Could Proxima b Actually Be Habitable, or Is That Just Wishful Thinking?

Written by OC Wanderer, author of Destiny Among the Stars. Originally published April 6, 2026.

When I picture arriving at another world, I want to know what happens when the hatch opens. What does the light look like? Is anything moving beyond the landing site? Could I stand there and breathe? Those questions pulled me into science fiction, and they are why this blog starts with the planet orbiting our nearest neighboring star. From here, I want to follow one idea outward: if another world were within reach, what would it take to get there, and what would we find?

Proxima Centauri is about 4.2 light-years away. In 2016, astronomers reported a planet orbiting it every 11.2 days, with a minimum mass then estimated at about 1.3 times Earth's.¹ That gave the destination in my head a real name: Proxima b. Give me the word habitable and my imagination is already at an ocean, a shoreline, and somebody stepping out of a spacecraft. I want to know how much of that imagined arrival a real planet could offer.

So is Proxima b habitable, or am I wishing? I think it could be, and the possibility is worth chasing. The orbit puts water within reach. Whether a world can keep it under this particular star is where the adventure gets interesting.

The orbit puts water within reach

There could be liquid water on a world orbiting our nearest neighboring star. That is what makes Proxima b so hard to leave alone: its orbit falls inside the habitable zone, where a planet with the right atmosphere could keep water on its surface. Astronomers found the planet by measuring how Proxima wobbles as it tugs on the star. That gives us the orbit and a minimum mass; the surface is still ours to wonder about.

In Destiny Among the Stars, the crew first sees the planet through their telescope, clouds swirling and a faint ring around it, and Ryan reads off its atmospheric composition, magnetic field and surface temperatures and tells them it could support human life. They name it New Dawn. Those are the answers I want from the real world, too: what turns a promising orbit into a place someone could visit?

The air has to survive the star

I would want a very good space-weather report before landing. Proxima is an active red dwarf, and in one roughly fifty-day stretch, the TESS space telescope caught seventy-two flares.² That record suggests superflares about three times a year. TESS watched near the low point of the star's magnetic cycle, so even that rate may run low.

The planet would also need to weather a wind of charged particles, hitting it about 100 to 300 times harder than the solar wind hits Earth.³ A magnetic field can push back, making the size of its protective bubble an important part of the landing picture. Calculations assuming a field weaker than Earth's put the balance point between wind and field about 3 to 11 planet radii out, depending on where Proxima b is in its orbit. Earth's balance point sits about 10 Earth radii from its center.⁴

Keeping the air is the harder question. Give Proxima b an Earth-like atmosphere and even a magnetic field leaves an escape route at the poles. Charged particles leak away in a process called the polar wind, which Proxima's extra extreme-ultraviolet light speeds up. A model of those losses concluded that an Earth-twin would not survive there.⁵ But I love how quickly that sends the imagination beyond an Earth copy. What would a world need to cope with its own star? Simulations with a field like Earth's or larger found that, under calm conditions, the wind stopped far enough out to shield the surface at nearly every field tilt, except near 90 degrees.⁶ That is a promising piece of the puzzle, though surface shielding alone does not establish that an atmosphere survives.

A thick atmosphere of carbon dioxide and nitrogen could also cut the ultraviolet reaching the ground. And the biology has a surprise of its own: in laboratory tests without atmospheric shielding, some cells of two microbes survived a simulated typical flare, while some cells of one tested bacterium survived the strongest superflare exposure.⁷ I wonder what surviving repeated flares would demand of a living world. A single laboratory exposure leaves that question open, but it gives me more to imagine than a surface where every flare ends the story.

That is the ground I built New Dawn on. In the crew's analysis, the atmospheric data, magnetic shielding and orbital stability all look promising. When Luca finally stands on the surface, the valley below him is red and violet under the red dwarf's light, and he wonders at how the plants and animals have adapted to its radiation. I made every living thing on the planet I invented adapt to that radiation.

The models leave room for water, and the tools are coming

Imagine a sea beneath a sun that never moves across the sky. Climate models leave room for exactly that kind of world: if Proxima b is tidally locked, with one side always facing the star, a planet with enough water can keep it liquid at least beneath the overhead sun. Other modeled combinations of atmosphere, water and rotation also allowed surface liquid water. If the planet turns three times for every two orbits, an atmosphere about as thick as Earth's, with a small amount of carbon dioxide added, can keep water from freezing.⁸ Those are very different skies to stand under, and both give me a reason to keep wondering about that shoreline.

