Mercury
This large impact basin on Mercury is about 1,550 km across and was created by a massive asteroid collision.
What is the Caloris Basin
Venus rotates in this unusual direction compared to most planets.
What is retrograde rotation?
This scientific field studies earthquake waves to learn about Earth’s interior.
What is seismology?
This apparent backward motion of Mars in Earth’s sky confused early astronomers.
What is retrograde motion?
This is the innermost planet and also the smallest terrestrial planet.
What is Mercury?
These cliff-like features on Mercury formed as the planet cooled and shrank.
What are scarps?
This property measures how much sunlight Venus reflects due to its thick clouds.
What is albedo?
Earth’s magnetic field is generated primarily by movement in this part of the planet.
What is the outer core?
This giant volcano is the largest in the solar system.
What is Olympus Mons?
This planet has the highest average surface pressure among the terrestrial planets.
What is Venus?
This “weird terrain” on Mercury is thought to have formed from shock waves originating from the Caloris impact.
What is jumbled terrain?
These positions describe Venus appearing farthest east or west from the Sun in the sky.
What are elongation angles?
This process in Earth’s mantle helps drive plate tectonics.
What is convection?
This enormous canyon system stretches across much of Mars’s surface.
What is Valles Marineris?
This planet has a day that is longer than its year.
What is Venus?
This spacecraft became the first to orbit Mercury in 2011.
What is MESSENGER?
Observations of these changing appearances of Venus helped support the heliocentric model.
What are the phases of Venus?
These moving sections of Earth’s crust interact at convergent, divergent, and transform boundaries.
What are tectonic plates?
This massive volcanic region contains several giant shield volcanoes on Mars.
What is the Tharsis region?
This terrestrial planet has two moons named Phobos and Deimos.
What is Mars?
This joint European and Japanese mission launched in 2018 and is currently studying Mercury.
What is BepiColombo?
This NASA spacecraft used radar mapping to reveal Venus’s volcanic surface beneath its clouds.
What is Magellan?
Scientists believe this major event contributed to the dinosaurs' extinction.
What is an asteroid impact?
These frozen regions at Mars’s poles contain water ice and carbon dioxide ice.
What are the polar ice caps?
This planet has the greatest average density in the solar system.
What is Earth?