Pluto: A Complex and Changing World : Big Pictures and a real article

http://news.discovery.com/space/pluto-high-resolution-hubble.html

Our solar system has glamorous planets: ringed Saturn, multicolored Jupiter,
and ruddy red Mars. But arguably one of the most popular worlds for the public
is the tiny and distant Pluto.

And, it has much more of a kinship with the other major planets than you might
imagine as revealed today in high resolution pictures from NASA's Hubble Space
Telescope.

Since its discovery in 1930, Pluto has been a speck of light in the lenses of
the largest ground-based telescopes. From Earth, the disk of Pluto is ten times
smaller than the typical resolution limit of a ground-based telescope. In other
words, apart from that speck of light, no features on the dwarf planet's
surface can be seen.

But using the power of Hubble, Marc Buie of the Southwest Research Institute in
Boulder Colorado has persevered to assemble the most detailed view of Pluto ever.

Completing an intensive four years of image processing on 20 computers, Buie
used Hubble images to assemble a photomap of the planet in unprecedented
detail, a task as challenging as trying to see the markings on a soccer ball 40
miles away.

The new map is so good that astronomers have even been able to detect changes
on the dwarf planet's surface by comparing Hubble images taken in 1994 with the
newer images taken in 2002-2003.

Hubble's view isn't sharp enough to see impact craters that presumably pockmark
Pluto's surface. But the space telescope reveals a complex-looking and
variegated world with white, dark-orange and charcoal-black terrain. The
mottled appearance, in terms of resolution, is comparable to our naked-eye view
of the full moon. We see splotches of light and darker material on the moon,
but no craters (except for the young impact features Copernicus and Tycho).

Pluto's coloring is believed to be a result of ultraviolet radiation from the
distant Sun breaking up methane that is present on Pluto's surface, leaving
behind a dark molasses-colored carbon-rich residue. This material, called
"Tholin" (Greek for "mud"), is found on other icy minor bodies but not Earth.

Astronomers were very surprise to seen that Pluto's brightness has changed over
a few years. The northern pole is brighter and the southern hemisphere darker
and redder. Summer is approaching Pluto's north pole and this may cause surface
ices to melt and refreeze in the colder shadowed southern pole of the planet.

Only two other solar system bodies go through a comparable range of visible
surface changes based on the melting or sublimation of ices: Earth and Mars.

The Hubble pictures underscore that Pluto is not simply a ball of ice and rock
but a dynamic world that undergoes dramatic changes. These are driven by
seasonal changes that are as much propelled by the planet's 248-year elliptical
orbit as its axial tilt, unlike Earth where the tilt alone drives seasons.

You would think that each season is 62 years long, except that Pluto is in a
very elliptical orbit. When it is closest to the sun it is moving fastest along
its orbit. Therefore, spring transitions to summer quickly in the northern
hemisphere.

The Hubble images are invaluable to planning the details of the NASA New
Horizons mission to flyby Pluto in 2015. New Horizons will pass by Pluto so
quickly that only one hemisphere will be photographed in the highest possible
detail. The target hemisphere, identified in the Hubble map, has a mysterious
bright spot that is unusually rich in carbon monoxide frost. Adjoining it is a
coal-black region.

"What makes you think the bright spot is interesting," quipped one NASA
scientist, "maybe the black region is more interesting."

Hubble's map is the best view of Pluto we'll have until the New Horizons probe
is six months from close encounter.

On Fri, 05 Feb 2010 00:03:43 -0800, Thad Floryan
wrote:

http://news.discovery.com/space/pluto-high-resolution-hubble.html

Our solar system has glamorous planets: ringed Saturn, multicolored Jupiter,
and ruddy red Mars. But arguably one of the most popular worlds for the public
is the tiny and distant Pluto.

snip

Which all goes to show that Pluto promises to be a very interesting
place. As far as I'm concerned, the IAU's distinction of "planet" and
"dwarf planet" is a distinction without a difference.

On Feb 5, 12:03*am, Thad Floryan wrote:
http://news.discovery.com/space/pluto-high-resolution-hubble.html

Our solar system has glamorous planets: ringed Saturn, multicolored Jupiter,
and ruddy red Mars. But arguably one of the most popular worlds for the public
is the tiny and distant Pluto.

And, it has much more of a kinship with the other major planets than you might
imagine as revealed today in high resolution pictures from NASA's Hubble Space
Telescope.

Since its discovery in 1930, Pluto has been a speck of light in the lenses of
the largest ground-based telescopes. From Earth, the disk of Pluto is ten times
smaller than the typical resolution limit of a ground-based telescope. In other
words, apart from that speck of light, no features on the dwarf planet's
surface can be seen.

But using the power of Hubble, Marc Buie of the Southwest Research Institute in
Boulder Colorado has persevered to assemble the most detailed view of Pluto ever.

Completing an intensive four years of image processing on 20 computers, Buie
used Hubble images to assemble a photomap of the planet in unprecedented
detail, a task as challenging as trying to see the markings on a soccer ball 40
miles away.

The new map is so good that astronomers have even been able to detect changes
on the dwarf planet's surface by comparing Hubble images taken in 1994 with the
newer images taken in 2002-2003.

Hubble's view isn't sharp enough to see impact craters that presumably pockmark
Pluto's surface. But the space telescope reveals a complex-looking and
variegated world with white, dark-orange and charcoal-black terrain. The
mottled appearance, in terms of resolution, is comparable to our naked-eye view
of the full moon. We see splotches of light and darker material on the moon,
but no craters (except for the young impact features Copernicus and Tycho).

Pluto's coloring is believed to be a result of ultraviolet radiation from the
distant Sun breaking up methane that is present on Pluto's surface, leaving
behind a dark molasses-colored carbon-rich residue. This material, called
"Tholin" (Greek for "mud"), is found on other icy minor bodies but not Earth.

Astronomers were very surprise to seen that Pluto's brightness has changed over
a few years. The northern pole is brighter and the southern hemisphere darker
and redder. Summer is approaching Pluto's north pole and this may cause surface
ices to melt and refreeze in the colder shadowed southern pole of the planet.

Only two other solar system bodies go through a comparable range of visible
surface changes based on the melting or sublimation of ices: Earth and Mars.

The Hubble pictures underscore that Pluto is not simply a ball of ice and rock
but a dynamic world that undergoes dramatic changes. These are driven by
seasonal changes that are as much propelled by the planet's 248-year elliptical
orbit as its axial tilt, unlike Earth where the tilt alone drives seasons..

You would think that each season is 62 years long, except that Pluto is in a
very elliptical orbit. When it is closest to the sun it is moving fastest along
its orbit. Therefore, spring transitions to summer quickly in the northern
hemisphere.

The Hubble images are invaluable to planning the details of the NASA New
Horizons mission to flyby Pluto in 2015. New Horizons will pass by Pluto so
quickly that only one hemisphere will be photographed in the highest possible
detail. The target hemisphere, identified in the Hubble map, has a mysterious
bright spot that is unusually rich in carbon monoxide frost. Adjoining it is a
coal-black region.

"What makes you think the bright spot is interesting," quipped one NASA
scientist, "maybe the black region is more interesting."

Hubble's map is the best view of Pluto we'll have until the New Horizons probe
is six months from close encounter.

Final composite image resolution ? 24 km ?

~ BG