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KidZone Science
Jupiter Facts

Jupiter is the largest planet in the solar system, but it spins very quickly on its axis.  A day on Jupiter lasts only 9 hours and 55 minutes.  Ack, I get dizzy just thinking about it!

Jupiter is so big that you could fit all the other planets in the solar system inside it.

source:  NASA - Cassini

Jupiter Fast Facts

Distance from Sun
  Approximately 466 million miles

Number of Moons
  62 moons have been identified
   Ganymede is the largest moon -- it is bigger than both Mercury and Pluto

Diameter
   85,788 miles
   the largest planet -- more than 12 Earths could line up across it!
   scientists use the planet's gravity to accelerate spacecraft so they can reach Saturn, Uranus and Neptune

Composition
   a giant ball of mostly hydrogen and helium

Length of Day
  9 hours, 55 minutes in Earth time (the length of one rotation)

Length of a Year
  12 Earth years   (the length of one orbit around the sun)

Name
  named for the king of the Roman gods.

Visited by
  Pioneer 11, Viking, Galileo, Cassini and others

source:  NASA - Voyager

Jupiter's Spot

One of the most familiar facts about Jupiter is that it has a big red spot known as Jupiter's Great Red Spot.

What is Jupiter's Great Red Spot?
The red spot is a huge storm that has been continuously going on Jupiter for over 400 years.  Winds inside this storm reach speeds of about 270 mph.  The red spot of Jupiter is the biggest, most violent storm in the known universe -- that spot is at least three times the size of earth!

Is that the only storm on Jupiter?
Jupiter looks swirly from a distance.  It is a gaseous planet -- its atmosphere is like an ocean of gases.  The currents in these gases -- similar to wind here on Earth -- cause ever changing swirls.

Why are the winds so colorful?  
We don't know!  Scientists believe a combination of sulfur and phosphorus in the atmosphere make the lovely colors.  But we still aren't sure why the swirls continue to change.  Some believe the winds, and thus the changes, are caused by the internal heat of the planet while others feel they occur because of Jupiter's fast rotation speed. 

source:  This mosaic of Jupiter's ring system
    was acquired by NASA's Galileo spacecraft
    when the Sun was behind the planet, and the
    spacecraft was in Jupiter's shadow peering
    back toward the Sun.

Rings on Jupiter?  

When Voyager visited the outer planets of the solar system we discovered that all of the gaseous planets have rings.

Jupiter's rings are much thinner and therefore less visible than Saturn's but they're there!  Even up close and personal, the spacecraft needed to be at just the right angle to spot the rings.