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Hubble Finds Two Chaotically Tumbling Pluto Moons

June 3, 2015 1 comment

Artist's illustrations. Credit: NASA, ESA, M. Showalter (SETI Institute), and G. Bacon (STScI)

Artist’s illustrations. Credit: NASA, ESA, M. Showalter (SETI Institute), and G. Bacon (STScI)

If you lived on one of Pluto’s moons Nix or Hydra, you’d have a hard time setting your alarm clock. That’s because you could not know for sure when, or even in which direction, the sun would rise.

A comprehensive analysis of all available Hubble Space Telescope data shows that two of Pluto’s moons, Nix and Hydra, are wobbling unpredictably. Scientists believe the other two small moons, Kerberos and Styx, are likely in a similar situation, pending further study.

“Hubble has provided a new view of Pluto and its moons revealing a cosmic dance with a chaotic rhythm,” said John Grunsfeld, associate administrator of NASA’s Science Mission Directorate in Washington, D.C. “When the New Horizons spacecraft flies through the Pluto system in July we’ll get a chance to see what these moons look like up close and personal.”

Why the chaos? Because the moons are embedded inside a dynamically shifting gravitational field caused by the system’s two central bodies, Pluto and Charon, whirling about each other. The variable gravitational field induces torques that send the smaller moons tumbling in unpredictable ways. This torque is strengthened by the fact the moons are football shaped rather than spherical.

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NASA Pluto-Bound Spacecraft Crosses Neptune’s Orbit

August 25, 2014 Leave a comment

Image credit: NASA/JPL

Image credit: NASA/JPL

NASA’s Pluto-bound New Horizons spacecraft has traversed the orbit of Neptune. This is its last major crossing en route to becoming the first probe to make a close encounter with distant Pluto on July 14, 2015.

The sophisticated piano-sized spacecraft, which launched in January 2006, reached Neptune’s orbit — nearly 2.75 billion miles (4.4. billion kilometers) from Earth — in a record eight years and eight months. New Horizons’ milestone matches precisely the 25th anniversary of the historic encounter of NASA’s Voyager 2 spacecraft with Neptune on Aug. 25, 1989.

“It’s a cosmic coincidence that connects one of NASA’s iconic past outer solar system explorers, with our next outer solar system explorer,” said Jim Green, director of NASA’s Planetary Science Division, NASA Headquarters in Washington. “Exactly 25 years ago at Neptune, Voyager 2 delivered our ‘first’ look at an unexplored planet. Now it will be New Horizons’ turn to reveal the unexplored Pluto and its moons in stunning detail next summer on its way into the vast outer reaches of the solar system.

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New Horizons Camera Spots Pluto’s Largest Moon


NASA’s Pluto-bound New Horizons spacecraft, using its highest-resolution telescopic camera, has spotted Pluto’s Texas-sized, ice-covered moon Charon for the first time. This represents a major milestone on the spacecraft’s 9½-year journey to conduct the initial reconnaissance of the Pluto system and the Kuiper Belt and, in a sense, begins the mission’s long-range study of the Pluto system.

The largest of Pluto’s five known moons, Charon orbits about 12,000 miles (more than 19,000 kilometers) away from Pluto itself. As seen from New Horizons, that’s only about 0.01 degrees away.

“The image itself might not look very impressive to the untrained eye, but compared to the discovery images of Charon from Earth, these ‘discovery’ images from New Horizons look great!” says New Horizons Project Scientist Hal Weaver, of the Johns Hopkins University Applied Physics Laboratory, Laurel, Md. “We’re very excited to see Pluto and Charon as separate objects for the first time from New Horizons.”

Full Story: http://www.pluto.jhuapl.edu/news_center/news/20130710.php

Astronomers Ask Public To Help Name Pluto’s New Moons

February 14, 2013 Leave a comment

By tradition, the moons of Pluto have names associated with Hades and the underworld. Beginning today, people can vote by visiting:

http://www.plutorocks.com/

Voting ends at noon EST on Monday, February 25th, 2013.

