Proxima b: Closest Earth-Like Planet Discovery in Pictures

Welcome to Proxima b

ESO/M. Kornmesser

On Aug. 24, 2016, scientists announced the discovery of Proxima b, a potentially Earth-like world orbiting Proxima Centauri - the closest star to our own sun. This historic find marks the closest alien planet - and potentially habitable to boot - ever found. See images from the discovery in our gallery here starting with this amazing artist's concept of what the sky may look like from the surface of Proxima b, with the Proxima Centauri on the horizon and the twin stars of the Alpha Centauri system higher up.

Proxima Centauri and Alpha Centauri AB

Digitized Sky Survey 2 Acknowledgement: Davide De Martin/Mahdi Zamani

Proxima b orbits around Proxima Centauri (lower right), the closest stellar neighbor to our own sun. Proxima Centauri is about 4.22 light-years from the sun, while the twin stars of Alpha Centauri are about 4.37 light-years away.

A World Like Our Own

ESO/M. Kornmesser

This artist’s impression shows the exoplanet Proxima b, which orbits the red dwarf star Proxima Centauri. The double star Alpha Centauri AB appears in the image between the exoplanet and its star. Proxima b appears to be at least 1.3 times the mass of Earth, making it slightly larger than our home planet.

Finding Proxima b

Y. Beletsky (LCO)/ESO/ESA/NASA/M. Zamani

The planet Proxima b was discovered by scientists using a telescope at the European Southern Observatory in Chile. The top panel in this image offers a view of the southern skies over the ESO 3.6-meter telescope at the La Silla Observatory in Chile. The lower panel shows real images of the stars Proxima Centauri (lower right) and the double star Alpha Centauri AB (lower left), taken with the NASA/ESA Hubble Space Telescope.

Proxima Centauri Habitable Zone

ESO/M. Kornmesser/G. Coleman

The orbit of Proxima b is inside a cosmic sweet spot known as the "habitable zone" of Proxima Centauri, a region in which scientists think liquid water can exist. But Proxima Centauri's habitable zone is much closer to the star than that of the sun, as shown in this orbit diagram.

Where is Proxima Centauri

ESO/IAU and Sky & Telescope

This chart of the night sky shows the constellation Centaurus and most stars that are visible to the naked eye. Proxima Centauri is marked in red.

Proxima Centauri and Sun Angular Size

ESO/G. Coleman

Proxima Centauri is a red dwarf star, meaning it is much smaller than the sun. However, because its planet Proxima b is so much closer to the star than Earth is to the sun, the star would appear larger from Proxima b's surface that the sun appears from Earth.

Proxima Centauri Relative Size


Here's a handy comparison of stars to put the size of Proxima Centauri into perspective.

Proxima Centauri Doppler Wobble

ESO/G. Anglada-Escudé

This plot shows Proxima Centauri's motion during 2016. The star very slowly and periodically moves toward and away from Earth. This "Doppler wobble" is the result of exoplanet Proxima b orbiting the star while tugging it around with its own gravity.

Proxima Centauri: Pale Red Dot

ESO/Pale Red Dot

Composite image showing a diagram of the three-star system containing Proxima Centauri with the Milky Way and ESO’s 3.6-meter telescope at La Silla Observatory in Chile.

Proxima Centauri in Milky Way

A. Fujii

This wide-field image of the Milky Way shows the three-star system containing Proxima Centauri as a bright yellow-white star to the left.

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