Planetary and Asteroid Studies

NASA Announces Coverage, Media Activities for Juno Mission Arrival at Jupiter

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NASA’s solar-powered Juno spacecraft will arrive at Jupiter July 4, 2016. Credits: NASA

 

This Fourth of July, NASA’s solar-powered Juno spacecraft will arrive at Jupiter after an almost five-year journey. News briefings, photo opportunities and other media events will be held at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, and air live on NASA Television and the agency’s website. 

Juno was launched August 5, 2011 from Cape Canaveral in Florida on an Atlas V rocket. It was estimated to take five years for the satellite to reach Jupiter, the only other gas giant without a dedicated satellite.

In the evening of July 4, Juno will perform a suspenseful orbit insertion maneuver, a 35-minute burn of its main engine, to slow the spacecraft by about 1,212 miles per hour (542 meters per second) so it can be captured into the gas giant’s orbit. Once in Jupiter’s orbit, the spacecraft will circle the Jovian world 37 times during 20 months, skimming to within 3,100 miles (5,000 kilometers) above the cloud tops. This is the first time a spacecraft will orbit the poles of Jupiter, providing new answers to ongoing mysteries about the planet’s core, composition and magnetic fields.

Juno will improve our understanding of the solar system’s beginnings by revealing the origin and evolution of Jupiter.

Specifically, Juno will… 

  • Determine how much water is in Jupiter’s atmosphere, which helps determine which planet formation theory is correct (or if new theories are needed)
  • Look deep into Jupiter’s atmosphere to measure composition, temperature, cloud motions and other properties
  • Map Jupiter’s magnetic and gravity fields, revealing the planet’s deep structure
  • Explore and study Jupiter’s magnetosphere near the planet’s poles, especially the auroras – Jupiter’s northern and southern lights – providing new insights about how the planet’s enormous magnetic force field affects its atmosphere.

Juno’s principal goal is to understand the origin and evolution of Jupiter. Underneath its dense cloud cover, Jupiter safeguards secrets to the fundamental processes and conditions that governed our solar system during its formation. As our primary example of a giant planet, Jupiter can also provide critical knowledge for understanding the planetary systems being discovered around other stars.

With its suite of science instruments, Juno will investigate the existence of a solid planetary core, map Jupiter’s intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet’s auroras.

While the events below are for the media, the public is invited to watch each of the events starting on June 16. The following are televised events are: 

NASA TV Events Schedule 

For all media briefings, reporters may ask questions by phone by contacting Gina Fontes at 818-354-9380 or georgina.d.fontes@jpl.nasa.gov. All times are Eastern.
 

Thursday, June 16
2 p.m. — Mission status briefing at NASA Headquarters in Washington

Thursday, June 30
4 p.m. — Mission overview news briefing at JPL
5 p.m. — Mission outreach briefing at JPL

Monday, July 4 – Orbit Insertion Day
Noon — Pre-orbit insertion briefing at JPL
10:30 p.m. — Orbit insertion and NASA TV commentary begin

Tuesday, July 5
1 a.m. — Post-orbit insertion briefing at JPL

 

To watch all of these events online, visit: http://www.nasa.gov/nasatv or http://www.ustream.tv/nasa or http://www.ustream.tv/nasajpl


Additional material on Juno’s mission was added from additional sources by George McGinn to add more about why these events are important to planetary science.  – George McGinn 

Media Invited to See NASA’s Orion Crew Module for its Journey to Mars

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January 20, 2016
MEDIA ADVISORY M16-005

*** NOTE: Press release are usually published under that page “Media Releases (Information for Journalist).” These press releases are usually meetings or presentation of studies. The public will most of the time have access to view or listen to most of these, but only credentialed media can ask question.

Also, before the meeting documentation may be made available, sometimes weeks before the meeting. If the documents are embargoed, we in the press know that means the information cannot be published before the embargo date and time. We use the time to pre-write our stories and prepare questions, but the embargo must be honored by all.

–  George McGinn, Examining Life (And Things of Interest), Daily Defense News and Cosmology and Space Exploration news websites.


Orion’s pressure vessel was completed Jan. 13, 2016 at NASA’s Michoud Assembly Facility in New Orleans. The pressure vessel is the spacecraft’s underlying structure on which all of the spacecraft’s systems and subsystems are built and integrated. (Credit: NASA)

 

NASA’s Orion crew module will be available to media at two NASA locations Jan. 26th and in early February, as engineers continue to prepare the spacecraft to send astronauts deeper into space than ever before, including to an asteroid placed in lunar orbit and on the journey to Mars.

