Compare the planets, and where liquid water could exist

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. 1.

   What is a star's habitable zone, by Ari's reading (NASA)?

   • The same distance from each star
   • Where liquid water could exist on a planet's surface
   • Where life has been found
   • The hottest region next to the star
2. 2.

   A planet orbits in its star's habitable zone. What does that tell Bo?

   • Liquid water could exist on its surface
   • It has oceans for sure, covering its surface
   • Life lives there
   • It is the same as Earth
3. 3.

   The Sun and a red dwarf. Compared with the Sun's habitable zone, where is a dim red dwarf's, by Kira's reading (NASA)?

   • Much farther from the star
   • At the same distance as the Sun's
   • Red dwarfs have no habitable zone
   • Much closer to the star

4. Read this first

   Planets (NASA Planetary Fact Sheet)

   Planet	Distance (million km)	Mean temperature (°C)	Density (kg/m³)
   Mercury	57.9	167	5,429
   Venus	108.2	464	5,243
   Earth	149.6	15	5,514
   Mars	228.0	−65	3,934
   Jupiter	778.5	−110	1,326
   Saturn	1,432.0	−140	687

5. 4.

   Which planet in the table is hottest on average, by Jun's reading (NASA)?

   • Mercury, since it is closest
   • Venus, at 464 °C
   • Earth, at 15 °C
   • Jupiter, since it is biggest
6. 5.

   Why is Venus hotter than Mercury, though farther from the Sun, by Luz's reading (NASA)?

   • Venus is closer to the Sun
   • Venus is made of hotter rock
   • Venus's thick atmosphere traps heat
   • Closer planets are cooler
7. 6.

   Which planets are terrestrial, with solid rocky surfaces, by Noah's reading (NASA)?

   • Mercury, Venus, Earth and Mars
   • Venus and Uranus
   • Jupiter, Saturn, Uranus and Neptune
   • Earth and Saturn
8. 7.

   Orbit diagram with Jupiter and Saturn marked. What are Jupiter and Saturn called, by Pia's reading (NASA)?

   • Gas giants
   • Dwarf planets
   • Ice giants
   • Terrestrial planets
9. 8.

   Cutaway of a gas giant with no hard surface. Why are Jupiter and Saturn unlikely places for liquid-water surfaces, by Ren's reading (NASA)?

   • They are inside the Sun's habitable zone
   • Life has already been found there
   • They have no hard surface for water to pool on
   • They have rocky surfaces like Earth
10. 9.

    Counter labeled confirmed exoplanets (NASA). About how many exoplanets has NASA confirmed, by Tala's reading?

    • About 8, the planets in our system
    • About 60
    • More than 6,000
    • Zero so far
11. 10.

    What is an exoplanet, by Zee's reading (NASA)?

    • A moon of Jupiter
    • A planet beyond our solar system
    • A planet where life lives, like on Earth
    • A star with no planets