News

Whopping Galaxy Cluster Spotted with Help of NASA Telescopes

Posted on Updated on

The galaxy cluster called MOO J1142+1527 can be seen here as it existed when light left it 8.5 billion years ago. The red galaxies at the center of the image make up the heart of the galaxy cluster. Image credit: NASA/JPL-Caltech/Gemini/CARMA

 

Astronomers have discovered a giant gathering of galaxies in a very remote part of the universe, thanks to NASA’s Spitzer Space Telescope and Wide-field Infrared Survey Explorer (WISE). The galaxy cluster, located 8.5 billion light-years away, is the most massive structure yet found at such great distances.

Galaxy clusters are gravitationally bound groups of thousands of galaxies, which themselves each contain hundreds of billions of stars. The clusters grow bigger and bigger over time as they acquire new members.

How did these clusters evolve over time? What did they look like billions of years ago? To answer these questions, astronomers look back in time to our youthful universe. Because light takes time to reach us, we can see very distant objects as they were in the past. For example, we are seeing the newfound galaxy cluster — called Massive Overdense Object (MOO) J1142+1527 — as it existed 8.5 billion years ago, long before Earth formed.

As light from remote galaxies makes its way to us, it becomes stretched to longer, infrared wavelengths by the expansion of space. That’s where WISE andSpitzer help out.

For infrared space telescopes, picking out distant galaxies is like plucking ripe cherries from a cherry tree. In the infrared images produced by Spitzer, these distant galaxies stand out as red dots, while closer galaxies look white. Astronomers first combed through the WISE catalog to find candidates for clusters of distant galaxies. WISE catalogued hundreds of millions of objects in images taken over the entire sky from 2010 to 2011.

They then used Spitzer to narrow in on 200 of the most interesting objects, in a project named the “Massive and Distant Clusters of WISE Survey,” or MaDCoWS. Spitzer doesn’t observe the whole sky like WISE, but can see more detail.

“It’s the combination of Spitzer and WISE that lets us go from a quarter billion objects down to the most massive galaxy clusters in the sky,” said Anthony Gonzalez of the University of Florida in Gainesville, lead author of a new study published in the Oct. 20 issue of the Astrophysical Journal Letters.

From these observations, MOO J1142+1527 jumped out as one of the most extreme.

The W.M. Keck Observatories and Gemini Observatory on Mauna Kea in Hawaii were used to measure the distance to the cluster at 8.5 billion light-years. Using data from the Combined Array for Research in Millimeter-wave Astronomy (CARMA) telescopes near Owens Valley in California, the scientists were then able to determine that the cluster’s mass is a quadrillion times that of our sun — making it the most massive known cluster that far back in space and time.

MOO J1142+1527 may be one of only a handful of clusters of this heft in the early universe, according to the scientists’ estimates.

“Based on our understanding of how galaxy clusters grow from the very beginning of our universe, this cluster should be one of the five most massive in existence at that time,” said co-author Peter Eisenhardt, the project scientist for WISE at NASA’s Jet Propulsion Laboratory in Pasadena, California.

In the coming year, the team plans to sift through more than 1,700 additional galaxy cluster candidates with Spitzer, looking for biggest of the bunch.

“Once we find the most massive clusters, we can start to investigate how galaxies evolved in these extreme environments,” said Gonzalez.

JPL managed and operated WISE for NASA’s Science Mission Directorate in Washington. In September 2013, WISE was reactivated, renamed NEOWISE and assigned a new mission to assist NASA’s efforts to identify potentially hazardous near-Earth objects. JPL manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate, Washington. Science operations and data processing for Spitzer and NEOWISE take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

More information about WISE is online at: http://www.nasa.gov/wise

More information about Spitzer is online at: http://www.nasa.gov/spitzer and http://spitzer.caltech.edu

NASA Finds New Way to Track Ocean Currents from Space

Posted on Updated on

NASA’s GRACE satellites (artist’s concept) measured Atlantic Ocean bottom pressure as an indicator of deep ocean current speed. In 2009, this pattern of above-average (blue) and below-average (red) seafloor pressure revealed a temporary slowing of the deep currents. Image credit: NASA/JPL-Caltech

A team of NASA and university scientists has developed a new way to use satellite measurements to track changes in Atlantic Ocean currents, which are a driving force in global climate. The finding opens a path to better monitoring and understanding of how ocean circulation is changing and what the changes may mean for future climate.