At 10:30 a.m. EST on Tuesday, Jan. 26, the agency’s Michoud Assembly Facility in New Orleans will host a media viewing and facility tour of the spacecraft’s recently completed pressure vessel, the underlying structure of the crew module, before it ships to NASA’s Kennedy Space Center in Florida.

To attend the event at Michoud, reporters must contact Chip Howat at 504-257-0478 or carl.j.howat@nasa.gov by 3 p.m. Monday, Jan. 25. International media accreditation for this event is closed.

The Orion pressure vessel provides a sealed environment for astronaut life support in future human-rated crew modules. Technicians at Michoud began welding together the seven large aluminum pieces of Orion’s primary structure in precise detail last September. At Kennedy, Orion will be outfitted with the spacecraft’s systems and subsystems, processed and integrated with NASA’s Space Launch System (SLS) ahead of their first joint exploration mission, or EM-1.

Michoud also is where the massive core stage of SLS is being manufactured. Reporters will be able to view tooling and newly manufactured hardware for SLS, and hear about mission progress from personnel across NASA.

Individuals available for interviews during the tour include:

  • Bill Hill, deputy associate administrator for Exploration Systems Development at NASA Headquarters in Washington
  • Mike Sarafin, EM-1 mission manager at NASA Headquarters
  • Mark Kirasich, Orion program manager at NASA’s Johnson Space Center in Houston
  • Scott Wilson, Orion production manager at Kennedy
  • John Honeycutt, SLS program manager at the agency’s Marshall Space Flight Center in Huntsville, Alabama
  • Steve Doering, SLS core stage manager at Marshall
  • Mike Bolger, Ground Systems Development and Operations program manager at Kennedy
  • NASA astronaut Rick Mastracchio
  • Mike Hawes, Orion program manager for Lockheed Martin
  • Jim Bray, crew module director for Lockheed Martin 

Orion will depart Michoud on or about Feb. 1 and travel to Kennedy aboard NASA’s Super Guppy airplane. Additional details for Orion’s arrival at Kennedy, including media accreditation, are forthcoming.

For more information about Orion, visit: http://www.nasa.gov/orion

-end- 

 

Lowdown on Ceres: Images From Dawn’s Closest Orbit

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This image of Ceres was taken in Dawn’s low-altitude mapping orbit around a crater chain called Gerber Catena. A 3-D view is also available. Image (Credit: NASA/JPL-CaltechCaltech/UCLA/MPS/DLR/IDA)

 

NASA’s Dawn spacecraft, cruising in its lowest and final orbit at dwarf planet Ceres, has delivered the first images from its best-ever viewpoint. The new images showcase details of the cratered and fractured surface. 3-D versions of two of these views are also available.

Dawn took these images of the southern hemisphere of Ceres on Dec. 10, at an approximate altitude of 240 miles (385 kilometers), which is its lowest-ever orbital altitude. Dawn will remain at this altitude for the rest of its mission, and indefinitely afterward. The resolution of the new images is about 120 feet (35 meters) per pixel.

Among the striking views is a chain of craters called Gerber Catena, located just west of the large crater Urvara. Troughs are common on larger planetary bodies, caused by contraction, impact stresses and the loading of the crust by large mountains — Olympus Mons on Mars is one example. The fracturing found all across Ceres’ surface indicates that similar processes may have occurred there, despite its smaller size (the average diameter of Ceres is 584 miles, or 940 kilometers). Many of the troughs and grooves on Ceres were likely formed as a result of impacts, but some appear to be tectonic, reflecting internal stresses that broke the crust.

“Why they are so prominent is not yet understood, but they are probably related to the complex crustal structure of Ceres,” said Paul Schenk, a Dawn science team member at the Lunar and Planetary Institute, Houston.

The images were taken as part of a test of Dawn’s backup framing camera. The primary framing camera, which is essentially identical, began its imaging campaign at this lowest orbit on Dec. 16. Both cameras are healthy.

Dawn’s other instruments also began their intense period of observations this month. The visible and infrared mapping spectrometer will help identify minerals by looking at how various wavelengths of light are reflected by the surface of Ceres. The gamma ray and neutron detector is also active. By measuring the energies and numbers of gamma rays and neutrons, two components of nuclear radiation, it will help scientists determine the abundances of some elements on Ceres.

Earlier in December, Dawn science team members revealed that the bright material found in such notable craters as Occator is consistent with salt — and proposed that a type of magnesium sulfate called hexahydrite may be present. A different group of Dawn scientists found that Ceres also contains ammoniated clays. Because ammonia is abundant in the outer solar system, this finding suggests that Ceres could have formed in the vicinity of Neptune and migrated inward, or formed in place with material that migrated in from the outer solar system.

