Yuri Gagarin, the first human in space, orbited Earth in 1961.
the first human in space
Hubble, a powerful space telescope, has sent back images of distant galaxies.
a powerful space telescope
Mars, the fourth planet from the Sun, is known as the Red Planet.
the fourth planet from the Sun
Buzz Aldrin, the second man on the Moon, followed Neil Armstrong in 1969.
the second man on the Moon
Saturn, the planet with the largest rings, is the sixth planet from the Sun.
the planet with the largest rings
The Milky Way, our home galaxy, contains billions of stars.
our home galaxy
Sputnik 1, the first artificial satellite, was launched in 1957.
the first artificial satellite
Michael Collins, the Apollo 11 pilot, stayed in orbit around the Moon.
the Apollo 11 pilot
Europa, one of Jupiter’s moons, may have an ocean under its ice.
one of Jupiter’s moons
Halley’s Comet, a famous comet, appears about every 76 years.
a famous comet
The Andromeda Galaxy, our nearest large neighbor, is moving closer to the Milky Way.
our nearest large neighbor
The Big Dipper, a famous constellation, is part of Ursa Major.
a famous constellation
The Kuiper Belt, a region beyond Neptune, is full of icy bodies.
region beyond Neptune
Laika, the first dog in space, flew on Sputnik 2 in 1957.
the first dog in space
The Sun, a medium-sized star, gives energy to Earth.
a medium-sized star
Edwin Hubble, an American astronomer, showed that the universe is expanding.
an American astronomer