In the Atlantic, currents at the ocean surface, such as the Gulf Stream, carry sun-warmed water from the tropics northeastward. As the water moves through colder regions, it sheds its heat. By the time it gets to Greenland, it’s so cold and dense that it sinks a couple of miles down into the ocean depths. There it turns and flows back south. This open loop of shallow and deep currents is known to oceanographers as the Atlantic Meridional Overturning Circulation (AMOC) — part of the “conveyor belt” of ocean currents circulating water, heat and nutrients around the globe and affecting climate.

Because the AMOC moves so much heat, any change in it is likely to be an important indicator of how our planet is responding to warming caused by increasing greenhouse gases. In the last decade, a few isolated measurements have suggested that the AMOC is slowing down and moving less water. Many researchers are expecting the current to weaken as a consequence of global warming, but natural variations may also be involved. To better understand what is going on, scientists would like to have consistent observations over time that cover the entire Atlantic

“This [new] satellite approach allows us to improve projections of future changes and — quite literally — get to the bottom of what drives ocean current changes,” said Felix Landerer of NASA’s Jet Propulsion Laboratory, Pasadena, California, who led the research team.

Landerer and his colleagues used data from the twin satellites of NASA’s Gravity Recovery and Climate Experiment (GRACE) mission. Launched in 2002, GRACE provides a monthly record of tiny changes in Earth’s gravitational field, caused by changes in the amount of mass below the satellites. The mass of Earth’s land surfaces doesn’t change much over the course of a month; but the mass of water on or near Earth’s surface does, for example, as ice sheets melt and water is pumped from underground aquifers. GRACE has proven invaluable in tracking these changes.

At the bottom of the atmosphere — on Earth’s surface — changes in air pressure (a measure of the mass of the air) tell us about flowing air, or wind. At the bottom of the ocean, changes in pressure tell us about flowing water, or currents. Landerer and his team developed a way to isolate in the GRACE gravity data the signal of tiny pressure differences at the ocean bottom that are caused by changes in the deep ocean currents.

“We’ve wanted to observe this phenomenon with GRACE since we launched 13 years ago, but it took us this long to figure out how to squeeze the information out of the data stream,” said Michael Watkins, director of the Center for Space Research at the University of Texas at Austin, former GRACE project scientist and a co-author of the study.

The squeezing process required some very advanced data processing, but not as many data points as one might think. “In principle, you’d think you’d have to measure every 10 yards or so across the ocean to know the whole flow,” Landerer explained. “But in fact, if you can measure the farthest eastern and western points very accurately, that’s all you need to know how much water is flowing north and south in the entire Atlantic at that section. That theory has long been known and is exploited in buoy networks, but this is the first time we’ve been able to do it successfully from space.”

The new measurements agreed well with estimates from a network of ocean buoys that span the Atlantic Ocean near 26 degrees north latitude, operated by the Rapid Climate Change (RAPID) group at the U.K.’s National Oceanography Centre, Southampton. The agreement gives the researchers confidence that the technique can be expanded to provide estimates throughout the Atlantic. In fact, the GRACE measurements showed that a significant weakening in the overturning circulation, which the buoys recorded in the winter of 2009-10, extended several thousand miles north and south of the buoys’ latitude.

Gerard McCarthy, a research scientist in the RAPID group who was not involved with the study, said, “The results highlight synergies between [direct measurements] like [those from] RAPID and remote sensing — all the more important given the rapid and surprising changes occurring in the North Atlantic at the present time.” Eric Lindstrom, NASA’s Physical Oceanography Program manager at the agency’s headquarters in Washington, pointed out, “It’s awesome that GRACE can see variations of deep water transport, [but] this signal might never have been detected or verified without the RAPID array. We will continue to need both in situ and space-based systems to monitor the subtle but significant variations of the ocean circulation.”

