dimanche 23 octobre 2016

Cygnus Attached to Station’s Unity Module

Orbital ATK - Antares / Cygnus OA-5 Mission logo.

October 23, 2016

U.S. Commercial Cargo Ship Arrives at the Space Station. Video: NASA TV

Orbital ATK’s Cygnus cargo spacecraft was berthed to the Unity module of the International Space Station at 10:53 a.m. EDT. The Expedition 49 crew will begin unloading approximately 5,000 pounds of science investigations, food and supplies when the hatch between the newly arrived spacecraft and the Unity module of the space station is opened. The spacecraft is scheduled to spend a little more than a month attached to the station.

Image above: Today’s installation of the Orbital ATK Cygnus resupply ship makes four spaceships attached to the International Space Station. Image Credit: NASA TV.

Expedition 49 Flight Engineers Takuya Onishi of the Japan Aerospace Exploration Agency and Kate Rubins of NASA successfully captured Orbital ATK’s Cygnus spacecraft with the station’s robotic arm at 7:28 a.m. EDT. NASA TV coverage of operations to install Cygnus to the space station’s Unity module begins at 9 a.m.

Image above: The Cygnus resupply ship slowly approaches the space station before the Canadarm2 reaches out and grapples it. Image Credit: NASA TV.

Orbital ATK’s Cygnus was launched on the company’s Antares rocket Monday, Oct 17, from the Mid-Atlantic Regional Spaceport Pad 0A at NASA’s Wallops Flight Facility in Virginia. Cygnus will remain attached to Unity until a planned departure in November sends the spacecraft toward a destructive re-entry in Earth’s atmosphere.

For more information about newly arrived science investigations aboard the Cygnus, visit: http://www.nasa.gov/station

Images (mentioned), Video (mentioned), Text, Credits: NASA/Mark Garcia.

Best regards, Orbiter.ch

vendredi 21 octobre 2016

NASA Establishes the Small Spacecraft Systems Virtual Institute

NASA patch.

Oct. 21, 2016

Small satellites or CubeSats launched in space from ISS. Image Credit: NASA

NASA announces the addition of its newest virtual institute to advance the field of small spacecraft systems. The Small Spacecraft Systems Virtual Institute (S3VI), hosted at NASA’s Ames Research Center in Moffett Field, California, will leverage the growing small spacecraft community, promote innovation, identify emerging technology opportunities, and provide an efficient channel for communication about small spacecraft systems with industry, academia, and other government agencies.

“NASA sees enormous benefits from investing in research and technology development in small spacecraft systems, such as propulsion, that will be essential in advancing the commercial space sector,” said Steve Jurczyk, associate administrator for NASA’s Space Technology Mission Directorate (STMD). “Over the past several years, NASA has increased the generation of new, innovative applications of small spacecraft, with several mission directorates using small spacecraft to meet their goals.”

STMD established the Small Spacecraft Technology Program in 2011 to develop and demonstrate the unique capabilities of small spacecraft to support science, exploration and space operations. The Science Mission Directorate (SMD) and the Human Exploration and Operations Mission Directorate (HEOMD) each are using small spacecraft for a range of activities: earth and space science measurements to help understand our environment; investigations of microgravity effects on organisms to enable the safe exploration of space; and robotic precursors to maximize the productive use of space.

Animation above: Taken by astronauts on May 16, 2016, these images show a CubeSat deployment from the International Space Station. The bottom-most CubeSat is the NASA-funded MinXSS CubeSat, built by the University of Colorado, Boulder. Animation Credit: NASA.

The S3VI will coordinate with key activities such as STMD’s Cube Quest Challenge and HEOMD’s CubeSat Launch Initiative (CLSI). These efforts will continue to offer opportunities for university students and industry to fly small spacecraft as auxiliary payloads on NASA launches.

“The S3VI will provide the first one-stop shop for technical knowledge in the rapidly burgeoning small spacecraft technology fields,” said Jay Bookbinder, director of programs and projects at Ames. “This will result in more efficient development efforts, and enable smaller vendors to compete more effectively in this market.”

Depending on the mission objective, a small spacecraft can range in size from a postage-stamp (under an ounce) up to the size of a refrigerator (about 400 pounds). Many recently launched NASA small spacecraft conform to the CubeSat standards - established by academia - in which a single cube (called a one-unit, or 1U) measures about 4 inches on each side, has an approximate volume of one quart, and weighs less than three pounds. The variety of sizes offers spacecraft capabilities tailored to specific science instruments, exploration sensors, or technology demonstrations.

