surrounded by subsidence. They also show
a very turbulent region to the northwest
of the Great Red Spot. The Subaru image is
available here.
The NASA Juno spacecraft was launched in
August 2011 and began orbiting Jupiter in
early July 2016. A primary goal of the mis-
sion is to improve our understanding of Ju-
piter — from its atmospheric properties, to
our understanding of how Jupiter and other
planets in the outer Solar System formed.
Juno’s payload of nine instruments can
probe Jupiter’s atmospheric composition,
temperature, and cloud dynamics, as well as
the properties of the planet’s intense mag-
netic field and aurora.
Gemini’s near-infrared images are particu-
larly helpful to Juno’s Jupiter Infrared Au-
roral Mapper (JIRAM). JIRAM takes images
at 3.5 and 4.8 microns and moderate-reso-
lution spectra at 2 - 5 microns. The Gemini
images provide a high-resolution spatial
context for JIRAM’s spectroscopic observa-
tions and cover wavelengths and regions of
the planet not observed by JIRAM. They also
place an upper-atmospheric constraint on
Jupiter’s circulation in the deep atmosphere
determined by Juno’s Microwave Radiom-
eter (MWR) experiment.
Orton leads the observing team for the
adaptive-optics imaging and Wong heads
the observing team for the thermal im-
aging. Additional team members include
Andrew Stephens (Gemini Observatory);
Thomas Momary, James Sinclair (JPL); Kevin
Baines (JPL, University of Wisconsin); Mi-
chael Wong, Imke de Pater (University of
California, Berkeley); Patrick Irwin (Univer-
sity of Oxford); Leigh Fletcher (University of
Leicester); Gordon Bjoraker (NASA Goddard
Space Flight Center); and John Rogers (Brit-
ish Astronomical Association).
In the full campaign of Earth-based support,
the Gemini observations provide a key ele-
July 2017
ment that extends the spectral coverage of
other facilities, as well as providing a stra-
tegic sampling to compare with the lower-
resolution but more frequent imaging by
NASA’s Infrared Telescope Facility (IRTF) that
tracks the evolution of atmospheric features.
These Gemini data are also a useful measure
of cloud properties to compare with mid-in-
frared thermal imaging and spectroscopy of
Jupiter’s atmosphere, such as that provided
by Subaru’s COMICS experiment. The space
platforms involved in the Juno-support
campaign include the XMM, Chandra and
NuSTAR X-ray observatories, and the Hisaki
ultraviolet observatory, together with the
Hubble Space Telescope. The many ground-
based observatories include the Very Large
Telescope (VLT), the Atacama Large Millime-
ter Array (ALMA), Calar Alto Observatory, and
a suite of visible and radio observatories. Full
details of the campaign can be found here.
Figure 3.
At longer infrared
wavelengths, Jupiter
glows with thermal
(heat) emission. In dark
areas of this 4.8-micron
image, thick clouds block
the emission from the
deeper atmosphere. The
Great Red Spot is visible
just below center. This
image, obtained with the
Gemini North telescope’s
Near-InfraRed Imager
(NIRI), was obtained on
January 11, 2017, so
the relative positions of
discrete features have
changed with respect to
the near-infrared image
in Figure 1.
Image credit: Gemini
Observatory/AURA/NSF/
UC Berkeley
Peter Michaud is the Public Information Out-
reach Manager of Gemini Observatory. He can
be reached at: [email protected]
GeminiFocus
11