What is the mass of an object divided by its volume? (when talking about solids or gases)
density
What happens to the planets as they rotate about their axes?
They spin
How cold is outer space?
Minus 270.45 degrees Celsius
What the verb that means "turn in a circle, especially around a fixed point"?
To rotate (The Earth rotates around its axis).
What is the 3D measurement of the size of a planet? (Measured in cubic kilometers (km³) or cubic miles (mi³))
Planet volume
What is Earth's ozone layer?
Thin layer of gas in the Earth's atmosphere that protects the planet, absorbing the sun's ultraviolet.
What is the name of powerful greenhouse gas in Earth's atmosphere that can cause global warming?
Methane (CH4)
What do we call the planets planets made mostly of gases, such as hydrogen and helium, with a small rocky core?
Gas giants (Neptune, Uranus, Saturn, and Jupiter)
What is the empty area outside Earth's atmosphere, where the planets and the stars are?
space
Who discovered Pluto?
Clyde Tombaugh, an American astraunomer
What are the eight planets of the Solar system?
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
What is a dwarf planet?
Object that is similar to a planet, but is smaller. However, it is large enough to have gravity and round shape.
What do we call something that is very special and one of its kind?
a unique thing (Our Solar System is unique)
What does it mean: "to move around a central point or line following an orbit"?
to revolve - Planets revolve around the Sun.
Name at least 2 dwarf planets.
Ceres, Pluto, Haumea, Makemake, and Eris.
Who first observed Mars through a telescope in 1610?
Galileo Galilei
What is atmosphere?
a jacket of gases that surrounds our planet
What do "extremely cold" and "extremely hot" mean?
very cold / very hot
Terrestial planets like Mercury, Venus, Earth, and Mars are called so because they have a ....
solid surface