Online ballot casting allowing the public to vote for the name of two recently discovered moons of the dwarf planet -- for now known as just P4 and P5 -- ended Friday, with Vulcan in first place followed by Cerberus.

Although a late addition to the candidate names the public could vote on, Vulcan piled up a big lead after Shatner, who played Capt. James T. Kirk in the popular television series and movies, campaigned for the name on Twitter.

Vulcan was the home planet of Kirk's first officer, Spock, played by Leonard Nimoy.

Officials at SETI, which conducted the public poll, said they considered it an appropriate candidate since Vulcan is also the name of the god of fire in Roman mythology.

"Vulcan is the Roman god of lava and smoke, and the nephew of Pluto. (Any connection to the 'Star Trek' TV series is purely coincidental, although we can be sure that ['Star Trek' creator] Gene Roddenberry read the classics,)" SETI scientist Mark Showalter wrote in a blog when the name was added to the list on Feb. 12. "Thanks to William Shatner for the suggestion!"

Although Vulcan and Cerberus won the name poll, the final decision on names for the moons will rest with the International Astronomical Union.

Astronomers have found five moons around Pluto so far, with three of them named: Charon, Nix and Hydra.

P4 was discovered in 2011, and P5 in 2012; both are only about 20 miles in diameter.

]]> Mon, 20 MAY 2013 12:29:51 AEST Mountain View, Calif. (UPI) Feb 11, 2013 - The U.S.-led team that discovered two new moons of the dwarf planet Pluto says they're asking the public to vote on potential names for the distant worlds.

The fourth and fifth moons of Pluto, named for the Greek god of the underworld, are currently known simply as P4 and P5.

Tradition hold the names of Pluto's moons are taken from Greek and Roman mythology and relate to Hades and the underworld; the first three of Pluto's moons discovered are named Charon, discovered in 1978, and Nix and Hydra, both discovered in 2005.

Among the potential names for P4 and P5 are Cerburus, Hercules and Orpheus, NewScientist.com reported Monday.

Mark Showalter of the SETI Institute in Mountain View, Calif., head of the team that discovered the new moon, said write-in votes also would be considered, as long as they follow the naming tradition.

Astronomer Clyde Tombaugh, who first spotted Pluto in 1930, chose the name following the suggestion of an 11-year-old girl named Venetia Burney.

"I like to think that we are doing honor to Tombaugh's legacy by now opening up the naming of Pluto's two tiniest known moons to everyone," Showalter said.

People can vote by visiting http://plutorocks.seti.org.

The final decision on the moons' names will be up to the International Astronomical Union.

]]> Mon, 20 MAY 2013 12:29:51 AEST Boulder CO (SPX) Jan 21, 2013 - It's been seven years since New Horizons' launch on Jan. 19, 2006, and our spacecraft remains healthy and on course. We're more than halfway between the orbits of Uranus and Neptune. In fact, we're so far along the journey that we'll cross the orbit of Neptune and enter "Pluto space" in August of next year!

After seven years in flight - longer than many science missions operate - it's fair to say the project team can feel that the Pluto encounter is almost around the corner. After all, 2015 is just the year after next! There's an increased pace of activity, a sense of anticipation, and a palpable thirst for the images and other data we'll soon have as our reward for hard work on a project with roots going back to 1989. I call this new phenomenon our "seven-year itch." And it's a good itch!

Anniversaries and anticipations aside, let me turn to project news.

This month's spacecraft wakeup - we were in hibernation from July 6, 2012, until Jan. 6 - is proceeding, with various maintenance and checkout activities, spacecraft tracking work, and a new software load (to squash a pesky bug) all going well. We'll keep the spacecraft active until Jan. 30, then we'll put her back into hibernation until May 21, when we wake up for a very busy summer of checkouts and encounter rehearsal activities.

Also this summer, the New Horizons project will be hosting a major conference for the planetary science community. At this conference, which will be held in late July near our mission control center at the Johns Hopkins Applied Physics Laboratory in Maryland, planetary scientists from around the world will gather to review everything we know about the Pluto system.

They'll plan ground-based and space-based Pluto system observations to take place in concert with the New Horizons encounter, make scientific predictions about what we will learn from New Horizons, and learn about the spacecraft and payload's capabilities so they can prepare - as we are - to analyze data from the long flyby.