A paper in the journal Geophysical Research Letters describing the new technique and first results is available online in prepublication form: http://onlinelibrary.wiley.com/doi/10.1002/2015GL065730/abstract?campaign=wolacceptedarticle

Halloween Skies to Include Dead Comet Flyby

Posted on Updated on

 

 

The large space rock that will zip past Earth this Halloween is most likely a dead comet that, fittingly, bears an eerie resemblance to a skull.

Scientists observing asteroid 2015 TB145 with NASA’s Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii, have determined that the celestial object is more than likely a dead comet that has shed its volatiles after numerous passes around the sun.

The belated comet has also been observed by optical and radar observatories around the world, providing even more data, including our first close-up views of its surface. Asteroid 2015 TB145 will safely fly by our planet at just under 1.3 lunar distances, or about 302,000 miles (486,000 kilometers), on Halloween (Oct. 31) at 1 p.m. EDT (10 a.m. PDT, 17:00 UTC).

The first radar images of the dead comet were generated by the National Science Foundation’s 305-meter (1,000-foot) Arecibo Observatory in Puerto Rico. The radar images from Arecibo indicate the object is spherical in shape and approximately 2,000 feet (600 meters) in diameter and completes a rotation about once every five hours. 

“The IRTF data may indicate that the object might be a dead comet, but in the Arecibo images it appears to have donned a skull costume for its Halloween flyby,” said Kelly Fast, IRTF program scientist at NASA Headquarters and acting program manager for NASA’s NEO Observations Program.

These first radar images from the National Science Foundation’s 1,000-foot (305-meter) Arecibo Observatory in Puerto Rico, indicate the near-Earth object is spherical in shape and approximately 2,000 feet (600 meters) in diameter. The radar images were taken on Oct. 30, 2015, and the image resolution is 25 feet (7.5 meters) per pixel.Image credit: NAIC-Arecibo/NSF

Managed by the University of Hawaii for NASA, the IRTF’s 3-meter (10 foot) telescope collected infrared data on the object. The data may finally put to rest the debate over whether 2015 TB145, with its unusual orbit, is an asteroid or is of cometary origin.

“We found that the object reflects about six percent of the light it receives from the sun,” said Vishnu Reddy, a research scientist at the Planetary Science Institute, Tucson, Arizona. “That is similar to fresh asphalt, and while here on Earth we think that is pretty dark, it is brighter than a typical comet which reflects only 3 to 5 percent of the light. That suggests it could be cometary in origin — but as there is no coma evident, the conclusion is it is a dead comet.”

Radar images generated by the Arecibo team are available at:

https://www.facebook.com/notes/national-astronomy-and-ionosphere-center-arecibo-observatory/near-earth-asteroid-2015-tb145-passes-by-without-a-fright/1082765941733673

Asteroid 2015 TB145 was discovered on Oct. 10, 2015, by the University of Hawaii’s Pan-STARRS-1 (Panoramic Survey Telescope and Rapid Response System) on Haleakala, Maui, part of the NASA-funded Near-Earth Object Observations (NEOO) Program. The next time the asteroid will be in Earth’s neighborhood will be in September 2018, when it will make a distant pass at about 24 million miles (38 million kilometers), or about a quarter the distance between Earth and the sun.

Radar is a powerful technique for studying an asteroid’s size, shape, rotation, surface features and surface roughness, and for improving the calculation of asteroid orbits. Radar measurements of asteroid distances and velocities often enable computation of asteroid orbits much further into the future than would be possible otherwise.

NASA places a high priority on tracking asteroids and protecting our home planet from them. In fact, the U.S. has the most robust and productive survey and detection program for discovering near-Earth objects (NEOs). To date, U.S.-funded assets have discovered over 98 percent of the known NEOs.

In addition to the resources NASA puts into understanding asteroids, it also partners with other U.S. government agencies, university-based astronomers, and space science institutes across the country, often with grants, interagency transfers and other contracts from NASA, and also with international space agencies and institutions that are working to track and better understand these objects. In addition, NASA values the work of numerous highly skilled amateur astronomers, whose accurate observational data helps improve asteroid orbits after they are found.

NASA’s Jet Propulsion Laboratory, Pasadena, California, hosts the Center for Near-Earth Object Studies for NASA’s Near-Earth Object Observations Program within the agency’s Science Mission Directorate.

