The visible surface of the sun.
What is the photosphere?
The force that keeps planets in orbit.
What is gravity?
The planet closest to the sun.
What is Mercury?
These large planets are mostly made of gas.
What are gas giants?
The sun and everything that orbits it.
What is the solar system?
A year with an extra day.
What is a leap year?
A dark, cooler area on the sun.
What is a sunspot?
When Earth spins on its axis.
What is rotation?
The hottest planet due to thick clouds.
What is Venus?
The largest planet in the solar system.
What is Jupiter?
The shape of a planet’s orbit.
What is an ellipse?
Beautiful lights seen near Earth’s poles.
What is an aurora?
A sudden explosion of energy from the sun.
What is a solar flare?
When Earth travels around the sun.
What is revolution?
The planet that supports life.
What is Earth?
The planet known for its large ring system.
What is Saturn?
The path a planet follows around the sun.
What is an orbit?
The planet tilted on its side.
What is Uranus?
The outer glowing layer seen during an eclipse.
What is the corona?
The imaginary line that divides Earth into Northern and Southern halves.
What is the equator?
The Red Planet.
What is Mars?
The planet visited by Voyager 2 after a long journey.
What is Uranus?
The model that explains formation from gas and dust.
What is the nebular system?
The planet that rotates once in about 16 hours.
What is Neptune?
A large arch of glowing gas rising from the sun.
What is a solar prominence?
The time of day when shadows are shortest.
What is noon?
The four rocky planets closest to the sun.
What are Mercury, Venus, Earth, and Mars?
The planet with the Great Red Spot storm.
What is Jupiter?
The belt between Mars and Jupiter.
What is the asteroid belt?
These planets are small and rocky.
What are the inner planets?
A stream of charged particles sent out from the sun.
What is solar wind?
A country near the equator that stays warm all year.
What is Singapore?
The inner planet that has seasons similar to Earth.
What is Mars?
Neptune’s largest moon.
What is Triton?
The belt beyond Neptune filled with icy objects.
What is the Kuiper Belt?
The reason Pluto is extremely cold.
What is it is very far from the sun?