Eight planets, two trillion galaxies, and one pale blue dot. How well do you know the universe you live in?
10 questions that go from our solar system to the edge of what we can see. Planets, stars, black holes, telescopes, and the missions that got us there. No jargon, just the universe.
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Astronomy is the study of everything beyond Earth's atmosphere. It is one of humanity's oldest sciences, with records of celestial observations dating back over 5,000 years. From Babylonian star catalogues to the James Webb Space Telescope, the scale of what we can observe has grown from the naked-eye planets to galaxies forming less than 400 million years after the Big Bang.
The observable universe contains an estimated two trillion galaxies, each home to hundreds of billions of stars. Our Sun is just one of roughly 200 billion stars in the Milky Way. In 2019, the Event Horizon Telescope produced the first image of a black hole. In 2022, the James Webb Space Telescope delivered the deepest infrared images of the universe ever captured. We are living in a golden age of space discovery.
All ten easy level questions, with the answer and the reasoning behind it.
Correct answer: Jupiter
Jupiter, more massive than all the other planets put together.
Correct answer: Venus
Venus, because of its dense atmosphere, even though Mercury is closer to the Sun.
Correct answer: International Space Station
International Space Station, occupied without a break since 2000.
Correct answer: Buzz Aldrin
Buzz Aldrin, about twenty minutes after Neil Armstrong.
Correct answer: Jupiter
Jupiter, and the storm has been raging for at least a couple of centuries.
Correct answer: Halley's Comet
Halley's Comet, next due back in 2061.
Correct answer: Orion
Orion, the Hunter, easy to spot in the winter sky.
Correct answer: Galileo
Galileo. Copernicus was Polish, and he worked without a telescope.
Correct answer: An astronaut
An astronaut, or a cosmonaut in Russia. Astrologers stay firmly on the ground.
Correct answer: Its position relative to the Sun
Its position relative to the Sun and Earth. Earth's shadow only matters during an eclipse.
Want to warm up before playing or double-check something? Open any question to reveal the correct answer and a short explanation.
Correct answer: Mercury
Mercury orbits closest to the Sun at an average distance of 58 million kilometres. Despite this, it is not the hottest planet in the solar system. That title goes to Venus, whose thick atmosphere traps heat through an extreme greenhouse effect, reaching surface temperatures of 465 °C.
Correct answer: About 8 minutes
Sunlight takes approximately 8 minutes and 20 seconds to reach Earth, travelling 150 million kilometres at 300,000 km/s. This means that if the Sun suddenly stopped shining, we would not know for over eight minutes.
Correct answer: Neil Armstrong
Neil Armstrong became the first person to walk on the Moon on 20 July 1969 during the Apollo 11 mission. Buzz Aldrin joined him shortly after, while Michael Collins remained in lunar orbit aboard the command module Columbia.
Correct answer: Saturn
Saturn holds the record with over 140 known moons as of 2023, overtaking Jupiter which has around 95. Saturn's largest moon, Titan, is the only moon in the solar system with a dense atmosphere and liquid methane lakes on its surface.
Correct answer: A region of space where gravity is so strong that nothing can escape
A black hole is a region of spacetime where gravity is so intense that nothing, not even light, can escape. They typically form when massive stars collapse at the end of their lives. The first image of a black hole (M87*) was revealed in 2019 by the Event Horizon Telescope collaboration.
Correct answer: James Webb
The James Webb Space Telescope (JWST) launched on 25 December 2021. It primarily observes in infrared, allowing it to detect the earliest and most distant galaxies ever seen. Its first images, released in July 2022, revealed the universe in unprecedented detail.
Correct answer: The Sagittarius Dwarf Galaxy
The Sagittarius Dwarf Elliptical Galaxy is the closest known galaxy to the Milky Way, at roughly 70,000 light-years away. Andromeda (M31), often cited as the answer, is the nearest large spiral galaxy at about 2.5 million light-years, but several dwarf galaxies are closer.
Correct answer: 5,500 °C
The Sun's surface (the photosphere) is approximately 5,500 °C. Its core, however, reaches about 15 million degrees, the temperature needed to sustain the nuclear fusion reactions that convert hydrogen into helium and power the Sun.
Correct answer: 8
Since 2006, the solar system officially has 8 planets. Pluto was reclassified as a 'dwarf planet' by the International Astronomical Union (IAU) because it has not cleared the neighbourhood around its orbit, sharing its zone with other Kuiper Belt objects.
Correct answer: The Moon passes between the Sun and Earth
A solar eclipse occurs when the Moon passes between the Sun and Earth, casting its shadow onto our planet. During a total solar eclipse, the Sun is completely blocked for a few minutes. This is possible because the Moon and the Sun appear almost the same size when viewed from Earth, a remarkable cosmic coincidence.
Stuck on one, or just curious how nasty it gets? Every hard mode question is here with its answer and the reasoning behind it.
Correct answer: Voyager 1
Voyager 1, launched in 1977 and now in interstellar space.
Correct answer: Sirius
Sirius, the Dog Star, and not the North Star, as many people assume.
Correct answer: Europa
Europa, whose ice is thought to hide a salty ocean. The probe is named Europa Clipper.
Correct answer: 9.5 trillion km
About 9.5 trillion kilometres. The first figure is the distance light travels in a second, the second the distance from Earth to the Sun.
Correct answer: Luna 9
Luna 9, a Soviet probe, which sent back the first pictures from the lunar surface.
Correct answer: Neptune
Neptune, predicted by Le Verrier from irregularities in the orbit of Uranus.
Correct answer: Ceres
Ceres, which is classed as a dwarf planet.
Correct answer: Andromeda
Andromeda, about 2.5 million light-years away, and heading towards us.
Correct answer: Cassini
Cassini, which ended its mission by plunging into the planet.
Correct answer: Valentina Tereshkova
Valentina Tereshkova, a Soviet cosmonaut. Sally Ride was the first American woman, in 1983.