – Asteroids – Comets – Space rocks

Measurement in Astronomy

Scientists find it hard to work with the measurements we use on earth, like kilometers and miles, because the distances are so great it is hard

for us to comprehend such enormous numbers.

Light Years

• A light year is equal to the distance that light travels in one year.

• Light travels 300,000 km per second

• A light year equals 9.5 trillion km

Cool facts!

• It would take eight minutes for light from the sun to reach earth.

• The farthest objects are about 13.5 billion light years away.

Galaxies

• Galaxies are clusters of stars pulled together by gravity.

• There are three kinds of galaxies:

– Elliptical– Irregular– Spiral

Spiral Galaxies

• Look like giant, flat discs with a bulge in the middle with spiral arms flaring out from the center.

• These are typically the largest galaxies.

Spiral Galaxy

Elliptical Galaxies

• Look like rounded, lightly flattened balls.

• These are medium sized galaxies with very old stars.

Elliptical Galaxy

Irregular Galaxies

• These galaxies have no regular shape.

• They are the smallest and faintest galaxies, but they are also the most common.

Irregular Galaxy

What galaxy do we live in?

• We live in the galaxy called the Milky Way Galaxy.

• It is a spiral shaped galaxy that contains about 100,000 billion stars.

• Our sun is located about 2/3s of the way from the center of the galaxy in one of the spiral arms.

• The distance from the sun to the center is about 30,000 light years.

• All objects in the Milky Way rotate around the center, and it would take the sun and our solar system about 240 million years to make one trip around the center of the galaxy.

Milky Way Galaxy

What is your space address?

• Pretend you have an alien friend coming to visit you from another galaxy. You need to give your friend directions, so what information would you need to give the alien to help them find you?

My Space Address

Street address: __________________________City: __________________________State: __________________________Country: __________________________Planet: __________________________Solar System: __________________________Galaxy: __________________________