Mostrando entradas con la etiqueta The Kuiper Belt. Mostrar todas las entradas
Mostrando entradas con la etiqueta The Kuiper Belt. Mostrar todas las entradas

martes, 10 de noviembre de 2015

NASA : Four Months after Pluto Flyby, NASA’s New Horizons Yields Wealth of Discovery .- Cuatro meses después de Plutón sobrevuelo, New Horizons de la NASA Rinde Riqueza de Descubrimiento


Most inner moons in the solar system keep one face pointed toward their central planet; this animation shows that certainly isn’t the case with the small moons of Pluto, which behave like spinning tops. Pluto is shown at center with, in order from closest to farthest orbit, its moons Charon, Styx, Nix, Kerberos and Hydra.
Credits: NASA/JHUAPL/SwRI/M. Showalter


New Horizons images of Pluto’s surface to make 3-D topographic maps
Using New Horizons images of Pluto’s surface to make 3-D topographic maps, scientists discovered that two of Pluto’s mountains, informally named Wright Mons and Piccard Mons, could be ice volcanoes. The color depicts changes in elevation, blue indicating lower terrain and brown showing higher elevation. Green terrains are at intermediate heights.
Credits: NASA/JHUAPL/SwRI
 
From possible ice volcanoes to twirling moons, NASA’s New Horizons science team is discussing more than 50 exciting discoveries about Pluto at this week’s 47th Annual Meeting of the American Astronomical Society’s Division for Planetary Sciences in National Harbor, Maryland.

“The New Horizons mission has taken what we thought we knew about Pluto and turned it upside down,” said Jim Green, director of planetary science at NASA Headquarters in Washington. “It's why we explore -- to satisfy our innate curiosity and answer deeper questions about how we got here and what lies beyond the next horizon."

For one such discovery, New Horizons geologists combined images of Pluto’s surface to make 3-D maps that indicate two of Pluto’s most distinctive mountains could be cryovolcanoes -- ice volcanoes that may have been active in the recent geological past.

“It’s hard to imagine how rapidly our view of Pluto and its moons are evolving as new data stream in each week. As the discoveries pour in from those data, Pluto is becoming a star of the solar system,” said mission Principal Investigator Alan Stern of the Southwest Research Institute in Boulder, Colorado. “Moreover, I’d wager that for most planetary scientists, any one or two of our latest major findings on one world would be considered astounding. To have them all is simply incredible.”

The two cryovolcano candidates are large features measuring tens of miles or kilometers across and several miles or kilometers high.
“These are big mountains with a large hole in their summit, and on Earth that generally means one thing -- a volcano,” said Oliver White, New Horizons postdoctoral researcher at NASA’s Ames Research Center in Moffett Field, California. “If they are volcanic, then the summit depression would likely have formed via collapse as material is erupted from underneath. The strange hummocky texture of the mountain flanks may represent volcanic flows of some sort that have traveled down from the summit region and onto the plains beyond, but why they are hummocky, and what they are made of, we don't yet know.”  

While their appearance is similar to volcanoes on Earth that spew molten rock, ice volcanoes on Pluto are expected to emit a somewhat melted slurry of substances such as water ice, nitrogen, ammonia, or methane. If Pluto proves to have volcanoes, it will provide an important new clue to its geologic and atmospheric evolution.

“After all, nothing like this has been seen in the deep outer solar system,” said Jeffrey Moore, New Horizons Geology, Geophysics and Imaging team leader, at Ames. 

Pluto’s Long History of Geologic Activity

Pluto’s surface varies in age -- from ancient, to intermediate, to relatively young --according to another new finding from New Horizons.

To determine the age of a surface area of the planet, scientists count crater impacts. The more crater impacts, the older the region likely is. Crater counts of surface areas on Pluto indicate that it has surface regions dating to just after the formation of the planets of our solar system, about four billion years ago.

But there also is a vast area that was, in geological terms, born yesterday -- meaning it may have formed within the past 10 million years. This area, informally named Sputnik Planum, appears on the left side of Pluto’s “heart” and is completely crater-free in all images received, so far.

New data from crater counts reveal the presence of intermediate, or “middle-aged,” terrains on Pluto, as well. This suggests Sputnik Planum is not an anomaly -- that Pluto has been geologically active throughout much of its more than 4-billion-year history.

“We’ve mapped more than a thousand craters on Pluto, which vary greatly in size and appearance,” said postdoctoral researcher Kelsi Singer, of the Southwest Research Institute (SwRI) in Boulder, Colorado. “Among other things, I expect cratering studies like these to give us important new insights into how this part of the solar system formed.”
 