In July 2014, a similar meeting will be held for the public and educators. That meeting will be broadly webcast, so that thousands or tens of thousands or even more interested people can follow and learn.

Before I close this brief update, I do want to answer a question I get a lot: After all this work, why isn't New Horizons going into orbit around Pluto?

The reason is actually pretty simple: getting into orbit isn't practical because of our speed. Remember, New Horizons was the fastest spacecraft ever launched. Even after climbing uphill against the Sun's gravity for nine years, when we reach Pluto we'll still be going 30,000-plus miles per hour - very roughly twice the speed of a space shuttle or satellite in Earth orbit.

To enter orbit around Pluto we'd need to bleed almost all of that speed off with rockets. And that would require very large rocket engines and a lot of fuel, given our fast trajectory.

The only alternative would have been a slower, longer flight - many decades long - that would have meant a slower arrival, but that wasn't in the cards either politically or budgetary - not to mention from a standpoint of all of our lifetimes! So, long story short, we can't get into orbit, and could not find a practical way to design such a mission that could actually be sold to NASA and Congress when we proposed it.

It's also fair to point out that a flyby has other advantages beyond being a quick mission - taking only 9 0.5 years to cross more than 3 billion miles. The flyby allows us to go on and explore farther into the frontier of the Kuiper Belt, and we like that!

I'll close with that thought. I plan to provide another update as we near summer's intensive mission operations. Thanks again for following our journey across the deep ocean of space, to a new planet and a truly new frontier.

Until I write again, I hope you'll keep on exploring - just as we do!

]]> Mon, 20 MAY 2013 12:29:51 AEST Laurel MD (SPX) Jan 15, 2013 - Like many of us, New Horizons is starting the new year with a workout regimen. After six months of cruising quietly through the outer solar system, NASA's Pluto-bound spacecraft came out of hibernation last weekend for three weeks of activity that include system checks, a new flight software upload and science data downloads.

The mission operations team at the Johns Hopkins University Applied Physics Laboratory (APL) in Maryland "woke" New Horizons from electronic slumber on Jan. 6.

First tasks included evaluating real-time spacecraft data (which indicated New Horizons was in good health), sending operating commands to the spacecraft's main computer, and gathering tracking data that will help the navigation team keep New Horizons on course toward the Pluto system.

Operators are communicating with New Horizons through NASA's largest Deep Space Network antennas in Spain, Australia and the U.S. (California).

If you can't wait mere minutes to download a new app, this will make you cringe: With radio signals needing nearly 3 hours and 40 minutes to reach the spacecraft - which is about 2.4 billion miles (3.9 billion kilometers) from Earth, between the orbits of Uranus and Neptune - the full software upload will take about 44 continuous hours, says New Horizons Mission Operations Manager Alice Bowman, of APL.

"The Mission Operations Center must remain in constant contact with New Horizons in case the unexpected happens, despite the numerous preparations and precautions the team has taken," Bowman says.

"I think of the C and DH system software update as a 'tune-up' at the 2.4 billion-mile marker," says APL's Glen Fountain, New Horizons project manager.

Other activities planned over the next 20 days include radio frequency system and Radio Science Experiment checkouts, and a download of cruise science data from New Horizons' space plasma instruments - SWAP and PEPSSI - which have been studying the charged-particle populations of the outer solar system.

Additionally, New Horizons' solid-state digital recorders (filled with data from last summer's near-Pluto encounter rehearsal) will be erased in preparation for this summer's rehearsal of the nine days surrounding Pluto close approach. The spacecraft will be put back into hibernation on Jan 30.

C and DH: The Brains 'Inside' New Horizons
The command and data handling system - a radiation-hardened 12-megahertz Mongoose V processor guided by intricate flight software - is the spacecraft's "brain."

The processor distributes operating commands to each subsystem, collects and processes instrument data, and sequences information sent back to Earth. It also runs the advanced "autonomy" algorithms that allow the spacecraft to check the status of each system and, if necessary, correct any problems, switch to backup systems or contact operators on Earth for help.

Hibernating Spacecraft:
New Horizons has spent about 80 percent of the past five years in hibernation, a low-power mode that reduces operation costs, frees up Deep Space Network tracking resources for other missions and lessens wear and tear on spacecraft electronics. During the past two years, this hibernation mode has been enhanced to enable New Horizons to collect plasma science data in interplanetary space.

The team wakes New Horizons two or three times a year to check systems and run tests, but after May 2014 the spacecraft will remain "on" without hibernating through the 2015 Pluto encounter.

