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Exoplanet

Adapted from Wikipedia · Explorer experience

A stunning image of the exoplanet HIP 65426b, captured by the SPHERE instrument on the Very Large Telescope, showing its position relative to its star.

What is an Exoplanet?

An exoplanet is a planet that orbits a star that is not our Sun. These planets are far away from our Solar System and can be very different from the planets we know.

Finding Exoplanets

Scientists have special ways to find exoplanets. One way is to watch a star’s brightness. When a planet passes in front of the star, the star gets a little dimmer. This is called the transit method. Another way is to see how the star wobbles because of the planet’s gravity. This is called the Doppler spectroscopy method.

Fun Facts About Exoplanets

  • The first exoplanet was found in 1992 around a fast-spinning star called a pulsar.
  • Some exoplanets are very big, like HR 2562 b, which is about 30 times the size of Jupiter!
  • The smallest known exoplanet, Draugr, is only about twice the size of our Moon.
  • There could be billions of planets with the right conditions for liquid water in the Milky Way.

Why Exoplanets Are Exciting

Finding exoplanets helps scientists wonder if there could be life somewhere else. Planets in the habitable zone—not too hot and not too cold—might have liquid water, which is important for life as we know it. The James Webb Space Telescope is helping us learn more about these distant worlds.

Images

A comparison of the sizes of planets in the Kepler-37 system to the Moon and planets in our solar system.
An informative graphic showing current and future missions to explore planets outside our solar system.
A chart showing how many exoplanets have been discovered each year up to August 2023.
Astronomers using special telescopes observed a tiny planet orbiting the star AB Pictoris.
Image of three gas giant planets orbiting the star HR8799, located 120 light-years away, captured by the Hale Telescope.
An image of the brown dwarf 2M J044144 and its orbiting planet, showing amazing discoveries in space science.
A colorful diagram showing different kinds of planets discovered in space by the Kepler mission, with dots representing planets found using various methods.
A chart showing how small planets come in two different sizes, helping us learn about worlds beyond our solar system.
Diagram showing planets that might support liquid water, similar to Earth, orbiting stars in space.
Animation showing the orbit of the exoplanet β Pic b around its star, illustrating how the planet moves in relation to the star's bright light.
An artist’s illustration of a planet orbiting two small stars far away in space.
An animated diagram showing a star with a planet orbiting around it.
Animation showing a planet orbiting its star in space.

Related articles

Planet
Star
Solar System
Doppler spectroscopy
Pulsar
HR 2562 b

This article is a child-friendly adaptation of the Wikipedia article on Exoplanet, available under CC BY-SA 4.0.

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