The 365 Days of Astronomy Travelers in the Night Eps. 349E & 350E: Trappist-1 Planets & Brute
Nov 16, 2025
Explore the intriguing TRAPPIST-1 system, located just 40 light-years away, which features seven Earth-sized planets. Discover how astronomers measure their properties through clever transit timing and light-curve analysis. Learn about the rocky compositions and potential water content of these planets, alongside future atmospheric studies planned with the James Webb Space Telescope. Plus, hear the story of asteroid 2017 MB1, its discovery, tracking efforts, and what it means for Earth's safety.
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Seven Earth-Sized Worlds Around TRAPPIST-1
- The TRAPPIST-1 system has seven Earth-sized planets orbiting a red dwarf about 40 light-years away.
- Transit timing and light-curve analysis let astronomers measure each planet's period, radius, and approximate mass.
Rocky Planets And A Potential Water World
- Numerical simulations show six TRAPPIST-1 planets are likely rocky while one could be water-rich.
- One planet may be ~25% water by mass compared to Earth's 0.02%, implying very different interiors and climates.
Use JWST To Study TRAPPIST-1 Atmospheres
- Use the James Webb Space Telescope to probe TRAPPIST-1 atmospheres and look for biosignatures.
- Follow-up spectroscopic observations are the logical next step to characterize these worlds.