Astro 150 F 24 Trivia 1

What does an Astronomical Unit (a.u.) measure?

• The distance light travels in a year

• The mean distance between Earth and Moon

• The mean distance between Earth and Sun

• About 10,000 Kilometers

From smallest to largest size, which is the correct order?

• Solar System, Galaxy, Local Group, Universe

• Solar System, Local Group, Galaxy, Universe

• Local Group, Solar System, Galaxy, Universe

• Universe, Solar System, Galaxy, Local Group

What is a light-year?

• The amount of time relative to the speed of light

• The distance light travels in one year

• The amount of time light takes to travel from the sun to the earth

• A popular character from the Toy Story movies

Answer explanation

A light-year is a measurement of DISTANCE, not time. One light-year is the distance light travels in a year.

Approximately how far away is the closest star to the sun, Proxima Centauri?

• 5 light-years

• 50 light-years

• 500 light-years

• 5000 light-years

Approximately how far away is the nearest galaxy, Andromeda?

• 2.5 light-years

• 250 light-years

• 25,000 light-years

• 2.5 million light-years

Approximately how many times larger is the Sun's diameter compared to the Earth's diameter?

• 100 times larger

• 10000 times larger

• A million times larger

• 10 million times larger

An alien 10 billion light-years away looks in a telescope pointed towards the earth. What would the alien see?

• Humans and cities

• Dinosaurs

• The beginning of life on earth

• The alien cannot see the earth yet

Answer explanation

The earth is approximately 4.5 billion years old, so an alien viewing the earth in a galaxy 10 billion light-years away cannot see the earth since it hasn't been created yet.

Which of the following is FALSE?

• The speed of light is the fastest speed in the universe

• There are more stars in the universe than all the grains of sand on earth

• We are very close to the center of our galaxy

• The only stars we see at night are from our Milkyway galaxy

Answer explanation

We are closer to the edge of our galaxy than the center. The radius of the Milkyway galaxy is 50,000 lys and we are 30,000 lys from the center.

THE SUN JUST EXPLODED! What happens on earth immediately after?

• The earth becomes pitch black

• Nothing until 8.3 minutes

• The sky lights up from the explosion

• The earth is launched out of orbit

Answer explanation

The sun is about 8.3 light-minutes from the earth. We wouldn't know the sun exploded until 8.3 minutes pass.

Results from a scientific experiment should be...

• Free of errors

• Reproducible

• Found with the latest equipment

• Validated by experts before publication

Answer explanation

Unless scientific results are reproducible, they are not verifiable and therefore conclusions drawn from those results are cast into doubt.