Locations of more than 1,000 craters mapped on Pluto by NASA’s New Horizons mission
Locations of more than 1,000 craters mapped on Pluto by NASA’s New Horizons mission indicate a wide range of surface ages, which likely means Pluto has been geologically active throughout its history.
Credits: NASA/JHUAPL/SwRI
Building Blocks of the Solar System

Crater counts are giving the New Horizons team insight into the structure of the Kuiper Belt itself. The dearth of smaller craters across Pluto and its large moon Charon indicate the Kuiper Belt, which is an unexplored outer region of our solar system, likely had fewer smaller objects than some models had predicted.

This leads New Horizons scientists to doubt a longstanding model that all Kuiper Belt objects formed by accumulating much smaller objects --less than a mile wide. The absence of small craters on Pluto and Charon support other models theorizing that Kuiper Belt objects tens of miles across may have formed directly, at their current -- or close to current -- size.    

In fact, the evidence that many Kuiper Belt objects could have been “born large” has scientists excited that New Horizons’ next potential target -- the 30-mile-wide (40-50 kilometer wide) KBO named 2014 MU69 -- which may offer the first detailed look at just such a pristine, ancient building block of the solar system.

Pluto’s Spinning, Merged Moons

The New Horizons mission also is shedding new light on Pluto’s fascinating system of moons, and their unusual properties. For example, nearly every other moon in the solar system -- including Earth’s moon -- is in synchronous rotation, keeping one face toward the planet. This is not the case for Pluto’s small moons.

Pluto’s small lunar satellites are spinning much faster, with Hydra -- its most distant moon -- rotating an unprecedented 89 times during a single lap around the planet. Scientists believe these spin rates may be variable because Charon exerts a strong torque that prevents each small moon from settling down into synchronous rotation.
Another oddity of Pluto’s moons: scientists expected the satellites would wobble, but not to such a degree.

“Pluto’s moons behave like spinning tops,” said co-investigator Mark Showalter of the SETI Institute in Mountain View, California.

Images of Pluto’s four smallest satellites also indicate several of them could be the results of mergers of two or more moons.

New Horizons data indicates that at least two (and possibly all four) of Pluto’s small moons may be the result of mergers betwee
Data from NASA's New Horizons mission indicates that at least two -- and possibly all four -- of Pluto’s small moons may be the result of mergers between still smaller moons. If this discovery is borne out with further analysis, it could provide important new clues to the formation of the Pluto system.
Credits: NASA/JHUAPL/SwRI

“We suspect from this that Pluto had more moons in the past, in the aftermath of the big impact that also created Charon,” said Showalter.

To view more images and graphics being presented by New Horizons scientists at the 47th Annual Meeting of the American Astronomical Society’s Division for Planetary Sciences, visit:


For more information on NASA’s New Horizons mission, including fact sheets, videos and images, visit:


-end-
Dwayne Brown / Laurie Cantillo
Headquarters, Washington                                                             
202-358-1726 / 202-358-1077
dwayne.c.brown@nasa.gov / laura.l.cantillo@nasa.gov

Mike Buckley
Johns Hopkins University Applied Physics Laboratory, Laurel, Md.
240-228-7536
michael.buckley@jhuapl.edu
Last Updated: Nov. 9, 2015
Editor: Karen Northon

NASA
Guillermo Gonzalo Sánchez Achutegui
Incríbete en el Foro del blog y participa : A Vuelo De Un Quinde - El Foro!

lunes, 16 de junio de 2014

NASA : NASA Hubble to Begin Search Beyond Pluto for a New Horizons Mission Target


