Our Closest Neighbor: Proxima Centauri b Quiz

4.2 light-years is the correct answer. This makes it the closest known planet outside our solar system, though it would still take thousands of years to reach with current rockets.

False. Proxima b is classified as a terrestrial (rocky) planet, with a mass only slightly larger than Earth's.

Red is the correct answer. Red dwarfs are smaller, cooler, and much longer-lived than our Sun.

Habitable zone, 11-day year, and tidally locked are the correct answers. Because its star is so cool, the planet must orbit very closely to stay warm.

Intense radiation flares is the correct answer. Red dwarfs like Proxima Centauri are very active and frequently blast their planets with X-ray radiation.

True. Even though the star is smaller than our Sun, the planet is so close to it that the star would appear about 3 times larger in the sky.

Tidally is the correct answer. This results in a permanent "day side" and a permanent "night side."

Alpha Centauri is the correct answer. Proxima is the smallest and closest of the three stars in that system.

Water, atmosphere, and oxygen are the correct answers. These are the key ingredients we look for when searching for "Earth 2.0."

Measuring the "wobble" (Radial Velocity) is the correct answer. The planet's gravity pulls on the star slightly, causing a change in the light we see from Earth.

False. Because it orbits in the habitable zone, it receives enough energy to potentially have temperatures similar to Earth's.

Light-year is the correct answer. It is a unit of distance, not time, used to measure the vast gaps between stars.

Star is too dim and planet is too small is the correct answer. Red dwarfs are too faint to see without a telescope, and planets are lost in the star's glare.

Extremely cold, always dark, and covered in ice are the correct answers. Without sunlight to warm it, the night side would be a frozen wasteland.

True. It is slightly "heavier" than Earth, which means its gravity would feel a bit stronger if you stood on its surface.

Goldilocks is the correct answer. Just like the porridge in the story, the temperature in this zone is "just right" for liquid water.

8.4 years is the correct answer. The signal takes 4.2 years to go there, and the reply takes another 4.2 years to return.

All four are correct because they observe the planet using different wavelengths: the VLT measures the star's "wobble" to confirm the planet's mass, Hubble monitors ultraviolet radiation to check for atmospheric loss, Chandra tracks lethal X-ray flares, and the James Webb (JWST) analyzes infrared light to search for signs of water or an atmosphere.

Reddish-Orange is the correct answer. Since it is a Red Dwarf, its light is much cooler and redder than the yellow-white light of our Sun.

False. Scientists have found evidence of at least two other potential planets (Proxima c and d) in the same system.