Underground Magma Ocean Could Explain Io's 'Misplaced' Volcanoes

NASA's Goddard Space Flight Center logo.

Sep. 10, 2015

Tides flowing in a subsurface ocean of molten rock, or magma, could explain why Jupiter's moon Io appears to have its volcanoes in the "wrong" place. New NASA research implies that oceans beneath the crusts of tidally stressed moons may be more common and last longer than expected. The phenomenon applies to oceans made from either magma or water, potentially increasing the odds for life elsewhere in the universe.

Animation above: This five-frame sequence of images from the New Horizons spacecraft captures the giant plume from Io's Tvashtar volcano. Animation Credits: NASA/JHU Applied Physics Laboratory/Southwest Research Institute.

"This is the first time the amount and distribution of heat produced by fluid tides in a subterranean magma ocean on Io has been studied in detail," said Robert Tyler of the University of Maryland, College Park and NASA's Goddard Space Flight Center in Greenbelt, Maryland. "We found that the pattern of tidal heating predicted by our fluid-tide model is able to produce the surface heat patterns that are actually observed on Io." Tyler is lead author of a paper on this research published June 2015 in the Astrophysical Journal Supplement Series.

Io is the most volcanically active world in the solar system, with hundreds of erupting volcanoes blasting fountains of lava up to 250 miles (about 400 kilometers) high. The intense geological activity is the result of heat produced by a gravitational tug-of-war between Jupiter's massive gravity and other smaller but precisely timed pulls from Europa, a neighboring moon to Io that orbits further from Jupiter. Io orbits faster, completing two orbits every time Europa finishes one. This regular timing means that Io feels the strongest gravitational pull from its neighbor in the same orbital location, which distorts Io's orbit into an oval shape. This modified orbit causes Io to flex as it moves around Jupiter, causing material within Io to shift position and generate heat by friction, just as rubbing your hands together briskly makes them warmer.

Previous theories of how this heat is generated within Io treated the moon as a solid but deformable object, somewhat like clay. However, when scientists compared computer models using this assumption to a map of the actual volcano locations on Io, they discovered that most of the volcanoes were offset 30 to 60 degrees to the East of where the models predicted the most intense heat should be produced.

The pattern was too consistent to write it off as a simple anomaly, such as magma flowing diagonally through cracks and erupting nearby. "It’s hard to explain the regular pattern we see in so many volcanoes, all shifting in the same direction, using just our classical solid-body tidal heating models," said Wade Henning of the University of Maryland and NASA Goddard, a co-author of the paper.

The mystery of Io's misplaced volcanoes called for a different explanation—one that had to do with the interaction between heat produced by fluid flow and heat from solid-body tides.

Image above: This is a composite image of Io and Europa taken March 2, 2007 with the New Horizons spacecraft. Here Io is at the top with three volcanic plumes visible. The 300-kilometer (190-mile) high plume from the Tvashtar volcano is at the 11 o'clock position on Io's disk, with a smaller plume from the volcano Prometheus at the 9 o'clock position on the edge of Io's disk, and the volcano Amirani between them along the line dividing day and night. Image Credits: NASA/JHU Applied Physics Laboratory/Southwest Research Institute.

"Fluids – particularly 'sticky' (or viscous) fluids – can generate heat through frictional dissipation of energy as they move," said co-author Christopher Hamilton of the University of Arizona, Tucson. The team thinks much of the ocean layer is likely a partially molten slurry or matrix with a mix of molten and solid rock. As the molten rock flows under the influence of gravity, it may swirl and rub against the surrounding solid rock, generating heat. "This process can be extremely effective for certain combinations of layer thickness and viscosity which can generate resonances that enhance heat production," said Hamilton.

The team thinks a combination of fluid and solid tidal heating effects may best explain all the volcanic activity observed on Io. "The fluid tidal heating component of a hybrid model best explains the equatorial preference of volcanic activity and the eastward shift in volcano concentrations, while simultaneous solid-body tidal heating in the deep-mantle could explain the existence of volcanoes at high latitudes," said Henning. "Both solid and fluid tidal activity generate conditions that favor each other's existence, such that previous studies might have been only half the story for Io."

The new work also has implications for the search for extraterrestrial life. Certain tidally stressed moons in the outer solar system, such as Europa and Saturn's moon Enceladus, harbor oceans of liquid water beneath their icy crusts. Scientists think life might originate in such oceans if they have other key ingredients thought to be necessary, such as chemically available energy sources and raw materials, and they have existed long enough for life to form. The new work suggests that such subsurface oceans, whether composed of water or of any other liquid, will be more common and last longer than expected, both within our solar system and beyond.