After careful consideration and analysis, the Hubble Space Telescope Time Allocation Committee has recommended using Hubble to search for an object the Pluto-bound NASA New Horizons mission could visit after its flyby of Pluto in July 2015.
This is an artist's rendering of the New Horizons spacecraft encountering a Kuiper Belt object — a city-sized icy relic left over from the birth of our solar system. The sun, more than 4.1 billion miles (6.7 billion kilometers) away, shines as a bright star embedded in the glow of the zodiacal dust cloud. Jupiter and Neptune are visible as orange and blue "stars" to the right of the sun.
This is an artist's rendering of the New Horizons spacecraft encountering a Kuiper Belt object — a city-sized icy relic left over from the birth of our solar system. The sun, more than 4.1 billion miles (6.7 billion kilometers) away, shines as a bright star embedded in the glow of the zodiacal dust cloud. Jupiter and Neptune are visible as orange and blue "stars" to the right of the sun.
Image Credit: JHUAPL/SwRI
The planned search will involve targeting a small area of sky in search of a Kuiper Belt object (KBO) for the outbound spacecraft to visit. The Kuiper Belt is a vast debris field of icy bodies left over from the solar system's formation 4.6 billion years ago. A KBO has never been seen up close because the belt is so far from the sun, stretching out to a distance of 5 billion miles into a never-before-visited frontier of the solar system.
"I am pleased that our science peer-review process arrived at a consensus as to how to effectively use Hubble's unique capabilities to support the science goals of the New Horizons mission," said Matt Mountain, director of the Space Telescope Science Institute (STScI) in Baltimore, Maryland.
Fully carrying out the KBO search is contingent on the results from a pilot observation using Hubble data. 
The space telescope will scan an area of sky in the direction of the constellation Sagittarius to try and identify any objects orbiting within the Kuiper Belt. To discriminate between a foreground KBO and the clutter of background stars in Sagittarius, the telescope will turn at the predicted rate that KBOs are moving against the background stars. In the resulting images, the stars will be streaked, but any KBOs should appear as pinpoint objects.
If the test observation identifies at least two KBOs of a specified brightness it will demonstrate statistically that Hubble has a chance of finding an appropriate KBO for New Horizons to visit. At that point, an additional allotment of observing time will continue the search across a field of view roughly the angular size of the full moon.
Astronomers around the world apply for observing time on the Hubble Space Telescope. Competition for time on the telescope is extremely intense and the requested observing time significantly exceeds the observing time available in a given year. Proposals must address significant astronomical questions that can only be addressed with Hubble's unique capabilities, and are beyond the capabilities of ground-based telescopes. The proposals are peer reviewed annually by an expert committee, which looks for the best possible science that can be conducted by Hubble and recommends to the Space Telescope Science Institute director a balanced program of small, medium, and large investigations.
Though Hubble is powerful enough to see galaxies near the horizon of the universe, finding a KBO is a challenging needle-in-haystack search. A typical KBO along the New Horizons trajectory may be no larger than Manhattan Island and as black as charcoal.
Even before the launch of New Horizons in 2006, Hubble has provided consistent support for this edge-of-the-solar system mission. Hubble was used to discover four small moons orbiting Pluto and its binary companion object Charon, providing new targets to enhance the mission’s scientific return. And Hubble has provided the most sensitive search yet for potentially hazardous dust rings around the Pluto. Hubble also has made a detailed map of the dwarf planet's surface, which astronomers are using to plan New Horizon's close-up reconnaissance photos.
In addition to Pluto exploration, recent Hubble solar system observations have discovered a new satellite around Neptune, probed the magnetospheres of the gas-giant planets, found circumstantial evidence for oceans on Europa, and uncovered several bizarre cases of asteroids disintegrating before our eyes. Hubble has supported numerous NASA Mars missions by monitoring the Red Planet's seasonal atmospheric changes. Hubble has made complementary observations in support of the Dawn asteroid mission, and comet flybys. In July 1994, Hubble documented the never-before-seen string of comet collisions with Jupiter that resulted from the tidal breakup of comet Shoemaker-Levy 9.
"The planned search for a suitable target for New Horizons further demonstrates how Hubble is effectively being used to support humankind's initial reconnaissance of the solar system," said Mountain. "Likewise, it is also a preview of how the powerful capabilities of the upcoming James Webb Space Telescope will further bolster planetary science. We are excited by the potential of both observatories for ongoing solar system exploration and discovery."
For images and more information about Hubble, visit:
and
 
NASA
Guillermo Gonzalo Sánchez Achutegui

domingo, 9 de octubre de 2011

Water on Earth: Space Observatory Provides Clues to Creation of Earth's Oceans

Hi my Friends: A VUELO DE UN QUINDE EL BLOG., Astronomers have found a new cosmic source for the same kind of water that appeared on Earth billions of years ago and created the oceans. The findings may help explain how Earth's surface ended up covered in water.
The Same Here as There
New measurements from the Herschel Space Observatory have discovered water with the same chemical signature as our oceans in a comet called Hartley 2 (pictured at right). Previously, astronomers thought icy comets impacting on a young Earth had deposited only about 10 percent of the water comprising our oceans. The new findings, however, suggest that comets played a much bigger role.
The image of comet Harley 2 at top right was taken by NASA's EPOXI mission. The image at bottom right is an artist's concept of a comet.
Image credit: NASA/JPL-Caltech

