New Hubble images show similar colors for Pluto's moons

March 10, 2006
New Hubble images show similar colors for Pluto's moons
These NASA Hubble Space Telescope images of Pluto were taken on March 2, 2006. Credit: NASA, ESA, A. Stern (Southwest Research Institute), H. Weaver (Johns Hopkins University/Applied Physics Lab), and the HST Pluto Companion Search Team.

Using new Hubble Space Telescope observations, a research team led by Dr. Hal Weaver of the Johns Hopkins University Applied Physics Laboratory and Dr. Alan Stern of the Southwest Research Institute has found that Pluto's three moons are essentially the same color – boosting the theory that the Pluto system formed in a single, giant collision.

Publishing their findings in an International Astronomical Union Circular (No. 8686), the team determined that Pluto's two "new" satellites, discovered in May 2005 and provisionally called S/2005 P 1 and S/2005 P 2, have identical colors to one another and are essentially the same, neutral color as Charon, Pluto's large moon discovered in 1978.

All three satellites have surfaces that reflect sunlight with equal efficiency at all wavelengths, which means they have the same color as the Sun or Earth's moon. In contrast, Pluto has more of a reddish hue.

The new observations were obtained March 2 with the high-resolution channel of the Hubble's Advanced Camera for Surveys. The team determined the bodies' colors by comparing the brightness of Pluto and each moon in images taken through a blue filter with those taken through a green/red filter.

"The high quality of the new data leaves little doubt that the hemispheres of P1 and P2 that we observed have essentially identical, neutral colors," says Weaver.

The new results further strengthen the hypothesis that Pluto and its satellites formed after a collision between two Pluto-sized objects nearly 4.6 billion years ago. "Everything now makes even more sense," says Stern. "If all three satellites presumably formed from the same material lofted into orbit around Pluto from a giant impact, you might well expect the surfaces of all three satellites to have similar colors."

The researchers hope to make additional Hubble color observations, in several more filters, to see if the similarity among the satellites persists to longer (redder) wavelengths. They have proposed to obtain compositional information on the new satellites by observing them at near-infrared wavelengths, where various ice and mineral absorptions are located. The researchers also hope to better refine the orbits of P1 and P2 and measure the moons' shapes and rotational periods.

The Hubble observations were made in support of NASA's New Horizons mission to Pluto and the Kuiper Belt. New Horizons launched on Jan. 19, 2006, and will fly through the Pluto system in July 2015, providing the first close-up look at the ninth planet and its moons. Stern leads the mission and science team as principal investigator; Weaver serves as the mission's project scientist. The Johns Hopkins University Applied Physics Laboratory, Laurel, Md., manages the mission for NASA's Science Mission Directorate and operates the New Horizons spacecraft.

Source: Johns Hopkins University

Explore further: Astrophysicist discusses Pluto flyby findings

Related Stories

Astrophysicist discusses Pluto flyby findings

July 15, 2015

NASA's New Horizons spacecraft reached its closest approach to Pluto on Tuesday, swooping to within 7,800 miles of the dwarf planet out beyond Neptune, snapping pictures and gathering data.

Pluto, Charon could spout icy plumes

July 15, 2015

When NASA's New Horizons mission flies past Pluto on July 14, it may see signs of plumes on the dwarf planet or its moon, Charon, or at least evidence of their past existence. A new study of similar objects in the outer reaches ...

Some of the best pictures of the planets in our solar system

January 19, 2015

Our Solar System is a pretty picturesque place. Between the Sun, the Moon, and the Inner and Outer Solar System, there is no shortage of wondrous things to behold. But arguably, it is the eight planets that make up our Solar ...

New Horizons only one year from Pluto (w/ Video)

July 15, 2014

In July 2015, NASA will discover a new world. No one knows what to expect when the alien landscape comes into focus. There could be icy geysers, towering mountains, deep valleys, even planetary rings.

Mission to mysterious Uranus

October 12, 2011

Scientists want to send an orbiter and probe to the ice giant planet Uranus, but do the resources exist to support such an ambitious project?

Recommended for you

'Expansion entropy': A new litmus test for chaos?

July 28, 2015

Can the flap of a butterfly's wings in Brazil set off a tornado in Texas? This intriguing hypothetical scenario, commonly called "the butterfly effect," has come to embody the popular conception of a chaotic system, in which ...

Lobster-Eye imager detects soft X-ray emissions

July 28, 2015

Solar winds are known for powering dangerous space weather events near Earth, which, in turn, endangers space assets. So a large interdisciplinary group of researchers, led by the U.S. National Aeronautics and Space Administration ...

'Carbon sink' detected underneath world's deserts

July 28, 2015

The world's deserts may be storing some of the climate-changing carbon dioxide emitted by human activities, a new study suggests. Massive aquifers underneath deserts could hold more carbon than all the plants on land, according ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.