This
story was updated at 2:37 p.m. EST.
Visions of
a volcanic plume spewing out of Jupiter’s
moon Io
and a swirling storm are among the first images returned by a NASA probe as it
approached an early-Wednesday swing
past the gas giant.
NASA’s
New
Horizons spacecraft sent home the new look at Jupiter’s “Little
Red Spot” [image]
and the planet’s volcanic moon Io [image]
as it closed in on the gas giant during a planetary flyby that reached
its closest approach at about 12:43 a.m. EST (0543 GMT).
"This
is the best image of a large volcanic plume on Io since the Voyager flybys in
1979," John Spencer, deputy leader of the New Horizons Jupiter Encounter
Science Team at Colorado’s Southwest Research Institute (SwRI), said in a
written statement.
The flyby [image]
is a major milestone for New Horizons’ flight and allows mission
scientists to collect new Jupiter observations in a dress rehearsal for the
probe’s planned Pluto encounter
in 2015 [VIDEO:
Follow the Jupiter flyby].
Alan
Stern, the mission’s principal investigator at SwRI, said New
Horizons was aiming for a 500-mile (804-kilometer) corridor around Jupiter as
it flew along its path some 500 million miles (804 million kilometers) from
Earth. The spacecraft is now hurtling away from the Sun at 52,000 miles per
hour (83,600 kph).
“We
hit that aim point,” Alice Bowman, New Horizons mission operations
manager, told SPACE.com after the successful flyby. “It means we
are on our way to Pluto.”
At its
closest pass, New Horizons swung within 1.4 million miles (2.3 million
kilometers) of Jupiter before shooting onward on a course through the gas
giant’s long magnetotail [image]
-- the non-Sunward side of the Jovian magnetic field. It is during that time
that astronomers hope to uncover new secrets of the interactions between Jupiter’s
magnetosphere, the Sun’s
solar wind and the gas
giant’s aurora displays [VIDEO:
Passport to Pluto].
“This
is really the payback time,” SwRI’s David McComas, principal
investigator for New Horizon’s Solar Wind Around at Pluto (SWAP)
instrument, told SPACE.com before today’s planned flyby.
“The big show, it probably isn’t just one day or
two…we’ll be inside the magnetosphere of Jupiter for many
weeks.”
Launched
in January 2006, New Horizons grabbed a 9,000-mile per hour
(14,484 kph) speed
boost from its pass through Jupiter’s strong gravity field. The extra
speed, mission managers have said, will cut three years on New Horizon’s
long trek for its flyby of Pluto
and its three
moons Charon,
Nix and
Hydra [image].
The Applied
Physics Laboratory at Johns Hopkins University in Maryland is overseeing the
mission for NASA and reported Wednesday that the spacecraft is in good health
after its closest Jupiter approach.
A clutch
of Jovian moons
As a sort
of flyby appetizer, the fresh look at Io by New Horizons has provided the
clearest view to date of the Jovian moon’s Tvashtar volcano, mission
managers said in a written statement.
The probe
used its Long Range Reconnaissance Imager (LORRI) to photograph Io from a range
of about 2.5 million miles (four million kilometers) on Feb. 26, 2007 as it
neared Jupiter. Other images from the camera in the last two days include a new
portrait of Jupiter’s moons Ganymede [image]
and Europa [image],
and the immense “Little
Red Spot,” a swirling storm about half the size to the planet’s
“Great
Red Spot” [image].
“People
were over there in the science area and those guys were just grinning
ear-to-ear looking at the stuff that’s coming down,” Bowman said,
adding New Horizons’ new Little Red Spot and Tvashtar volcano portraits
are her current flyby favorites. “It feels good.”
First
discovered in 1999 in ground observations and by the Galileo
probe, the Tvashtar volcano is one of Io’s most active features and
can be seen spouting a dust plume more than 150 miles (241 kilometers) high to
form an umbrella-like shape [image]
in the New Horizons view.
Io’s
Tvashtar volcano can be seen in another New Horizons image, a three-millisecond
exposure aimed at resolving surface features, where it appears to be a dark
spot in the 11 o’clock position surrounded by a dark ring [image].
The eruption’s volcanic fallout covers a region the size of Texas,
New Horizons officials said.
The new Io
images of the plume resolve features as small as 12 miles (20 kilometers) in
size, which is about 12 times sharper than those taken by the Hubble Space Telescope and
three times sharper than views snapped by the Cassini spacecraft, which flew
past Jupiter in late 2000 on its way to its current orbit around Saturn, New Horizons officials said.
"If
the Tvashtar plume remains active, the images we take later in the encounter
should be even better," Spencer said.
New
Horizons fresh Jovian system images are just some of the more than 700
science observations planned during the probe’s Jupiter flyby. The
bulk of those images, however, will remain locked inside the spacecraft’s
computer for later downlink to Earth
in March and April, mission managers have said.
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