]]> Mon, 20 MAY 2013 12:29:51 AEST Laurel MD (SPX) Nov 30, 2012 - Today the Pluto-bound New Horizons spacecraft passed the halfway point between the orbits of Uranus and Neptune, zooming past another milepost on its historic trek to the planetary frontier. New Horizons, launched in January 2006 and set to visit the Pluto system in July 2015, is the first spacecraft to cross this distant region since NASA's Voyager probes in the late 1980s.

New Horizons is now more than 25 astronomical units from Earth - one AU being the distance between the Earth and sun, 93 million miles or 150 million kilometers. New Horizons crossed the orbit of Uranus on March 18, 2011.

It'll pass the orbit of Neptune on Aug. 25, 2014 - exactly 25 years after Voyager 2 made its historic exploration of that planet. The distance between the orbits of the two gas giants is about a billion miles.

So far, New Horizons has traveled more than 2.3 billion miles since launch. Pluto itself is a "mere" 711 million miles (1.14 billion kilometers) away from the spacecraft - nearly eight times the distance between Earth and the sun - and currently closer to New Horizons than any other planet.

New Horizons remains healthy and on course toward Pluto and Kuiper Belt beyond. Mission operators at the Johns Hopkins University Applied Physics Laboratory in Maryland received a "green" beacon transmission from the craft on Nov. 26, indicating all systems were normal.

The Solar Wind Around Pluto (SWAP), Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) and Student Dust Counter (SDC) instruments are currently collecting data while most of New Horizons cruises in electronic hibernation.

"This continues to be an essentially textbook cruise to the very frontier of our solar system," says New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute in Boulder, Colo.

The New Horizons mission operations team will wake the craft in early January for a quick systems checkout, which also includes uploading a software update into New Horizons' main computer and downloading science data from SWAP, PEPSSI and SDC.

]]> Mon, 20 MAY 2013 12:29:51 AEST Munich, Germany (SPX) Nov 22, 2012 - Dwarf planet Makemake [1] is about two thirds of the size of Pluto, and travels around the Sun in a distant path that lies beyond that of Pluto but closer to the Sun than Eris, the most massive known dwarf planet in the Solar System.

Previous observations of chilly Makemake have shown it to be similar to its fellow dwarf planets, leading some astronomers to expect its atmosphere, if present, to be similar to that of Pluto. However, the new study now shows that, like Eris, Makemake is not surrounded by a significant atmosphere.

The team, led by Jose Luis Ortiz (Instituto de Astrofisica de Andalucia, CSIC, Spain), combined multiple observations using three telescopes at ESO's La Silla and Paranal observing sites in Chile - the Very Large Telescope (VLT), New Technology Telescope (NTT), and TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) - with data from other small telescopes in South America [2], to look at Makemake as it passed in front of a distant star [3].

"As Makemake passed in front of the star and blocked it out, the star disappeared and reappeared very abruptly, rather than fading and brightening gradually. This means that the little dwarf planet has no significant atmosphere," says Jose Luis Ortiz.

"It was thought that Makemake had a good chance of having developed an atmosphere - that it has no sign of one at all shows just how much we have yet to learn about these mysterious bodies. Finding out about Makemake's properties for the first time is a big step forward in our study of the select club of icy dwarf planets."

Makemake's lack of moons and its great distance from us make it difficult to study [4], and what little we do know about the body is only approximate.

The team's new observations add much more detail to our view of Makemake - determining its size more accurately, putting constraints on a possible atmosphere and estimating the dwarf planet's density for the first time.

They have also allowed the astronomers to measure how much of the Sun's light Makemake's surface reflects - its albedo [5]. Makemake's albedo, at about 0.77, is comparable to that of dirty snow, higher than that of Pluto, but lower than that of Eris.

It was only possible to observe Makemake in such detail because it passed in front of a star - an event known as a stellar occultation. These rare opportunities are allowing astronomers for the first time to find out a great deal about the sometimes tenuous and delicate atmospheres around these distant, but important, members of the Solar System, and providing very accurate information about their other properties.

Occultations are particularly uncommon in the case of Makemake, because it moves in an area of the sky with relatively few stars. Accurately predicting and detecting these rare events is extremely difficult and the successful observation by a coordinated observing team, scattered at many sites across South America, ranks as a major achievement.

