Transcript Midterm 1
Goal: To understand the workings
of the moons of Jupiter and how
this might apply to life in our
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
• 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
volcanoes on the
• Io is so volcanic
that its surface is
• But why?
Tug of war!
• By itself, Io should be dead. It is tidally
locked to Jupiter, so should not be heated
• 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 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
• 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 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!
• What are the most basic building blocks of
life (the things that NO life form can live
without!)? Please brainstorm at least 6.
and Metis )
Europa – is there life?
What does this look like?
• And notice, still very few if any craters.
• Under a few miles of ice,
Europa probably has an
ocean bigger than any ocean
• Where there is liquid water is
largest moon in
the solar system
• What is
• What are
• How old is
• Cancels out
• This is probably
due to a very
How many more does Jupiter
• There are 63
known moons, but
there are probably
about 100 more.
• Near Jupiter, even the moons are big!
• Io is the most volcanic object in the solar
• Europa has the biggest ocean, and may have
• Ganymede is the biggest moon in the solar
• Callisto, well we need to find something for poor
• And Jupiter has more known moons than any
other planet (but look out Saturn is catching up