Ultraviolet and
infrared images from NASA's Cassini spacecraft and Hubble Space Telescope show
active and quiet auroras at Saturn's north and south poles. Image credit:
NASA/JPL-Caltech/University of Colorado/Central Arizona College and
NASA/ESA/University of Leicester and NASA/JPL-Caltech/University of
Arizona/Lancaster University
Ένα
ακόμη εντυπωσιακό βίντεο έδωσε στη δημοσιότητα η NASA. Το βίντεο τιτλοφορείται «Ο Χορός του Σέλαος του Κρόνου» και
παρουσιάζει το σέλας στον βόρειο πόλο του πλανήτη.
While the
curtain-like auroras we see at Earth are green at the bottom and red at the
top, NASA's Cassini spacecraft has shown us similar curtain-like auroras at
Saturn that are red at the bottom and purple at the top. Image credit:
NASA/JPL-Caltech/SSI
Ultraviolet and
infrared images from NASA's Cassini spacecraft and Hubble Space Telescope show
active and quiet auroras at Saturn's north and south poles. Saturn's auroras
glow when energetic electrons dive into the planet's atmosphere and collide
with hydrogen molecules. Sometimes a blast of fast solar wind, composed of
mostly electrons and protons, creates an active aurora at Saturn, as occurred
on April 5 and May 20, 2013. The first set of images, as seen in the
ultraviolet part of the spectrum by Hubble, shows an active aurora dancing
around Saturn's north pole on April 5. The movie then shows a relatively quiet
time between April 19 to 22 and between May 18 and 19. The aurora flares up
again in Hubble images from May 20. This version, shown in false-color, has
been processed to show the auroras more clearly. A second set of ultraviolet
images shows a closer view of an active north polar aurora in white. This set
comes from Cassini ultraviolet imaging spectrograph observations on May 20 and
21. The last set of images, in the infrared, shows a quiet southern aurora (in
green) in observations from Cassini's visual and infrared mapping spectrometer
on May 17. Saturn's inner heat glows in red, with dark areas showing where high
clouds block the heat. Image credit: NASA/JPL-Caltech/University of
Colorado/Central Arizona College and NASA/ESA/University of Leicester and
NASA/JPL-Caltech/University of Arizona/Lancaster University
Το
βίντεο έχει δημιουργηθεί από εικόνες του φαινομένου που έχουν καταγράψει το Cassini (το σκάφος που εξερευνά το σύστημα του
Κρόνου την τελευταία δεκαετία) και το διαστημικό τηλεσκόπιο Hubble.
The dark region
seen on the face of the sun at the end of March 2013 is a coronal hole (just
above and to the right of the middle of the picture), which is a source of fast
solar wind leaving the sun, and caused the
aurora on Saturn. Image credit: NASA/SDO/AIA
Σύμφωνα
με τα στελέχη της NASA
το βίντεο αυτό θα βοηθήσει τους ειδικούς να μελετήσουν καλύτερα το φαινόμενο
στον Κρόνο αλλά και να κατανοήσουν καλύτερα την εξέλιξη των μετεωρολογικών
φαινομένων σε γίγαντες αερίων.
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