If your night sky is clear this weekend, try taking a look at
Jupiter, our solar system’s largest planet. Jupiter is in
opposition on April 7th, meaning the planet is directly opposite
in the sky from the Sun and it’s relatively close and bright.
Jupiter is rising as the Sun sets and setting as the Sun
rises, so it’s up all night long in the constellation Virgo, and
depending on the time of night, you can view three or four of
Jupiter’s largest moons through binoculars or a small telescope.
And if you want to know what Jupiter looks like through a big
telescope, here's an image of Jupiter that NASA’s Hubble Space
Telescope took just a few days ago, on April 3rd, 2017. Hubble
regularly takes observations of Jupiter as part of its Outer
Planets Atmospheres Legacy program, or OPAL. That program
has been able to observe movements in Jupiter’s clouds to
measure the speeds of Jupiter’s winds, study color changes, and
watch changes on the Great Red Spot, a huge storm on the
planet. The Great Red Spot is larger than the size of Earth,
and has been shrinking over the past 100 years, becoming more
and more round. The OPAL program makes global maps of Jupiter
that can be rendered onto a spherical model, and the team
will be working in the coming weeks on a new set of global
maps of Jupiter from these latest observations. So this
image we’ve shown you is really just a preview of what’s to
come. But that’s not the only way Hubble observes Jupiter.
Hubble has been able to observe auroras on Jupiter in
ultraviolet wavelengths with its Space Telescope Imaging
Spectrograph. And Hubble has been able to observe the greater
Jovian system of Jupiter and its moons - it’s taken images like
this one of Callisto, Europa, and Io transiting across the
disk of Jupiter; Hubble has observed Ganymede’s auroras move
in a way that suggests the moon has an underground saltwater
ocean; and Hubble has seen evidence of water vapor plumes
erupting from the surface of Europa. NASA uses Hubble
observations of Jupiter to help guide its robotic planetary
explorers - the global maps of Jupiter from the OPAL program
provide context for the Juno spacecraft’s up-close
observations, and Hubble’s evidence of water vapor plumes
on Europa provides targets for the upcoming Europa Clipper
mission. So while you're looking at Jupiter in your own night
sky, take a minute to celebrate the robots and spacecraft, like
the Hubble Space Telescope, that are ever expanding what we know
about our solar system.
www.nasa.gov/hubble @NASAHubble