"Pluto, Eris and Makemake are among the larger examples of the numerous icy bodies orbiting far away from our Sun," says Jose Luis Ortiz. "Our new observations have greatly improved our knowledge of one of the biggest, Makemake - we will be able to use this information as we explore the intriguing objects in this region of space further."

Notes
[1] Makemake was initially known as 2005 FY9. It was discovered a few days after Easter in March 2005, earning it the informal nickname of Easterbunny. In July 2008 it was given the official name of Makemake. Makemake is the creator of humanity and god of fertility in the myths of the native people of Easter Island.

Makemake is one of five dwarf planets so far recognised by the International Astronomical Union. The others are Ceres, Pluto, Haumea and Eris. Further information about dwarf planets and planets is available from the International Astronomical Union.

[2] Another of the telescopes used in this observing campaign was an 0.84-metre telescope installed by the Catolica del Norte University of Chile. This telescope is sited on Cerro Armazones, the future site of the European Extremely Large Telescope (E-ELT).

[3] Makemake passed in front of faint star NOMAD 1181-0235723 (where NOMAD refers to the Naval Observatory Merged Astrometric Dataset) on 23 April 2011. The team observed this event using seven different telescopes across Brazil and Chile. The event only lasted about one minute, so the astronomers took advantage of a specialised high-speed camera known as ULTRACAM (eso0520) and a high-speed infrared imager named ISAAC to capture the event.

[4] In the case of objects that are orbited by one or more moons the motions of the moons can be used to deduce the mass of the object. This was not possible in the case of Makemake.

[5] The dwarf planet was calculated to have a geometrical albedo of 0.77 +/- 0.03, greater than Pluto's, but smaller than that of Eris. An albedo of 1 represents a perfectly reflecting body, and 0 a black surface that does not reflect at all. The observations, together with previous results, indicate that Makemake has a density of 1.7 +/- 0.3 grams per cubic centimetre, which in turn allowed the team to infer the shape and appearance of an oblate spheroid - a sphere flattened slightly at both poles - with axes of 1430 +/- 9 kilometres and 1502 +/- 45 kilometres. Makemake shows no global Pluto-like atmosphere at a level of one thousandth of that of Pluto's atmosphere. However, it may have an atmosphere that only covers part of the surface. Such a local atmosphere, which is possible in theory, is not excluded by the observations.

This research was presented in a paper "Albedo and atmospheric constraints of dwarf planet Makemake from a stellar occultation" to appear in the 22 November 2012 issue of the journal Nature. The team is composed of J. L. Ortiz (Instituto de Astrofisica de Andalucia, CSIC, Spain), B. Sicardy (Observatoire de Paris; CNRS; Universite Pierre et Marie Curie; Universite Paris Diderot; Institut Universitaire de France), F. Braga-Ribas (Observatoire de Paris, CNRS, France; Observatorio Nacional/MCTI, Brazil), A. Alvarez-Candal (European Southern Observatory, Chile; Instituto de Astrofisica de Andalucia, CSIC, Spain), E. Lellouch (Observatoire de Paris, CNRS, France), et al.

]]> Mon, 20 MAY 2013 12:29:51 AEST Laurel, MD (SPX) Oct 17, 2012 - NASA's New Horizons spacecraft is now almost seven years into its 9.5-year journey across the solar system to explore Pluto and its system of moons. Just over two years from now, in January 2015, New Horizons will begin encounter operations, which will culminate in a close approach to Pluto on July 14, 2015, and the first-ever exploration of a planet in the Kuiper Belt.

As New Horizons has traveled through space, its science team has become increasingly aware of the possibility that dangerous debris may be orbiting in the Pluto system, putting the spacecraft and its exploration objectives into harm's way.

"We've found more and more moons orbiting near Pluto - the count is now up to five," says Alan Stern, principal investigator of the New Horizons mission and an associate vice president of the Space Science and Engineering Division at Southwest Research Institute (SwRI). "And we've come to appreciate that those moons, as well as those not yet discovered, act as debris generators, populating the Pluto system with shards from collisions between those moons and small Kuiper Belt objects."

"Because our spacecraft is traveling so fast - more than 30,000 miles per hour - a collision with a single pebble, or even a millimeter-sized grain, could cripple or destroy New Horizons," adds New Horizons Project Scientist Hal Weaver, of the Johns Hopkins University Applied Physics Laboratory (APL), "so we need to steer clear of any debris zones around Pluto."

