Three Frontiers in the Search for Life Beyond Earth with Sara Seager

Biosignatures and Venus's Atmosphere

• 💡 Oxygen has historically been considered a key biosignature, but its presence is limited to a fraction of Earth's history, making it less universal for exoplanet searches.
• 🔬 The detection of phosphine on Venus sparked interest, but its signal, identification, and association with life remain highly debated due to noisy data and potential unknown chemical processes.
• 🌡️ Despite Venus's scorching surface, the atmosphere approximately 50 kilometers above has temperatures suitable for life, though its clouds are composed of concentrated sulfuric acid.

Lab Discoveries for Venus Life

• 🧪 Laboratory experiments have shown that biomolecular building blocks like amino acids, nucleic acid bases, PNA (peptide nucleic acid), and lipids are surprisingly stable in concentrated sulfuric acid.
• 🌱 This stability suggests that life could potentially exist in Venus's clouds, utilizing slightly different chemical components than Earth-based life.
• ✅ These findings challenge the conventional view that Venus's harsh cloud environment is entirely inhospitable to organic molecules and, by extension, life.

Morning Star Missions to Venus

• 🚀 The Morning Star Missions propose a series of small, focused missions to Venus, aiming to complement larger NASA/ESA initiatives and enable more frequent exploration.
• 🛰️ The first mission, in collaboration with Rocket Lab (targeting 2026), involves a privately funded probe designed to detect organic molecules via autofluorescence and analyze cloud particle composition.
• 🎈 Future plans include a parachute mission equipped with miniature molecular sensors, such as carbon nanotubes, to specifically identify complex organic molecules in Venus's atmosphere.
• 🌍 Precursor weather balloon tests on Earth have successfully demonstrated the functionality of sensor and parachute systems for these ambitious Venus missions.

The Frontier of Ionic Liquids

• 💧 An accidental rediscovery revealed ionic liquids formed from amino acids and sulfuric acid, which are biomolecule-friendly and remain liquid below 100°C.
• 🧊 These unique liquids exhibit very low vapor pressure, meaning they would not easily evaporate even in space, and can host biomolecules like DNA and enzymes.
• 🔭 Ionic liquids offer a new paradigm for habitable exoplanets, suggesting that life could exist on worlds too warm for water, expanding the potential scope of the search for extraterrestrial life.

Starshade: A Vision for Exoplanet Imaging

• ✨ The Starshade concept involves a giant, specially shaped screen designed to block starlight, enabling direct imaging of exoplanets by a separate telescope.
• 🎯 This method offers broadband efficiency in blocking starlight, making it a more effective approach for exoplanet characterization compared to internal coronagraphs.
• 🌌 With unlimited resources, the speaker's dream project would be to deploy Starshade to comprehensively survey nearby sun-like stars and map their entire planetary systems.