Test your knowledge with these top questions!
Which NASA rover landed on Mars in 2021 carrying the first helicopter flown on another planet?
Perseverance is searching Jezero Crater, an ancient lake bed, for signs of past microbial life.
About how much would a 100-pound person weigh on Mars?
Mars' gravity is only about 38 percent of Earth's, so the same jump would carry a person roughly two and a half times higher there.
Mars has two small moons, Phobos and Deimos. Which one is spiraling steadily inward toward the planet?
Phobos moves about 1.8 meters closer to Mars per century and may eventually crash into the planet or break into a ring.
What color is the sky around the setting Sun on Mars?
Fine dust scatters blue light forward around the setting sun, while the same particles give the daytime Martian sky a butterscotch tint.
How does Venus's sidereal day compare with its year?
Venus rotates once every 243 Earth days but orbits the Sun in about 225 days, making its sidereal day longer.
Venus's bright cloud layers mainly contain:
Venus's cloud decks contain sulfuric acid droplets, not water clouds; the planet's surface stays hidden below them.
Why does Mercury have long cliffs called scarps?
As Mercury's interior cooled, the planet contracted, squeezing its crust into the long lobate scarps seen across its surface.
What kind of exoplanet is Kepler-10b?
At about 1.5 Earth radii and 3.3 Earth masses, Kepler-10b is far smaller and denser than a gas giant.
What gives Mars much of its reddish color?
Iron minerals in Martian dust oxidized, forming rust-like compounds that tint the surface red.
What kind of rotation does Venus have compared with Earth?
Venus rotates opposite Earth's direction, so the Sun appears to rise in the west and set in the east.