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:
http://www.slate.com/blogs/bad_astronomy/
2015/08/07/crash_course_astronomy_exoplanets
.html
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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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PHOTOS/VIDEOS
Stars as viewed from
ISS https://www.youtube.com/watch?v=TOQrx-7qgak [credit:
Alex Rivest &
NASA]
Jupiter http://www.nasa.gov/centers/goddard/multimedia/largest/Jupiter_sphere
.jpg.html [credit: NASA]
Mars http://mars.jpl.nasa.gov/multimedia/images/?ImageID=2633 [credit: NASA/JPL-Caltech/
MSSS]
Mercury http://solarsystem.nasa.gov/multimedia/display
.cfm?
Category=Planets&IM;_ID=7543 [credit: NASA/
Johns Hopkins University Applied Physics Laboratory/
Carnegie Institution of Washington]
Earth https://www.nasa.gov/topics/earth/overview/index.html [credit: NASA]
Uranus http://photojournal.jpl.nasa.gov/catalog/PIA18182 [credit: NASA/JPL-Caltech]
Lost in the
Glare http://planetquest.jpl.nasa.gov/video/23 [credit: NASA
Kepler Mission/
Dana Berry]
Reflexive
Motion gifs http://spaceplace.nasa.gov/barycenter/en/ [credit: NASA]
Artist's conception of
PSR B1257+12's system of planets https://en.wikipedia.org/wiki/Pulsar_planet#/media/
File:Artist%27s_concept_of_PSR_B1257%2B12_system.jpg [credit: NASA/JPL-Caltech/R.
Hurt (
SSC)]
Artist’s impression of the exoplanet
51 Pegasi b (image) http://www.eso.org/public/usa/images/eso1517a/ [credit:
ESO/M. Kornmesser/
Nick Risinger (skysurvey.org)]
Artist’s impression of the exoplanet 51 Pegasi b (video) http://www.eso.org/public/usa/videos/eso1517b/ [credit: ESO/M. Kornmesser/Nick Risinger (skysurvey.org)]
Kepler Transit Graph http://planetquest.jpl.nasa.gov/video/22 [credit NASA Kepler Mission/Dana Berry]
Kepler “
Beauty Shot” http://planetquest.jpl.nasa.gov/video/2 [credit: NASA/
Kepler mission/Dana Berry]
The
Brown Dwarf 2M1207 and its
Planetary Companion https://www.eso.org/public/usa/images/eso0515a/ [credit: ESO]
Beta Pictoris b http://www.eso.org/public/archives/images/screen/eso1024c.jpg [credit: ESO]
A size comparison of the planets in the Kepler-37 system and objects in the
Solar System http://photojournal.jpl.nasa.gov/catalog/PIA16694 [credit:
NASA/Ames/JPL-Caltech]
Water World http://planetquest.jpl.nasa.gov/video/39 [credit: NASA Kepler Mission/Dana Berry]
Earth-like World http://planetquest.jpl.nasa.gov/video/42 [credit: NASA Kepler Mission/Dana Berry]