Ep 2. How to Find an Exoplanet

The Search for Exoplanets: What Astronomers Know is a show that explores the world beyond our solar system, and delves into the latest scientific discoveries on exoplanets. In season 1 episode 2, entitled "How to Find an Exoplanet," viewers learn how scientists are able to detect these distant worlds.

The episode begins with a brief review of last week's episode and the topic of exoplanets. Viewers see breathtaking shots of the cosmos and hear from researchers who have dedicated their lives to finding these planets. From here, the episode moves onto the challenge of actually detecting exoplanets.

Scientists have several methods at their disposal when it comes to discovering exoplanets. The first method, called the radial velocity method, is based on the fact that planets orbiting a star cause the star to move slightly in response. By measuring these small changes in the star's movement, astronomers can infer the presence of one or more planets orbiting around it. The episode breaks down the science behind the radial velocity method, showing viewers how it works and why it is so effective.

The next method discussed is the transit method. This method involves measuring the tiny dip in a star's brightness that occurs when a planet passes in front of it. By tracking these dips, scientists can determine a planet's size, orbit, and even composition. This method is also explained in detail, with clear illustrations that show how it works.

After discussing these two main methods, the show moves onto other techniques that are used by astronomers to find exoplanets. The gravitational microlensing method is a technique that uses the gravitational pull of a planet to bend and magnify the light of a more distant star behind it. This method is particularly useful when looking for planets that are much further away than those found by the radial velocity and transit methods.

Next, viewers are introduced to the direct imaging method, which involves taking pictures of planets directly. This is a difficult and demanding technique, but with new technology and advances in imaging, scientists are now able to directly image planets orbiting nearby stars.

The show then shifts to the Kepler Space Telescope, one of the most important tools for discovering exoplanets. The Kepler mission revealed thousands of potential exoplanets, but the task of confirming these discoveries is equally challenging. The episode discusses the techniques that astronomers use to confirm exoplanets and avoid false positives.

Throughout the episode, viewers are introduced to the scientists leading the charge in exoplanet research. Viewers hear from experts like Sara Seager, an astrophysicist and planetary scientist who helped develop techniques to detect the atmospheric signatures of exoplanets using spectroscopy, and Dimitar Sasselov, who founded the Harvard Origins of Life Initiative. The show also features interviews with researchers who have dedicated years to observing the cosmos, using state of the art telescopes, and breaking down data in order to find these wondrous alien worlds.

Overall, the episode offers a comprehensive look at the different methods astronomers use to detect exoplanets, from the radial velocity method to the direct imaging method. The scientific details are explained in an easy-to-understand manner, making it accessible for viewers with varying levels of scientific knowledge. Fans of space exploration and astronomy will find this episode of The Search for Exoplanets: What Astronomers Know to be both educational and fascinating.