Jupiter:
Jupiter Hot Spot Makes Trouble For Theory
This image of Jupiter shows
concentrations of auroral X-rays near the north and
south magnetic poles. While Chandra observed
Jupiter for its entire 10-hour rotation, the northern
auroral X-rays were discovered to be due to a single
'hot spot' that pulsates with a period of 45 minutes,
similar to high-latitude radio pulsations previously
detected by NASA's Galileo and Cassini
spacecraft.
Although there had been prior detections of X-rays
from Jupiter with other X-ray telescopes, no one
expected that the sources of the X-rays would be
located so near the poles. The X-rays are thought to be
produced by energetic oxygen and sulfur ions that are
trapped in Jupiter's magnetic field and crash into its
atmosphere. Before Chandra's observations, the favored
theory held that the ions were mostly coming from
regions close to the orbit of Jupiter's moon, Io.
Chandra's ability to pinpoint the source of the X-rays
has cast serious doubt on this model. Ions coming from
near Io's orbit cannot reach the observed high
latitudes. The energetic ions responsible for the
X-rays must come from much further away than previously
believed.
One possibility is that particles flowing out from the
Sun are captured in the outer regions of Jupiter's
magnetic field, then accelerated and directed toward
its magnetic pole. Once captured, the ions would bounce
back and forth in the magnetic field, from Jupiter's
north pole to south pole in an oscillating motion that
could explain the pulsations.
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Fast Facts for
Jupiter:
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Credit
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NASA/CXC/SWRI/G.R.Gladstone et al.
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Scale
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Image is 1.5 arcmin on a side.
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Category
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Solar System
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Observation
Date
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December 18, 2000
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Observation
Time
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10 hours
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Obs.
ID
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1862
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Color
Code
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Intensity
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Instrument
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HRC
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Reference
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G.R. Gladstone et al. Nature 415, 1000 (28 Feb 2002)
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Distance Estimate
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Jupiter was approximately 650 million kilometers from Earth at the time of observation
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Release Date
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February 27, 2002
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