The Universe
_______________________________________________________________________________________________________________________________________________________________________________________________________________________

5. How do scientists learn about space?

Figure 10.2 The Andromeda galaxy
Many scientists can touch the materials they study.


Most can do experiments to test those materials. Biologists can collect cells, seeds, or sea urchins to study in the laboratory.

Physicists can test the strength of metal or smash atoms into each other.

Geologists can chip away at rocks and test their chemistry.

What can astronomers use to study space?

Astronomers use the light and other energy that comes to us to gather information about the Universe.

The image on the right shows the Andromeda Galaxy as it appeared 2.5 million years ago. Why is the light so old?.

 The Speed of Light

In space, light travels at about 300.000.000 meters per second.

How fast is that. If you travelled around the Earth with the speed of light, you would make a complete tour of our planet 7,5 times in just one second.

Even light from the nearest star, our sun, takes about eight minutes to reach Earth.

A

L

N

N

C