Less than a year from now, NASA's New Horizons spacecraft will make the
first-ever visit to Pluto, potentially revolutionizing scientists'
understanding of the dwarf planet.
Because Pluto is so far away —
it orbits the sun at an average distance of 3.65 billion miles (5.87
billion kilometers) — many questions about the dwarf planet's
composition and activity remain unanswered. Researchers hope New
Horizons will lay some of those questions to rest when it flies by Pluto
on July 15, 2015.
Many predictions have been made by the science community, including
possible rings, geyser eruptions, and even lakes," Adriana Ocampo,
program executive for NASA's New Frontiers program, said in a statement.
"Whatever we find, I believe Pluto and its satellites will surpass all
our expectations and surprise us beyond our imagination.
Orbiting the sun once every 248 years, Pluto lies
outside the reach of most visible instruments. The best images from
NASA's famous Hubble Space Telescope simply show Pluto's spherical shape
and reddish color. Changes in the dwarf planet's color patterns over
the years hint that something is happening there, but no one knows
exactly what.
By late April 2015, New Horizons
will be close enough to Pluto and its moons to capture pictures
rivaling those of Hubble. On July 14, 2015, the craft will make a close
flyby of the icy world, ultimately zooming within about 6,200 miles
(10,000 kilometers) of its surface. If it cruised past Earth at that
range, New Horizons would be able to recognize individual buildings and
their shapes.
Because Pluto has never been visited up-close by a spacecraft from
Earth, everything we see will be a first," Ocampo said. "I know this
will be an astonishing experience full of history-making moments."
New Horizons principal investigator Alan Stern, of the Southwest
Research Institute in Colorado, likened the upcoming visit to the way
Mariner 4revolutionized understanding of Marsin July 1965. At the time,
many people thought the Red Planet was a life-friendly world possibly
harboring liquid water and even plants. The New Horizons flyby could
change perceptions of Pluto just as dramatically, Stern said
The flight in won't be without its challenges. Since New Horizons
launched in 2006, two new moons have been discovered orbiting Pluto,
upping the total known satellite countto five: Charon, Nix, Kerberos,
Styxand Hydra. As many as 10 other moonscould still await detection in
the system, one study suggested.
According to simulations, meteorites striking Pluto's moons could send
tiny rocks flying into space, where many of them would enter orbit
around the dwarf planet. The debris field likely changes with time as it
orbits, growing larger as new material is added. As the New Horizons
probe gets closer and closer to Pluto, the mission team will need to
keep watch on the system in case evasive maneuvers are required.
"The New Horizons team continues to do a magnificent job in keeping the
spacecraft healthy and ready for this incredible rendezvous," said
Ocampo. "The spacecraft is in good hands."
No comments:
Post a Comment