James Webb Just Saw a Planet Around Our Nearest Sun-Like Star — Then It Vanished

In August 2024 the James Webb Space Telescope pointed its MIRI coronagraph at Alpha Centauri A — the closest Sun-like star to Earth, just 4.3 light-years away — and saw a faint point of light that should not have been there: a candidate planet, ten thousand times dimmer than its star, sitting about twice as far from Alpha Centauri A as the Earth sits from the Sun. Then, in February and April 2025, Webb looked again. Nothing. The planet was gone. This is the full story of "S1": why a Saturn-mass gas giant in the habitable zone of our nearest solar twin is exactly the kind of world a binary star system should not be able to keep, how a million simulated orbits say it may simply be hiding in the glare of its own sun, what a Mars-sized moon of S1 could look like, why Alpha Centauri B's 80-year dance limits where any planet can survive, and the three telescopes racing to settle it — Webb's follow-up window around August 2026, the Nancy Grace Roman Space Telescope's deformable-mirror coronagraph (launch by May 2027), and Australia's tiny TOLIMAN mission. Plus the neighbour we already know is real: Proxima b. 🔔 Subscribe for space, planetary science, and the stories behind the headlines. 💬 Drop a comment — do you think S1 is a real planet hiding behind the glare, or a dust cloud that fooled Webb? Vote: PLANET or DUST. 📢 Share this video to help us grow this community. — ⚠️ DISCLAIMER: This video is for educational and informational purposes. Content is based on the JWST/MIRI coronagraphic observations of Alpha Centauri A (Sanghi, Beichman et al., Astrophysical Journal Letters, August 2025), the 2019 NEAR/VISIR candidate detection at the VLT, NASA/JPL and STScI mission statements on the Webb follow-up programme, published orbital-stability studies of the Alpha Centauri AB binary, NASA's Roman Space Telescope coronagraph documentation, the TOLIMAN mission description (University of Sydney), and the Proxima b discovery paper (Anglada-Escudé et al., Nature, 2016). S1 is an unconfirmed candidate; sections describing its surface, moons, or a future confirmation are clearly labelled as speculative. #AlphaCentauri #JamesWebb #Exoplanet