Q 01/05

What informal name do astronomers give to a star of the Sun's type?

A) Red dwarf

B) Red giant

C) Yellow dwarf

D) Yellow giant

Answer · why

C) Yellow dwarf

Yellow dwarf is the informal name for a G-type main-sequence star, one that fuses hydrogen steadily for about 10 billion years before it swells into a...

Q 02/05

Approximately how long does it take sunlight to reach Earth?

A) About 30 seconds

B) About 8 minutes

C) About 24 minutes

D) About 1 hour

Answer · why

B) About 8 minutes

About 8 minutes, or 8 minutes 20 seconds on average, means nobody ever sees the Sun as it is now, only as it was when that light set out.

Q 03/05

Which invisible rays in sunlight are the main cause of sunburn?

A) Infrared

B) Ultraviolet

C) Microwaves

D) Gamma rays

Answer · why

B) Ultraviolet

Ultraviolet rays cause both suntan and sunburn; ozone high in the atmosphere absorbs part of them, so a thinner ozone layer means more reach the groun...

Q 04/05

What process powers the Sun and produces its energy?

A) Chemical combustion

B) Nuclear fusion

C) Nuclear fission

D) Gravitational collapse

Answer · why

B) Nuclear fusion

Nuclear fusion forces hydrogen nuclei together in the core at about 15 million °C, and the energy released then takes many thousands of years to work ...

Q 05/05

What color would the Sun appear if viewed from space, without atmospheric interference?

A) White

B) Orange

C) Yellow

D) Red

Answer · why

A) White

The Sun actually emits white light. It appears yellow or orange from Earth's surface because the atmosphere scatters shorter (blue) wavelengths, makin...