A New Red Spot on Jupiter

National Aeronautics and Space Administration
A New Red Spot on Jupiter
Taken from:
Hubble 2008: Science Year in Review
Produced by NASA Goddard Space Flight Center and the
Space Telescope Science Institute.
The full contents of this book include more Hubble science
articles, an overview of the telescope, and more. The complete
volume and its component sections are available for download
online at:
www.hubblesite.org/hubble_discoveries/science_year_in_review
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Hubble 2008: science Year in Review
A New Red Spot on Jupiter
Since the mid-1600s, astronomers have marveled at changing spots and bands seen telescopically on the planet Jupiter.
Larger, better telescopes revealed them to be dynamic features in Jupiter’s dense atmosphere. The bands mark zones of
prevailing winds, somewhat analogous to Earth’s jet streams. The spots are cyclonic storms that rage along the turbulent
boundaries of the jet streams. The largest of these, dubbed the Great Red Spot (GRS), is a cold, high pressure area 2–3
times wider than planet Earth. Its winds travel at approximately 400 miles per hour—far surpassing the 155 miles per
hour wind speed of Earth’s own Category 5 hurricanes.
In the 1930s, astronomers documented the collapse of a white jet stream just south of the GRS that resulted in the creation
of three elongated features. During the next decade, astronomers watched these features morph into three distinct white
cyclonic storms. In 1998, these storms merged together to form one giant white storm. Its wind speeds now rival those of
the GRS and it has grown to nearly half its size. Then, abruptly in 2006—for reasons still not completely understood—that
storm turned red. Astronomers named it “Red Spot Jr,” or more formally, “Oval BA.”
In 2008, yet another red spot developed. Named “Baby Red Spot,” or “2008 Oval 2,” this new storm was just a fraction of
the size of the other two red spots. And unlike the others, its life span would be short—as it would be caught and absorbed
within months by the anticyclonic spin of the GRS.
All three red spots were imaged in detail using Hubble, by two teams of astronomers led by Imke de Pater of the University
of California, Berkeley and Amy Simon-Miller of NASA’s Goddard Space Flight Center. Hubble’s first image of 2008 Oval
2 was taken in May 2008. The spot was located just to the west of the GRS and was at the same basic latitude. Oval BA
was located between the two, although at a lower latitude.
On May 9 and 10, Hubble took this image, which revealed a new red spot on Jupiter (left-most spot). The Great Red Spot, larger than two
Earths, can be seen to the right.
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Hubble 2008: science Year in Review
This sequence of images shows the movement of the three red spots clustered together in Jupiter’s atmosphere. For the second time since turning red, Oval
BA skirts past the Great Red Spot apparently unscathed. However, 2008 Oval 2 (identified by an arrow in the third panel) gets captured in the anticyclonic spin
of the Great Red Spot.
The close alignment among the red spots was short-lived. Hubble images taken one and two months after 2008 Oval 2’s
discovery revealed that the small spot had traversed from the west side of the GRS to the east side. The small spot’s appearance, however, was changed. The June and July images showed that 2008 Oval 2 was now trapped by the forces of
the GRS storm. As it slipped into the maelstrom of the GRS, 2008 Oval 2 was disintegrating and losing its color.
No one is certain what gives these storms their red color. One theory is that the storms are so powerful that they dredge
up gases or particulates from deep in Jupiter’s atmosphere to higher altitudes, where ultraviolet radiation disassociates the
elements within their molecules. Subsequent chemical reactions may lead to the red color. Astronomers speculate that the
color loss in 2008 Oval 2 was due to the loss of its upward cyclonic circulation once it was trapped and consumed by the
GRS.
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Hubble 2008: science Year in Review
Multi-wavelength images showed that the clouds in 2008 Oval 2 did indeed rise high into Jupiter’s atmosphere before
merging into the GRS. The cloud levels were documented in visible-light images captured by Hubble and by near-infrared
data collected by the W.H. Keck Telescope in Hawaii. Astronomers determined that all three storms (the GRS, Oval BA, and
2008 Oval 2) appeared bright in near-infrared light, signaling that they were towering above the methane in Jupiter’s atmosphere. Methane absorbs infrared light, so methane-rich planets like Jupiter appear dark in reflected sunlight.
