Getting your questions ready
Getting your questions ready
Beat the crowd
10 questions No timer
60 free Atmosphere trivia questions with answers — science & nature quiz, new questions added Aug 2026.
This atmosphere trivia quiz covers the science of the air above us, from the ground to the edge of space. It starts with the basics an eighth-grader should know (what air is mostly made of, which layer holds the weather, why the sky is blue) and works up to the details that trip up adults: which layer is the coldest place on Earth, why the thermosphere's 1,500 °C would not feel hot, and how much hydrogen the planet leaks into space every second. History and people get their share too. You will meet the French physicists who discovered the ozone layer in 1913, the Japanese meteorologist whose jet stream discovery went unnoticed because he published in Esperanto, the 1995 Nobel laureates who explained CFCs, and the treaty that became the first in UN history to be ratified by every country. A final stretch leaves Earth for the crushing carbon-dioxide air of Venus, the thin air of Mars and Titan's methane rain. Every answer was checked against Wikipedia's articles on the atmosphere, its layers and related topics, and each question quotes the sentence that supports it, so teachers, quiz hosts and curious readers can trust what they are asking.
30 of 60 questions with answers and explanations. Play the quiz
Q 01By volume, roughly 78% of dry air is which gas?
Nitrogen
It became the dominant component of Earth's 'second atmosphere' about 3.4 billion years ago, long before oxygen showed up.
Q 02About what percentage of dry air is oxygen?
21%
That share is not fixed forever: it has swung over the past 600 million years and once peaked around 35%, high enough to feed giant dragonflies.
Q 03After the two dominant gases, what is the third most abundant gas in dry air?
Argon
At 0.93% it outweighs CO2 more than twenty to one. Neon, helium and krypton are also present in trace amounts.
Q 04CO2 makes up roughly what fraction of dry air by volume?
0.04%
Small as it is, that trace of CO2 with water vapor keeps the surface roughly 33 °C warmer than it would otherwise be.
Q 05At what altitude is the Kármán line, the conventional edge of space?
100 km
Theodore von Kármán actually calculated an aeroplane flight limit of 83.8 km; the round-number line above it was fixed in the 1960s and has no distinct physical significance.
Q 06Which record-keeping body's Kármán line definition separates aeronautics from astronautics?
The FAI
The Fédération Aéronautique Internationale counts anything below the line as an air sport and anything above it as astronautics; international law still has no legal definition of where space begins.
Q 07Which is the lowest layer of the atmosphere, where nearly all weather happens?
Troposphere
It holds roughly 80% of the atmosphere's mass and nearly all its water vapor, and it is the only layer propeller aircraft can reach.
Q 08The ozone layer sits within which layer of the atmosphere?
Stratosphere
Because ozone absorbs solar UV there, this is the one layer where temperature rises with altitude, which makes it very stable and almost cloud-free.
Q 09Which layer of the atmosphere is the coldest place on Earth and where most meteors burn up?
Mesosphere
Its top averages around −85 °C. It is too high for jets and balloons and too low for orbiting spacecraft, so it is mostly studied with sounding rockets.
Q 10The International Space Station orbits within which layer of the atmosphere?
Thermosphere
Enough air remains at 400 km that the station needs regular reboosts to counter drag, otherwise its orbit would decay.
Q 11What is the outermost layer of Earth's atmosphere called?
Exosphere
It is so tenuous that particles travel hundreds of kilometres without colliding, and some scientists count it as interplanetary space rather than atmosphere.
Q 12The name of the lowest atmospheric layer comes from the Greek word tropos, meaning what?
Turn
The name refers to the constant vertical mixing driven by warm surface air rising and cooler air sinking.
Q 13Temperature rises with height in the ozone layer because ozone absorbs what?
Ultraviolet radiation
That inversion suppresses turbulence, which is why airliners cruising at the bottom of this region get such a smooth ride.
Q 21The UN's International Day for the Preservation of the Ozone Layer falls on which date?
September 16
It marks the day the Montreal Protocol was agreed. April 22 is Earth Day and June 5 is World Environment Day.
Q 22Springtime ozone losses of up to 70% over Antarctica were first reported in which year?
1985
Joseph Farman and colleagues published the finding; reactions on polar stratospheric clouds explain why the hole is deepest over Antarctica.
Q 23What did Paul Crutzen, Mario Molina and Sherwood Rowland jointly receive in 1995 for their work on ozone?
Nobel Prize in Chemistry
Rowland and Molina's 1974 CFC hypothesis was denounced by DuPont's chairman as 'a science fiction tale ... utter nonsense'.
Q 14What phenomenon, in which shorter wavelengths scatter more than longer ones, makes the sky look blue?
Rayleigh scattering
The same effect reddens sunsets: with a longer path through the air, most of the blue has been scattered away before the light reaches you.
Q 15Without greenhouse gases, what would Earth's average surface temperature be?
About −18 °C
The actual average is about 15 °C. Water vapor and CO2 absorb and re-emit infrared while letting visible sunlight through.
Q 16Which two French physicists discovered the ozone layer in 1913?
Charles Fabry and Henri Buisson
They noticed sunlight reaching the ground was missing everything below about 310 nm and matched the absent spectrum to a single known chemical.
Q 17The Dobson unit, used to measure ozone overhead, honors G. M. B. Dobson, who was what?
A British meteorologist
He built a simple spectrophotometer and, between 1928 and 1958, set up a worldwide network of ozone monitoring stations that still operates.
Q 18Roughly what share of the Sun's medium-frequency UV light does the ozone layer absorb?
97 to 99%
That band, roughly 200 to 315 nm, is the part that damages DNA; the layer itself only holds 8 to 15 parts per million of ozone.
Q 19In what year was the Montreal Protocol on ozone-depleting substances agreed?
1987
It entered into force on 1 January 1989 and has been amended eight times since, most recently in Kigali (2016) and Quito (2018).
Q 20What distinction does the Montreal Protocol hold among treaties?
First universally ratified treaty in UN history
All 197 states plus the European Union have ratified it, and Kofi Annan called it perhaps the single most successful international agreement to date.
Q 24Which manufactured chemicals were the main cause of ozone depletion?
Chlorofluorocarbons
CFCs were used as refrigerants, solvents, propellants and foam-blowing agents; halons and HCFCs are also on the banned list.
Q 25The common green colour of an aurora is emitted by which excited species?
Atomic oxygen
Red auroras come from the same atoms higher up, at 630 nm, and need stronger solar activity to be visible; blue and purple come from other molecules lower down.
Q 26The word 'aurora' comes from the Roman goddess of what?
The dawn
She travelled from east to west announcing the coming of the Sun. 'Borealis' and 'australis' come from the gods of the north and south winds.
Q 27Which scientist used the term 'aurora borealis' in his writings about the lights in 1619?
Galileo Galilei
Pierre Gassendi, who had read Galileo, popularized it in a 1649 description of a display seen all over France; the term entered English in 1828.
Q 28Noctilucent clouds, the highest clouds in the atmosphere, are made of what?
Water ice crystals
They form near 76 to 85 km and can only be seen in twilight, when the ground is dark but the clouds are still lit by the Sun.
Q 29Noctilucent clouds were first recorded in 1885, two years after the eruption of which volcano?
Krakatoa
Whether the eruption created them or simply had more people staring at spectacular sunsets is still unclear.
Q 30What does 'noctilucent' roughly mean in Latin?
Night shining
They are too faint to see in daylight and are mostly spotted in summer between latitudes 50° and 70°.