The New Horizons team is already using every available tool - from sophisticated computer simulations of the stability of debris orbiting Pluto, to giant ground-based telescopes, to stellar occultation probes of the Pluto system, to the Hubble Space Telescope - to search for debris in orbit. At the same time, the team is plotting alternative, more distant courses through the Pluto system that would preserve most of the science mission but avert deadly collisions if the current flyby plan is found to be too hazardous.

"We're worried that Pluto and its system of moons, the object of our scientific affection, may actually be a bit of a black widow," says Stern, who discusses this aspect of the flyby Tuesday at the annual meeting of the American Astronomical Society's Division for Planetary Sciences in Reno, Nevada.

"We're making plans to stay beyond her lair if we have to," adds New Horizons Deputy Project Scientist Leslie Young, of Southwest Research Institute. "From what we have determined, we can still accomplish our main objectives if we have to fly a 'bail-out trajectory' to a safer distance from Pluto. Although we'd prefer to go closer, going farther from Pluto is certainly preferable to running through a dangerous gauntlet of debris (and possibly rings) that may orbit close to Pluto among its complex system of moons."

"We may not know whether to fire our engines on New Horizons and bail out to safer distances until just 10 days before reaching Pluto, so this may be a bit of a cliffhanger," Stern says. "Stay tuned."

]]> Mon, 20 MAY 2013 12:29:51 AEST Madison WI (SPX) Oct 18, 2012 - In 1986, when Voyager swept past Uranus, the probe's portraits of the planet were "notoriously bland," disappointing scientists, yielding few new details of the planet and its atmosphere, and giving it a reputation as a bore of the solar system. Now, however, thanks to a new technique applied at the Keck Observatory, Uranus is coming into sharp focus through high-resolution infrared images, revealing in incredible detail the bizarre weather of the seventh planet from the Sun.

The images were released in Reno, Nevada, at a meeting of the American Astronomical Society's Division for Planetary Sciences and provide the best look to date at Uranus' complex and enigmatic weather.

The planet's deep blue-green atmosphere is thick with hydrogen, helium and methane, Uranus' primary condensable gas. Winds blow mainly east to west at speeds up to 560 miles per hour, in spite of the small amounts of energy available to drive them. Uranus' atmosphere is almost equal to Neptune's as the coldest in our solar system with cloud-top temperatures in the minus-360-degree Fahrenheit range, cold enough to freeze methane.

Large weather systems, which are probably much less violent than the storms we know on Earth, behave in bizarre ways on Uranus, explains Larry Sromovsky, a University of Wisconsin-Madison planetary scientist who led the new study using the Keck II telescope.

"Some of these weather systems," Sromovsky notes, "stay at fixed latitudes and undergo large variations in activity. Others are seen to drift toward the planet's equator while undergoing great changes in size and shape. Better measures of the wind fields that surround these massive weather systems are the key to unraveling their mysteries."

To get a better picture of atmospheric flow on Uranus, Sromovsky and colleagues Pat Fry, also of UW-Madison, Heidi Hammel of the Association of Universities for Research in Astronomy (AURA), and Imke de Pater of the University of California at Berkeley, used new infrared techniques to detect smaller, more widely distributed weather features whose movements can help scientists trace the planet's pattern of blustery winds.

"We're seeing some new things that before were buried in the noise," says Sromovsky, a senior staff scientist at UW-Madison's Space Science and Engineering Center.

"My first reaction to these images was 'wow' and then my second reaction was 'WOW,'" says AURA's Heidi Hammel, a co-investigator on the new observations and an expert on the atmospheres of the solar system's outer planets.

"These images reveal an astonishing amount of complexity in Uranus' atmosphere. We knew the planet was active, but until now much of the activity was masked by noise in our data."

The complexity of Uranus' weather is puzzling, Sromovsky explains. The primary driving mechanism must be solar energy because there is no detectable internal energy source. "But the Sun is 900 times weaker there than on Earth because it is 30 times further from the Sun, so you don't have the same intensity of solar energy driving the system," explains Sromovsky.

"Thus the atmosphere of Uranus must operate as a very efficient machine with very little dissipation. Yet the weather variations we see seem to defy that requirement."

The new Keck II pictures of the planet, according to Sromovsky, are the "most richly detailed views of Uranus yet obtained by any instrument on any observatory. No other telescope could come close to producing this result."

