The Sun
The Sun is composed primarily of this gas.
What is hydrogen?
Of rock or ice, it is what the moons of the Jovian planets are primarily composed of.
What is ice?
To within half a billion years, this is the age of the Earth.
What is 4.5 billion years?
The Asteroid Belt lies between these two planets.
What are Mars and Jupiter?
It's the planet with the lowest density. (Give me a ring when you figure it out!)
What is Saturn?
The name for the "surface" of the Sun. Its temperature is about 5800 K.
What is the photosphere?
It is believed to have formed when a Mars-sized planetesimal collided with the early Earth.
What is the Earth's moon?
The primary constituent of Earth's atmosphere.
What is nitrogen?
What is C-type (carbonaceous)?
The colorful name of the giant, persistent storm system on Jupiter?
What is the Great Red Spot?
The Solar Cycle, the period of activity of sunspots and magnetic field change on the Sun, lasts about this many years on average.
What is 11?
One of the Galilean satellites, it is the largest moon in the Solar System - even having a radius bigger than that of Mercury.
What is Ganymede?
Of the two types of Earth's crust, this type has the higher density.
What is Oceanic crust?
If you combined all the asteroids in the Asteroid Belt, the total mass would be about a third the mass of this familar object.
What is the Moon? (Earth's moon)
The smallest of the Jovian planets, it is still nearly 15 times the mass of the Earth.
What is Uranus? (and I hope that you pronounced it correctly)
Hot gas erupted from flares hangs in these coffee-mug-handle-shaped features.
What are prominences?
This moon of Jupiter is the most geologically-active body in the Solar System.
What is Io?
There are this many types of plate boundary activity.
What is 4? (rift zones, subduction zones, fault zones, and collisions)
This population of asteroids orbit the Sun at the same distance as Jupiter, but at locations "before" and "after" Jupiter. It's all Greek to me!
What are the Trojans?
Rotation of hurricanes on Earth is a result of this effect, which also explains atmospheric features on Jupiter.
What is the Coriolis Effect?
This British researcher in charge of radar efforts in WWII determined that sunspot activity was associated with radio emission.
Who was Hey? (Hey. James Stanley Hey. Shaken, not stirred.)
This largest moon of Saturn has a thick nitrogen atmosphere.
What is Titan?
What are a magnetic field and an atmosphere?
It's the largest asteroid, and was briefly considered a planet in the mid-1800s.
What is Ceres?
The only man-made satellite to have passed by both Uranus and Neptune and collect images and other data.
What is Voyager 2?