Angie Henkel
Astronomy
Group Project
Q: WHAT DID JUPITER SAY TO SATURN?
A: HEY! GIVE ME A RING SOMETIME!
Jupiter is the largest planet in our Solar System. It’s the fifth closest planet to
our Sun and is categorized with three other gaseous giants, Saturn, Uranus and
Neptune, comprising what we now collectively refer to as the Jovian Planets.
Ancient Astronomers named Jupiter after the king of the Roman Gods. Jupiter has a
mass 318 times greater than the Earth’s and a diameter that is 11 times larger. The
mass of Jupiter is 70% of the total mass of all the other planets in our Solar System.
Its volume is large enough to contain 1,300 planets the size of Earth. Jupiter rotates
faster than any other planet in our Solar System. In fact, it rotates so quickly that
the days are only ten hours long, but it takes twelve Earth years for Jupiter to
complete an orbit around the Sun (Planet Facts.Net) (Bennett, Donahue, Schneider,
& Voit).
The atmosphere of Jupiter consists of about 84% Hydrogen and about 15%
Helium. Small amounts of acetylene, ammonia, ethane, methane, phosphine and
water vapor make up the other 1% of the atmosphere. An ocean of hydrogen covers
the surface of Jupiter with a sludgy like consistency. At greater depths, metallic,
liquid Hydrogen exists. Liquid metallic hydrogen consists of ionized protons and
electrons (like the interior of the Sun, but at a far lower temperature). At the
temperature and pressure of Jupiter's interior hydrogen is a liquid, not a gas. It is an
electrical conductor and the source of Jupiter's magnetic field. This layer probably
also contains some helium and traces of various “ices.” The outermost layer of
Jupiter is primarily composed of hydrogen and helium, which is liquid in the interior
and gaseous further out. The atmosphere we see is just the very top of this deep
layer. Recent experiments have shown that hydrogen does not change phase
suddenly. Therefore, it can be assumed that the interior of Jupiter probably has
indistinct boundaries between the various interior layers (nineplanets.org)
(Bennett, Donahue, Schneider, & Voit).
We don’t know indefinitely, but the interior core of Jupiter is assumed to be
made of rock and ice and is about fifteen times the mass of Earth. In 1969, Frank
Low found that Jupiter is generating internal energy. It radiates twice as much
energy than it receives from the Sun. It could be from primordial heat when Jupiter
originally formed, or Jupiter could be continuing to contract slightly. The interior of
Jupiter is screaming HOT! We estimate the core to be about 20,000 K. The internal
energy is generated by the Kelvin-Helmholtz mechanism, which is the slow
gravitational compression of the planet. Unlike the Sun, Jupiter does NOT produce
energy by nuclear fusion. It is far too small and its interior is to cool to ignite
nuclear reactions. The interior heat more than likely causes convection deep within
Jupiter’s liquid layers and is probably responsible for the complex motions we see in
the cloud tops (nineplanets.org) (Planet Facts.Net).
On the surface of Jupiter lies what’s known as the “Great Red Spot.” The
Great Red Spot is a giant storm on Jupiter’s surface. It’s similar to a hurricane but
much larger in size. In fact, three Earth’s could fit in the size of the Great Red Spot.
Astronomer Robert Hooke first discovered Jupiter’s Great Red Spot in the 1600’s.
The longevity of this storm is at least partially due to the fact that the storm never
goes over land. Similar to when hurricanes reach land, they lose steam, but the
Great Red Spot never encounters land simply because Jupiter’s surface doesn’t have
any. Scientists at the University of California, Berkeley have discovered that the size
of the storm has decreased 15% between 1996 and 2006. It is possible that the
storm will disappear someday. Glenn Orton of NASA also echoes the Great Red Spot
may not always be the largest and strongest storm on Jupiter. New storms are
continually spawning and dying, but the Great Red Spot is still king (Bennett,
Donahue, Schneider, & Voit) (nineplanets.org) (Planet Facts.Net).
Jupiter is the fourth brightest object in the sky (after the Sun, the Moon and
Venus). Jupiter has over 60 known satellites, or moons. Seventeen of them are
natural moons but most are extremely small and faint. Jupiter has been known
since prehistoric times as a bright “wandering star.” In 1610, Galileo first pointed a
telescope at the sky he discovered Jupiter’s four largest moons; Io, Europa,
Ganymede and Callisto. These are known collectively as the Galilean moons. Galileo
also recorded their motions back and forth around Jupiter. This was the first
discovery of a center of motion not apparently centered on the Earth. Jupiter also
has 3 natural rings made out of microscopic dust and particles. Because they sit on
the Sun’s ecliptic, these rings are unable to be seen from Earth (Bennett, Donahue,
Schneider, & Voit) (Planet Facts.Net) (nineplanets.org).
We have been able to see Jupiter quite well from Space since Jupiter was first
visited by Pioneer 10 in 1973 and again by Pioneer 11, Voyager 1, Voyager 2 and
Ulysses. The spacecraft Galileo orbited Jupiter for eight years and the Hubble Space
Telescope still regularly observes it. Just like everything else in space, what we do
know with 100% surety is that our ideas and data on space are currently evolving.
We continue to build more accurate tools for testing and as a result continually
obtain new information. While there is still a lot unknown about Jupiter, over time
we will get to know this planet more accurately (nineplanets.org).
Works Cited
Bennett, J., Donahue, M., Schneider, N., & Voit, M. The Essential Cosmic Perspective (
5th Edition ed.). (N. Whilton, Ed.) San Francisco, CA, United States: Pearson
Addison-Wesley.
nineplanets.org. (n.d.). Jupiter. Retrieved April 4, 2012, from nineplanets.org:
http://nineplanets.org/jupiter.html
Planet Facts.Net. (n.d.). Jupiter. Retrieved April 4, 2012, from Planet Facts.Net:
http://www.planetfacts.net/Jupiter-Facts.html