Heavy and Light just Right
Using the Herschel Space Observatory, astronomers have discovered that comet Hartley 2 possesses a ratio of "heavy water" to light, or normal, water that matches what's found in Earth's oceans. In heavy water, one of the two hydrogen atoms has been replaced by the heavy hydrogen isotope known as deuterium. Hartley 2 contains half as much heavy water as other comets analyzed to date
Herschel's "Heterodyne Instrument for the Far Infrared," or HIFI, was used to obtain the spectral signatures of the water molecules, as shown here in the graphs. The image of comet Harley 2 was taken by NASA's EPOXI mission.
Image credit: NASA/JPL-Caltech

PASADENA, Calif. -- Astronomers have found a new cosmic source for the same kind of water that appeared on Earth billions of years ago and created the oceans. The findings may help explain how Earth's surface ended up covered in water.

New measurements from the Herschel Space Observatory show that comet Hartley 2, which comes from the distant Kuiper Belt, contains water with the same chemical signature as Earth's oceans. This remote region of the solar system, some 30 to 50 times as far away as the distance between Earth and the sun, is home to icy, rocky bodies including Pluto, other dwarf planets and innumerable comets.

"Our results with Herschel suggest that comets could have played a major role in bringing vast amounts of water to an early Earth," said Dariusz Lis, senior research associate in physics at the California Institute of Technology in Pasadena and co-author of a new paper in the journal Nature, published online today, Oct. 5. "This finding substantially expands the reservoir of Earth ocean-like water in the solar system to now include icy bodies originating in the Kuiper Belt."

Scientists theorize Earth started out hot and dry, so that water critical for life must have been delivered millions of years later by asteroid and comet impacts. Until now, none of the comets previously studied contained water like Earth's. However, Herschel's observations of Hartley 2, the first in-depth look at water in a comet from the Kuiper Belt, paint a different picture.

Herschel peered into the comet's coma, or thin, gaseous atmosphere. The coma develops as frozen materials inside a comet vaporize while on approach to the sun. This glowing envelope surrounds the comet's "icy dirtball"-like core and streams behind the object in a characteristic tail.

Herschel detected the signature of vaporized water in this coma and, to the surprise of the scientists, Hartley 2 possessed half as much "heavy water" as other comets analyzed to date. In heavy water, one of the two normal hydrogen atoms has been replaced by the heavy hydrogen isotope known as deuterium. The ratio between heavy water and light, or regular, water in Hartley 2 is the same as the water on Earth's surface. The amount of heavy water in a comet is related to the environment where the comet formed.

By tracking the path of Hartley 2 as it swoops into Earth's neighborhood in the inner solar system every six-and-a-`half years, astronomers know that it comes from the Kuiper Belt. The five comets besides Hartley 2 whose heavy-water-to-regular-water ratios have been obtained all come from an even more distant region in the solar system called the Oort Cloud. This swarm of bodies, 10,000 times farther afield than the Kuiper Belt, is the wellspring for most documented comets.

Given the higher ratios of heavy water seen in Oort Cloud comets compared to Earth's oceans, astronomers had concluded that the contribution by comets to Earth's total water volume stood at approximately 10 percent. Asteroids, which are found mostly in a band between Mars and Jupiter but occasionally stray into Earth's vicinity, looked like the major depositors. The new results, however, point to Kuiper Belt comets having performed a previously underappreciated service in bearing water to Earth.

How these objects ever came to possess the telltale oceanic water is puzzling. Astronomers had expected Kuiper Belt comets to have even more heavy water than Oort Cloud comets because the latter are thought to have formed closer to the sun than those in the Kuiper Belt. Therefore, Oort Cloud bodies should have had less frozen heavy water locked in them prior to their ejection to the fringes as the solar system evolved.

"Our study indicates that our understanding of the distribution of the lightest elements and their isotopes, as well as the dynamics of the early solar system, is incomplete," said co-author Geoffrey Blake, professor of planetary science and chemistry at Caltech. "In the early solar system, comets and asteroids must have been moving all over the place, and it appears that some of them crash-landed on our planet and made our oceans."

Herschel is a European Space Agency cornerstone mission, with science instruments provided by consortia of European institutes. NASA's Herschel Project Office is based at the agency's Jet Propulsion Laboratory in Pasadena, Calif., which contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at Caltech in Pasadena, supports the U.S. astronomical community. Caltech manages JPL for NASA.

More information is online at : http://www.herschel.caltech.edu/



Mi lista de blogs