Exoplanets and Extraterrestrial Life
Episode 28 of Redefining Reality

Show More

Related videos

The Search for Life on Exoplanets
Join the quest for life on exoplanets, focusing on the search for extraterrestrial intelligence (SETI)--a hunt for signals from alien civilizations inspired by a landmark paper in 1959. See how the famous Drake equation points to factors that determine how many such civilizations may exist.
Why Study Exoplanets?
Learn about the exciting mission of exoplanetary science--the study of planets orbiting stars beyond the Sun. Review the eight planets in our solar system, which provide a baseline for understanding the more than 1,000 worlds recently discovered in our region of the Milky Way galaxy.
How to Find an Exoplanet
Given the extreme faintness of a planet relative to the star it orbits, how can astronomers possibly find it? Learn about direct and indirect methods of detection. As an example of the indirect method, discover why a planet causes a star's position to change, providing a strategy for locating exoplanets…
Doppler and Transit Planet-Finding Methods
Explore two other indirect approaches for finding exoplanets: first, by measuring the Doppler shift in the color of a star due to the pull of an unseen orbiting planet; and second, by measuring the tiny drop in the brightness of a star as a planet transits in front of it.
Pioneers of Planet Searching
Chart the history of exoplanet hunting--from a famous false signal in the 1960s, through ambiguous discoveries in the 1980s, to the big breakthrough in the 1990s, when dozens of exoplanets turned up. Astronomers were stunned to find planets unlike anything in the solar system.
The Misplaced Giant Planets
Investigate 51 Pegasi b, the first planet detected around a Sun-like star, which shocked astronomers by being roughly the size of Jupiter but in an orbit much closer to its star than Mercury is to the Sun. Probe the strange characteristics of these "hot Jupiters," which have turned up around…
Explaining the Misplaced Giant Planets
The standard theory of planet formation is based on our solar system. But does this view require revision based on the existence of misplaced giant planets--hot Jupiters circling close to their parent stars? Compare competing theories that try to resolve this conflict.
The Transits of Exoplanets
A tiny percentage of exoplanets can be detected transiting--or passing in front of--their host stars. Combined with Doppler shifts, transits provide information about a planet's size, mass, density, and likely composition. Learn how ambitious amateur astronomers can use this detection technique in their own backyards.
Sniffing Planetary Atmospheres
Survey the history of spectroscopy to understand how a telescope and a diffraction grating can disclose the composition of a star and its planet. Then learn how transits and occultations are ideal for analyzing planetary atmospheres, paving the way for the search for signatures of life.
Stellar Rotation and Planetary Revolution
Trace Professor Winn's own search for the subtle signs that tell whether a star has a tilted axis. Discover why this is an important clue in the mystery of misplaced giant planets. Also hear how he chanced into the field of exoplanetary science.
Super-Earths or Mini-Neptunes?
Learn how a sensitive new instrument led the way in finding planets smaller than the Jupiter-sized giants that dominated the earliest exoplanetary discoveries. Halfway in size between Earth and Neptune, these worlds have uncertain properties. For clues about their nature, consider how our solar system formed.
Transiting Planets and the Kepler Mission
The planet search took a giant leap forward in 2009 with the launch of the Kepler spacecraft, which used the transit technique to observe nearly 200,000 stars over a four-year period. Study Kepler's goals, results, and the persistence of the astronomer who championed it.