“As we take the highest-resolution data ever from Ceres, we will continue to examine our hypotheses and uncover even more surprises about this mysterious world,” said Chris Russell, principal investigator of the Dawn mission, based at the University of California, Los Angeles.

Dawn is the first mission to visit a dwarf planet, and the first mission outside the Earth-moon system to orbit two distinct solar system targets. It orbited protoplanet Vesta for 14 months in 2011 and 2012, and arrived at Ceres on March 6, 2015.

Dawn’s mission is managed by the Jet Propulsion Laboratory for NASA’s Science Mission Directorate in Washington. Dawn is a project of the directorate’s Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit: http://dawn.jpl.nasa.gov/mission

More information about Dawn is available at the following sites: http://dawn.jpl.nasa.gov and http://www.nasa.gov/dawn

NASA’s Curiosity Rover Inspects Unusual Bedrock (High-Silica ‘Lamoose’ Rock)

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A rock fragment dubbed “Lamoose” is shown in this picture taken by the Mars Hand Lens Imager (MAHLI) on NASA’s Curiosity rover. Like other nearby rocks in a portion of the “Marias Pass” area of Mt. Sharp, Mars, it has unusually high concentrations of silica. ( Image credit: NASA/JPL-Caltech/MSSS)

Fast Facts:

  • Rover examines geological contact zone near ‘Marias Pass’
  • Silica-rich rocks identified nearby with laser-firing instrument
  • Test of rover’s drill prepares for next use on Mars rock

Approaching the third anniversary of its landing on Mars, NASA’s Curiosity Mars rover has found a target unlike anything it has studied before — bedrock with surprisingly high levels of silica. Silica is a rock-forming compound containing silicon and oxygen, commonly found on Earth as quartz.

This area lies just downhill from a geological contact zone the rover has been studying near “Marias Pass” on lower Mount Sharp.

In fact, the Curiosity team decided to back up the rover 46 meters (151 feet) from the geological contact zone to investigate the high-silica target dubbed “Elk.” The decision was made after they analyzed data from two instruments, the laser-firing Chemistry & Camera (ChemCam) and Dynamic Albedo of Neutrons (DAN), which showed higher amounts of silicon and hydrogen, respectively. High levels of silica in the rock could indicate ideal conditions for preserving ancient organic material, if present, so the science team wants to take a closer look.

“One never knows what to expect on Mars, but the Elk target was interesting enough to go back and investigate,” said Roger Wiens, the principal investigator of the ChemCam instrument from the Los Alamos National Laboratory in New Mexico. ChemCam is coming up on its 1,000th target, having already fired its laser more than 260,000 times since Curiosity landed on Mars Aug. 6, 2012, Universal Time (evening of Aug. 5, Pacific Time).

In other news, an engineering test on the rover’s sample-collecting drill on July 18 is aiding analysis of intermittent short circuits in the drill’s percussion mechanism, in preparation for using the drill in the area where the rover has been working for the past two months. The latest test did not result in any short circuits, so the team plans to continue with more tests, performed on the science targets themselves.

Before Curiosity began further investigating the high-silica area, it was busy scrutinizing the geological contact zone near Marias Pass, where a pale mudstone meets darker sandstone.

 

A rock outcrop dubbed “Missoula,” near Marias Pass on Mars, is seen in this image mosaic taken by the Mars Hand Lens Imager on NASA’s Curiosity rover. Pale mudstone (bottom of outcrop) meets coarser sandstone (top) in this geological contact zone, which has piqued the interest of Mars scientists. (Image credit: NASA/JPL-Caltech/MSSS)

 

“We found an outcrop named Missoula where the two rock types came together, but it was quite small and close to the ground. We used the robotic arm to capture a dog’s-eye view with the MAHLI camera, getting our nose right in there,” said Ashwin Vasavada, the mission’s project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California. MAHLI is short for Mars Hand Lens Imager.

The rover had reached this area after a steep climbed a 20-foot (6-meter) hill. Near the top of the climb, the ChemCam instrument fired its laser at the target Elk, and took a spectral reading of its composition.

“ChemCam acts like eyes and ears of the rover for nearby objects,” said Wiens.

The rover had moved on before analyzing the Elk data, so the rover performed a U-turn to get more data. Upon its return, the rover was able to study a similar target, “Lamoose,” up close with the MAHLI camera and the arm-mounted Alpha Particle X-ray Spectrometer (APXS).

Curiosity has been working on Mars since early August 2012. It reached the base of Mount Sharp last year after fruitfully investigating outcrops closer to its landing site and then trekking to the mountain. The main mission now is to look at successively higher layers of Mount Sharp.

