________ are planets found around stars outside the solar system.

• A. Asteroids
• B. Exoplanets
• C. Meteors
• D. Moons

Answer: (B)

Exoplanets are planets that orbit stars outside the solar system. This term fits the description precisely because it identifies planets that exist around stars other than the Sun. Scientists discover exoplanets using methods like the transit technique (watching a star’s light dip when a planet passes in front) and the radial-velocity method (observing tiny wobbles in a star’s motion caused by a planet’s gravity), among others, which confirms their presence even when the planets aren’t directly visible.

The other options refer to different objects or phenomena: asteroids are small rocky objects mostly found in our own solar system; meteors are the bright streaks we see when meteoroids burn up in Earth’s atmosphere; moons are natural satellites that orbit planets within a solar system. None of these describe planets orbiting stars beyond our Sun, so the correct term is exoplanets.