More information about asteroids and near-Earth objects is at these websites:

http://neo.jpl.nasa.gov

http://www.jpl.nasa.gov/asteroidwatch

 

 

NASA Spots the ‘Great Pumpkin’: Halloween Asteroid a Treat for Radar Astronomers

Posted on

This is a graphic depicting the orbit of asteroid 2015 TB145. The asteroid will safely fly past Earth slightly farther out than the moon’s orbit on Oct. 31 at 10:05 a.m. Pacific (1:05 p.m. EDT and 17:05 UTC). Image credit: NASA/JPL-Caltech

NASA scientists are tracking the upcoming Halloween flyby of asteroid 2015 TB145 with several optical observatories and the radar capabilities of the agency’s Deep Space Network at Goldstone, California. The asteroid will fly past Earth at a safe distance slightly farther than the moon’s orbit on Oct. 31 at 10:01 a.m. PDT (1:01 p.m. EDT). Scientists are treating the flyby of the estimated 1,300-foot-wide (400-meter) asteroid as a science target of opportunity, allowing instruments on “spacecraft Earth” to scan it during the close pass.

Published on Oct 29, 2015JPL scientist Marina Brozovic explains how radar will be used to study asteroid 2015 TB145 when it safely passes Earth on Oct. 31, 2015. Scientists are tracking the Halloween flyby with several optical observatories and the radar capabilities of the agency’s Deep Space Network at Goldstone, California. Radar images should be available within a few days of the flyby. The asteroid will fly past Earth at a safe distance slightly farther than the moon’s orbit on Oct. 31 at 10:01 a.m. PDT (1:01 p.m. EDT). Scientists are treating the flyby of the estimated 1,300-foot-wide (400-meter) asteroid as a science target of opportunity. 

Asteroid 2015 TB145 was discovered on Oct. 10, 2015, by the University of Hawaii’s Pan-STARRS-1 (Panoramic Survey Telescope and Rapid Response System) on Haleakala, Maui, part of the NASA-funded Near-Earth Object Observation (NEOO) Program. According to the catalog of near-Earth objects (NEOs) kept by the Minor Planet Center, this is the closest currently known approach by an object this large until asteroid 1999 AN10, at about 2,600 feet (800 meters) in size, approaches at about 1 lunar distance (238,000 miles from Earth) in August 2027.

“The trajectory of 2015 TB145 is well understood,” said Paul Chodas, manager of the Center for Near Earth Object Studies at NASA’s Jet Propulsion Laboratory, Pasadena, California. “At the point of closest approach, it will be no closer than about 300,000 miles — 480,000 kilometers or 1.3 lunar distances. Even though that is relatively close by celestial standards, it is expected to be fairly faint, so night-sky Earth observers would need at least a small telescope to view it.

The gravitational influence of the asteroid is so small it will have no detectable effect on the moon or anything here on Earth, including our planet’s tides or tectonic plates

The Center for NEO Studies at JPL is a central node for NEO data analysis in NASA’s Near-Earth Object Observation Program and a key group involved with the international collaboration of astronomers and scientists who keep watch on the sky with their telescopes, looking for asteroids that could be a hazard to impact our planet and predicting their paths through space for the foreseeable future

“The close approach of 2015 TB145 at about 1.3 times the distance of the moon’s orbit, coupled with its size, suggests it will be one of the best asteroids for radar imaging we’ll see for several years,” said Lance Benner, of JPL, who leads NASA’s asteroid radar research program. “We plan to test a new capability to obtain radar images with two-meter resolution for the first time and hope to see unprecedented levels of detail.”

During tracking, scientists will use the 34-meter (110-foot) DSS 13 antenna at Goldstone to bounce radio waves off the asteroid. Radar echoes will in turn be collected by the National Radio Astronomy Observatory’s Green Bank Telescope in Green Bank, West Virginia, and the National Astronomy and Ionosphere Center’s Arecibo Observatory, Puerto Rico. NASA scientists hope to obtain radar images of the asteroid as fine as about 7 feet (2 meters) per pixel. This should reveal a wealth of detail about the object’s surface features, shape, dimensions and other physical properties

“The asteroid’s orbit is very oblong with a high inclination to below the plane of the solar system,” said Benner. “Such a unique orbit, along with its high encounter velocity — about 35 kilometers or 22 miles per second — raises the question of whether it may be some type of comet. If so, then this would be the first time that the Goldstone radar has imaged a comet from such a close distance.”