Over the next year, the S3VI will establish both a physical and virtual presence within NASA and the small spacecraft community at large. Strategic direction and tactical focus for the Institute will result from a series of community activities and workshops. The S3VI will engage with the small spacecraft communities, including academia, industry, and other government agencies to:

- Establish the Institute as the common portal into NASA for all small spacecraft activities. The Institute will capture information on small spacecraft activities and lessons learned; identify small spacecraft collaborative opportunities; and identify NASA points of contact for a variety of small spacecraft activities across the centers.

- Engage subject matter experts from across the small spacecraft communities to define the technical scope, policy issues and direction for the Institute.

- Host the Small Spacecraft Body of Knowledge (SSBK) as an online resource. This includes STMD’s Small Spacecraft Technology State of the Art report, a small spacecraft lessons learned library, a systems test data repository, reliability practices, etc.

The S3VI portal will go live in early 2017, and is jointly sponsored by NASA’s Space Technology Mission Directorate and the Science Mission Directorate. The S3VI is hosted at and managed by NASA’s Ames Research Center in Moffett Field, California.

For more information about the Space Technology Mission Directorate, visit: http://www.nasa.gov/spacetech

For more information about the Science Mission Directorate, visit: https://science.nasa.gov

For more information about small satellites, visit: http://www.nasa.gov/smallsats

Image (mentioned), Animation (mentioned), Text, Credits: NASA/Ames Research Center/Loura Hall.

Greetings, Orbiter.ch

Changing Colors in Saturn's North

NASA Cassini-Huygens Mission to Saturn & Titan patch.

Oct. 21, 2016

These two natural color images from NASA's Cassini spacecraft show the changing appearance of Saturn's north polar region between 2012 and 2016.

Scientists are investigating potential causes for the change in color of the region inside the north-polar hexagon on Saturn. The color change is thought to be an effect of Saturn's seasons. In particular, the change from a bluish color to a more golden hue may be due to the increased production of photochemical hazes in the atmosphere as the north pole approaches summer solstice in May 2017.

Researchers think the hexagon, which is a six-sided jetstream, might act as a barrier that prevents haze particles produced outside it from entering. During the seven-year-long Saturnian winter, the polar atmosphere became clear of aerosols produced by photochemical reactions -- reactions involving sunlight and the atmosphere. Since the planet experienced equinox in August 2009, the polar atmosphere has been basking in continuous sunshine, and aerosols are being produced inside of the hexagon, around the north pole, making the polar atmosphere appear hazy today.

Other effects, including changes in atmospheric circulation, could also be playing a role. Scientists think seasonally shifting patterns of solar heating probably influence the winds in the polar regions.

Both images were taken by the Cassini wide-angle camera.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of Caltech in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini. The Cassini imaging team homepage is at http://ciclops.org and ESA's website http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

Image, Text, Credits: NASA/Tony Greicius/JPL-Caltech/Space Science Institute/Hampton.University.

Best regards, Orbiter.ch

NASA, Citizen Scientists Discover Potential New Hunting Ground for Exoplanets

NASA logo.

Oct. 21, 2016

Image above: Artist’s concept of the newly discovered disk. Image Credits: Jonathan Holden.

Via a NASA-led citizen science project, eight people with no formal training in astrophysics helped discover what could be a fruitful new place to search for planets outside our solar system – a large disk of gas and dust encircling a star known as a circumstellar disk.

A paper, published in The Astrophysical Journal Letters and coauthored by eight citizen scientists involved in the discovery, describes a newly identified red dwarf star, AWI0005x3s, and its warm circumstellar disk, the kind associated with young planetary systems. Most of the exoplanets, which are planets outside our solar system, that have been imaged to date dwell in disks similar to the one around AWI0005x3s.

The disk and its star are located in what is dubbed the Carina association – a large, loose grouping of similar stars in the Carina Nebula approximately 212 light years from our sun. Its relative proximity to Earth will make it easier to conduct follow-on studies.

"Most disks of this kind fade away in less than 30 million years," said Steven Silverberg, a graduate student at Oklahoma University and lead author of the paper. "This particular red dwarf is a candidate member of the Carina association, which would make it around 45 million years old. It's the oldest red dwarf system with a disk we've seen in one of these associations."

Since the launch of NASA’s Disk Detective website in January 2014, approximately 30,000 citizen scientists have performed roughly two million classifications of stellar objects, including those that led to this discovery. Through Disk Detective, citizen scientists study data from NASA’s Wide-field Infrared Survey Explorer mission (WISE), the agency’s Two-Micron All Sky Survey project, and other stellar surveys.