Sromovsky and his colleagues used Keck II, located on the summit of Hawaii's 14,000-foot extinct volcano Mauna Kea, to capture a series of images that, when combined, help increase the signal-to-noise ratio and thus tease out weather features that are otherwise obscured.

In two nights of observing under superb conditions, Sromovsky's group was able to obtain exposures of the planet that provide a clear view of the planet's cloudy features, including several new to science. The group used two different filters in an effort to characterize cloud features at different altitudes.

"The main objective was to find a larger number of cloud features by detecting those that were previously too subtle to be seen, so we could better define atmospheric motions,"

Sromovsky notes. New features found by the Wisconsin group include a scalloped band of clouds just south of Uranus' equator and a swarm of small convective features in the north polar regions of the planet, features that have never been seen in the southern polar regions.

"This is a very asymmetric situation," says the Wisconsin scientist. "There is certainly something different going on in those two polar regions."

One possible explanation, is that methane is pushed north by an atmospheric conveyor belt toward the pole where it wells up to form the convective features observed by Sromovsky's group.

"The 'popcorn' appearance of Uranus' pole reminds me very much of a Cassini image of Saturn," adds de Pater.

Saturn's south pole is characterized by a polar vortex or hurricane surrounded by numerous small cloud features indicative of strong convection, analogous to the heavily precipitating clouds encircling the eye of terrestrial hurricanes, she notes. Her group suggested a similar phenomenon would be present on Neptune, based upon Keck observations of that planet.

"Perhaps we will also see a vortex at Uranus' pole when it comes into view," she says.

The phenomena may be seasonal, Sromovsky notes, but the group has so far been unable to establish a clear seasonal trend in the winds of Uranus.

"Uranus is changing," he says. "We don't expect things at the north pole to stay the way they are now."

The scalloped band of clouds near the planet's equator may indicate atmospheric instability or wind shear: "This is new and we don't fully understand what it means. We haven't seen it anywhere else on Uranus."

Caption: The most detailed images of Uranus ever obtained from Earth. These two images of Uranus are composites of 117 images from 25 July 2012 (left) and 118 images from 26 July 2012 (right), all obtained with the near-infrared NIRC2 camera on the Keck II telescope. NIRC2 is coupled to Keck's adaptive optics system, which is used to remove much of the image blur caused by Earth's atmospheric turbulence. Two different near-infrared filters were used. The broad H filter centered near 1.6 microns samples both weak and strong absorptions by methane gas. The narrow Hcont filter is near the same wavelength, but samples only regions of weak methane absorption. Using these filters together, we can determine the altitudes of cloud features, since cloud altitude is correlated with the amount of absorption in the atmosphere above the cloud.

Most of the features in these images are quite subtle and require long exposures to be detectable above the background noise. But during long exposures, the features are smeared out by planetary rotation and zonal winds. To deal with that, we took many short exposure images and then removed the effects of rotation and winds before averaging.

Although noise is reduced through averaging, the subtlest features still can't be seen because of more intense large-scale variations (bright and dark latitude bands, for example). To remove those variations, we use a high-pass spatial filter: a smoothed version of each image is subtracted from the original, leaving only small-scale variations behind. The contrast of these features can then be increased to reveal the details that otherwise be buried either in large-scale variations or noise.

To produce the color image, the H images were assigned to blue and green colors and the Hcont images to red. In the final images, white features are high altitude optically-thick clouds (like Earth's cumulus clouds), and bright blue-green features are at high-altitude but optically thin (akin to cirrus clouds on Earth). Reddish tints indicate deeper cloud layers. Very few of the discrete features are deep. Most are probably between 1 bar and 2 bars, which is the typical cloud-top range for Uranus. The narrow bright blue arc on the left of each image is due to the main (Epsilon) ring of Uranus. The bright perimeter of the planet is an artifact of the high-pass filtering process, which enhances brightness changes over small distances; the sharpest variation is at the edge of the planet where there is a sudden transition from dark space to bright planet.

In each image, the north pole is at the right and slightly below center. The small "convective" spots appear mainly in a region from about 55 degrees N to the pole, and were not seen in the south polar region when it was imaged by Keck at similar wavelengths in 2003. They are highly reminiscent of features imaged on Saturn's pole by the Cassini spacecraft. The broad bright band just to the left of the disk center covers the latitude range from the equator to about 10 degrees N. Just south of the equator, and never before seen on Uranus, is a scalloped wave pattern, which is similar to instabilities that develop in regions of horizontal wind shear. Near the bottom of the left image is a small dark spot with bright companion clouds.