NASA’s Near-Earth Object Observations Program detects, tracks and characterizes asteroids and comets passing within 30 million miles of Earth using both ground- and space-based telescopes. The NEOO Program, sometimes called “Spaceguard,” discovers these objects, characterizes the physical nature of a subset of them, and predicts their paths to determine if any could be potentially hazardous to our planet. There are no known credible impact threats to date — only the ongoing and harmless in-fall of meteoroids, tiny asteroids that burn up in the atmosphere

JPL hosts the Center for Near-Earth Object Studies for NASA’s Near-Earth Object Observations Program within the agency’s Science Mission Directorate. JPL is a division of the California Institute of Technology in Pasadena.

More information about asteroids and near-Earth objects is at:  http://neo.jpl.nasa.gov and http://www.jpl.nasa.gov/asteroidwatch

Saturn’s Geyser Moon Shines in Close Flyby Views

Posted on

NASA’s Cassini spacecraft has begun transmitting its latest images of Saturn’s icy, geologically active moon Enceladus, acquired during the dramatic Oct. 28 flyby in which the probe passed about 30 miles (49 kilometers) above the moon’s south polar region. The spacecraft will continue transmitting its data from the encounter for the next several days.

“Cassini’s stunning images are providing us a quick look at Enceladus from this ultra-close flyby, but some of the most exciting science is yet to come,” said Linda Spilker, the mission’s project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.

Researchers will soon begin studying data from Cassini’s gas analyzer and dust detector instruments, which directly sampled the moon’s plume of gas and dust-sized icy particles during the flyby. Those analyses are likely to take several weeks, but should provide important insights about the composition of the global ocean beneath Enceladus’ surface and any hydrothermal activity occurring on the ocean floor. The potential for such activity in this small ocean world has made Enceladus a prime target for future exploration in search of habitable environments in the solar system beyond Earth.

In addition to the processed images, unprocessed, or “raw,” images appear on the Cassini mission website at: http://saturn.jpl.nasa.gov/mission/flybys/enceladus20151028

Cassini’s next and final close Enceladus flyby will take place on Dec. 19, when the spacecraft will measure the amount of heat coming from the moon’s interior. The flyby will be at an altitude of 3,106 miles (4,999 kilometers).

Additional information and multimedia products for Cassini’s final Enceladus flybys are available at: http://solarsystem.nasa.gov/finalflybys

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA’s Jet Propulsion Laboratory in Pasadena, California, manages the mission for the agency’s Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. The Cassini imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about Cassini, visit: http://www.nasa.gov/cassini or http://saturn.jpl.nasa.gov

NASA’s Cassini spacecraft has begun transmitting its latest images of Saturn’s icy, geologically active moon Enceladus, acquired during the dramatic Oct. 28 flyby in which the probe passed about 30 miles (49 kilometers) above the moon’s south polar region. The spacecraft will continue transmitting its data from the encounter for the next several days.

“Cassini’s stunning images are providing us a quick look at Enceladus from this ultra-close flyby, but some of the most exciting science is yet to come,” said Linda Spilker, the mission’s project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.
Researchers will soon begin studying data from Cassini’s gas analyzer and dust detector instruments, which directly sampled the moon’s plume of gas and dust-sized icy particles during the flyby. Those analyses are likely to take several weeks, but should provide important insights about the composition of the global ocean beneath Enceladus’ surface and any hydrothermal activity occurring on the ocean floor. The potential for such activity in this small ocean world has made Enceladus a prime target for future exploration in search of habitable environments in the solar system beyond Earth.
In addition to the processed images, unprocessed, or “raw,” images appear on the Cassini mission website at: http://saturn.jpl.nasa.gov/mission/flybys/enceladus20151028

