Exoplanets: Crash Course Astronomy #27

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Exoplanets: Crash Course Astronomy #27

Today Phil explains that YES, there are other planets out there and astonomers have a lot of methods for detecting them. Nearly 2000 have been found so far. The most successful method is using transits, where a planet physically passes in front of its parent star, producing a measurable dip in the star’s light. Another is to measuring the Doppler shift in a star’s light due to reflexive motion as the planet orbits. Exoplanets appear to orbit nearly every kind of star, and we’ve even found planets that are the same size as Earth. We think there may be many billions of Earth-like planets in our galaxy.

This is a reupload of last week’s episode to correct an error in the way we covered reflexive motion.
For more information on the change and reflexive motion, you can check out Phil’s blog:

Table of Contents
Other Planets Orbit Other Stars 2:10
Nearly 2000 Have Been Found 9:29
Transits 5:44
Doppler Shift 3:30
Exoplanets Orbit Nearly Every Kind of Star 8:44
Billions of Earth-Like Planets 9:33

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Stars as viewed from ISS [credit: Alex Rivest & NASA]
Jupiter [credit: NASA]
Mars [credit: NASA/JPL-Caltech/MSSS]
Mercury [credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington]
Earth [credit: NASA]
Uranus [credit: NASA/JPL-Caltech]
Lost in the Glare [credit: NASA Kepler Mission/Dana Berry]
Reflexive Motion gifs [credit: NASA]
Artist’s conception of PSR B1257+12’s system of planets [credit: NASA/JPL-Caltech/R. Hurt (SSC)]
Artist’s impression of the exoplanet 51 Pegasi b (image) [credit: ESO/M. Kornmesser/Nick Risinger (skysurvey.org)]
Artist’s impression of the exoplanet 51 Pegasi b (video) [credit: ESO/M. Kornmesser/Nick Risinger (skysurvey.org)]
Kepler Transit Graph [credit NASA Kepler Mission/Dana Berry]
Kepler “Beauty Shot” [credit: NASA/Kepler mission/Dana Berry]
The Brown Dwarf 2M1207 and its Planetary Companion [credit: ESO]
Beta Pictoris b [credit: ESO]
A size comparison of the planets in the Kepler-37 system and objects in the Solar System [credit: NASA/Ames/JPL-Caltech]
Water World [credit: NASA Kepler Mission/Dana Berry]
Earth-like World [credit: NASA Kepler Mission/Dana Berry]

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