Solar System — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. The Voyager 1 spacecraft launched in 1977 is now the farthest human-made object from Earth.
Voyager 1 has been traveling since 1977 and has passed beyond the boundary of the Sun's influence, making it the farthest human-made object from Earth at over 15 billion miles away.
2. NASA's Juno mission orbits Jupiter to study its atmosphere, magnetic field, and interior.
The Juno spacecraft arrived at Jupiter in 2016 and orbits the giant planet to study its swirling atmosphere, powerful magnetic field, and what lies beneath its thick cloud layers.
3. The Cassini spacecraft spent thirteen years studying Saturn and its rings before its mission ended in 2017.
Cassini orbited Saturn from 2004 to 2017, discovering new details about its complex ring system made of billions of particles of ice and rock ranging from tiny grains to house-sized chunks.
4. A light year is the distance light travels in one year, roughly 5.88 trillion miles.
A light year measures distance, not time — it equals about 5.88 trillion miles, the distance a beam of light covers in one full year traveling at 186,000 miles per second.
5. The Kuiper Belt is a region of icy objects beyond the orbit of Neptune.
The Kuiper Belt begins just past Neptune's orbit and stretches far into space, containing millions of icy objects including the dwarf planet Pluto.
6. The New Horizons mission flew past Pluto in 2015, revealing mountains of ice on its surface.
New Horizons reached Pluto in July 2015 after a nine-year journey, revealing surprising features like mountains of water ice towering 11,000 feet and a heart-shaped nitrogen glacier.
7. A space shuttle is a reusable vehicle that can launch like a rocket and land like an airplane.
The Space Shuttle was NASA's reusable spacecraft that launched vertically with rocket boosters and glided back to land on a runway like an airplane, flying 135 missions from 1981 to 2011.
8. The Perseverance rover collects rock samples on Mars to be returned to Earth by a future mission.
Perseverance drills into Martian rocks and seals the samples in special tubes left on the surface, so a future mission can bring them back to Earth for detailed laboratory analysis.
9. Our solar system is located in a galaxy called the Milky Way.
Our solar system sits in one of the spiral arms of the Milky Way galaxy, which contains an estimated 100 to 400 billion stars and gets its name from the milky band of light visible on clear dark nights.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Voyager missions
→ Flew past all four outer planets sending data back to Earth
First crewed mission to land on the Moon in 1969
Hubble Space Telescope
→ Orbiting telescope that captures images of distant stars and galaxies
Explores the Martian surface collecting data and rock samples
Apollo 11
→ First crewed mission to land on the Moon in 1969
Orbiting telescope that captures images of distant stars and galaxies
Mars rovers
→ Explores the Martian surface collecting data and rock samples
Flew past all four outer planets sending data back to Earth
Each mission had a distinct purpose: the Voyager probes flew past all four outer planets during a rare planetary alignment; the Hubble orbits above Earth's atmosphere for clear deep-space images; Apollo 11 achieved the first Moon landing in 1969; and Mars rovers explore the planet's surface searching for signs of past water and life.