Question 1

Which planet is closest to the Sun?

Accepted Answer

Mercury. Mercury is the closest planet to the Sun. Its year (one orbit) takes only about 88 Earth days.

Question 2

Which planet is the largest in our solar system?

Accepted Answer

Jupiter. Jupiter is the largest — more than twice as massive as all the other planets combined.

Question 3

Roughly how long does light from the Sun take to reach Earth?

Accepted Answer

8 minutes. Sunlight takes about 8 minutes and 20 seconds to travel the roughly 150 million km from the Sun to Earth.

Question 4

What galaxy is Earth located in?

Accepted Answer

Milky Way. Earth sits in the Milky Way galaxy, roughly two-thirds of the way out from the galactic center on the Orion Arm.

Question 5

Which planet has the most moons (as of recent counts)?

Accepted Answer

Saturn. As of recent surveys, Saturn has the most confirmed moons — well over 140 — narrowly edging out Jupiter.

Question 6

What causes the Moon's phases?

Accepted Answer

The changing angle of sunlight on the Moon as it orbits Earth. The Moon's phases are caused by our changing view of its sunlit half as it orbits Earth. Earth's shadow only causes eclipses, not phases.

Question 7

What is a light-year a unit of?

Accepted Answer

Distance. A light-year is a unit of distance — the distance light travels in a year, about 9.46 trillion kilometers.

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