National Geographic Specials Season 3 Episode 2 Alien Earths: Revealed

Alien Earths: Revealed is the second episode of the third season of National Geographic Specials. In this episode, the show explores the possibility of extraterrestrial life and the existence of Earth-like planets in our galaxy.

The episode begins by introducing the Kepler mission, a project launched by NASA in 2009 with the goal of discovering habitable planets outside our solar system. Kepler uses a space telescope to observe the brightness of stars and look for small dips in brightness that might indicate a planet crossing in front of the star. The show explains the science behind how scientists use this information to determine the planet's size, orbit, and distance from its star.

Next, the show explores the concept of a habitable zone, also known as the Goldilocks Zone, which is the range of distance from a star where a planet may have conditions suitable for life. The show explains the criteria needed for a planet to be considered habitable, including the presence of liquid water and a stable atmosphere.

Scientists have discovered thousands of exoplanets, or planets outside our solar system, with new ones being discovered regularly. The show examines some of the most promising Earth-like exoplanets and the potential for life on these distant worlds.

The show then delves into the challenges of detecting life on exoplanets. Scientists are actively searching for biosignatures, or evidence of life on other planets. However, detecting these signatures is a complex task, as they could be hiding in an atmosphere behind dust or other factors. The episode explains how researchers are developing new techniques and technologies to increase the chances of finding these biosignatures, such as studying the atmospheric composition of exoplanets.

The episode also touches upon the controversial topic of if we should attempt to contact extraterrestrial life. The show examines the various arguments for and against contacting other civilizations and the potential consequences.

Overall, Alien Earths: Revealed takes a fascinating look into the world of exoplanets and the possibility of finding life beyond our planet. The episode presents the latest discoveries and technologies used in the ongoing search for extraterrestrial life and the exciting prospects for future discoveries.