Just as a precisely timed push on a swing will make it go higher, oceans can fall into a resonance state and sometimes produce significant heat through tidal flow. "Long-term changes in heating or cooling rates within a subsurface ocean are likely to produce a combination of ocean layer thickness and viscosity that generates a resonance and produces considerable heat," said Hamilton. "Therefore the mystery may be not how such subsurface oceans could survive, but how they could perish. Consequently, subsurface oceans within Io and other satellites could be even more common than what we've been able to observe so far."

The research was funded by a grant from the NASA Outer Planets Research program.

For earlier related Io volcano research, visit:
http://www.nasa.gov/topics/solarsystem/features/io-volcanoes-displaced.html

Related link:

New Horizons: http://www.nasa.gov/mission_pages/newhorizons/main/index.html

NASA Goddard Space Flight Center: http://www.nasa.gov/centers/goddard/home/index.html

Animation (mentioned), Image (mentioned), Text, Credits: NASA's Goddard Space Flight Center/William Steigerwald/Bill Steigerwald.

Greetings, Orbiter.ch

New Pluto Images from NASA’s New Horizons: It’s Complicated

NASA - New Horizons Mission logo.

Sep. 10, 2015

Image above: This synthetic perspective view of Pluto, based on the latest high-resolution images to be downlinked from NASA’s New Horizons spacecraft, shows what you would see if you were approximately 1,100 miles (1,800 kilometers) above Pluto’s equatorial area, looking northeast over the dark, cratered, informally named Cthulhu Regio toward the bright, smooth, expanse of icy plains informally called Sputnik Planum. The entire expanse of terrain seen in this image is 1,100 miles (1,800 kilometers) across. The images were taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). Image Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

New close-up images of Pluto from NASA’s New Horizons spacecraft reveal a bewildering variety of surface features that have scientists reeling because of their range and complexity.

“Pluto is showing us a diversity of landforms and complexity of processes that rival anything we’ve seen in the solar system,” said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute (SwRI), Boulder, Colorado. “If an artist had painted this Pluto before our flyby, I probably would have called it over the top — but that’s what is actually there.”

Image above: Mosaic of high-resolution images of Pluto, sent back from NASA’s New Horizons spacecraft from Sept. 5 to 7, 2015. The image is dominated by the informally-named icy plain Sputnik Planum, the smooth, bright region across the center. This image also features a tremendous variety of other landscapes surrounding Sputnik. The smallest visible features are 0.5 miles (0.8 kilometers) in size, and the mosaic covers a region roughly 1,000 miles (1600 kilometers) wide. The image was taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). Image Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

New Horizons began its yearlong download of new images and other data over the Labor Day weekend. Images downlinked in the past few days have more than doubled the amount of Pluto’s surface seen at resolutions as good as 400 meters (440 yards) per pixel. They reveal new features as diverse as possible dunes, nitrogen ice flows that apparently oozed out of mountainous regions onto plains, and even networks of valleys that may have been carved by material flowing over Pluto’s surface. They also show large regions that display chaotically jumbled mountains reminiscent of disrupted terrains on Jupiter’s icy moon Europa. 

Image above: In the center of this 300-mile (470-kilometer) wide image of Pluto from NASA’s New Horizons spacecraft is a large region of jumbled, broken terrain on the northwestern edge of the vast, icy plain informally called Sputnik Planum, to the right. The smallest visible features are 0.5 miles (0.8 kilometers) in size. This image was taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). Image Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

“The surface of Pluto is every bit as complex as that of Mars,” said Jeff Moore, leader of the New Horizons Geology, Geophysics and Imaging (GGI) team at NASA’s Ames Research Center in Moffett Field, California. “The randomly jumbled mountains might be huge blocks of hard water ice floating within a vast, denser, softer deposit of frozen nitrogen within the region informally named Sputnik Planum.”

New images also show the most heavily cratered -- and thus oldest -- terrain yet seen by New Horizons on Pluto next to the youngest, most crater-free icy plains. There might even be a field of dark wind-blown dunes, among other possibilities.

Image above: This 220-mile (350-kilometer) wide view of Pluto from NASA’s New Horizons spacecraft illustrates the incredible diversity of surface reflectivities and geological landforms on the dwarf planet. The image includes dark, ancient heavily cratered terrain; bright, smooth geologically young terrain; assembled masses of mountains; and an enigmatic field of dark, aligned ridges that resemble dunes; its origin is under debate. The smallest visible features are 0.5 miles (0.8 kilometers) in size. This image was taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). Image Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

“Seeing dunes on Pluto -- if that is what they are -- would be completely wild, because Pluto’s atmosphere today is so thin,” said William B. McKinnon, a GGI deputy lead from Washington University, St. Louis. “Either Pluto had a thicker atmosphere in the past, or some process we haven’t figured out is at work. It’s a head-scratcher.”

