This factor determines how much energy a planet receives from its star.
What is distance from the star?
Scientists look for this liquid because all known life needs it.
What is water?
Why is Mars red?
What is rust (iron oxide)?
This type of gas in an atmosphere helps trap heat and keep a planet warm enough for liquid water.
What are greenhouse gases?
Living things need this gas to breathe on Earth.
What is oxygen?
What do we call a planet outside our solar system?
What is an exoplanet?
This planetary feature helps protect life from harmful solar radiation.
What is a magnetic field?
Besides Earth, this planet in our solar system is considered the most likely place to find signs of past or present life.
What is Mars?
This is the largest volcano in the solar system, found on mars.
What is Olympus mons?
Too much of this specific greenhouse gas can cause a runaway heating effect like on Venus.
What is carbon dioxide?
Scientists look for this element because it is the main building block of life on Earth.
What is carbon?
We have been to the moon (manned missions) this amount of times.
What is six?
A planet’s ability to hold onto an atmosphere depends strongly on this property.
What is it’s gravity (or mass)?
Many tiny living things on Earth release this gas into the air. (It also makes up the lakes and rivers on the moon Titan!)
What is methane?
This moon is the only one in our solar system with a thick atmosphere.
What is Titan?