Images of Jupiter's Great Red Spot, taken by the
Hubble Space Telescope over a span of 20 years, shows how the planet's trademark
spot has decreased in size over the years
Image Credit:
NASA/ESA
Jupiter's trademark Great Red Spot -- a swirling anti-cyclonic storm larger
than Earth -- has shrunk to its smallest size ever measured.
According to Amy Simon of NASA's Goddard Space Flight Center in Greenbelt,
Maryland, recent NASA Hubble Space Telescope observations confirm the Great Red
Spot now is approximately 10,250 miles across. Astronomers have followed this
downsizing since the 1930s.
Historic observations as far back as the late 1800s gauged the storm to be as
large as 25,500 miles on its long axis. NASA Voyager 1 and Voyager 2 flybys of
Jupiter in 1979 measured it to be 14,500 miles across. In 1995, a Hubble photo
showed the long axis of the spot at an estimated 13,020 miles across. And in a
2009 photo, it was measured at 11,130 miles across.
Beginning in 2012, amateur observations revealed a noticeable increase in the
rate at which the spot is shrinking -- by 580 miles per year -- changing its
shape from an oval to a circle.
"In our new observations it is apparent very small eddies are feeding into
the storm," said Simon. "We hypothesized these may be responsible for the
accelerated change by altering the internal dynamics and energy of the Great Red
Spot."
Simon's team plans to study the motions of the small eddies and the internal
dynamics of the storm to determine whether these eddies can feed or sap momentum
entering the upwelling vortex, resulting in this yet unexplained shrinkage.
The Hubble Space Telescope is a project of international cooperation between
NASA and the European Space Agency. Goddard Space Flight Center manages the
telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts
Hubble science operations. STScI is operated for NASA by the Association of
Universities for Research in Astronomy, Inc., in Washington.
For images and more information about Hubble, visit:
NASA
Guillermo Gonzalo Sánchez Achutegui
Inscríbete en el Foro del blog y participa : A Vuelo De Un Quinde - El Foro!
No hay comentarios:
Publicar un comentario