‘Fire Amoeba’ Likes It Hot, And A Faraway Lava Planet - Science Friday Recap

Podcast: Science Friday

Published: 2025-12-18

Duration: 18 minutes

Guests: Dr. Angela Oliverio, Dr. Johanna Teske

Summary

This episode dives into the discovery of a heat-loving amoeba, Incendiamoeba cascadensis, and explores the intriguing features of the exoplanet TOI-561b.

What Happened

During a research trip in Lassen Volcanic National Park, a team of scientists discovered an amoeba capable of surviving and reproducing at a record high temperature of 145 degrees Fahrenheit. This amoeba, named Incendiamoeba cascadensis, was found in a seemingly ordinary stream that most researchers would overlook. Microbiologist Angela Oliverio explains that the amoeba's genome contains genes associated with thermal stress signaling and proteostasis, allowing it to thrive in such extreme conditions.

The amoeba exhibits fascinating adaptability, possessing the ability to shift quickly between different physical forms - a long, skinny worm-like shape and a classic amoeboid blob. This rapid transformation might enable it to evade excessively hot conditions. Furthermore, when the amoeba forms a cyst, it tolerates even higher temperatures, up to 158 Fahrenheit, a feature that could be advantageous in a warming world.

The discovery challenges long-held scientific assumptions about the temperature limits of eukaryotic life, which were thought to be capped at 60 degrees Celsius since the 1970s. This finding opens up new avenues for research into the adaptability of life in extreme environments.

The episode also explores the distant exoplanet TOI-561b, observed by the James Webb Space Telescope. This rocky planet, described as a 'wet lava ball,' presents surprising evidence of an atmosphere despite its extreme proximity to its star, with an orbital period of just 0.4 days.

Planetary scientist Johanna Teske discusses the planet's unique features, including its low density, which suggests the presence of volatiles. The star it orbits is much older and has a different elemental composition compared to our sun, which might influence the planet's ability to retain an atmosphere.

The presence of an atmosphere on TOI-561b, despite its extreme heat, defies expectations and raises questions about the migration history of ultra-short period planets. These planets may have moved closer to their stars over time, retaining some atmospheric elements in the process.

The episode concludes with the implications of these discoveries for understanding the formation and evolution of rocky planets, including the potential for secondary atmospheres to provide insights into planetary interiors.

Key Insights