Ep 16. Alien Planets & Eyeball Earths: The Search for Habitable Planets

Cosmic Journeys season 1 episode 16, "Alien Planets & Eyeball Earths: The Search for Habitable Planets," explores the search for potentially habitable planets beyond our solar system.

The episode begins with a discussion of the Kepler space telescope, which was launched in 2009 with the goal of finding Earth-like planets orbiting other stars. Kepler was able to detect these planets by observing the dimming of a star's light as a planet passed in front of it. Throughout its mission, Kepler discovered thousands of exoplanets, many of which are Earth-sized and located in their star's habitable zone, the region around a star where liquid water can exist on a planet's surface.

The episode then introduces the concept of "eyeball Earths," which are planets that are similar in size and composition to Earth, but have a vastly different appearance due to extreme conditions. For example, one planet discussed is covered in a global ocean that reflects so much light that it appears as a giant, glowing eyeball in space.

Scientists now have a better understanding of the conditions necessary for a planet to support life, including a stable climate, a magnetic field to protect from harmful radiation, and the presence of liquid water. The episode discusses the techniques used to study the atmospheres of exoplanets in order to determine their habitability, such as observing starlight passing through a planet's atmosphere and analyzing the chemical composition of the atmosphere.

The search for habitable planets has led to many exciting discoveries, such as the TRAPPIST-1 system, which contains seven Earth-sized planets, three of which are located in the habitable zone. The episode also discusses ongoing efforts to search for signs of life on exoplanets, such as the upcoming James Webb Space Telescope, which will be able to analyze the atmospheres of exoplanets in even greater detail.

Overall, "Alien Planets & Eyeball Earths: The Search for Habitable Planets" highlights the progress that has been made in the search for Earth-like planets beyond our solar system and the exciting discoveries yet to come.