Cassini’s next and final close Enceladus flyby will take place on Dec. 19, when the spacecraft will measure the amount of heat coming from the moon’s interior. The flyby will be at an altitude of 3,106 miles (4,999 kilometers).
Additional information and multimedia products for Cassini’s final Enceladus flybys are available at: http://solarsystem.nasa.gov/finalflybys

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA’s Jet Propulsion Laboratory in Pasadena, California, manages the mission for the agency’s Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. The Cassini imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about Cassini, visit: http://www.nasa.gov/cassini or http://saturn.jpl.nasa.gov

Voyager 1 Helps Solve Interstellar Medium Mystery

Posted on

IMG_4459

NASA’s Voyager 1 spacecraft made history in 2012 by entering interstellar space, leaving the planets and the solar wind behind. But observations from the pioneering probe were puzzling with regard to the magnetic field around it, as they differed from what scientists derived from observations by other spacecraft.

A new study offers fresh insights into this mystery. Writing in the Astrophysical Journal Letters, Nathan Schwadron of the University of New Hampshire, Durham, and colleagues reanalyzed magnetic field data from Voyager 1 and found that the direction of the magnetic field has been slowly turning ever since the spacecraft crossed into interstellar space. They believe this is an effect of the nearby boundary of the solar wind, a stream of charged particles that comes from the sun.

“This study provides very strong evidence that Voyager 1 is in a region where the magnetic field is being deflected by the solar wind,” said Schwadron, lead author of the study.

Researchers predict that in 10 years Voyager 1 will reach a more “pristine” region of the interstellar medium where the solar wind does not significantly influence the magnetic field.

Voyager 1’s crossing into interstellar space meant it had left the heliosphere — the bubble of solar wind surrounding our sun and the planets. Observations from Voyager’s instruments found that the particle density was 40 times greater outside this boundary than inside, confirming that it had indeed left the heliosphere.

But so far, Voyager 1’s observation of the direction of the local interstellar magnetic field is more than 40 degrees off from what other spacecraft have determined. The new study suggests this discrepancy exists because Voyager 1 is in a more distorted magnetic field just outside the heliopause, which is the boundary between the solar wind and the interstellar medium.

“If you think of the magnetic field as a rubber band stretched around a beach ball, that band is being deflected around the heliopause,” Schwadron said.

In 2009, NASA’s Interstellar Boundary Explorer (IBEX) discovered a “ribbon” of energetic neutral atoms that is thought to hold clues to the direction of the pristine interstellar magnetic field. The so-called “IBEX ribbon,” which forms a circular arc in the sky, remains mysterious, but scientists believe it is produced by a flow of neutral hydrogen atoms from the solar wind that were re-ionized in nearby interstellar space and then picked up electrons to become neutral again.

The new study uses multiple data sets to confirm that the magnetic field direction at the center of the IBEX ribbon is the same direction as the magnetic field in the pristine interstellar medium. Observations from the NASA/ESA Ulysses and SOHO spacecraft also support the new findings.

“All of these different data sets that have been collected over the last 25 years have been pointing toward the same meeting point in the field,” Schwadron said.

Over time, the study suggests, at increasing distances from the heliosphere, the magnetic field will be oriented more and more toward “true north,” as defined by the IBEX ribbon. By 2025, if the field around Voyager 1 continues to steadily turn, Voyager 1 will observe the same magnetic field direction as IBEX. That would signal Voyager 1’s arrival in a less distorted region of the interstellar medium.

“It’s an interesting way to look at the data. It gives a prediction of how long we’ll have to go before Voyager 1 is in the medium that’s no longer strongly perturbed,” said Ed Stone, Voyager project scientist, based at the California Institute of Technology in Pasadena, who was not involved in this study.

While Voyager 1 will continue delivering insights about interstellar space, its twin probe Voyager 2 is also expected to cross into the interstellar medium within the next few years. Voyager 2 will make additional observations of the magnetic field in interstellar space and help scientists refine their estimates.

Voyager 1 and Voyager 2 were launched 16 days apart in 1977. Both spacecraft flew by Jupiter and Saturn. 

