Question 1

True or false: Most known exoplanets were found by directly photographing them through telescopes.

Accepted Answer

False. Direct imaging is rare. Over 90% of exoplanets are found indirectly via the transit method (watching stars dim) or radial velocity method.

Question 2

True or false: Most exoplanets discovered so far are smaller than Neptune but larger than Earth.

Accepted Answer

True. Surprisingly, 'super-Earths' and 'mini-Neptunes' dominate exoplanet discoveries, not gas giants like Jupiter. Our solar system is the oddball.

Question 3

True or false: Some exoplanets orbit their star in just a few hours, making a year shorter than a day on Earth.

Accepted Answer

True. Ultra-short-period planets like Kepler-78b complete an orbit in 8.5 hours—so close to their star they're tidally locked and scorching hot.

Question 4

True or false: Exoplanets have been discovered in the Andromeda Galaxy, millions of light-years away.

Accepted Answer

False. No exoplanets have been confirmed in the Andromeda Galaxy. All known exoplanets are in the Milky Way, as current detection methods cannot reliably find planets in other galaxies.

Question 5

True or false: All exoplanets orbit stars, just like planets in our own solar system.

Accepted Answer

True. By definition, exoplanets are planets that orbit stars outside our solar system. Rogue planets, which drift through space without a star, are not classified as exoplanets.

Question 6

True or false: Scientists have confirmed an exoplanet where it rains molten iron from the sky.

Accepted Answer

True. On WASP-76b, temperatures exceed 4,000°F, vaporizing iron on the dayside. Winds carry it to the cooler nightside where it rains liquid iron.

Question 7

True or false: One exoplanet has an atmosphere where clouds are made of sand and quartz crystals.

Accepted Answer

True. On the hot Jupiter WASP-107b, silicate vapor condenses into tiny quartz clouds, confirmed by JWST in 2023.

Question 8

True or false: The first exoplanet ever discovered was found orbiting a Sun-like star.

Accepted Answer

False. The first confirmed exoplanets (1992) orbited a pulsar, a dead neutron star. The first around a Sun-like star came in 1995.

Exoplanets Trivia Questions