Saturday April 11th
Lecturer: Saphira Brandenberger (Leiden Observatory)
Language: English
Student Lecture – Ocean Worlds Beyond Earth: Could They Be Habitable?
We have discovered thousands of exoplanets so far — but one of the most important questions
remains: which of these worlds could host liquid water as a minimal requirement for life, and could
any of them be a true ”Earth 2.0”? In this talk, I will explain what we can measure about distant
planets, what scientists mean by habitability, and why the habitable zone is only part of the story.
We will then look beyond the classic Earth-like picture and explore a surprising class of planets
that seems to be extremely common in our galaxy: Sub-Neptunes — worlds larger than Earth but
smaller than Neptune, and unlike anything in our Solar System. Because their internal structures
are very difficult to pin down with current methods, several different planet types can match the
same observations.
One particularly exciting idea for what these planets could look like is the ”Hycean” scenario:
a Sub-Neptune with a hydrogen-rich atmosphere and a global ocean. Could such worlds even exist?
And if yes, would they be stable and potentially habitable? I will end by sharing how my research
at Leiden Observatory investigates this question and what we might learn from future telescopes.
N.B: This lecture will be given in English.