Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation: Why would clouds form a hexagon on Saturn? Nobody
is yet sure. Originally discovered during the Voyager flybys of Saturn
in the 1980s, nobody has ever seen anything like it anywhere else in the
Solar System. If Saturn's South
Pole wasn't strange enough with its rotating vortex,
Saturn's North Pole might now be considered even stranger. The bizarre
cloud pattern is shown above
in a recent infrared image taken by the Saturn-orbiting
Cassini spacecraft.
The images show the stability of the hexagon even 20 years
after Voyager. Movies of
Saturn's North Pole show the cloud structure maintaining its hexagonal structure
while rotating. Unlike individual clouds appearing like a hexagon on Earth,
the Saturn cloud
pattern appears to have six well defined sides of nearly equal length.
Four Earths
could fit inside the hexagon.
Although full explanations
are not yet available, planetary scientists are sure to continue to study
this most unusual
cloud formation for quite some time
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http://antwrp.gsfc.nasa.gov/apod/ap070404.html
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation: Spewed from a volcano, a complex plume
rises over 300 kilometers above the horizon of Jupiter's moon Io in this
image from cameras onboard the New Horizons spacecraft. The
volcano, Tvashtar,
is marked by the bright glow (about 1
o'clock) at the moon's edge, beyond the terminator or night/day shadow line.
The shadow of Io cuts across the plume itself. Also capturing stunning
details on the dayside surface, the high
resolution image was recorded when the spacecraft was 2.3 million kilometers
from Io. Later it was combined with lower resolution color
data by astro-imager Sean Walker to produce this sharp portrait of the
solar system's most active moon.
Outward bound at almost 23 kilometers per second, the New Horizons
spacecraft should cross the orbit of Saturn in June next year, and is ultimately
destined
to encounter Pluto
in 2015.
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