The Solar System Trivia Quiz

Our Sun is the star at the center of the Solar System, a giant ball of hot plasma powered by nuclear fusion. That means that it converts hydrogen into helium, releasing energy as light and heat. With a diameter of 1.39 million kilometers, it's about 109 times wider than Earth and accounts for 99.8% of the total mass of the Solar System. It is the Sun's gravity which keeps the planets, moons, asteroids, and comets in orbit.

Its surface, or photosphere, reaches 5,500 °C, while its core is over 15 million °C. The Sun's energy supports life on Earth, drives weather, and influences climate. It emits solar wind, a stream of charged particles, which interacts with Earth's magnetic field to create phenomena like auroras.

Formed 4.6 billion years ago, the Sun has enough fuel to burn for another 5 billion years. It will eventually become a red giant before shedding its outer layers, leaving behind a dense core called a white dwarf.

The name 'Sun' comes from the Old English word 'sunne' and its Germanic root sunnō. It is named for its role as the central and most important celestial body in our Solar System. In many cultures, the Sun has been associated with gods or deities due to its essential role in providing light and life.

Mercury, the smallest and closest planet to the Sun, is just 4,880 kilometers in diameter. It has no significant atmosphere; this exposes its surface to extreme temperatures: up to a burning 430°C during the day and a frigid -180°C at night. Its rocky surface is covered with craters from impacts over billions of years.

Mercury orbits the Sun in just 88 Earth days, making it the fastest planet. However, its rotation is slow, with one day lasting 59 Earth days. Despite its proximity to the Sun, it lacks volcanic activity or weather. Mercury has a large iron core which generates a weak magnetic field. The planet's surface features cliffs, or scarps, formed as it cooled and shrank. Mercury is visible from Earth during twilight and was named after the Roman messenger god due to its speed. Spacecraft like Mariner 10 and Messenger have travelled to this planet and provided us with detailed images and data.

Venus, pretty much Earth's twin in size and structure, is the hottest planet in the Solar System, with its surface temperatures exceeding 470°C. Its thick atmosphere, made mostly of carbon dioxide, creates a runaway greenhouse effect. Clouds of sulphuric acid reflect sunlight, making Venus the brightest object in Earth's night sky, after the Moon, of course. Its surface has vast plains, volcanic regions, and mountains, with evidence suggesting active volcanism.

Venus rotates very slowly and in the opposite direction to most planets; one Venusian day lasts 243 Earth days, which is longer than its 225-day year. Despite its harsh conditions, studying Venus helps scientists understand climate systems and planetary evolution. NASA missions like Magellan have mapped its surface using radar, although a landing on the surface is (so far) impossible due to the strong acid atmosphere.

Venus was named after the Roman goddess of love and beauty and has been a focus of myth and science for centuries due to its brilliance and proximity. It is also known as both the Morning and the Evening Star since its closeness to the Sun causes it to be visible at both of these times.

Home sweet home, the Earth, just the third planet from the Sun, is unique for being the only planet we know of that can support life. It has a breathable atmosphere of mostly nitrogen and oxygen, with liquid water covering 71% of its surface, and a protective magnetic field. Earth's surface is divided into continents and oceans, shaped by tectonic activity, erosion, and climate. It orbits the Sun in approximately 365.25 days which is what we call a year, and rotates once every 24 hours, what we know as day and night.

Earth's tilted axis causes seasons, varying climates, and diverse ecosystems. Our Moon stabilizes Earth's rotation and influences tides. Earth formed 4.5 billion years ago and has evolved through volcanic activity, ice ages, and biological development. Its biodiversity is unparalleled, ranging from microscopic life to complex organisms. The atmosphere shields Earth from extreme harmful radiation (although a little bit is good for mutations, without which we would not be here), while a good balance of greenhouse gases help maintain temperatures suitable for life.

The name 'Earth' comes from Old English 'eorþe' and similar Germanic roots, meaning 'ground' or 'soil'. Unlike other planets, Earth's name is not derived from mythology but reflects our planet's identity as our home for humanity and as the ground beneath our feet.

Mars is the fourth planet from the Sun. It is a cold, dusty world with a reddish hue due to iron oxide on its surface giving it its nickname the "Red Planet". It's about half Earth's size, with a thin atmosphere mostly of carbon dioxide. Temperatures range from about -125°C to 20°C and there is very little weather to speak of.

Mars is named after the Roman god of war because of its reddish colour, reminiscent of blood. Ancient astronomers associated its distinct hue with warfare and strife leading to its warlike namesake.

Mars has the tallest volcano in the entire Solar System, Olympus Mons, and the longest canyon, Valles Marineris. Its surface also shows evidence of ancient rivers, suggesting it once had liquid water. Mars has two small moons, Phobos and Deimos, thought to be captured asteroids. With its potential for past life and human exploration, Mars has been a focus of robotic missions like Perseverance and Curiosity, but also for science fiction stories telling about the life that could have been. Future missions aim to study its soil for signs of microbial life, but so far, no luck. A Martian day is 24.6 hours, similar to an Earth day, but its year lasts 687 Earth days.

Jupiter, the largest planet in the Solar System, is a gas giant primarily composed of hydrogen and helium. It's not a failed star, but it comes close. With a diameter of about 140 thousand kilometes, it could fit over 1,300 Earths inside it. Jupiter's most famous feature is the Great Red Spot, a massive storm that has raged for centuries and is larger than Earth itself.