Voyager 2 also flew by Uranus and Neptune. Voyager 2, launched before Voyager 1, is the longest continuously operated spacecraft. Voyager 1 is the most distant object touched by human hands.
JPL, a division of Caltech, built the twin Voyager spacecraft and operates them for the Heliophysics Division within NASA’s Science Mission Directorate in Washington.
For more information about Voyager, visit: http://voyager.jpl.nasa.gov

Seven Key Facts About Cassini’s Oct. 28 ‘Plume Dive’

Posted on

Cassini Flyby

 

NASA’s Cassini spacecraft will sample the ocean of Saturn’s moon Enceladus on Wednesday, Oct. 28, when it flies through the moon’s plume of icy spray.

Cassini launched in 1997 and entered orbit around Saturn in 2004. Since then, it has been studying the huge planet, its rings and its magnetic field. Here are some things to know about the mission’s upcoming close flyby of Enceladus:

  • Enceladus is an icy moon of Saturn. Early in its mission, Cassini discovered Enceladus has remarkable geologic activity, including a towering plume of ice, water vapor and organic molecules spraying from its south polar region. Cassini later determined the moon has a global ocean and likely hydrothermal activity, meaning it could have the ingredients needed to support simple life.
  • The flyby will be Cassini’s deepest-ever dive through the Enceladus plume, which is thought to come from the ocean below. The spacecraft has flown closer to the surface of Enceladus before, but never this low directly through the active plume.
  • The flyby is not intended to detect life, but it will provide powerful new insights about how habitable the ocean environment is within Enceladus.
  • Cassini scientists are hopeful the flyby will provide insights about how much hydrothermal activity — that is, chemistry involving rock and hot water — is occurring within Enceladus. This activity could have important implications for the potential habitability of the ocean for simple forms of life. The critical measurement for these questions is the detection of molecular hydrogen by the spacecraft.
  • Scientists also expect to better understand the chemistry of the plume as a result of the flyby. The low altitude of the encounter is, in part, intended to afford Cassini greater sensitivity to heavier, more massive molecules, including organics, than the spacecraft has observed during previous, higher-altitude passes through the plume
  • The flyby will help solve the mystery of whether the plume is composed of column-like, individual jets, or sinuous, icy curtain eruptions — or a combination of both. The answer would make clearer how material is getting to the surface from the ocean below.
  • Researchers are not sure how much icy material the plumes are actually spraying into space. The amount of activity has major implications for how long Enceladus might have been active.

An online toolkit for all three final Enceladus flybys is available at:  http://solarsystem.nasa.gov/finalflybys

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. JPL manages the mission for NASA’s Science Mission Directorate in Washington.

For more information about Cassini, visit:

http://www.nasa.gov/cassini

http://saturn.jpl.nasa.gov

From Mountains to Moons: Multiple Discoveries from NASA’s New Horizons Pluto Mission

Posted on Updated on

July 15, 2015
RELEASE 15-152

Mountains on Pluto
New close-up images of a region near Pluto’s equator reveal a giant surprise — a range of youthful mountains rising as high as 11,000 feet (3,500 meters) above the surface of the icy body. Credits: NASA/JHU APL/SwRI

Icy mountains on Pluto and a new, crisp view of its largest moon, Charon, are among the several discoveries announced Wednesday by the NASA’s New Horizons team, just one day after the spacecraft’s first ever Pluto flyby.

“Pluto New Horizons is a true mission of exploration showing us why basic scientific research is so important,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “The mission has had nine years to build expectations about what we would see during closest approach to Pluto and Charon. Today, we get the first sampling of the scientific treasure collected during those critical moments, and I can tell you it dramatically surpasses those high expectations.”

“Home run!” said Alan Stern, principal investigator for New Horizons at the Southwest Research Institute (SwRI) in Boulder, Colorado. “New Horizons is returning amazing results already. The data look absolutely gorgeous, and Pluto and Charon are just mind blowing.”

A new close-up image of an equatorial region near the base of Pluto’s bright heart-shaped feature shows a mountain range with peaks jutting as high as 11,000 feet (3,500 meters) above the surface of the icy body.

The mountains on Pluto likely formed no more than 100 million years ago — mere youngsters in a 4.56-billion-year-old solar system. This suggests the close-up region, which covers about one percent of Pluto’s surface, may still be geologically active today.