"Without the help of the citizen scientists examining these objects and finding the good ones, we might never have spotted this object," said Marc Kuchner, an astrophysicist at NASA’s Goddard Space Fight Center in Greenbelt, Maryland, who leads Disk Detective. "The WISE mission alone found 747 million objects, of which we expect a few thousand to be circumstellar disks.”

The eight citizen scientist co-authors, members of an advanced user group, volunteered to help by researching disk candidates. Their data led to the discovery of this new disk.

“I’ve loved astronomy since childhood and wanted to be part of the space program, as did every boy my age,” adds Milton Bosch, a citizen scientist co-author from California. “I feel very fortunate to be part of such a great group of dedicated people, and am thrilled to partake in this adventure of discovery and be a co-author on this paper.”

Disk Detective is a collaboration between NASA, Zooniverse, the University of Oklahoma, University of Córdoba in Argentina, National Astronomical Observatory of Japan, Space Telescope Science Institute, Harvard-Smithsonian Center for Astrophysics, Carnegie Institution of Washington, University of Hawaii and Korea Astronomy and Space Science Institute.

To learn more about opportunities for the public to participate in NASA science and technology projects, visit: http://www.nasa.gov/solve

The Astrophysical Journal Letters: http://iopscience.iop.org/article/10.3847/2041-8205/830/2/L28/meta

NASA’s Disk Detective website: https://www.diskdetective.org/

NASA’s Wide-field Infrared Survey Explorer mission (WISE): https://www.nasa.gov/mission_pages/WISE/main/

Image (mentioned), Text, Credits: NASA/Sarah Ramsey.

Best regards, Orbiter.ch

Photonics Dawning as the Communications Light For Evolving NASA Missions

NASA - Goddard Space Flight Center logo.

Oct. 21, 2016

A largely unrecognized field called photonics may provide solutions to some of NASA’s most pressing challenges in future spaceflight.

Photonics explores the many applications of generating, detecting and manipulating photons, or particles of light that, among other things, make up laser beams. On this day in 1983, the General Conference of Weights and Measures adopted the accepted value for the speed of light, an important photonics milestone. Oct. 21, 2016, is Day of Photonics, a biennial event to raise awareness of photonics to the general public. The study has multiple applications across NASA missions, from space communications to reducing the size of mission payloads to performing altitude measurements from orbit.

NASA and Photonics: Making the Connection

Video above: NASA is using photonics to solve some of the most pressing upcoming challenges in spaceflight, such as better data communications from space to Earth. Video Credits: NASA's Goddard Space Flight Center/Amber Jacobson, producer.

One major NASA priority is to use lasers to make space communications for both near-Earth and deep-space missions more efficient. NASA’s communications systems have matured over the decades, but they still use the same radio-frequency (RF) system developed in the earliest days of the agency. After more than 50 years of using solely RF, NASA is investing in new ways to increase data rates while also finding more efficient communications systems.

Photonics may provide the solution. Several centers across NASA are experimenting with laser communications, which has the potential to provide data rates at least 10 to 100 times better than RF. These higher speeds would support increasingly sophisticated instruments and the transmission of live video from anywhere in the solar system. They would also increase the bandwidth for communications from human exploration missions in deep space, such as those associated with Journey to Mars.

NASA’s Goddard Space Flight Center in Greenbelt, Maryland, launched the first laser communications pathfinder mission in 2013. The Lunar Laser Communications Demonstration (LLCD) proved that a space-based laser communications system was viable and that the system could survive both launch and the space environment. But the mission was short-lived by design, as the host payload crashed into the lunar surface in a planned maneuver a few months after launch.

Animation above: Conceptual animation depicting a satellite using lasers to relay data from Mars to Earth. Animation Credits: NASA's Goddard Space Flight Center.

The Goddard team is now planning a follow-on mission called the Laser Communications Relay Demonstration (LCRD) to prove the proposed system’s longevity. It will also provide engineers more opportunity to learn the best way to operate it for near-Earth missions.

“We have been using RF since the beginning, 50 to 60 years, so we’ve learned a lot about how it works in different weather conditions and all the little things to allow us to make the most out of the technology, but we don’t have that experience with laser comm,” said Dave Israel, Exploration and Space Communications architect at Goddard and principal investigator on LCRD. “LCRD will allow us to test the performance over all different weather conditions and times of day and learn how to make the most of laser comm.”

