![Page 1: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/1.jpg)
Planet Searching• After Uranus and Neptune, some
began searching for yet another planet, among them was P. Lowell from 1905-1916
• Search resumed in 1929 by C. Tombaugh, who identified a candidate on 2/18/1930
• The name “Pluto” was suggested by an English girl of age 11.
![Page 2: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/2.jpg)
Discoveries: Pluto at left and moon Charon at
right
ClydeTombaugh
JamesChristy
![Page 3: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/3.jpg)
Hubble Image of Pluto & Charon
![Page 4: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/4.jpg)
Pluto and Charon to Scale
![Page 5: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/5.jpg)
Mapping Pluto
Charon’s orbit is such as to eclipse Pluto at times, allowing us to map its surfaceDone in 1985
HST mapped Pluto to a resolution of 150 km, revealing a strong variation of reflectivity
![Page 6: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/6.jpg)
Pluto-Charon Eclipses
![Page 7: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/7.jpg)
Charon-Pluto Eclipse Visual
![Page 8: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/8.jpg)
Surface Mapping with HST
![Page 9: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/9.jpg)
A Map of Pluto
![Page 10: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/10.jpg)
Pluto is ODD!• Similar to Triton• Cold at T=50K• Has frozen CH4
• Mostly rock and ice• Largest eccentricity,
with D ~ 30-50 AU (sometimes closer than Neptune)
• Large orbital inclination
• Smaller than planets• Large moon in relative
size
Origin of Pluto-Charon:• Pluto ejected from
Neptune – problem is Charon
• Pluto and Charon formed together (?)
• Pluto captured Charon (?)
• Giant impact like Earth-Moon system (?)
![Page 11: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/11.jpg)
Orbits for Pluto and Neptune
![Page 12: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/12.jpg)
Atmosphere of Pluto
It is possible to study Pluto’s atmosphere from Earth using occultation of starlight.
The light passes through the tenuous atmosphere. In this way we can “see” the atmosphere.
![Page 13: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/13.jpg)
Spectroscopy reveals composition of Pluto and
Charon
![Page 14: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/14.jpg)
Charon
• Discovered in 1978 by J. Christy• Has an icy surface of frozen N and tenuous
CH4 atmosphere• Orbital plane is nearly perpendicular to
ecliptic• In synchronous orbit with Pluto (and vice
versa)• Ratio of masses: MC/MP=0.13• Ratio of sizes: RC/RP=0.51• As seen from Pluto, Charon subtends an angle
of 4o, but the Sun is only 1’ !
![Page 15: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/15.jpg)
Structure of Pluto and Charon
![Page 16: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/16.jpg)
Synchronous Orbits for Pluto and Charon
![Page 17: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/17.jpg)
New Moons: Nix, Hydra,
and “P4”
![Page 18: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/18.jpg)
New Horizons
![Page 19: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/19.jpg)
Dwarf Planets
A "dwarf planet" is a celestial body that, within the Solar System:
1. is in orbit around the Sun2. has sufficient mass for its self-gravity to overcome
rigid body forces so that it assumes a (near-spherical) shape
3. has not cleared the neighborhood around its orbit4. is not a satellite
The term "dwarf planet" applies only to objects in the Solar System and is distinct from "planet" and "small solar system body".
![Page 20: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/20.jpg)
Eris and moon Dysnmonia(goddess of discord and daughter of
lawlessness)
GabrielleXena
![Page 21: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/21.jpg)
Orbit of Eris
![Page 22: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/22.jpg)
Comparison of Pluto with Eris
![Page 23: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/23.jpg)
Ceres Ceres is now a dwarf
planet that was previously the largest of the asteroids. It was discovered on Jan 1, 1801, by Giuseppe Piazzi. With a diameter of about 950 km. Ceres is in the asteroid belt, and it was the largest and most massive body there, but now is the 3rd of the dwarf planets. Interestingly, it contains approximately a third of the belt's total mass.
![Page 24: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/24.jpg)
![Page 25: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/25.jpg)
Rotation and Surface of Ceres
![Page 26: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/26.jpg)
Interior of Ceres
![Page 27: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/27.jpg)
Two Other Dwarf Planets
Haumea
Makemake
![Page 28: Planet Searching After Uranus and Neptune, some began searching for yet another planet, among them was P. Lowell from 1905-1916 Search resumed in 1929](https://reader036.vdocuments.site/reader036/viewer/2022062515/56649f495503460f94c6afe5/html5/thumbnails/28.jpg)
Future Dwarf Planets?