Credit: NASA/ESA/L. A. Sromovsky/P. M. Fry/H. B. Hammel/I. de Pater/K. A. Rages

]]> Mon, 20 MAY 2013 12:29:51 AEST Hilo, HI (SPX) Sep 27, 2012 - Despite being infamously demoted from its status as a major planet, Pluto (and its largest companion Charon) recently posed as a surrogate extrasolar planetary system to help astronomers produce exceptionally high-resolution images with the Gemini North 8-meter telescope.

Using a method called reconstructive speckle imaging, the researchers took the sharpest ground-based snapshots ever obtained of Pluto and Charon in visible light, which hint at the exoplanet verification power of a large state-of-the-art telescope when combined with speckle imaging techniques.

The data also verified and refined previous orbital characteristics for Pluto and Charon while revealing the pair's precise diameters.

"The Pluto-Charon result is of timely interest to those of us wanting to understand the orbital dynamics of this pair for the 2015 encounter by NASA's New Horizons spacecraft," said Steve Howell of the NASA Ames Research Center, who led the study. In addition, Howell notes that NASA's Kepler mission, which has already proven a powerful exoplanet discovery tool, will benefit greatly from this technique.

Kepler identifies planet candidates by repeatedly measuring the change in brightness of more than 150,000 stars to detect when a planet passes in front of, or affects the brightness of, its host star.

Speckle imaging with the Gemini telescope will provide Kepler's follow-up program with a doubling in its ability to resolve objects and validate Earth-like planets.

It also offers a 3- to 4-magnitude sensitivity increase for the sources observed by the team. That's about a 50-fold increase in sensitivity in the observations Howell and his team made at Gemini. "This is an enormous gain in the effort underway to confirm small Earth-size planets," Howell added.

To institute this effort Howell and his team - which included Elliott Horch (Southern Connecticut State University), Mark Everett (National Optical Astronomy Observatory), and David Ciardi (NASA Exoplanet Science Institute/Caltech) - temporarily installed a camera, called the Differential Speckle Survey Instrument (DSSI), among the suite of instruments mounted on the Gemini telescope.

"This was a fantastic opportunity to bring DSSI to Gemini North this past July," said Horch. "In just a little over half an hour of Pluto observations, collecting light with the large Gemini mirror, we obtained the best resolution ever with the DSSI instrument - it was stunning!"

The resolution obtained in the observations, about 20 milliarcseconds, easily corresponds to separating a pair of automobile headlights in Providence, Rhode Island, from San Francisco, California.

To achieve this level of definition, Gemini obtained a large number of very quick "snapshots" of Pluto and Charon. The researchers then reconstructed them into a single image after subtracting the blurring effects and ever-changing speckled artifacts caused by turbulence in the atmosphere and other optical aberrations.

With enough snapshots (each image was exposed for only 60 milliseconds or about 1/20 of a second) only the light from the actual objects remains constant, and the artifacts reveal their transient nature, eventually canceling each other out.

DSSI was built at SCSU between 2007-2008 as a part of a United States National Science Foundation Astronomical Instrumentation grant and mounted on the Gemini North telescope for a limited observing run. The instrument is likely to return to Gemini North for observations in mid-2013 for general user programs from across the international Gemini partnership. Any such arrangement will be announced along with the call for proposals for Semester 13B, in February 2013.

This work was funded in part by the National Science Foundation and NASA's Kepler discovery mission and will be published in the journal Publications of the Astronomical Society of the Pacific in October 2012.

]]> Mon, 20 MAY 2013 12:29:51 AEST Boulder CO (SPX) Aug 29, 2012 - New Horizons remains healthy and on course, now more than 24 times as far from the Sun as the Earth is. This summer's spacecraft and payload checkout went extremely well, as did both major flight-software updates we loaded aboard New Horizons. And, the spacecraft's rehearsal of the closest-approach day of the Pluto encounter went just about perfectly.

After finishing all of this at the beginning of July, we put New Horizons back into hibernation, and we've been cruising that way for almost eight weeks. As those who follow New Horizons on Twitter (@NewHorizons2015) know, every Monday New Horizons checks in with a beacon that tells us if all is well, or not. And almost every week we've been able to report a "green beacon Monday" to our 22,000-plus Twitter followers, indicating the spacecraft is in good health.