What I want next is light from the planet itself, carrying clues about which of those worlds, if any, is really there. Pulling that faint light out of the neighboring star's glare is the job of an instrument being built called RISTRETTO.⁹ The Extremely Large Telescope in Chile is scheduled for first light in 2029, with science instruments following in 2030.¹⁰ The 2016 climate study anticipated that telescopes like it could image Proxima b and possibly tell us whether its surface is habitable. That is the prospect I find thrilling: a real observation beginning to fill in the world behind the name.

My crew runs into the same gap between reading a planet from far away and standing on it. They confirmed the atmosphere from orbit. At the landing, Luca reaches for his helmet release anyway, and Joey stops him and scans first. Only then does Luca open his visor and breathe air that smells like rain on dirt.

Why I still want to open the hatch

So could Proxima b be habitable? I think it could, and I want a telescope to give that imagined arrival something firmer to stand on. Even a barren Proxima b would show us what a star like Proxima does to its planets. Until we can read its own light, I still have a shoreline to wonder about and a hatch I want to open.

Next door, two brighter stars, Alpha Centauri A and B, have kept astronomers searching for planets even longer, and that search is hard. Why is Alpha Centauri so hard to find planets around?

Endnotes

1. Guillem Anglada-Escudé et al., “A terrestrial planet candidate in a temperate orbit around Proxima Centauri,” Nature 536 (2016), 437–440. DOI · Accepted manuscript. ↩

2. Krisztián Vida et al., “Flaring Activity of Proxima Centauri from TESS Observations: Quasiperiodic Oscillations during Flare Decay and Inferences on the Habitability of Proxima b,” The Astrophysical Journal 884 (2019), 160. DOI · The flare rate was about 1.5 per day. The projected recurrence is for flares of about 10³³ erg (three per year) and 10³⁴ erg, ten times stronger (one per two years); the observations came from TESS Sectors 11 and 12. Paper record. ↩

3. C. Garraffo et al., “Revisiting the space weather environment of Proxima Centauri b,” The Astrophysical Journal Letters 941 (2022), L8. The 100 to 300 times figure is the average wind pressure across three simulated cases; the 3 to 11 planet radii standoff assumes a 0.1 gauss planetary field, compared with Earth's roughly 0.3 gauss. DOI. ↩

4. NOAA Space Weather Prediction Center, “Earth’s Magnetosphere.” The balance point between a planet’s field and the stellar wind is called the magnetopause; Earth’s dayside magnetopause sits about 10 Earth radii from the planet’s center. NOAA. ↩

5. Katherine Garcia-Sage et al., “On the Magnetic Protection of the Atmosphere of Proxima Centauri b,” The Astrophysical Journal Letters 844 (2017), L13. DOI · NASA paper record. ↩

6. L. Peña-Moñino et al., “Magnetohydrodynamic simulations of the space weather in Proxima b: Habitability conditions and radio emission,” Astronomy & Astrophysics 688 (2024), A138. DOI · Accepted manuscript. ↩

7. X. C. Abrevaya et al., “UV surface habitability of Proxima b,” Monthly Notices of the Royal Astronomical Society: Letters 494 (2020), L69–L74. Atmospheric models used carbon dioxide/nitrogen compositions at 100 to 5,000 millibars; Earth's sea-level pressure is about 1,000. The biological experiments assumed no UV shielding. Both Haloferax volcanii and Pseudomonas aeruginosa were tested at 8.7 W/m² for a typical flare; the reported superflare experiment exposed P. aeruginosa to 92 W/m². Repeated-flare survival remained open. DOI · Manuscript. ↩

8. Martin Turbet et al., “The habitability of Proxima Centauri b. II. Possible climates and observability,” Astronomy & Astrophysics 596 (2016), A112. In the 3:2 case the abstract gives about 1 bar of nitrogen plus about 10 millibars of carbon dioxide; the authors also say that within a decade E-ELT and JWST could image the planet. DOI · Accepted manuscript. ↩

9. N. Blind et al., “The Phase Induced Amplitude Apodizer and Nuller: High transmission, high dispersion coronagraphy at 2λ/D” (2025). The paper reports simulations and a laboratory prototype of optics for the RISTRETTO instrument. Manuscript. ↩

10. ESO, “ELT Timeline.” Telescope first light 2029; first observations with scientific instruments expected December 2030. ESO. ↩