Page 6 - BBC Sky at Night - September 2017 UK

06

Juno on the

spot

Jupiter’s Great Red Spot appears as we’ve never seen
it before, courtesy of the Juno spacecraft’s recent
close pass over this swirling, centuries-old storm

JUNO SPACECRAFT, 11 JULY 2017

September marks 40 years since the conditions on Jupiter. It is a detail of a
launch of the Voyager spacecraft, which larger image that was processed by citizen
visited the four outer giant planets of the scientist Kevin Gill, who used raw data
Solar System and 48 of their moons. It captured by Juno that was made available
was humanity’s reconnaissance mission, to the public on NASA’s Juno website
enticing us with incredible planetary (www.missionjuno.swri.edu).
encounters and inspiring the current Zooming in on the Great Red Spot shows
era of planetary exploration: Cassini, the whorls of the storm in detail, but also a
New Horizons and most recently the certain amount of graininess in the final
Juno mission to Jupiter. image. This is because JunoCam captures
In July this year Juno celebrated its images that are about 1,600 pixels wide, a
own anniversary – one year since its relatively low resolution. Nevertheless, this
arrival in Jupiter’s orbit – with a close image is the best close-up of the Great Red
flyby over the Great Red Spot, gifting Spot ever achieved, and a testament to the
us with an unprecedented view of the success of the Juno mission so far.
huge storm. On 11 July at 01:55 UT it Ultimately, the purpose of Juno is to
flew within 9,000km over the ruddy follow up and delve deep where Voyager
anticyclone, capturing images of it with scratched the surface. Its goal is to help
the JunoCam instrument. scientists understand the formation and
The Great Red Spot appears to be
evolution of the planet by analyzing its core,
NASA/JPL-CALTECH/SWRI/MSSS/KEVIN GILL wide, which still makes it about 1.3 times arriving at Jupiter in July 2016, and is
magnetic field, its atmosphere and aurorae.
shrinking, but it’s an astounding 16,350km
Juno launched in August 2011, finally
as wide as Earth. It has been monitored
by humanity since about 1830, and may
scheduled to end its mission in February
have been raging for over 350 years.
2018 by deorbiting into the planet.
When this image was taken, Juno was
9,886km above the planet’s cloud tops.
A gallery of these
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and more stunning
The view shows a tempestuous atmosphere
and provides a glimpse of the stormy
skyatnightmagazine.com 2017 CONTENT space images