Discoveries being made from the new imagery are not limited to Pluto’s surface. Better images of Pluto’s moons Charon, Nix, and Hydra will be released Friday at the raw images site for New Horizons’ Long Range Reconnaissance Imager (LORRI), revealing that each moon is unique and that big moon Charon’s geological past was a tortured one. 

Image above: This image of Pluto’s largest moon Charon, taken by NASA’s New Horizons spacecraft 10 hours before its closest approach to Pluto on July 14, 2015 from a distance of 290,000 miles (470,000 kilometers), is a recently downlinked, much higher quality version of a Charon image released on July 15. Charon, which is 750 miles (1,200 kilometers) in diameter, displays a surprisingly complex geological history, including tectonic fracturing; relatively smooth, fractured plains in the lower right; several enigmatic mountains surrounded by sunken terrain features on the right side; and heavily cratered regions in the center and upper left portion of the disk. There are also complex reflectivity patterns on Charon’s surface, including bright and dark crater rays, and the conspicuous dark north polar region at the top of the image. The smallest visible features are 2.9 miles 4.6 kilometers) in size. Image Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

Images returned in the past days have also revealed that Pluto’s global atmospheric haze has many more layers than scientists realized, and that the haze actually creates a twilight effect that softly illuminates nightside terrain near sunset, making them visible to the cameras aboard New Horizons.

Image above: This image of Pluto from NASA’s New Horizons spacecraft, processed in two different ways, shows how Pluto’s bright, high-altitude atmospheric haze produces a twilight that softly illuminates the surface before sunrise and after sunset, allowing the sensitive cameras on New Horizons to see details in nighttime regions that would otherwise be invisible. The right-hand version of the image has been greatly brightened to bring out faint details of rugged haze-lit topography beyond Pluto’s terminator, which is the line separating day and night. The image was taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). Image Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

“This bonus twilight view is a wonderful gift that Pluto has handed to us,” said John Spencer, a GGI deputy lead from SwRI. “Now we can study geology in terrain that we never expected to see.”

Image above: Two different versions of an image of Pluto’s haze layers, taken by New Horizons as it looked back at Pluto's dark side nearly 16 hours after close approach, from a distance of 480,000 miles (770,000 kilometers), at a phase angle of 166 degrees. Pluto's north is at the top, and the sun illuminates Pluto from the upper right. These images are much higher quality than the digitally compressed images of Pluto’s haze downlinked and released shortly after the July 14 encounter, and allow many new details to be seen. The left version has had only minor processing, while the right version has been specially processed to reveal a large number of discrete haze layers in the atmosphere. In the left version, faint surface details on the narrow sunlit crescent are seen through the haze in the upper right of Pluto’s disk, and subtle parallel streaks in the haze may be crepuscular rays- shadows cast on the haze by topography such as mountain ranges on Pluto, similar to the rays sometimes seen in the sky after the sun sets behind mountains on Earth. Image Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

The New Horizons spacecraft is now more than 3 billion miles (about 5 billion kilometers) from Earth, and more than 43 million miles (69 million kilometers) beyond Pluto. The spacecraft is healthy and all systems are operating normally.

Follow the mission at http://www.nasa.gov/newhorizons and http://pluto.jhuapl.edu. 

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 science mission, payload operations, and encounter science planning.

Related link:

New Horizons’ Long Range Reconnaissance Imager (LORRI): http://pluto.jhuapl.edu/soc/Pluto-Encounter/index.php

For more information about New Horizons mission, visit: http://www.nasa.gov/mission_pages/newhorizons/main/index.html

Images (mentioned), Text, Credits: NASA/Tricia Talbert.

Greetings, Orbiter.ch

Telescopes Find Galaxy Cluster with Vibrant Heart

NASA - Spitzer Space Telescope patch / NASA - Hubble Space Telescope patch.

Sep. 10, 2015

Astronomers have discovered a rare beast of a galaxy cluster whose heart is bursting with new stars. The unexpected find, made with the help of NASA's Spitzer and Hubble space telescopes, suggests that behemoth galaxies at the cores of these massive clusters can grow significantly by feeding off gas stolen from another galaxy.

"Usually, the stars at the centers of galaxy clusters are old and dead, essentially fossils," said Tracy Webb of McGill University, Montreal, Canada, lead author of a new paper on the findings accepted for publication in the Astrophysical Journal. "But we think the giant galaxy at the center of this cluster is furiously making new stars after merging with a smaller galaxy."

