Recently astronomers have gained concrete evidence that, in addition to being full of stars, the universe is also full of

• A. Planets are abundant in the universe.
• B. Only stars populate the universe.
• C. The universe has no planets.
• D. The universe is full of comets.

Answer: (D)

The idea being tested is that planets around other stars are common, not just the stars themselves. Over the past few decades, astronomers have confirmed thousands of exoplanets orbiting many different stars using methods like transits (watching for tiny dips in starlight when a planet passes in front) and radial velocity (measuring a star’s slight wobble due to a planet’s gravity). This broad and repeated evidence shows that planetary systems are widespread, so saying the universe is full of planets best matches what we’ve learned.

While comets exist in our own solar system and there have been occasional hints of comets in other systems, the strongest, most consistent evidence across the cosmos points to planets being abundant. Statements claiming there are no planets or that only stars populate the universe contradict observations, making them less accurate.