The planet has faint rings and at least 95 proper moons, including Europa, which may harbour a liquid ocean beneath its icy crust, an exciting prospect when one realizes that water is (probably) essential for life as we know it. Jupiter rotates rapidly, completing a day in just 10 hours, while its orbit around the Sun takes nearly twelve Earth years. Its immense gravity influences the Solar System, shaping the asteroid belt and protecting inner planets from comet impacts. Jupiter emits more heat than it receives from the Sun due to its internal processes.

Jupiter is named after the king of the Roman gods in their mythology. Its immense size and dominant position in the Solar System made it a fitting namesake for the most powerful deity in Roman culture.

In our Solar System, Saturn is the second-largest planet and is famous for its spectacular ring system, made of ice, rock, and dust. It is a gas giant just like Jupiter, meaning that Saturn is made up mostly of hydrogen and helium, with a diameter of 115 thousand kilometers. Despite its size, it's the least dense planet, and would float if you could place it in water.

Saturn's year lasts about 29.5 Earth years, while its day is only a short 10.7 hours. It has over 80 moons, including Titan, which has rivers and lakes of liquid methane and ethane, making it another candidate for studying the origin of life. Saturn's rings are thought to be remnants of comets, asteroids, or shattered moons. The planet's strong magnetic field generates constant auroras at its poles. Many missions to the planet have explored its rings, moons, and atmosphere, revealing a complex and dynamic system, although not one that humans would survive in.

Saturn is named after the Roman god of agriculture and wealth, who was also Jupiter's father. The slow movement of Saturn in the sky compared to other visible planets likely contributed to its association with this ancient, wise deity.

Uranus is the seventh planet from the Sun and is unique for its tilted axis, meaning that it rotates on its side. This ice giant has a pale blue-green colour from the methane in its atmosphere. With a diameter of just over 50 thousand kilometers, it's about four times wider than Earth. Uranus has faint rings and at least 27 moons.

The planet's atmosphere is composed of hydrogen, helium, and methane, with temperatures plunging to -224°C, making it the coldest planet. A year on Uranus lasts 84 Earth years, and its day is about 17 hours long. The planet's tilted orientation leads to extreme seasonal changes, with each pole experiencing 42 years of continuous sunlight or darkness.

Uranus is named after the Greek titan, god of the sky - Ouranos. The name reflects its position high in the heavens. It was the first planet discovered with a telescope, and its name breaks the tradition of using Roman gods, honouring its discoverer's preference for a Greek deity.

Neptune is the eighth and farthest planet from the Sun. It's a deep blue ice giant with strong winds that can exceed 2,000 km/h. Its diameter is just under 50 thousand kilometers, slightly smaller than Uranus. Neptune's atmosphere contains hydrogen, helium, and methane, giving it its vivid colour. It has 14 known moons, with Triton being the largest; Triton orbits Neptune in retrograde, meaning, the opposite direction of its rotation, suggesting it was a captured object.

Neptune takes a really long 165 Earth years to complete one orbit but rotates quickly, every 16 hours. It has storms, like its famous Great Dark Spot which lasted from 1989 to 1994. These are short-lived but intense weather, and there are often storms starting and stopping. Neptune was the first planet predicted mathematically before being observed in 1846. NASA's Voyager 2 remains the only spacecraft to visit Neptune, though future missions may explore its icy moons and atmosphere further.

Neptune is named after the Roman god of the sea due to its deep blue colour, evoking the vastness of the then-perceived oceans. Its discovery in 1846 came after mathematical predictions, and the name was chosen to align with the mythological theme of planetary names.

Pluto is a dwarf planet in the Kuiper Belt, and was once infamously considered the ninth planet. It is small, really small, with a diameter of 2,377 kilometers, and made mostly of ice and rock. Pluto's orbit is highly elliptical and also tilted, occasionally bringing it closer to the Sun than Neptune. Its surface has plains, mountains, and potential ice volcanoes.

Pluto has five moons, with Charon being the largest, actually almost half Pluto's size. Together, they form a binary system, as they orbit a point between them. A Pluto year lasts 248 Earth years, and its day is 6.4 Earth days. The New Horizons mission revealed Pluto's complex geology and thin atmosphere of nitrogen, methane, and carbon monoxide. Despite its reclassification in 2006, Pluto remains a symbol of discovery and exploration, representing the edge of our planetary neighbourhood.

Pluto is named after the Roman god of the underworld, reflecting its distant, cold, and dark nature far from the Sun. The name was suggested by an 11-year-old English girl, Venetia Burney, and was officially adopted in 1930 after Pluto's discovery.

The asteroid belt, located between Mars and Jupiter, is a region containing millions of rocky objects left over from the Solar System's formation. It was once thought to be the remnants of a planet that exploded but we know now that it's not the case. It spans about 140 million kilometers and holds objects ranging from as small as dust particles to as large as the dwarf planet Ceres, which is nearly a thousand kilometers in diameter.

The asteroids vary in composition, with some made of metal (like one that became a hot topic of discussion in late 2024 with its richness) and others of rock or carbon. Despite their number, the belt is mostly empty space, and collisions between asteroids are rare.

Jupiter's gravity prevented the objects from forming a planet. The belt is an important source of meteorites that occasionally fall to Earth. It offers clues about the early Solar System and is a target for exploration. We have sent probes to study objects like Vesta and Ceres which showed us diverse landscapes and interesting opportunities. The asteroid belt acts as a boundary between the inner rocky planets and the outer gas giants marking a transition between the types of planets in our Solar System.