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Earth’s closest extra-solar neighbor, a planet called Proxima b, orbits the red dwarf star Proxima Centauri, 4.2 light-years — or nearly 26 trillion miles — away. It’s probably a rocky world close in size to Earth and has 1.3 times the mass of Earth or larger.

The Goldilocks Zone

Proxima Centauri is much smaller than our sun and radiates less energy. Proxima b orbits the star within a so-called Goldilocks, or habitable zone, 3.9 million to 7.6 million miles from the star. It’s close enough that liquid water, a key ingredient for life, may exist.

Life on Proxima b

The new planet could be very different from Earth. Proxima Centauri radiates less than 1% of the energy from our sun. It’s also a flare star, periodically emitting bursts of radiation that may fry Proxima b.

Proxima Centauri/NASA photograph

How far away is it?

It takes light about 4.2 years to travel from Proxima Centauri to Earth. It would take about 80,000 years to send a spacecraft to the new planet, using current technology.

Proxima b and Proxima Centauri/Artist conception

Sources: Pale Red Dot project; NASA; European Southern Observatory; Space.com; phys.org; Der Speigel; USA TODAY research