The U.S. Department of Energy’s Los Alamos National Laboratory developed ChemCam in partnership with scientists and engineers funded by the French national space agency. Russia’s space agency provided Curiosity’s DAN instrument. JPL, a division of the California Institute of Technology in Pasadena, built the rover and manages the project for NASA’s Science Mission Directorate in Washington.

For more information about Curiosity, visit: http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl

You can also follow the mission on Facebook and Twitter at: http://www.facebook.com/marscuriosity and http://www.twitter.com/marscuriosity

NASA’s New Horizons Discovers Frozen Plains in the Heart of Pluto’s ‘Heart’

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July 17, 2015
RELEASE 15-154

Closeup of Pluto surface heart-shaped feature showing plain
In the center left of Pluto’s vast heart-shaped feature – informally named “Tombaugh Regio” – lies a vast, craterless plain that appears to be no more than 100 million years old, and is possibly still being shaped by geologic processes. This frozen region is north of Pluto’s icy mountains and has been informally named Sputnik Planum (Sputnik Plain), after Earth’s first artificial satellite. The surface appears to be divided into irregularly-shaped segments that are ringed by narrow troughs. Features that appear to be groups of mounds and fields of small pits are also visible. This image was acquired by the Long Range Reconnaissance Imager (LORRI) on July 14 from a distance of 48,000 miles (77,000 kilometers). Features as small as one-half mile (1 kilometer) across are visible. The blocky appearance of some features is due to compression of the image.
Credits: NASA/JHUAPL/SWRI

In the latest data from NASA’s New Horizons spacecraft, a new close-up image of Pluto reveals a vast, craterless plain that appears to be no more than 100 million years old, and is possibly still being shaped by geologic processes. This frozen region is north of Pluto’s icy mountains, in the center-left of the heart feature, informally named “Tombaugh Regio” (Tombaugh Region) after Clyde Tombaugh, who discovered Pluto in 1930.

“This terrain is not easy to explain,” said Jeff Moore, leader of the New Horizons Geology, Geophysics and Imaging Team (GGI) at NASA’s Ames Research Center in Moffett Field, California. “The discovery of vast, craterless, very young plains on Pluto exceeds all pre-flyby expectations.”

This fascinating icy plains region — resembling frozen mud cracks on Earth — has been informally named “Sputnik Planum” (Sputnik Plain) after the Earth’s first artificial satellite. It has a broken surface of irregularly-shaped segments, roughly 12 miles (20 kilometers) across, bordered by what appear to be shallow troughs. Some of these troughs have darker material within them, while others are traced by clumps of hills that appear to rise above the surrounding terrain. Elsewhere, the surface appears to be etched by fields of small pits that may have formed by a process called sublimation, in which ice turns directly from solid to gas, just as dry ice does on Earth.

Scientists have two working theories as to how these segments were formed. The irregular shapes may be the result of the contraction of surface materials, similar to what happens when mud dries. Alternatively, they may be a product of convection, similar to wax rising in a lava lamp. On Pluto, convection would occur within a surface layer of frozen carbon monoxide, methane and nitrogen, driven by the scant warmth of Pluto’s interior.

Pluto’s icy plains also display dark streaks that are a few miles long. These streaks appear to be aligned in the same direction and may have been produced by winds blowing across the frozen surface.

The Tuesday “heart of the heart” image was taken when New Horizons was 48,000 miles (77,000 kilometers) from Pluto, and shows features as small as one-half mile (1 kilometer) across. Mission scientists will learn more about these mysterious terrains from higher-resolution and stereo images that New Horizons will pull from its digital recorders and send back to Earth during the next year.

The New Horizons Atmospheres team observed Pluto’s atmosphere as far as 1,000 miles (1,600 kilometers) above the surface, demonstrating that Pluto’s nitrogen-rich atmosphere is quite extended. This is the first observation of Pluto’s atmosphere at altitudes higher than 170 miles above the surface (270 kilometers).

The New Horizons Particles and Plasma team has discovered a region of cold, dense ionized gas tens of thousands of miles beyond Pluto — the planet’s atmosphere being stripped away by the solar wind and lost to space.

“This is just a first tantalizing look at Pluto’s plasma environment,” said New Horizons co-investigator Fran Bagenal, University of Colorado, Boulder.

“With the flyby in the rearview mirror, a decade-long journey to Pluto is over –but, the science payoff is only beginning,” said Jim Green, director of Planetary Science at NASA Headquarters in Washington. “Data from New Horizons will continue to fuel discovery for years to come.”

