Until 1995, we didn’t know if planets existed outside our solar system. As of 2024, more than 5,500 exoplanets have been confirmed [1].
How Exoplanets Are Discovered
Transit Method
When a planet passes in front of its star, the star’s brightness dims slightly. The Kepler Space Telescope discovered more than 2,700 planets using this method [1].
Related: science of longevity
Radial Velocity Method
A planet’s gravity causes its star to wobble slightly. This wobble is measured using a spectrograph.
The Habitable Zone
The range of distances from a star where liquid water could exist is called the habitable zone (or Goldilocks Zone) [2]. The TRAPPIST-1 system has three Earth-sized planets within its habitable zone.
The Role of JWST
The James Webb Space Telescope can directly analyze the atmospheres of exoplanets — detecting CO2, methane, and even oxygen [3]. These could serve as indirect evidence of life.
A Teacher’s Reflection
The search for exoplanets is a perfect example to show students how rapidly science advances. A field that didn’t exist 30 years ago is now at the heart of astronomy.
Disclaimer: This article is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with any questions about a medical condition.
Your Next Steps
- Today: Pick one idea from this article and try it before bed tonight.
- This week: Track your results for 5 days — even a simple notes app works.
- Next 30 days: Review what worked, drop what didn’t, and build your personal system.
Last updated: 2026-03-16
About the Author
Written by the Rational Growth editorial team. Our health and psychology content is informed by peer-reviewed research, clinical guidelines, and real-world experience. We follow strict editorial standards and cite primary sources throughout.
References
- NASA Exoplanet Archive. (2024). Confirmed Exoplanets. exoplanetarchive.ipac.caltech.edu.
- Kasting, J. F., et al. (1993). Habitable zones around main sequence stars. Icarus, 101(1), 108-128.
- JWST Transiting Exoplanet Community ERS Team. (2023). Nature, 614, 649-652.