Scheduled to launch in 2019, LCRD will simulate real communications support, practicing for two years with a test payload on the International Space Station and two dedicated ground stations in California and Hawaii. The mission could be the last hurdle to implementing a constellation of laser communications relay satellites similar to the Space Network’s Tracking and Data Relay Satellites.

NASA’s Jet Propulsion Laboratory in Pasadena, California, and Glenn Research Center in Cleveland are also following up on LLCD’s success. But both will focus on how laser communications could be implemented in deep-space missions.

Missions to deep space impose special communication challenges because of their distance from Earth. The data return on these missions slowly trickle back to the ground a little at a time using radio frequency. Laser communications could significantly improve data rates in all space regions, from low-Earth orbit to interplanetary.

JPL’s concept, called Deep Space Optical Communications (DSOC), focuses on laser communications’ benefits to data rates and to space and power constraints on missions. The data-rate benefits of laser communications for deep-space missions are clear, but less recognized is that laser communications can also save mass, space and/or power requirements on missions. That could be monumental on missions like the James Webb Space Telescope, which is so large that, even folded, it will barely fit in the largest rocket currently available. Although Webb is an extreme example, many missions today face size constraints as they become more complex. The Lunar Reconnaissance Orbiter mission carried both types of communications systems, and the laser system was half the mass, required 25 percent less power and transferred data at six times the rate of the RF system. Laser communications could also benefit a class of missions called CubeSats, which are about the size of a shoebox. These missions are becoming more popular and require miniaturized parts, including communications and power systems.

Power requirements can become a major challenge on missions to the outer solar system. As spacecraft move away from the sun, solar power becomes less viable, so the less power a payload requires, the smaller the spacecraft battery, saving space, and the easier spacecraft components can be recharged.

Laser communications could help to solve all of these challenges.

The team at Glenn is developing an idea called Integrated Radio and Optical Communications (iROC) to put a laser communications relay satellite in orbit around Mars that could receive data from distant spacecraft and relay their signal back to Earth. The system would use both RF and laser communications, promoting interoperability amongst all of NASA’s assets in space. By integrating both communications systems, iROC could provide services both for new spacecraft using laser communications systems and older spacecraft like Voyager 1 that use RF.

But laser communications is not NASA’s only foray into photonics, nor is it the first. In fact, NASA began using lasers shortly after they were invented. Goddard successfully demonstrated satellite laser ranging, a technique to measure distances, in 1964.

Satellite Laser Ranging is still managed at Goddard. The system uses laser stations worldwide to bounce short pulses of light off of special reflectors installed on satellites. There are also reflectors on the moon that were placed there during the Apollo and Soviet rover programs. By timing the bounce of the pulses, engineers can compute distances and orbits. Measurements are accurate up to a few millimeters. This application is used on numerous NASA missions, such as ICESat-2, which will measure the altitude of the ice surface in the Antarctic and Greenland regions. It will provide important information regarding climate and the health of Earth’s polar regions.

NASA’s Satellite Laser Ranging system consists of eight stations covering North America, the west coast of South America, the Pacific, South Africa and western Australia. NASA and its partners and associated universities operate the stations. SLR is part of the larger International Laser Ranging Service, and NASA’s contribution comprises more than a third of the organization’s total data volume.

From communications to altimetry and navigation, photonics’ importance to NASA missions cannot be understated. As technology continues to evolve, many photonics applications may come to fruition over the next several decades. Others may also be discovered, especially as humanity pushes further out into the universe than ever before.

To find out more, visit http://day-of-photonics.org/.

Related links:

Lunar Laser Communications Demonstration (LLCD): http://esc.gsfc.nasa.gov/267/271.html

Laser Communications Relay Demonstration (LCRD): http://www.nasa.gov/mission_pages/tdm/lcrd/index.html

Tracking and Data Relay Satellites: http://www.nasa.gov/directorates/heo/scan/services/networks/txt_tdrs.html

Deep Space Optical Communications (DSOC): https://gameon.nasa.gov/projects/deep-space-optical-communications-dsoc/

Integrated Radio and Optical Communications (iROC): https://spaceflightsystems.grc.nasa.gov/sopo/scsmo/scan-technology/iroc/

Animation (mentioned), Video (mentioned), Text, Credits: NASA's Goddard Space Flight Center, by Ashley Hume/Rob Garner.

Greetings, Orbiter.ch

'Heartbeat Stars' Unlocked in New Study

NASA - Kepler Space Telescope patch.