New Horizons will cruise quietly in hibernation until Jan. 6, 2013, when we wake it up for a month of complex activities, including some advance work on next summer's checkout, and the third of the four major software upgrades needed before next summer's on-spacecraft rehearsal of the nine days surrounding Pluto closest approach.

Since activity on New Horizons is pretty quiet right now, I'll take this opportunity to mention that planetary science is celebrating the 20th anniversary of the discovery of the Kuiper Belt. That came in 1992, when the first Kuiper Belt Object (KBO) was discovered.

Actually, of course, the first object in the Kuiper Belt was discovered in 1930 - Pluto itself; and the second such object, Pluto's giant moon Charon, was discovered in 1978. The Kuiper Belt was first postulated - most famously by Gerard Kuiper - by planetary scientists back in the 1930s, '40s and '50s. But it took until 1992 for technology to mature sufficiently enough to find another object (outside the Pluto system) orbiting the Sun beyond Neptune.

Since 1992, more than 1,000 KBOs have been discovered. But only a tiny fraction of the sky has been surveyed for KBOs. It is estimated that more than 100,000 KBOs exist with diameters of 100 kilometers or larger, along with billions of smaller objects down to the size of cometary nuclei, just a kilometer or two across. (By comparison, Pluto is huge - its diameter is almost 2,400 kilometers, making a drive around its equator as far as from Manhattan to Moscow!)

Most of the known KBOs are just 100 to 300 kilometers across, about one-tenth of Pluto's diameter. But some are smaller than 100 kilometers across, and some are larger than 300 kilometers across. In fact, there is great diversity among KBOs:

+ Some are red and some are gray;

+ The surfaces of some are covered in water ice, but others (like Pluto) have exotic volatile ices like methane and nitrogen;

+ Many have moons, though none with more known moons than Pluto;

+ Some are highly reflective (like Pluto), others have much darker surfaces;

+ Some have much lower densities than Pluto, meaning they are primarily made of ice. Pluto's density is so high that we know its interior is about 70% rock in its interior; a few known KBOs are more dense than Pluto, and even rockier!

But I don't consider this surprising assortment of KBOs to be the most important contribution to our knowledge of the solar system that has come from telescope exploration of the Kuiper Belt.

In my opinion, the three greatest solar system lessons we've learned from the Kuiper Belt are:

+ That our planetary system is much larger than we used to think. In fact, we were largely unaware of the Kuiper Belt - the largest structure in our solar system - until it was discovered 20 years ago. It's akin to not having maps of the Earth that included the Pacific Ocean as recently as 1992!

+ That the locations and orbital eccentricities and inclinations of the planets in our solar system (and other solar systems as well) can change with time. This even creates whole flocks of migration of planets in some cases. We have firm evidence that many KBOs (including some large ones like Pluto), were born much closer to the Sun, in the region where the giant planets now orbit.

+ And, perhaps most surprisingly, that our solar system, and very likely very many others, was very good at making small planets, which dominate the planetary population! Today we know of more than a dozen dwarf planets in the solar system, and those dwarfs already outnumber the number of gas giants and terrestrial planets combined. But it is estimated that the ultimate number of dwarf planets we will discover in the Kuiper Belt and beyond may well exceed 10,000. Who knew? (And which class of planet is the misfit now?)

What an amazing set of paradigm shifts in our knowledge the Kuiper Belt has brought so far. Our quaint 1990s and earlier view of the solar system missed its largest structure! It didn't know about the existence of dwarf planets, the most populous class of planet in our solar system -and very likely the galaxy. It didn't even contemplate that dwarf planets would have such a wide range of colors, reflectivities, orbits and surface compositions. And it didn't realize that the locations of most planets in our solar system today - even including some of the very largest planets - are different from where they were born.

Just imagine what our close flybys of the Pluto system and smaller KBOs, combined with new giant telescopes coming on line to probe the sky, will teach us about the Kuiper Belt in the next 20 years. It's an exciting time, and its sometimes hard for me to believe after working on this since 1989, that our 2015 exploration of Pluto and its many moons is almost upon us-but it is!

Well, that's my update for now. Thanks again for following our journey across the deep ocean of space, to a new planet and a truly new frontier.

Until I write again, I hope you'll keep on exploring - just as we do!

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