“This is one of the youngest surfaces we’ve ever seen in the solar system,” said Jeff Moore of the New Horizons Geology, Geophysics and Imaging Team (GGI) at NASA’s Ames Research Center in Moffett Field, California.

Unlike the icy moons of giant planets, Pluto cannot be heated by gravitational interactions with a much larger planetary body. Some other process must be generating the mountainous landscape.

“This may cause us to rethink what powers geological activity on many other icy worlds,” says GGI deputy team leader John Spencer at SwRI.

The new view of Charon reveals a youthful and varied terrain. Scientists are surprised by the apparent lack of craters. A swath of cliffs and troughs stretching about 600 miles (1,000 kilometers) suggests widespread fracturing of Charon’s crust, likely the result of internal geological processes. The image also shows a canyon estimated to be 4 to 6 miles (7 to 9 kilometers) deep. In Charon’s north polar region, the dark surface markings have a diffuse boundary, suggesting a thin deposit or stain on the surface.

New Horizons also observed the smaller members of the Pluto system, which includes four other moons: Nix, Hydra, Styx and Kerberos. A new sneak-peak image of Hydra is the first to reveal its apparent irregular shape and its size, estimated to be about 27 by 20 miles (43 by 33 kilometers).

The observations also indicate Hydra’s surface is probably coated with water ice. Future images will reveal more clues about the formation of this and the other moon billions of years ago. Spectroscopic data from New Horizons’ Ralph instruments reveal an abundance of methane ice, but with striking differences among regions across the frozen surface of Pluto.

The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland designed, built and operates the New Horizons spacecraft and manages the mission for NASA’s Science Mission Directorate. SwRI leads the mission, science team, payload operations and encounter science planning. New Horizons is part of NASA’s New Frontiers Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama.

Follow the New Horizons mission on Twitter and use the hashtag #PlutoFlyby to join the conversation. Live updates also will be available on the mission Facebook page.

For more information on the New Horizons mission, including fact sheets, schedules, video and all the new images, visit: http://www.nasa.gov/newhorizons and http://solarsystem.nasa.gov/planets/plutotoolkit.cfm.

NASA to Release New Pluto Images, Science Findings at July 17 NASA TV Briefing

Posted on Updated on

July 16, 2015
MEDIA ADVISORY M15-109

New image of an area on Pluto's largest moon Charon
This new image of an area on Pluto’s largest moon Charon has a captivating feature — a depression with a peak in the middle, shown here in the upper left corner of the inset. The image shows an area approximately 240 miles (390 kilometers) from top to bottom, including few visible craters. The image was taken at approximately 6:30 a.m. EDT on July 14, 2015, about 1.5 hours before closest approach to Pluto, from a range of 49,000 miles (79,000 kilometers). Credits: NASA-JHUAPL-SwRI

NASA will hold a media briefing at 1 p.m. EDT Friday, July 17, to reveal new images of Pluto and discuss new science findings from Tuesday’s historic flyby.

The briefing will be held in James E. Webb Auditorium at NASA Headquarters, located at 300 E St. SW in Washington. NASA Television and the agency’s website will carry the briefing live.

Participants in the briefing will be:

  • Jim Green, director of Planetary Science at NASA Headquarters in Washington
  • Alan Stern, New Horizons principal investigator at Southwest Research Institute (SwRI) in Boulder, Colorado
  • Randy Gladstone, New Horizons co-investigator at SwRI in San Antonio
  • Jeffrey Moore, New Horizons co-investigator at NASA’s Ames Research Center in Moffett Field, California
  • Fran Bagenal, New Horizons co-investigator, University of Colorado, Boulder

Media may participate by phone. To join the briefing by phone, reporters must email their name, affiliation and telephone number to Karen Northon at karen.northon by noon Friday.

Media and the public also may ask questions during the briefing on Twitter using the hashtag #askNASA.

For NASA TV streaming video, scheduling and downlink information, visit:

http://www.nasa.gov/nasatv

For more information on the New Horizons mission, including fact sheets, schedules, video and images, visit:

http://www.nasa.gov/newhorizons