Alan Stern, New Horizons principal investigator from the Southwest Research Institute (SwRI), Boulder, Colorado, added, “We’ve only scratched the surface of our Pluto exploration, but it already seems clear to me that in the initial reconnaissance of the solar system, the best was saved for last.”

New Horizons is part of NASA’s New Frontiers Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama. 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.

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

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

NASA to Hold Media Call to Discuss Surprising Observations of Pluto’s Moons

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The NASA New Horizon’s Mission to Pluto, in a nutshell (Credit: NASA)

NASA will host a media teleconference at 1 p.m. EDT on Wednesday, June 3, to discuss the Hubble Space Telescope’s surprising observations of how Pluto’s moons behave, and how these new discoveries are being used in the planning for the New Horizons Pluto flyby in July.
Participants in the teleconference will be:

  • John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington
  • Mark Showalter, senior research scientist at the SETI Institute in Mountain View, California
  • Douglas Hamilton, professor of astronomy at the University of Maryland, College Park
  • John Spencer, scientist at Southwest Research Institute in Boulder, Colorado
  • Heidi Hammel, executive vice president of the Association of Universities for Research in Astronomy in Washington

To participate by phone, reporters must contact Felicia Chou at 202-358-0257 or felicia.chou@nasa.gov and provide their media affiliation no later than 10 a.m. Wednesday.

NASA’s public flyer (2-page PDF) on the New Horizon’s Project at: http://www.nasa.gov/sites/default/files/files/NHMissionFS082114HiPrint.pdf

Audio of the teleconference will be streamed live at: http://www.nasa.gov/newsaudio.

For information about NASA’s Hubble Space Telescope, visit: http://www.nasa.gov/hubble.

For information about Pluto and NASA’s New Horizons mission, visit: http://www.nasa.gov/newhorizons.

Misson to Pluto’s and NASA’s key milestones for the New Horizons Spacecraft (Credit NASA)

NASA Completes MESSENGER Mission with Expected Impact on Mercury’s Surface

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 Artist concept of the MESSENGER spacecraft in orbit around planet Mercury. Image Credit: NASA
Artist concept of the MESSENGER spacecraft in orbit around planet Mercury. Image Credit: NASA

A NASA planetary exploration mission came to a planned, but nonetheless dramatic, end Thursday when it slammed into Mercury’s surface at about 8,750 mph and created a new crater on the planet’s surface.

Mission controllers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, have confirmed NASA’s MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft impacted the surface of Mercury, as anticipated, at 3:26 p.m. EDT.

Mission control confirmed end of operations just a few minutes later, at 3:40 p.m., when no signal was detected by NASA’s Deep Space Network (DSN) station in Goldstone, California, at the time the spacecraft would have emerged from behind the planet. This conclusion was independently confirmed by the DSN’s Radio Science team, which also was monitoring for a signal from MESSENGER.

“Going out with a bang as it impacts the surface of Mercury, we are celebrating MESSENGER as more than a successful mission,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “The MESSENGER mission will continue to provide scientists with a bonanza of new results as we begin the next phase of this mission–analyzing the exciting data already in the archives, and unravelling the mysteries of Mercury.”

Prior to impact, MESSENGER’s mission design team predicted the spacecraft would pass a few miles over a lava-filled basin on the planet before striking the surface and creating a crater estimated to be as wide as 50 feet.

Mercury’s lonely demise on the small, scorched planet closest to the sun went unobserved because the probe hit the side of the planet facing away from Earth, so ground-based telescopes were not able to capture the moment of impact. Space-based telescopes also were unable to view the impact, as Mercury’s proximity to the sun would damage optics.

MESSENGER’s last day of real-time flight operations began at 11:15 a.m., with initiation of the final delivery of data and images from Mercury via a 230-foot (70-meter) DSN antenna located in Madrid, Spain. After a planned transition to a 111-foot (34-meter) DSN antenna in California, at 2:40 p.m., mission operators later confirmed the switch to a beacon-only communication signal at 3:04 p.m.

The mood in the Mission Operations Center at APL was both somber and celebratory as team members watched MESSENGER’s telemetry drop out for the last time, after more than four years and 4,105 orbits around Mercury.

“We monitored MESSENGER’s beacon signal for about 20 additional minutes,” said mission operations manager Andy Calloway of APL. “It was strange to think during that time MESSENGER had already impacted, but we could not confirm it immediately due to the vast distance across space between Mercury and Earth.”

MESSENGER was launched on Aug. 3, 2004, and began orbiting Mercury on March 17, 2011. Although it completed its primary science objectives by March 2012, the spacecraft’s mission was extended two times, allowing it to capture images and information about the planet in unprecedented detail.