As astronomers predicted, the GRS eventually consumed most of 2008 Oval 2, although some high clouds continued to
move eastward after the encounter. A steady energy source of small storms, such as that produced by 2008 Oval 2, may
be one reason why the huge GRS storm has sustained itself for so many years.
Jupiter May 9–10, 2008 • Hubble Space Telescope WFPC2
Planetographic Latitude (degrees)
+ 60
+ 30
0
2008 Oval 2
GRS
– 30
BA
– 60
360
330
300
270
240
210
180
150
120
90
60
30
0
System III West Longitude (degrees)
This false-color cylindrical map of Jupiter reveals the location of the newest red spot, 2008 Oval 2. Individual frames were obtained on May 9
and May 10, 2008 and mosaiced together to form this map with a resolution of a quarter degree in latitude and longitude. The red triangles at
the top and bottom of the image are all areas of missing data.
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Hubble 2008: science Year in Review
The mighty planet Jupiter is 11 times the diameter of Earth, but rotates in less than half the
time. Changing features within its turbulent atmosphere are noted and studied by amateur and
professional astronomers alike.
Further Reading
Aguirre, E.L., “Hubble Zooms in on Jupiter’s New Red Spot: The Great Red Spot’s Baby Brother Falls Under the Space Telescope’s
Powerful Gaze,” Sky & Telescope, 112(2), 26–29, 2006.
Aguirre, E.L., “Jupiter’s Mini Red Spot Survives Encounter,” Sky & Telescope, 112(6), 86–87, 2006.
Barrado-Izagirre, N., et al., “Jupiter’s Polar Clouds and Waves from Cassini and HST Images: 1993–2006,” Icarus, 194(1), 173–185,
2008.
Cheng, A.F., et al., “Changing Characteristics of Jupiter’s Little Red Spot,” Astronomical Journal, 135(6), 2446–2452, 2008.
McAnally, J.W., Jupiter and How to Observe It, London: Springer-Verlag, 2008.
Simon-Miller, A.A., et al., “Jupiter’s White Oval Turns Red,” Icarus, 185(2), 558–562, 2006.
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Hubble 2008: science Year in Review
Amy Simon-Miller has observed Jupiter with the Hubble Space Telescope since 1993, including observations of the Great Red Spot in 2008. These data have been used to study the planet’s ever-changing
atmosphere in an effort to understand what powers the enigmatic storms and powerful winds. Born
and raised in Union, New Jersey, Dr. Simon-Miller earned a B.S. in space sciences from the Florida
Institute of Technology in 1993, and a Ph.D. in astronomy from New Mexico State University in 1998.
She is Chief of the Planetary Systems Laboratory at the NASA Goddard Space Flight Center, where
her focus is on understanding the atmospheres of Jupiter and Saturn and on designing future robotic
space missions.
Imke de Pater is a professor in the departments of Astronomy, and Earth and Planetary Science at the
University of California at Berkeley. Born in Hengelo, Netherlands, she received her Ph.D. cum laude
in 1980 from Leiden University. She started her career observing and modeling Jupiter’s synchrotron
radiation, followed by detailed investigations of the planet’s thermal radio emission. In 1994, she
led a worldwide campaign at radio wavelengths to observe the impact of comet D/Shoemaker-Levy
9 with Jupiter. She is currently exploiting adaptive optics techniques in the infrared range to obtain
high angular-resolution data of the volcanic activity on Io, the weather on Titan, planetary rings, and
Jupiter’s new red oval. She used the Hubble Space Telescope to study weather on Jupiter (in particular,
the red Oval BA), and to complement adaptive optics observations of planetary rings with visible
wavelength data. She teamed up with Jack Lissauer to write a book called Planetary Sciences, which is
the graduate-level textbook in this field. (Photo credit: S. Anderson, Keck Observatory)
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