Discovering Exoplanets: Is there Anybody Out There?

Is there anybody out there? – a question humans have been asking since the beginning of our existence. It would most likely be the greatest discovery of human-kind if/when we discover the definitive answer to that question.

NASA has been a leader in exploring that question and searching for the answer. On February 22, 2017, NASA announced the discovery of the most Earth-sized planets found in the habitable zone of a single star, 40 light years away in the Aquarius constellation, called TRAPPIST-1 . TRAPPIST-1 is named for the Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile that discovered the first three planets orbiting its parent star in May 2016. NASA’s Spitzer Space Telescope’s infrared data revealed the other planets in this system. This is a system of seven rocky worlds where all of them have the potential for water on their surface. This is an exciting discovery in the search for possible habitats that could support life on other worlds beyond our solar system. These planets beyond our solar system are known as “exoplanets”.

The James Webb Space Telescope (JWST), scheduled for launch in late 2018, will use its infrared sensors to detect the chemical fingerprints of water, methane, oxygen, ozone, and other omponents of an exoplanet’s atmosphere. Webb also will analyze exoplanets’ temperatures and surface pressures – key factors in assessing their habitability. The NASA Kepler Space Telescope , named after Johannes Kepler, is a space-based telescope devoted only to detecting and exploring exoplanets, using the transit method. It has been searching for exoplanets in the Cygnus-Lyra region of the sky since 2009. As of March 2017, Kepler has confirmed a total of 2330 exoplanets. That number is still increasing.

As of March 2017, there has been a total of 3,458 confirmed exoplanets discovered, according to the NASA Exoplanet Exploration website. Of that total, 352 exoplanets are terrestrial – planets composed mostly of rock (silicates) and metals, like Earth, Venus, Mars, and Mercury.

NASA has many STEM educator resources showcasing the James Webb Space Telescope. And, educator resources showcasing the Kepler Space Telescope. A good example of one of the Kepler STEM resources is the activity, “Transit Tracks” . “Transit Tracks”, using real Kepler Space Telescope data, is an activity that enables students to describe a transit and the conditions when a transit may be seen, describe how a planet’s size and distance from its star affects the behavior of transits and interpret graphs of brightness vs time to deduce information about planet-star systems.

If you are interested in participating in citizen science searches for exoplanets, there is a resource just for you. In  2010, the Zooniverse launched the original Planet Hunters website to enlist the public’s help to search data from the NASA’s Kepler Space Telescope for the characteristic drop in light due to an orbiting extrasolar planets (exoplanets) crossing in front of their parent stars. Happy hunting.

Steve Culivan
Educator Professional Development Specialist, NASA STEM EPDC
Stennis Space Center