1.1.3 Explore the Universe

Explore the Universe
1.1.3

By Caitlin Ford

Objectives

- list different ways astronomers measure distances in space

- identify the differences between the solar system, galaxy, and universe

- explain why astronomers use large units to measure distances in space

Charles Messier

Astronomer in mid-to-late-1700s, used a small telescope.

Catalogued 103 objects (Messier's Objects) - what could these be???

Distances

LIGHT YEAR and ASTRONOMICAL UNIT (AU)

Light year - the distance a beam of light travels in one year. The sun is 8 light-minutes away. The nearest star (after the Sun) is 4.3 light years away. When we look at Proxima Centauri, we are looking at it 4.3 years in the past.

Astronomical Unit - the distance from the Earth to the Sun (93 million miles)

**light years are used for objects outside of our solar system, AUs are used for objects inside our solar system

Open Ended

What are some celestial objects we see in our solar system?

Other Objects

Asteroids - mostly found in the asteroid belt between Mars and Jupiter. Made of metals and rock

Comets - come from the outskirts of our solar system. Made of ice and dust. Has a distinct tail trailing behind it

Multiple Choice

What does a light year measure?

• distance

• time

• area

Beyond the Solar System

Other stars, planets, moons, asteroids, meteoroids, comets, galaxies, etc!

We have only scratched the surface when it comes to exploring the universe.

The Milky Way

Our solar system is in the Milky Way Galaxy - a 4-armed barred spiral galaxy containing between 100-400 billion stars all orbiting a center.

Neighboring Galaxies

​The Milky Way is not the only galaxy in the universe! At this point, we have discovered many others. Our closest neighbor is the Andromeda Galaxy.

Dropdown

The Milky Way is the galaxy that contains our​

Select answer

. It is shaped like a large disk with ​

Select answer

that fan out from the center. The center of the Milky Way contains a supermassive​

Select answer

. You can find billions and billions of ​

Select answer

in the Milky Way.

Match

Match the following distance measurements with where you would use them.

• two cities on Earth

• solar system

• nearby stars

kilometers

AU

light years

• kilometers

• AU

• light years

Categorize

Options (6)

made of rock

made of dust and ice

grows a tail as it nears the sun

will never have a tail

comes from a belt found between Mars and Jupiter

comes from the outskirts of the solar system

Categorize the features of comets and asteroids.

asteroid

comet

Great Job!

​Today you learned:

- about different ways astronomers measure distances in space

- about the differences between solar system, galaxy, and universe

- why astronomers use large units to measure distances in space.