Intro to Astronomy, Part 4: Galaxies

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Question 1: Do we live in the Andromeda Galaxy?

• No

• Yes

Answer explanation

Yes. We live in The Milky Way, which is a different galaxy.

Does light hold galaxies together?

• No

• Yes

Answer explanation

No. Gravity from the mass of heavy objects holds galaxies together: e.g., many galaxies have black holes near their centers.

Are new stars made inside a nebula?

• No

• Yes

Answer explanation

Yes. Sometimes these are called stellar nurseries.

Do people contain atoms that were made inside stars?

• No

• Yes

Answer explanation

Yes. Almost all the atoms inside us were made inside stars or when stars exploded or merged. This is called stellar nucleosynthesis.

Tags

NGSS.HS-ESS1-1

NGSS.HS-ESS1-3

Is there any invisible matter that has mass and creates a gravitational force?

• No

• Yes

Answer explanation

No. Black holes do and so does dark matter.

If a star is coming towards us, will it have a blueshift?

• No

• Yes

Answer explanation

Yes. And redshift is the color for stars that are going away from us.

Tags

NGSS.HS-ESS1-2

NGSS.HS-PS4-1

Is the distance between most galaxies shrinking?

• No

• Yes

Answer explanation

No. The distance between most galaxies is increasing.

Does gravity travel in waves?

• No

• Yes

Answer explanation

Yes. And we can detect those with an instrument called an interferometer, such as what LIGO uses.

Tags

NGSS.HS-PS4-3