Oct. 21, 2016

Image above: This artist's concept depicts "heartbeat stars," which have been detected by NASA's Kepler Space Telescope and others. Image Credits: NASA/JPL-Caltech.

Matters of the heart can be puzzling and mysterious -- so too with unusual astronomical objects called heartbeat stars.

Heartbeat stars, discovered in large numbers by NASA's Kepler space telescope, are binary stars (systems of two stars orbiting each other) that got their name because if you were to map out their brightness over time, the result would look like an electrocardiogram, a graph of the electrical activity of the heart. Scientists are interested in them because they are binary systems in elongated elliptical orbits. This makes them natural laboratories for studying the gravitational effects of stars on each other.

In a heartbeat star system, the distance between the two stars varies drastically as they orbit each other. Heartbeat stars can get as close as a few stellar radii to each other, and as far as 10 times that distance during the course of one orbit.

At the point of their closest encounter, the stars’ mutual gravitational pull causes them to become slightly ellipsoidal in shape, which is one of the reasons their light is so variable. This is the same type of "tidal force" that causes ocean tides on Earth. By studying heartbeat stars, astronomers can gain a better understanding of how this phenomenon works for different kinds of stars.

Tidal forces also cause heartbeat stars to vibrate or "ring" -- in other words, the diameters of the stars rapidly fluctuate as they orbit each other. This effect is most noticeable at the point of closest approach.

“You can think about the stars as bells, and once every orbital revolution, when the stars reach their closest approach, it's as if they hit each other with a hammer,” said Avi Shporer, NASA Sagan postdoctoral fellow at NASA's Jet Propulsion Laboratory, Pasadena, California, and lead author of a recent study on heartbeat stars. "One or both stars vibrate throughout their orbits, and when they get nearer to each other, it's as though they are ringing very loudly."    

Kepler, now in its K2 Mission, discovered large numbers of heartbeat stars just in the last several years. A 2011 study discussed a star called KOI-54 that shows an increase in brightness every 41.8 days. In 2012, a subsequent study characterized 17 additional objects in the Kepler data and dubbed them "heartbeat stars." To characterize these unique systems, further data and research were required.

Shporer's study, published in the Astrophysical Journal, measured the orbits of 19 heartbeat star systems -- the largest batch ever characterized in a single study. The authors followed up on known heartbeat stars, previously identified by the Kepler mission. Specifically, they used an instrument on the W.M. Keck Observatory telescope in Hawaii called the High Resolution Echelle Spectrometer (HIRES), which measures the wavelengths of incoming light, which are stretched out when a star is moving away from us and shorter in motion toward us. This information allows astronomers to calculate the speed of the objects along the line of sight, and measure the shape of the orbit.

"We found that the heartbeat stars in our sample tend to be hotter than the sun and bigger than the sun," Shporer said. "But it is possible that there are others with different temperature ranges that we did not yet measure."

Kepler Space Telescope. Image Credits: NASA/JPL-Caltech

Study authors also postulate that some binary systems of heartbeat stars could have a third star in the system that has not yet been detected, or even a fourth star.

“The mere existence of heartbeat stars is a bit of a puzzle," said Susan Mullally (formerly Thompson), a SETI Institute scientist working for the Kepler Mission at NASA's Ames Research Center in Moffett Field, California, and co-author of the study. "All the tidal stretching of these heartbeat stars should have quickly caused the system to evolve into a circular orbit. A third star in the system is one way to create the highly stretched-out, elliptical orbits we observe."

Researchers are currently pursuing follow-up studies to search for third-star components in heartbeat star systems.

"We look forward to continued collaboration between ground and space observatories to better understand the complex inner workings of heartbeat stars," Shporer said.

NASA Ames manages the Kepler and K2 missions for NASA's Science Mission Directorate. JPL managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. Work on this study was performed in part under contract with JPL funded by NASA through the Sagan Fellowship Program executed by the NASA Exoplanet Science Institute.

Astrophysical Journal: http://iopscience.iop.org/article/10.3847/0004-637X/829/1/34

For more information about the Kepler and K2 missions, visit: http://www.nasa.gov/kepler

Images (mentioned), Text, Credits: NASA/Tony Greicius/JPL, written by Elizabeth Landau/Ames Research Center/Michele Johnson.

Greetings, Orbiter.ch

Uranus May Have Two Undiscovered Moons

NASA - Voyager 1 & 2 Mission patch.