“The Greeks were great storytellers and they have given us a colorful cast of characters to work with,” said Mark Showalter, Senior Research Scientist at the Carl Sagan Center of the SETI Institute in Mountain View, California. He and the teams of astronomers who made the discoveries will select two names based on the outcome of the voting.

Full Story: http://www.seti.org/node/1592

Pluto’s Moons And Possible Rings May Be Hazards: New Horizons And The Gauntlet It May Encounter In 2015

October 17, 2012 Leave a comment

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 the solar system, its science team has become increasingly aware of the possibility that dangerous debris may be orbiting in the Pluto system, putting NASA’s New Horizons 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 Dr. 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. “And we’ve come to appreciate that those moons, as well as others not yet discovered, act as debris generators populating the Pluto system with shards from collisions between those moons and small Kuiper Belt objects.”

Full Story: http://www.swri.org/9what/releases/2012/newhorizons-pluto.htm

Sharpest-Ever Ground-Based Images Of Pluto And Charon: Proves A Powerful Tool For Exoplanet Discoveries

September 28, 2012 Leave a comment

Credit: Gemini Observatory/NSF/NASA/AURA

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.

Full Story: http://www.gemini.edu/node/11893

Hubble Discovers A Fifth Moon Orbiting Pluto

July 12, 2012 1 comment

A team of astronomers using NASA’s Hubble Space Telescope is reporting the discovery of another moon orbiting the icy dwarf planet Pluto.

The moon is estimated to be irregular in shape and 6 to 15 miles across. It is in a 58,000-mile-diameter circular orbit around Pluto that is assumed to be co-planar with the other satellites in the system.

The Pluto team is intrigued that such a small planet can have such a complex collection of satellites. The new discovery provides additional clues for unraveling how the Pluto system formed and evolved. The favored theory is that all the moons are relics of a collision between Pluto and another large Kuiper belt object billions of years ago.

Full Story: http://hubblesite.org/newscenter/archive/releases/2012/32/full/

Evidence for Complex Molecules on Pluto’s Surface

December 20, 2011 Leave a comment

The new and highly sensitive Cosmic Origins Spectrograph aboard the Hubble Space Telescope has discovered a strong ultraviolet-wavelength absorber on Pluto’s surface, providing new evidence that points to the possibility of complex hydrocarbon and/or nitrile molecules lying on the surface, according to a paper recently published in the Astronomical Journal by researchers from Southwest Research Institute and Nebraska Wesleyan University.

Such chemical species can be produced by the interaction of sunlight or cosmic rays with Pluto’s known surface ices, including methane, carbon monoxide and nitrogen.

The project, led by SwRI’s Dr. Alan Stern, also included SwRI researchers Dr. John Spencer and Adam Shinn, and Nebraska Wesleyan University researchers Dr. Nathaniel Cunningham and student Mitch Hain.

Full Story: http://www.swri.org/9what/releases/2011/pluto.htm

Faraway Eris Is Pluto’s Twin

October 27, 2011 Leave a comment

Credit: ESO/L. Calçada

Credit: ESO/L. Calçada

Astronomers have accurately measured the diameter of the faraway dwarf planet Eris for the first time by catching it as it passed in front of a faint star. This event was seen at the end of 2010 by telescopes in Chile, including the Belgian TRAPPIST telescope at ESO’s La Silla Observatory. The observations show that Eris is an almost perfect twin of Pluto in size. Eris appears to have a very reflective surface, suggesting that it is uniformly covered in a thin layer of ice, probably a frozen atmosphere. The results will be published in the 27 October 2011 issue of the journal Nature.

In November 2010, the distant dwarf planet Eris passed in front of a faint background star, an event called an occultation. These occurrences are very rare and difficult to observe as the dwarf planet is very distant and small. The next such event involving Eris will not happen until 2013. Occultations provide the most accurate, and often the only, way to measure the shape and size of a distant Solar System body.

The candidate star for the occultation was identified by studying pictures from the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory. The observations were carefully planned and carried out by a team of astronomers from a number of (mainly French, Belgian, Spanish and Brazilian) universities using — among others — the TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope, eso1023) telescope, also at La Silla.

Full Story: http://www.eso.org/public/news/eso1142/