Mercury is the closest planet to the sun. It has no atmosphere and is, as such, covered in craters. It's also incredibly hot but, surprisingly, has water ice hiding beneath its surface.

Check out the Crash Course Astronomy solar system poster here: http://store.dftba.com/products/crash...

--

Chapters:
Introduction: Mercury 00:00
Mercury's Orbit 1:21
Mercury's Rotation - 2:3 Orbit Ratio 2:45
A Weird Day on Mercury 4:34
Mercury's Craters 5:42
Mercury's Internal Structure 7:00
Deep Crater Water Ice on Mercury 8:39
Review 9:33
--

PBS Digital Studios:    / pbsdigitalstudios  

Follow Phil on Twitter:   / badastronomer  
Crash Course is on Patreon! You can support us directly by signing up at   / crashcourse  

Want to find Crash Course elsewhere on the internet?
Facebook -   / youtubecrashcourse  
Twitter -   / thecrashcourse  
Instagram -   / thecrashcourse  

CC Kids:    / crashcoursekids  


--

PHOTOS/VIDEOS
Mercury relief in Olomouc: http://commons.wikimedia.org/wiki/Fil... [credit: Michal Maňas]
Mercury: Phil Plait
Mercury in color: http://en.wikipedia.org/wiki/File:Mer... [credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington]
Earth Based View of Mercury: http://airandspace.si.edu/explore-and... [credit: Catalina Observatory]
Caloris Basin: http://apod.nasa.gov/apod/image/1503/... [credit: NASA, Johns Hopkins Univ. APL, Arizona State U., CIW]
MESSENGER photos:
http://messenger.jhuapl.edu/gallery/s...
http://messenger.jhuapl.edu/gallery/s...
http://messenger.jhuapl.edu/gallery/s...
[credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington]
Mercury’s core: http://astrosun2.astro.cornell.edu/~j... [credit: Nicolle Rager Fuller, National Science Foundation]
Mercury’s Ice Lockers: http://svs.gsfc.nasa.gov/cgi-bin/deta... [credit: NASA Goddard Space Flight Center/Massachusetts Institute of Technology/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington]
Mercury’s Tail: http://geeked.gsfc.nasa.gov/wp-conten... [credit: NASA]