Exploring space
Exploring space: a chapter of The Solar System Book, with planets you watch move on their orbits and the facts behind them.
12 cards · Science
Each Zap teaches up to 5 new cards, so you learn the deck a few at a time.
Checked by the Brain Zap team · reviewed 23 Oct 2026
Sources: Solar System (Wikipedia), Solar System (NASA Science)
Preview
Astronomer whose Sun-centred model was published in 1543
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Nicolaus Copernicus
Learn more: His book De revolutionibus put the Sun at the centre; it came out in 1543, the year he died.
Astronomer who discovered Jupiter's four largest moons
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Galileo Galilei
Learn more: In 1610 he saw Io, Europa, Ganymede and Callisto orbiting Jupiter: proof that not everything circles Earth.
Astronomer who discovered Uranus in 1781
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William Herschel
Learn more: Uranus was the first planet found with a telescope. He first took it for a comet, then named it after George III.
Astronomer who discovered Pluto in 1930
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Clyde Tombaugh
Learn more: He found Pluto in 1930 by comparing photographic plates. Some of his ashes flew past Pluto on New Horizons.
First artificial satellite to orbit Earth
Show answerHide answer: First artificial satellite to orbit Earth
Sputnik 1
Learn more: A 58 cm metal ball launched on 4 October 1957, it beeped for three weeks and started the Space Race.
About this topic
For centuries people watched the sky through their eyes, then through telescopes that moved the Sun to the centre and found new planets. In the last seventy years, satellites, astronauts and probes have gone to see for themselves.
This is a chapter of The Solar System Book. Some of its cards show the planets moving around the Sun at their real relative speeds, with one planet glowing: name it. Others ask for the facts that make each world special, with a hint before you answer and a short reason after. Once you know most of this chapter's cards, the next chapter starts arriving in your Daily Zap.
All 12 cards
Astronomer whose Sun-centred model was published in 1543
Nicolaus Copernicus
Learn more: His book De revolutionibus put the Sun at the centre; it came out in 1543, the year he died.
Astronomer who discovered Jupiter's four largest moons
Galileo Galilei
Learn more: In 1610 he saw Io, Europa, Ganymede and Callisto orbiting Jupiter: proof that not everything circles Earth.
Astronomer who discovered Uranus in 1781
William Herschel
Learn more: Uranus was the first planet found with a telescope. He first took it for a comet, then named it after George III.
Astronomer who discovered Pluto in 1930
Clyde Tombaugh
Learn more: He found Pluto in 1930 by comparing photographic plates. Some of his ashes flew past Pluto on New Horizons.
First artificial satellite to orbit Earth
Sputnik 1
Learn more: A 58 cm metal ball launched on 4 October 1957, it beeped for three weeks and started the Space Race.
First human in space
Yuri Gagarin
Learn more: On 12 April 1961 he orbited Earth once in 108 minutes. The date is now the International Day of Human Space Flight.
First crewed mission to land on the Moon
Apollo 11
Learn more: It landed in the Sea of Tranquillity on 20 July 1969. Michael Collins stayed in orbit in the command module.
First person to walk on the Moon
Neil Armstrong
Learn more: He stepped onto the Moon in July 1969, saying 'That's one small step for man, one giant leap for mankind'.
Year of the first crewed Moon landing
1969
Learn more: Apollo 11 landed on 20 July, meeting Kennedy's 1961 goal of a Moon landing before the decade was out.
First spacecraft to reach interstellar space
Voyager 1
Learn more: It crossed the heliopause into interstellar space in 2012, and is the farthest human-made object from Earth.
Spacecraft that flew past Pluto in 2015
New Horizons
Learn more: It flew past Pluto in July 2015 and sent the first close-up images, including its heart-shaped plain.
Infrared space telescope launched in December 2021
James Webb Space Telescope
Learn more: It orbits about 1.5 million km from Earth, at L2, behind a sunshield the size of a tennis court.
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