Introduction
Beyond the asteroids of space, is Jupiter, first and biggest of the nine
planets of our solar system. As exploration of Jupiter turned up some giant
surprises, we discovered many things like: a ring that no one has ever even
glimpsed at, moons unlike any others known, a storm that has lasted on
Jupiter ever since the 1600’s, the Voyager spacecrafts finding out that
Jupiter has lightning, the other spacecrafts that have already visited
Jupiter including the Galileo spacecraft and Ulysses spacecraft. This story
has all the information you need to know!
The Great Red Spot
The most famous feature of Jupiter is the Great Red Spot. It has been
likened to be a great hurricane and is caused by tremendous winds that
develop above the rapidly spinning planet. Winds blow counterclockwise
around this great storm at about 250 miles per hour. Hurricanes on Earth
rarely generate winds over 180 miles per hour.
Jupiter's Moons
Jupiter has 17 fascinating moons and a ring system. The four Galilean
satellites, Io, Europa, Ganymede, and Callisto, are among the most
interesting of all solar system bodies, particularly Io, with its active
volcanoes, and Europa with a possibility of water, and an environment
friendly to life. Other moons in order are: Metis, Adrastea, Thebe, Leda,
Himilia, Lysithea, Elara, Ananke, Carme, Pasiphae, Snope, and S/1999 JI.
These moons are part of a class of moons called small moons. Most of Jupiter’s
moons are named after mythological figures.
Spacecrafts That Were Sent To Jupiter
Beginning in 1973, the United States sent six spacecrafts to observe
Jupiter. Pioneer 10 and 11, along with Voyager 1and 2, Galileo, and Ulysses
are only some of the many spacecrafts that gathered images from this planet
that we still see today!
Some of Jupiter’s moons were first seen by the great scientist Galileo
with his small telescope over 350 years ago. The United States sent a
spacecraft named after Galileo into space in October 1989. The craft
released an atmospheric probe in July 1995. In December 1995, the probe
plunged into Jupiter’s atmosphere. It penetrated deep into the cloud
layers. One of Galileo’s most important missions was to measure the amount
of water and other chemicals in Jupiter’s atmosphere.
Pioneer 10 was launched in 1972 and flew within 81,000 miles of Jupiter
on Dec.3, 1973. The probe revealed the severe affects of Jupiter’s
radiation belt on the spacecraft. Pioneer 10 also reported the amount of
hydrogen and helium in the planet’s atmosphere. In addition, the probe
discovered that Jupiter has an enormous magnetic field.
Pioneer ~ Saturn flew within 27,000 miles in December 1974. The craft
provided close up photographs of Jupiter’s polar regions and data on the
great Red Spot, the magnetic fields and atmospheric temperatures.
Voyager 1 and 2 flew past Jupiter in March and July in 1979. These crafts
carried more sensitive instruments then the Pioneers did, and transmitted
much more information than them. Astronomers used photographs taken by the
Voyagers (1and 2) to make the first detailed map of the Galilean satellites.
The Voyagers also revealed sulfur volcanoes on Io (one of Jupiter’s moons)
discovered lightning on Jupiter’s clouds, and mapped flow patterns in the
cloud bands.
The lightning on Jupiter is very different from the lightning on Earth!
It’s about 100 times more energetic then a typical lightning flash on
Earth. It is most likely that the lightning is generated in the water clouds
that we expect to see in Jupiter’s atmosphere.
Ulysses was launched in October 1990 and passed by Jupiter in February
1992. The European Space Agency, an organization of Western European
nations, had built the probe mainly to study the sun’s polar regions.
Scientists used the tremendous gravitational force of Jupiter to put Ulysses
into orbit that would take it over the sun’s polar regions. As Ulysses
passed Jupiter, it gathered data indicating that the solar wind has a much
greater effect on Jupiter’s magnetosphere then earlier measurements had
suggested.
When You Can See Jupiter
You can see Jupiter in the morning sky about five months of each year and
in the evenings of those five months. At times (using a telescope) you may
even be able to see the four, faint points of light that are the largest of
Jupiter’s moons. The moons are named after the mythological King Jupiter’s
wives.
Jupiter's Surface
