Transcript Midterm 1
Goal: To understand the workings of the moons of Jupiter and how this might apply to life in our universe • • • • • Objectives: 1) To explore the Volcanoes on Io 2) To understand Building blocks for life. 3) To explore the Oceans on Europa 4) To learn about Anything interesting on Ganymade or Callisto • 5) To examine How many moons Jupiter has Io • Before the Voyager probe went past Io in the 1980s Io was thought to be a dead boring world much like the moon. • Luckily, they were wrong! What is this? Io is the most volcanic object in our solar system! • Io has over 100 volcanoes, but is about the size of our moon. This would be like having 2000 volcanoes on the earth! • Io is so volcanic that its surface is yellow from Sulfur! • But why? Tug of war! • By itself, Io should be dead. It is tidally locked to Jupiter, so should not be heated tidally. • However… There is a tug of war game. • Jupiter is on one side, and has quite a strong pull. On the other side are the other 3 Galilean moons (Europa, Ganymede, and Callisto). • Where is Io? But tides there are • The tide on the land of Io is 100 m high! • Io is at about the distance from Jupiter that our moon is from us. • Io orbits Jupiter once every 1.8 days. • For the most part this tide is locked into place, but with the help from its friends… Tidal heating • Tidal heating occurs when the interior of a body is being moved by tidal forces. • This causes friction which causes heating. • This is the same as rubbing your hands or squeezing and un-squeezing a tennis ball. Tidal forces on Io • Io has a slightly elliptical orbit as a result of a 1-2-4 orbital resonance with Europa and Ganymede. • This causes Io to change its distance from Jupiter slightly. This changes the amount of the tide. • Also, this causes the part of Io pointed directly at Jupiter to shift by 0.5 degrees over its period (imagine a 100 m tide moving back and forth over a distance of 20 mile distance every 1.8 days). The result: • The mantle of Io is hotter than the earth’s mantle has been in 2 billion years! • Also, the volcanoes on Io are mostly HUGE! • The largest is almost as large as Olympus Mons, but is bigger in volume. • Needless to say, the surface of Io if very young! • So, Io gives us a great look into how the earth must have been 2-3 billion years ago! LIFE! • What are the most basic building blocks of life (the things that NO life form can live without!)? Please brainstorm at least 6. (Thebe, Amalthea, and Metis ) Galileo Europa – is there life? What does this look like? • And notice, still very few if any craters. Close Up! • Under a few miles of ice, Europa probably has an ocean bigger than any ocean on Earth! • Where there is liquid water is there life? Ganymede largest moon in the solar system • What is Ganymede mostly made of? • What are the white circles? • How old is the surface of Ganymede? Callisto • Cancels out Jupiter’s magnetic field around itself. • This is probably due to a very salty ocean under the surface. How many more does Jupiter have? • There are 63 known moons, but there are probably about 100 more. • http://www.ifa.haw aii.edu/~sheppard /satellites/jupsatd ata.html Conclusion • Near Jupiter, even the moons are big! • Io is the most volcanic object in the solar system. • Europa has the biggest ocean, and may have life. • Ganymede is the biggest moon in the solar system. • Callisto, well we need to find something for poor Callisto. • And Jupiter has more known moons than any other planet (but look out Saturn is catching up quick)!