Class Notes (838,379)
Canada (510,867)
Astronomy (332)
Lecture

Astronomy Notes Moons of Jovian Planets.docx

3 Pages
84 Views
Unlock Document

Department
Astronomy
Course
Astronomy 1021
Professor
Trevor Kirsh
Semester
Fall

Description
Astronomy Notes November 28, 2012 This Class: Moons of the Jovian Planets  Jovian Planets have numerous moons o Jupiter: 67 known moons o Saturn: 62 known moons o Uranus: 27 known moons o Neptune: 13 known moons  The Medium and Large Moons o Enough gravity to be spherical o Resemble terrestrial worlds: solid, geology  Some have atmospheres, hot interiors, magnetic fields o Two moons are bigger than Mercury, and four more are bigger than Pluto o Substantial amounts of ice  Jovian Moon Formation o Formed in disks around the planets  Just like how planets formed around the sun o Circular orbits in equatorial plane, generally orbit in same direction as planet is rotating o Almost all have synchronous rotation: tidally locked  The small moons are far more numerous than medium and large moons o Large > 1,500km o Medium: 300-1,500km o Small < 300km  These don’t have enough gravity to become spherical  Maybe captured asteroids or comets, so they don’t follow usual patterns  Jupiter’s Moons o Io  No impact craters  Io has tons of volcanoes  It’s the most volcanically active place in the solar system  Lava plains, shield volcanoes, calderas  Constant resurfacing from the volcanoes, the entire surface is young, not a single impact crater is left  The resurfacing happens from volcanism  Outgassing: sulfur bearing species partly escape, and partly condense and fall back to the surface  Some sulfur-rich volcanoes deposit red, yellow and orange particles back to the surface  Io’s Plasma Torus: the particles blasted out from Io’s volcanoes are ionized, and therefore sometimes get caught up in Jupiter’s magnetic field and create auroras on Jupiter’s poles  Io’s volcanoes are caused by tidal heating: Io is squished and stretched as it orbits Jupiter  The Galilean moons have orbital resonances: every 7 days Io, Europa and Ganymede line up  The gravitational tugs add up over time, this causes the orbit of Io to be so elliptical o Europa  Entire surface is covered by water ice  Many cracks in the ice  Not a lot of impact craters, but a few  Many ridges between huge icebergs  What’s below the icebergs? We think there’s a huge ocean  Europa’s geology is driven by water  For the terrestrial planets, geology was driven by molten rock  For Europa (and some other moons) we see similar activity, but with molten ice instead of molten rock  Example: Cryovolcanism: a cryovolcano is an icy volcano  Europa has a magnetic field, probably caused by the convection in the water  Europa has tidal heating from Jupiter, but not as much as Io
More Less

Related notes for Astronomy 1021

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit