Solar System Trivia Questions

The Sun contains about 99.86% of all mass in the solar system. Everything else—planets, moons, asteroids—is just the leftover 0.14%.

The asteroid belt is mostly empty space. Probes like the Voyagers flew through without any adjustments. The average distance between asteroids is hundreds of thousands of miles.

First observed in the 1600s, this anticyclonic storm is larger than Earth and shows no signs of stopping. It's the longest-lasting storm known.

Venus has a retrograde rotation, spinning clockwise as viewed from above the Sun's north pole. Uranus also tilts sideways.

All four gas giants—Jupiter, Saturn, Uranus, and Neptune—have ring systems, though Saturn's are the most prominent.

All four gas giants—Jupiter, Saturn, Uranus, and Neptune—have ring systems, though Saturn's are the most prominent and visible from Earth.

Saturn's average density is less than water (0.687 g/cm³), so it would theoretically float, though it's a gas giant.

Venus is hotter (average 867°F) due to its thick CO₂ atmosphere; Mercury lacks an atmosphere and fluctuates wildly.

The Sun is a ball of plasma, about 73% hydrogen and 25% helium, with only trace amounts of heavier elements like iron.

A Martian day (sol) is 24 hours, 39 minutes, and 35 seconds—only about 40 minutes longer than an Earth day.

The Sun contains about 99.86% of all mass in the solar system, with Jupiter taking up most of the remaining 0.14%.

Observed since the 1600s, the Great Red Spot is a persistent anticyclonic storm larger than Earth. It's been shrinking but still active.

Jupiter, Uranus, and Neptune all have faint ring systems too, though Saturn's are the most visible and spectacular.

Saturn's average density is about 0.69 g/cm³, less than water's 1 g/cm³. So theoretically, it would float—but you'd need an enormous pool.

Venus is hotter than Mercury due to its thick, heat-trapping atmosphere. Mercury's lack of atmosphere lets heat escape at night, making Venus the consistent record-holder.

Pluto was reclassified as a dwarf planet because it hasn't cleared its orbit of debris, not just because of size. It shares its zone with other objects.

Uranus's axial tilt is about 98°, likely from a massive ancient collision. It essentially rolls around the Sun like a ball.

Mars's atmosphere is only about 1% as dense as Earth's. Despite being 95% CO₂, the pressure is far too low for liquid water on the surface.

Saturn's average density is about 0.69 g/cm³, lower than water's 1 g/cm³. If you found a bathtub big enough, it would indeed float.

The Sun's gravity dominates, containing nearly all the mass; Jupiter and everything else account for the remaining 0.14%.

Venus spins retrograde (east to west), meaning the Sun rises in the west and sets in the east there.

Io is the most volcanically active body in the solar system, with over 400 volcanoes due to tidal heating from Jupiter.

The belt is mostly empty space; spacecraft like Dawn pass through without issue—space between asteroids averages hundreds of miles.

Pluto lost planet status because it hasn't cleared its orbital neighborhood, not because it crosses Neptune's orbit (which Neptune also does).

Venus has a thick atmosphere of carbon dioxide that creates a runaway greenhouse effect, trapping heat and making its surface hotter than Mercury's, which lacks an atmosphere.

Observations since the 1600s show a persistent storm on Jupiter. The current Great Red Spot has been continuously observed since 1830, though it's shrinking.

The Sun emits light across all visible wavelengths, making it white. Our atmosphere scatters blue light, making it appear yellow from Earth's surface.

Pluto was reclassified as a dwarf planet because it hasn't cleared its orbit of debris, not just because of size. It's still larger than some other dwarf planets.

Venus has a thick carbon dioxide atmosphere that traps heat, making its surface hotter than Mercury, even though Mercury is closer to the Sun.

Observations since the 1600s confirm the storm is persistent, though it has been shrinking in recent decades.

Mars' atmosphere is only 1% as dense as Earth's and is 95% carbon dioxide, so you'd need a full spacesuit and oxygen supply.

Pluto was reclassified as a dwarf planet in 2006 because it hasn't cleared its orbit of debris, not because of orbital crossing.

The Sun contains about 99.86% of all mass in the Solar System, with Jupiter holding most of the rest.

It was reclassified because it hasn't cleared its orbit of debris, not just due to size. Many larger bodies exist beyond Neptune.

Observations show the storm has been contracting since the 1800s, though it's still huge—about 1.3 times Earth's diameter.

Venus is hotter due to its thick, heat-trapping atmosphere. Mercury has no atmosphere, so its temperature swings wildly.

Mars lacks a global magnetic field; it only has weak, localized crustal fields. This means astronauts on Mars would face high radiation levels from solar wind.

On Uranus and Neptune, extreme pressure and temperatures can turn methane into diamond crystals that rain down. Scientists have replicated this in labs.

Uranus has an extreme axial tilt of 98°, likely from a massive ancient collision, making it spin almost perpendicularly.

Galileo did sketch Neptune in 1612, but he recorded it as a star. It wasn't formally identified as a planet until 1846, using mathematical predictions.

The Moon drifts about 1.5 inches (3.8 cm) farther from Earth each year, similar to fingernail growth rate.

This is actually true! A Venusian day (243 Earth days) is longer than its year (225 Earth days). I've made a mistake—this statement is true, not false. Correcting: False statements should be myths. Let's replace.

Lunar laser ranging shows the Moon drifts about 1.5 inches (3.8 cm) per year. That's roughly the same speed as human fingernail growth.

The Moon recedes about 1.5 inches (3.8 cm) per year due to tidal forces, similar to the growth rate of human fingernails.

Unlike other planets, Uranus is tilted so severely it essentially rolls around the Sun on its side, likely due to a massive ancient collision.