During a final extension of the mission in March, referred to as XM2, the team began a hover campaign that allowed the spacecraft to operate within a narrow band of altitudes from five to 35 kilometers from the planet’s surface.

On Tuesday, the team successfully executed the last of seven daring orbit correction maneuvers that kept MESSENGER aloft long enough for the spacecraft’s instruments to collect critical information on Mercury’s crustal magnetic anomalies and ice-filled polar craters, among other features. After running out of fuel, and with no way to increase its altitude, MESSENGER was finally unable to resist the sun’s gravitational pull on its orbit.  

“Today we bid a fond farewell to one of the most resilient and accomplished spacecraft to ever explore our neighboring planets,” said Sean Solomon, MESSENGER’s principal investigator and director of Columbia University’s Lamont-Doherty Earth Observatory in Palisades, New York. “A resourceful and committed team of engineers, mission operators, scientists, and managers can be extremely proud that the MESSENGER mission has surpassed all expectations and delivered a stunningly long list of discoveries that have changed our views–not only of one of Earth’s sibling planets, but of the entire inner solar system.”

Among its many accomplishments, the MESSENGER mission determined Mercury’s surface composition, revealed its geological history, discovered its internal magnetic field is offset from the planet’s center, and verified its polar deposits are dominantly water ice.

APL built and operated the MESSENGER spacecraft and managed the mission for NASA’s Science Mission Directorate in Washington.

Learn more about the accomplishments of NASA’s MESSENGER mission at: https://www.youtube.com/watch?v=ENwD31EDFjc and http://www.nasa.gov/messenger

Icy Tendrils Reaching into Saturn Ring Traced to Their Source

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This collage, consisting of two Cassini images of long, sinuous, tendril-like features from Saturn’s moon Enceladus and two corresponding computer simulations of the same, illustrates how well the structures, and the sizes of the particles composing them, can be modeled by tracing the trajectories of tiny, icy grains ejected from Enceladus’ south polar geysers. Credit: NASA/JPL-Caltech/Space Science Institute

Long, sinuous, tendril-like structures seen in the vicinity of Saturn’s icy moon Enceladus originate directly from geysers erupting from its surface, according to scientists studying images from NASA’s Cassini spacecraft.

This result is published online today in a study in the Astronomical Journal, along with additional insights into the nature of the structures.

“We’ve been able to show that each unique tendril structure can be reproduced by particular sets of geysers on the moon’s surface,” said Colin Mitchell, a Cassini imaging team associate at the Space Science Institute in Boulder, Colorado, and lead author of the paper. Mitchell and colleagues used computer simulations to follow the trajectories of ice grains ejected from individual geysers. The geysers, which were discovered by Cassini in 2005, are jets of tiny water ice particles, water vapor and simple organic compounds.

Under certain lighting conditions, Cassini’s wide-view images showing icy material erupting from Enceladus reveal faint, finger-like features, dubbed “tendrils” by the imaging team. The tendrils reach into Saturn’s E ring — the ring in which Enceladus orbits — extending tens of thousands of miles (or kilometers) away from the moon. Since the tendrils were discovered, scientists have thought they were the result of the moon’s geysering activity and the means by which Enceladus supplies material to the E ring. But the ghostly features had never before been traced directly to geysers on the surface.

Because the team was able to show that tendril structures of different shapes correspond to different sizes of geyser particles, the team was able to zero in on the sizes of the particles forming them. They found the tendrils are composed of particles with diameters no smaller than about a hundred thousandth of an inch, a size consistent with the measurements of E-ring particles made by other Cassini instruments.

As the researchers examined images from different times and positions around Saturn, they also found that the detailed appearance of the tendrils changes over time. “It became clear to us that some features disappeared from one image to the next,” said John Weiss, an imaging team associate at Saint Martin’s University in Lacey, Washington, and an author on the paper.

The authors suspect that changes in the tendrils’ appearance likely result from the cycle of tidal stresses — squeezing and stretching of the moon as it orbits Saturn — and its control of the widths of fractures from which the geysers erupt. The stronger the tidal stresses raised by Saturn at any point on the fractures, the wider the fracture opening and the greater the eruption of material. The authors will investigate in future work whether this theory explains the tendrils’ changing appearance.

There is even more that can be extracted from the images, the scientists say. “As the supply lanes for Saturn’s E ring, the tendrils give us a way to ascertain how much mass is leaving Enceladus and making its way into Saturn orbit,” said Carolyn Porco, team leader for the imaging experiment and a coauthor on the paper. “So, another important step is to determine how much mass is involved, and thus estimate how much longer the moon’s sub-surface ocean may last.” An estimate of the lifetime of the ocean is important in understanding the evolution of Enceladus over long timescales.

