What Juno about Jupiter?
Jupiter Facts, Mysteries, and the Juno
Mission
Dr. Susan Stolovy
El Camino College
Ancient Jupiter and Juno
Modern Jupiter and Juno
Jupiter, 3 moons, 2 shadows
• New video from Hubble Space Telescope
Images of Jupiter
Some Jupiter Facts
Jupiter was the Roman King of the Gods (and also
the sky and lightning). In our Solar System, Jupiter
is truly “King of the Planets”. It has:
• the greatest mass (318 x Earth’s, more than all
other planets combined)
• the greatest size (11x Earth’s radius)
• the highest surface gravity (2.5 x Earth’s)
• the strongest magnetic field (20,000x Earth’s field
at the core, but about 14x Earth’s at it surface)
• Has the fastest rotation! (9.9 hours)
• the most moons (67!)
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More Jupiter facts
It takes 12 Earth years to orbit the Sun
It has rings!
It has auroras!
The center of mass of the solar system is
between the Sun and Jupiter and lies just
about at the radius of the Sun.
• If Jupiter were about 80 times more massive,
it would be a star!
• The Great Red Spot has been there for at least
300 years!
Jupiter Mysteries
• What causes the Great Red Spot and other oval
features and why is the great red spot shrinking?
• What causes the magnetic field and auroras?
• How were Jupiter’s rings formed?
• What is the chemical composition of the planet at
different depths?
• What material is the core made of (and does
metallic hydrogen even exist)?
NASA’s Juno Mission
Goals: Understand origin and evolution of Jupiter, look
for solid planetary core, map magnetic field, measure
water and ammonia in deep atmosphere, study
auroras.
• Launch - August 5, 2011
• Deep Space Maneuvers - August/September 2012
• Earth flyby gravity assist - October 2013
• Jupiter arrival - July 2016
• Spacecraft will orbit Jupiter for 20 months (37
orbits)
• End of mission (deorbit into Jupiter) - February 2018
• It is solar-powered!
Voyager image (1979) of Great Red
Spot (and White Oval)
Voyager Image
The Great Red Spot is Shrinking! (and
it is changing colors)
Jupiter ring from Voyager (false color)
Backlit Ring image (from Galileo)
Jupiter’s gravity
• Jupiter has likely shielded the inner solar system
from passing asteroids/comets.
• On the other hand, it may have also deflected some
objects INTO the inner solar system
• Comets that get close to Jupiter get tidally torn
about. The world witnessed this when comet
Shoemaker-Levy9 broke into about 20 pieces and
each piece crashed into Jupiter.
If you are a comet, don’t get too close
to Jupiter, or this will happen!
Jupiter after being hit by Comet
Schoemaker-Levy 9
Jupiter’s weird interior: a guess
Jupiter’s Magnetosphere