Do you know the answers to these 7 questions about space?

It’s quiz time!

Test your knowledge about space. How many answers can you get right? Read the questions below and click the arrow in the left side to unfold the box and read the answer.

Good luck!

Question 1:
Betelgeuse is a red super-giant. It has a mass 11 times larger than the Sun’s, and it is expected to one day explode in an enormous supernova explosion.

Which surface is hotter: The Sun’s or Betelgeuse’s?

Believe it or not, the surface of the Sun (5.700K) is much warmer than that of Betelgeuse (3.500K).

The reason for this counterintuitive surface temperature is found in the density. Betelgeuse might have a much larger mass than the Sun, but it is also much more “inflated”. Betelgeuse is at a stage in its life where it has expanded or “inflated” its outer layers, so they are now relatively much further away from the core than the Sun’s outer layers are from the Sun’s core. Less (heat) energy is therefore transported to the surface area of the star and hence it gets a lower temperature.

This effect is also responsible for Betelgeuse’s red color, which has a lower energy than the Sun’s yellow color.

Question 2:
Like Earth, Mars has two really cold poles that are both covered in ice.

Do Mars’ poles contain water ice or is it entirely ice from carbon dioxide, CO2?

The cold poles on Mars do indeed contain water ice. However, the water ice is mixed with dust and other particles making it dirty ice and not clear ice like what you have in your freezer. Above the layers of water ice is a solid ice cap made from icy carbon dioxide.

Question 3:
Helium makes up around 25 percent of all atoms in the universe. All stars, no matter the size, convert Hydrogen atoms into Helium atoms. There are more stars in the universe than grains of sand on all beaches on Earth combined.

True or false: More than half of the Helium present in the universe today were created in stars, while the rest were created in the Big Bang.

False.

Even with the large number of stars in mind and knowing how all of them create Helium, practically all Helium atoms in the universe were created in the Big Bang. That’s a lot of Helium!

Question 4:
A year is the time it takes for a planet to make one revolution around the sun, and a day is the time it takes for a planet to rotate once around its own axis.

Can a day be longer than a year?

Yes, absolutely.

In fact, you don’t need to travel to exotic exoplanets. It happens in our own solar system. On Venus, one year is shorter than one day on the same planet.

(Hmm…How do they plan birthdays there?)

Question 5:
More than 5,000 exoplanets are currently confirmed. An exoplanet is a planet that exists outside our own solar system.

Have we detected exoplanets that live in other galaxies than our own galaxy, the Milky Way?

No.

All confirmed exoplanets are found within our own galaxy. However, in 2021 astronomers might have detected an exoplanet in the Whirlpool galaxy, but this is still unconfirmed.

Question 6:
Almost all planets in the solar system has moons, only the two innermost planets Venus and Mercury have none.

Which planet has the biggest moon?

Jupiter has the biggest moon, and its name is Ganymede.

Ganymede is so big that its size exceeds that of Mercury and Pluto.

Question 7:
All planets, whether rocky or made out of gas, have a surface temperature. Surface temperatures mostly depend on the distance to the sun, but the atmospheric composition and surface also affect the temperature of the planet’s surface. The surface temperature of the Earth is around 14 degrees Celsius (57 degrees Fahrenheit).

Which planet in the solar system has the hottest surface?

Venus has a surface temperature of 471 degrees Celsius (880 degrees Fahrenheit).

You might think Mercury has the highest temperature because it is located closest to the sun. However, Mercury has no atmosphere like Venus to contain the heat. Mercury is still hot, though, with levels reaching 450 degrees Celsius (840 degrees Fahrenheit).