Because of its significance to the investigation of possible extraterrestrial habitable zones, Enceladus is a major target of investigation for the final years of the Cassini mission. Many observations, including imaging of the plume and tendril features, and thermal observations of the surface of its south polar geyser basin, are planned during the next couple of years.

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, Colo.

New images released today can be found at:

http://www.ciclops.org/view_event/205

More information about Cassini, visit:

http://www.nasa.gov/cassini

http://saturn.jpl.nasa.gov

Dawn’s Ceres Color Map Reveals Surface Diversity

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Dawn’s First Color Map of Ceres Dawn VIR Images of Ceres This map-projected view of Ceres was created from images taken by NASA’s Dawn spacecraft during its initial approach to the dwarf planet, prior to being captured into orbit in March 2015. Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
 


A new color map of dwarf planet Ceres, which NASA’s Dawn spacecraft has been orbiting since March, reveals the diversity of the surface of this planetary body. Differences in morphology and color across the surface suggest Ceres was once an active body, Dawn researchers said today at the 2015 General Assembly of the European Geosciences Union in Vienna. 

“This dwarf planet was not just an inert rock throughout its history. It was active, with processes that resulted in different materials in different regions. We are beginning to capture that diversity in our color images,” said Chris Russell, principal investigator for the Dawn mission, based at the University of California, Los Angeles. 

The Dawn mission made history on March 6 as the first spacecraft to reach a dwarf planet, and the first spacecraft to orbit two extraterrestrial targets. Previously, Dawn studied giant asteroid Vesta from 2011 to 2012, uncovering numerous insights about its geology and history. While Vesta is a dry body, Ceres is believed to be 25 percent water ice by mass. By comparing Vesta and Ceres, scientists hope to gain a better understanding of the formation of the solar system. 

Ceres’ surface is heavily cratered, as expected, but appears to have fewer large craters than scientists anticipated. It also has a pair of very bright neighboring spots in its northern hemisphere. More detail will emerge after the spacecraft begins its first intensive science phase on April 23, from a distance of 8,400 miles (13,500 kilometers) from the surface, said Martin Hoffmann, investigator on the Dawn framing camera team, based at the Max Planck Institute for Solar System Research, Göttingen, Germany. 

The visible and infrared mapping spectrometer (VIR), an imaging spectrometer that examines Ceres in visible and infrared light, has been examining the relative temperatures of features on Ceres’ surface. Preliminary examination suggests that different bright regions on Ceres’ surface behave differently, said Federico Tosi, investigator from the VIR instrument team at the Institute for Space Astrophysics and Planetology, and the Italian National Institute for Astrophysics, Rome. 

Based on observations from NASA’s Hubble Space Telescope, planetary scientists have identified 10 bright regions on Ceres’ surface. One pair of bright spots, by far the brightest visible marks on Ceres, appears to be located in a region that is similar in temperature to its surroundings. But a different bright feature corresponds to a region that is cooler than the rest of Ceres’ surface. 

The origins of Ceres’ bright spots, which have captivated the attention of scientists and the public alike, remain unknown. It appears the brightest pair is located in a crater 57 miles (92 kilometers) wide. As Dawn gets closer to the surface of Ceres, better-resolution images will become available.

“The bright spots continue to fascinate the science team, but we will have to wait until we get closer and are able to resolve them before we can determine their source,” Russell said. 

Both Vesta and Ceres are located in the main asteroid belt between Mars and Jupiter. The Dawn spacecraft will continue studying Ceres through June 2016. 

Dawn’s mission is managed by NASA’s Jet Propulsion Laboratory, Pasadena, California, for NASA’s Science Mission Directorate in Washington. Dawn is a project of the directorate’s Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit: 

http://dawn.jpl.nasa.gov/mission/

For more information about Dawn, visit:

http://dawn.jpl.nasa.gov

NASA’s New Horizons Spacecraft Nears Historic July 14 Encounter with Pluto

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Artist’s impression of NASA’s New Horizons spacecraft encountering Pluto and its largest moon, Charon, in July 2015. Image Credit: NASA/Applied Physics Laboratory/Southwest Research Institute
 


(PRESS RELEASE) – NASA’s New Horizons spacecraft is three months from returning to humanity the first-ever close up images and scientific observations of distant Pluto and its system of large and small moons.