Oct. 21, 2016

NASA's Voyager 2 spacecraft flew by Uranus 30 years ago, but researchers are still making discoveries from the data it gathered then. A new study led by University of Idaho researchers suggests there could be two tiny, previously undiscovered moonlets orbiting near two of the planet’s rings.

Rob Chancia, a University of Idaho doctoral student, spotted key patterns in the rings while examining decades-old images of Uranus' icy rings taken by Voyager 2 in 1986. He noticed the amount of ring material on the edge of the alpha ring -- one of the brightest of Uranus' multiple rings -- varied periodically. A similar, even more promising pattern occurred in the same part of the neighboring beta ring.

"When you look at this pattern in different places around the ring, the wavelength is different -- that points to something changing as you go around the ring. There's something breaking the symmetry," said Matt Hedman, an assistant professor of physics at the University of Idaho, who worked with Chancia to investigate the finding. Their results will be published in The Astronomical Journal and have been posted to the pre-press site arXiv.

Image above: Uranus is seen in this false-color view from NASA's Hubble Space Telescope from August 2003. The brightness of the planet's faint rings and dark moons has been enhanced for visibility. Image Credits: NASA/Erich Karkoschka (Univ. Arizona).

Chancia and Hedman are well-versed in the physics of planetary rings: both study Saturn's rings using data from NASA's Cassini spacecraft, which is currently orbiting Saturn. Data from Cassini have yielded new ideas about how rings behave, and a grant from NASA allowed Chancia and Hedman to examine Uranus data gathered by Voyager 2 in a new light. Specifically, they analyzed radio occultations -- made when Voyager 2 sent radio waves through the rings to be detected back on Earth -- and stellar occultations, made when the spacecraft measured the light of background stars shining through the rings, which helps reveal how much material they contain.

They found the pattern in Uranus' rings was similar to moon-related structures in Saturn's rings called moonlet wakes.

The researchers estimate the hypothesized moonlets in Uranus' rings would be 2 to 9 miles (4 to 14 kilometers) in diameter -- as small as some identified moons of Saturn, but smaller than any of Uranus' known moons. Uranian moons are especially hard to spot because their surfaces are covered in dark material.

"We haven't seen the moons yet, but the idea is the size of the moons needed to make these features is quite small, and they could have easily been missed," Hedman said. "The Voyager images weren't sensitive enough to easily see these moons."

Hedman said their findings could help explain some characteristics of Uranus' rings, which are strangely narrow compared to Saturn's. The moonlets, if they exist, may be acting as "shepherd" moons, helping to keep the rings from spreading out. Two of Uranus' 27 known moons, Ophelia and Cordelia, act as shepherds to Uranus' epsilon ring.

“The problem of keeping rings narrow has been around since the discovery of the Uranian ring system in 1977 and has been worked on by many dynamicists over the years,” Chancia said. “I would be very pleased if these proposed moonlets turn out to be real and we can use them to approach a solution.”

NASA's Voyager 2 spacecraft Uranus flyby. Image Credit: NASA

Confirming whether or not the moonlets actually exist using telescope or spacecraft images will be left to other researchers, Chancia and Hedman said. They will continue examining patterns and structures in Uranus’ rings, helping uncover more of the planet’s many secrets.

"It's exciting to see Voyager 2's historic Uranus exploration still contributing new knowledge about the planets," said Ed Stone, project scientist for Voyager, based at Caltech, Pasadena, California.

Voyager 2 and its twin, Voyager 1, were launched 16 days apart in 1977. Both spacecraft flew by Jupiter and Saturn, and Voyager 2 also flew by Uranus and Neptune. Voyager 2 is the longest continuously operated spacecraft. It is expected to enter interstellar space in a few years, joining Voyager 1, which crossed over in 2012. Though far past the planets, the mission continues to send back unprecedented observations of the space environment in the solar system, providing crucial information on the environment our spacecraft travel through as we explore farther and farther from home.

NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, built the twin Voyager spacecraft and operates them for the Heliophysics Division within NASA's Science Mission Directorate in Washington.

The Astronomical Journal: http://iopscience.iop.org/journal/1538-3881

Pre-press site arXiv: https://arxiv.org/abs/1610.02376

For more information about Voyager, visit: http://voyager.jpl.nasa.gov

Images (mentioned), Text, Credits: NASA, written by Tara Roberts/Tony Greicius/JPL/Elizabeth Landau/University of Idaho Communications/Tara Roberts.

Greetings, Orbiter.ch