Ep 4. The Earth Next Door

In The Earth Next Door, the fourth episode of the fifth season of NASA's Unexplained Files, viewers are taken on a journey to explore the latest discoveries in our solar system. Experts from NASA, astrophysicists, and space enthusiasts, share their knowledge to examine the possibility of life beyond our planet and answer several relevant questions.

The show starts by presenting a recent study conducted on the Venusian atmosphere that showed the presence of Phosphine, a gas that only microbial life is known to produce. Experts explain that while the discovery is not a confirmation of life on Venus, it does spark interest in further investigation of the planet. The episode then moves to Mars, where three missions have recently been launched. The Perseverance Rover, the Tianwen-1 mission by China, and the Hope Mars mission by the United Arab Emirates are all currently orbiting the planet and preparing to explore it in different ways.

The show also dedicates time to the newest space telescope, James Webb, which is set to launch in 2021. It will have the capabilities to detect chemicals on exoplanets and make direct observations of exoplanets. Overall, the episode aims to answer the question, "Could we find life beyond Earth in our lifetime?"

One of the most interesting parts of the episode is when the experts discuss the possibility of finding life on Saturn's moon, Enceladus. Since the Cassini mission discovered a subsurface ocean, researchers have been analyzing the data to understand the moon's potential for life. "We already know there's water, we already know there's energy, and we know there's organic material,” NASA Astrobiologist Chris McKay states. “Those are the three requirements for life."

To determine the composition of the water plumes present in Enceladus' subsurface ocean, NASA plans to use a new mission called the Europa Clipper, which will explore Jupiter's moon Europa. The mission will have the capability to measure the ions, metals, and water vapor found in the plumes. The show suggests that this new data could confirm the presence of essential chemicals for life on Enceladus.

Apart from discussing life beyond Earth, the episode also highlights the risks of space travel and the impact on astronaut's health. Space enthusiasts may be aware of the increased exposure to cosmic rays that arise when traveling beyond the protective atmosphere of our planet. But the episode points out an additional risk; the weakening of the immune system.

Recent studies show that when astronauts travel to space, their immune systems change in such a way that they become less effective at defending against viruses. After a year in space, Scott Kelly's cells showed that his immune system was effectively younger, which experts suggest may be attributed to the stress that space travel puts on the body. This new risk adds to the list of factors that need to be taken into account when planning space missions beyond our planet.

The episode concludes by emphasizing the awe-inspiring discoveries that have been made in our solar system. It suggests that if we find life beyond our planet, it will change our perspective and have a monumental impact on how we view ourselves. "Discovering life beyond Earth would be one of the most important discoveries in all of human history," says NASA Chief Scientist Jim Green. "It would change the way we think about ourselves as a species, about who we are, and about our place in the cosmos."

Overall, The Earth Next Door is an informative and exciting episode that explores the advancements that have been made in space exploration. It raises questions about the possibility of life and the challenges that arise when exploring deep space. The episode serves as an excellent reminder of the incredible possibilities that still exist beyond our planet.