“Scientific literature is filled with papers on the characteristics of Pluto and its moons from ground based and Earth orbiting space observations, but we’ve never studied Pluto up close and personal,” said John Grunsfeld, astronaut, and associate administrator of the NASA Science Mission Directorate at the agency’s Headquarters in Washington.  “In an unprecedented flyby this July, our knowledge of what the Pluto systems is really like will expand exponentially and I have no doubt there will be exciting discoveries.”  

The fastest spacecraft ever launched, New Horizons has traveled a longer time and farther away – more than nine years and three billion miles – than any space mission in history to reach its primary target. Its flyby of Pluto and its system of at least five moons on July 14 will complete the initial reconnaissance of the classical solar system. This mission also opens the door to an entirely new “third” zone of mysterious small planets and planetary building blocks in the Kuiper Belt, a large area with numerous objects beyond Neptune’s orbit.

The flyby caps a five-decade-long era of reconnaissance that began with Venus and Mars in the early 1960s, and continued through first looks at Mercury, Jupiter and Saturn in the 1970s and Uranus and Neptune in the 1980s.

Reaching this third zone of our solar system – beyond the inner, rocky planets and outer gas giants – has been a space science priority for years. In the early 2000s the National Academy of Sciences ranked the exploration of the Kuiper Belt – and particularly Pluto and its largest moon, Charon – as its top priority planetary mission for the coming decade.

New Horizons – a compact, lightweight, powerfully equipped probe packing the most advanced suite of cameras and spectrometers ever sent on a first reconnaissance mission – is NASA’s answer to that call.

“This is pure exploration; we’re going to turn points of light into a planet and a system of moons before your eyes!” said Alan Stern, New Horizons principal investigator from Southwest Research Institute (SwRI) in Boulder, Colorado. “New Horizons is flying to Pluto – the biggest, brightest and most complex of the dwarf planets in the Kuiper Belt. This 21st century encounter is going to be an exploration bonanza unparalleled in anticipation since the storied missions of Voyager in the 1980s.”

Pluto, the largest known body in the Kuiper Belt, offers a nitrogen atmosphere, complex seasons, distinct surface markings, an ice-rock interior that may harbor an ocean, and at least five moons. Among these moons, the largest – Charon – may itself sport an atmosphere or an interior ocean, and possibly even evidence of recent surface activity.

“There’s no doubt, Charon is a rising star in terms of scientific interest, and we can’t wait to reveal it in detail in July,” said Leslie Young, deputy project scientist at SwRI.

Pluto’s smaller moons also are likely to present scientific opportunities. When New Horizons was started in 2001, it was a mission to just Pluto and Charon, before the four smaller moons were discovered.

The spacecraft’s suite of seven science instruments – which includes cameras, spectrometers, and plasma and dust detectors – will map the geology of Pluto and Charon and map their surface compositions and temperatures; examine Pluto’s atmosphere, and search for an atmosphere around Charon; study Pluto’s smaller satellites; and look for rings and additional satellites around Pluto.

Currently, even with New Horizons closer to Pluto than the Earth is to the Sun, the Pluto system resembles little more than bright dots in the distance. But teams operating the spacecraft are using these views to refine their knowledge of Pluto’s location, and skillfully navigate New Horizons toward a precise target point 7,750 miles (12,500 kilometers) from Pluto’s surface. That targeting is critical, since the computer commands that will orient the spacecraft and point its science instruments are based on knowing the exact time and location that New Horizons passes Pluto.

“Our team has worked hard to get to this point, and we know we have just one shot to make this work,” said Alice Bowman, New Horizons mission operations manager at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, which built and operates the spacecraft. “We’ve plotted out each step of the Pluto encounter, practiced it over and over, and we’re excited the ‘real deal’ is finally here.”

The spacecraft’s work doesn’t end with the July flyby. Because it gets one shot at its target, New Horizons is designed to gather as much data as it can, as quickly as it can, taking about 100 times as much data on close approach as it can send home before flying away. And although the spacecraft will send select, high-priority datasets home in the days just before and after close approach, the mission will continue returning the data stored in onboard memory for a full 16 months.

“New Horizons is one of the great explorations of our time,” said New Horizons Project Scientist Hal Weaver at APL. “There’s so much we don’t know, not just about Pluto, but other worlds like it. We’re not rewriting textbooks with this historic mission – we’ll be writing them from scratch.”

APL manages the New Horizons mission for NASA’s Science Mission Directorate in Washington. Alan Stern of SwRI is the principal investigator. SwRI leads the science team, payload operations and encounter science planning. New Horizons is part of the New Frontiers Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama.

For more information on New Horizons, visit:

http://www.nasa.gov/newhorizons

and

http://pluto.jhuapl.edu