The Hycean Paradigm in the Search for Life Elsewhere
Professor Nikku Madhusudhan, University of Cambridge

Speaker:

Professor Nikku Madhusudhan, University of Cambridge

Bio:

Nikku Madhusudhan is a Professor of Astrophysics and Exoplanetary Science at the Institute of Astronomy at the University of Cambridge. His research spans various aspects of extrasolar planets. He is credited with pioneering atmospheric retrieval methods for determining the atmospheric properties of exoplanets using spectroscopic observations, besides other important developments in the understanding of the atmospheres, interiors, formation conditions, and habitability of exoplanets. Most recently, his work led to the identification of a new type of habitable planet, called Hycean worlds, and to the first detection of carbon-bearing molecules in a habitable-zone exoplanet which could be a Hycean world.

Topic:

Science

Date:

13 November 2024

Time:

7:30pm – 9:00pm

Venue:

Sir Charles Wilson Building, University of Glasgow

Lecture review

Summary

The search for life elsewhere is one of the major frontiers of modern astronomy. The detection of atmospheric signatures of habitable Earth-like exoplanets is challenging due to their small planet-star size contrast and thin atmospheres with high mean molecular weight. A recently-proposed new class of habitable exoplanets, called Hycean worlds, promises to expand and accelerate the search for planetary habitability and life elsewhere. Hycean planets are expected to be temperate ocean-covered worlds with H2-rich atmospheres. Their large sizes and extended atmospheres, compared to rocky planets of similar mass, make Hycean worlds significantly more accessible to atmospheric spectroscopy. Several candidate Hycean worlds have been identified in recent studies orbiting nearby red dwarf stars that make them highly conducive for transmission spectroscopy with the James Webb Space Telescope (JWST). Recently, the first JWST spectrum of a possible Hycean world, K2-18 b, was reported with detections of multiple carbon-bearing molecules in its atmosphere. These developments are opening a promising new avenue in the search for life elsewhere, which will be the focus of this lecture. We will discuss new observational and theoretical developments in the exploration of candidate Hycean worlds, and future prospects in the search for habitable environments and life beyond the solar system.