PEP Assignment – Proxima Centauri B

This post is from Fusion, my school's interdisciplinary STEM program.

For our Planetary Exploration Project, my group chose Proxima Centauri b as the destination for a conceptual interstellar mission. The core reason is simple: it is the only Earth-mass world we found where a crewed vehicle mission is plausibly feasible within a human lifetime.

Quick Facts

Distance: 4.24 light-years — the closest known exoplanet to Earth
Mass: approximately Earth's mass
Orbital period: 11.2 days around its host red dwarf star
Surface gravity: likely similar to Earth's
Condition: almost certainly tidally locked — one side always faces the star, one side always faces away

Why This Target

The proximity is the decisive factor. At 4.24 light-years, Proxima Centauri b is a meaningful target for technologies like Breakthrough Starshot, which proposes sending light-sail probes at a significant fraction of the speed of light. Every other Earth-mass candidate we considered was orders of magnitude farther away, pushing any mission timeline well beyond a human lifetime.

The tidal locking is initially a problem but turns out to create an opportunity: the terminator zone, the perpetual twilight band between the permanent day side and permanent night side. Climate models suggest that atmospheric circulation keeps this region at relatively stable temperatures. It's the most plausible location for a surface habitat.

Opportunities

The terminator zone offers:

Moderate temperatures driven by atmospheric circulation between the hot and cold hemispheres
Consistent solar exposure from a low-angle star — useful for power generation
Potential for limited agriculture if the atmosphere supports it and radiation can be managed

The geometry of tidal locking, which sounds like a dealbreaker at first, actually concentrates all the habitable potential into one identifiable strip. That makes mission planning more tractable.

Challenges

Proxima Centauri b has serious problems that no amount of clever engineering fully solves:

Stellar radiation. The host star, Proxima Centauri, is a red dwarf that produces intense superflares — up to 68 times brighter than its baseline output. These events would strip an unprotected atmosphere and irradiate surface structures. Any habitat would need substantial radiation shielding.

Unknown atmosphere. We don't know if Proxima Centauri b has an atmosphere at all. If it does, we don't know its composition. The mission would need flexible atmospheric entry systems and in-situ analysis before any landing.

Tidal locking psychology. Perpetual daylight on the habitable zone would be genuinely disorienting for humans. Circadian rhythms depend on light cycles. This is a real human factors problem, not just an engineering one.

No direct confirmation. The planet's existence is inferred from its star's 1.38 m/s radial velocity wobble — detected at 0.1% precision by the Gaia telescope. We have never directly imaged it.

Mission Architecture

I proposed a phased approach:

Scout probes (20–30 year horizon): Light-sail probes conducting flybys, transmitting basic atmospheric and surface data back over decades.
Orbiters and landers: Larger spacecraft with flexible atmospheric entry systems and full surface analysis capability.
Surface habitats: Radiation-hardened structures in the terminator zone with thermal regulation and closed-loop life support.

Each phase gates the next. You don't commit to sending humans until the probes have given you enough data to know what you're landing in.

Research Process

I want to be transparent about methodology. I used AI during the ideation phase and for understanding complex concepts in astrophysics papers — things like parsing the implications of stellar flux calculations or making sense of atmospheric retention models. I then verified AI summaries against primary sources from Google Scholar, cycling between the two until I was confident the technical claims were accurate.

This is how I think research actually works now. The key discipline is using AI to accelerate understanding, not to replace verification. Every factual claim in this assignment traces back to a peer-reviewed source.

Originally published on ConnorK.