Transcript Juno Mission to Jupiter

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Juno Mission to Jupiter
Unlocking the Giant Planet Story
www.nasa.gov
Haven’t we already been to Jupiter? Why go back?
The Galileo mission dropped a probe into Jupiter’s atmosphere in 1995 and showed us
our planetary formation theories were wrong!
The probe results showed Jupiter’s atmosphere was enriched with heavy elements
(heavier than helium, that is), compared to the Sun. The amount of enrichment was
similar for everything measured, even compounds that should easily melt or
evaporate.
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Haven’t we already been to Jupiter? Why go back?
This meant that Jupiter might have formed farther from the Sun that its present orbit, where it was much
colder and easily melted materials could exist in the same amounts as materials that form at higher
temperatures. Or it could mean that the easily melted material was trapped inside ice that was able to
form near Jupiter’s present position.
In either case, understanding Jupiter’s formation can tell us a lot about what the early solar system was like.
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There are some BIG unanswered questions relevant
to giant planets…
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Over what period in the early solar system did gas giants form, and
how did birth of Jupiter and its gas-giant sibling, Saturn differ from
the “ice giants” Uranus and Neptune?
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What is the history of water and other volatile compounds across
our solar system?
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How do processes that shape the present character of planetary
bodies operate and interact?
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We see a lot of giant planets around other stars. What does our
solar system tell us about development and evolution of extrasolar
planetary systems, and vice versa?
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Launch Date
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Solar System Exploration Decadal Survey 2003 set some principal
objectives for a future Jupiter mission:
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Determine if Jupiter has a central core to constrain models of its
formation
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Determine the planetary water abundance
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Determine if the winds persist into Jupiter’s interior or are confined to
the weather layer
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Assess the structure of Jupiter’s magnetic field to learn how the internal
dynamo works
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Measure the polar magnetosphere to understand its rotation and
relation to the aurora
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The answer to all these questions is Juno!
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Seeing the invisible
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Juno’s Science Objectives
Origin
Determine the abundance of water and place an
upper limit on the mass of Jupiter’s solid core to
decide which theory of the planet’s origin is correct
Interior
Understand Jupiter's interior structure and how
material moves deep within the planet by mapping its
gravitational and magnetic fields
Atmosphere
Map variations in atmospheric composition,
temperature, cloud opacity and dynamics to depths
greater than 100 bars at all latitudes
Magnetosphere
Characterize and explore the three-dimensional
structure of Jupiter's polar magnetosphere and
auroras.
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Interior of Jupiter
Existence & size of the planet’s
solid core helps discriminate among
giant planet formation theories –
which one is correct or are new
explanations needed?
Whether the planet accreted onto a
solid core or resulted from
gravitational collapse of the solar
nebula leads to different histories
for Jupiter
Structure of Jupiter tells us how
interior rotates
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Gravity
Precise measurements of
spacecraft motion measure
gravity field
Gravity field tells us about
how the mass is distributed
inside the planet
Tides caused by the moons
provide further clues about
the planet’s interior structure
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Jupiter’s interior and deep atmosphere
Microwave antennas (radio waves)
probe deep into the cloud layers –
just the very top of the atmosphere,
where weather occurs
Magnetic fields probe into the region
where the magnetic field is
generated – the metallic hydrogen
layer
Gravity fields probe into the central
core region
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Microwave Radiometer Antennas sense the deep
atmosphere
How deep are the roots of
Jupiter’s storms and other
cloud features? We don’t
know!
They could be connected to
deep movements of the
interior, or they could be
shallow surface features.
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Magnetic Field
Precise magnetic field
measurements unveil
fundamental processes that
generate the planet’s powerful
magnetic field
Juno’s polar orbit provides
complete mapping of planet’s
asymmetric and highly structured
field
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Polar Magnetosphere
Electrically charged atomic
particles crash into the
atmosphere along magnetic
field lines.
When these particles crash
into the atmosphere they
create light (the auroral or
northern lights)
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Polar Magnetosphere Exploration
Juno passes directly through auroral
field lines
Measures particles precipitating into
atmosphere creating aurora
Plasma/radio waves reveal processes
responsible for particle acceleration
UV, IR images provides context
for in-situ observations
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The Juno Payload
Suite of instruments will collect data on:
–Jupiter’s Gravity Field
–Jupiter’s Magnetic Field
–Deep Atmospheric
–Aurora/Magnetosphere
Gravity Science system (JPL)
Magnetometer — MAG (GSFC)
Microwave Radiometer — MWR (JPL)
Energetic Particle Detector— JEDI (APL)
Jovian Auroral Distributions Experiment— JADE (SwRI)
Radio & Plasma Wave Detector (U of Iowa)
Ultraviolet Spectrometer— UVS (SwRI)
Infrared Camera – JIRAM (Italian Space Agency)
Visible Camera - JunoCam (Malin)
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The Juno Payload
Spacecraft
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Juno’s Flight Plan
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Jupiter’s radiation is dangerous!
Juno’s orbit avoids the worst of Jupiter’s dangerous radiation belts, but the orbit
shifts into increasingly intense radiation zones over the course of the mission.
Fortunately Juno completes its mission in about a year, before radiation can
destroy its sensitive electronics.
Images of Solar System Formation
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