Sara Seager - Modern Telescopes and Exoplanets

The Impact of Kepler Telescope

• 🚀 The Kepler Space Telescope, launched in 2009, revolutionized exoplanet research, demonstrating that planets are incredibly common.
• 💡 Kepler revealed that planets two to three times the size of Earth are the most common type in our galaxy.
• 🌍 It also showed that small rocky planets are very common, which are the kind of planets that could potentially host life.

Next-Gen Telescopes and Characterization

• 🔭 The upcoming James Webb Space Telescope (JWST), a collaboration between NASA, ESA, and Canada, will focus on characterizing planets rather than just finding them.
• 🔬 Current planet characterization is crude, primarily knowing only a planet's size, mass, and orbit.
• 🌡️ Future characterization aims to understand a planet's internal composition (e.g., rocky, liquid water) and its atmosphere, including gases and temperature.

The Enigma of Mini-Neptunes

• 🪐 Mini-Neptunes, planets two to three times the size of Earth with no solar system equivalent, are a focus of study.
• 🌊 The exoplanet K2-18b is a compelling mini-Neptune, thought to have a similar temperature to Earth and a giant envelope of hydrogen and helium.
• 🧊 There's a small possibility that K2-18b harbors a liquid water ocean beneath its atmosphere, potentially sitting atop a layer of high-pressure ice.

Interdisciplinary Exoplanet Research

• 🔬 Research into exoplanets like K2-18b involves proposals to look for atmospheric gases that could indicate the presence of an ocean.
• 🤝 A core team with expertise in data analysis and gas signature detection works on these problems.
• 🌐 The broader effort is highly interdisciplinary, including biologists, biochemists, photochemistry experts, and specialists in Earth's subsurface and volcanoes.
• 🧠 Understanding high-pressure interiors of planets is crucial for mini-Neptunes, requiring collaboration across many scientific disciplines.