Image above: A massive cluster of galaxies, called SpARCS1049+56, can be seen in this multi-wavelength view from NASA's Hubble and Spitzer space telescopes. Image Credits: NASA/STScI/ESA/JPL-Caltech/McGill.

Galaxy clusters are vast families of galaxies bound and grouped by the ties of gravity. Our own Milky Way resides in a small galaxy group, called the Local Group, which itself is on the periphery of the vast Laniakea supercluster of 100,000 galaxies. (Laniakea is Hawaiian for "immeasurable heaven.")

The cluster in the new study, referred to by astronomers as SpARCS1049+56, has at least 27 galaxy members, and a combined mass equal to nearly 400 trillion suns. It is located 9.8 billion light-years away in the Ursa Major constellation. The object was initially discovered using Spitzer and the Canada-France-Hawaii telescope, located on Mauna Kea in Hawaii, and confirmed using the W.M. Keck Observatory, also on Mauna Kea.

What makes this cluster unique is its luminous heart of new stars. At the core of most massive galaxy clusters lies one hulking galaxy that usually doesn’t produce new stars very quickly. The galaxy dominating the cluster SpARCS1049+56 is rapidly spitting out an enormous number of stars -- about 860 new ones a year. For reference, our Milky Way makes only about one to two stars per year.

"With Spitzer's infrared camera, we can actually see the ferocious heat from all these hot young stars," said co-author Jason Surace from NASA's Spitzer Science Center at the California Institute of Technology in Pasadena. Spitzer detects infrared light, so it can see the warm glow of hidden, dusty regions where stars form.

Follow-up studies with Hubble in visible light helped confirm the source of the fuel, or gas, for the new stars. A smaller galaxy seems to have recently merged with the monster galaxy in the middle of the cluster, lending its gas to the larger galaxy and igniting a fury of new stars.

"Hubble found a train wreck of a merger at the center of this galaxy," said Webb.

Hubble Space Telescope. Image Credit: NASA / ESA

Hubble specifically detected features in the smaller, merging galaxy called “beads on a string,” which are pockets of gas that condense where new stars are forming. Beads on a string are telltale signs of collisions between gas-rich galaxies, a phenomenon known to astronomers as wet mergers, where "wet" refers to the presence of gas. In these smash-ups, the gas is quickly converted to new stars.

Dry mergers, by contrast, occur when galaxies with little gas collide and no new stars are formed. Typically, galaxies at the centers of clusters grow in mass through dry mergers at their core, or by siphoning gas into their centers.

The new discovery is one of the first known cases of a wet merger at the core of a distant galaxy cluster. Hubble previously discovered another closer galaxy cluster containing a wet merger, but it wasn't forming stars as vigorously.

The researchers are planning more studies to find out how common galaxy clusters like SpARCS1049+56 are. The cluster may be an outlier, or it may represent an early time in our universe when gobbling up gas-rich galaxies was the norm.

Spitzer space telescopes. Image Credit: NASA

NASA's Jet Propulsion Laboratory, Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington.

For more information about Spitzer, visit: http://www.nasa.gov/spitzer

For more information on the Hubble Space Telescope, visit:

http://www.nasa.gov/hubble

http://hubblesite.org/

http://www.spacetelescope.org/

Images (mentioned), Text, Credits: NASA/Felicia Chou/JPL/Whitney Clavin/Space Telescope Science Institute/Ray Villard/Tony Greicius.

Best regards, Orbiter.ch

Methane Painting

NASA - Cassini Mission to Saturn patch.

Sep. 10, 2015

Why does Saturn look like it's been painted with a dark brush in this infrared image, but Dione looks untouched? Perhaps an artist with very specific tastes in palettes?

The answer is methane. This image was taken in a wavelength that is absorbed by methane. Dark areas seen here on Saturn are regions with thicker clouds, where light has to travel through more methane on its way into and back out of the atmosphere. Since Dione (698 miles or 1,123 kilometers across) doesn't have an atmosphere rich in methane the way Saturn does, it does not experience similar absorption -- the sunlight simply bounces off its icy surface.

Shadows of the rings are seen cast onto the planet at lower right.

This view looks toward Saturn from the unilluminated side of the rings, about 0.3 degrees below the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on May 27, 2015 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 728 nanometers.

The view was acquired at a distance of approximately 618,000 miles (994,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 84 degrees. Image scale is 37 miles (59 kilometers) per pixel.

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 the California Institute of Technology 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 or http://www.nasa.gov/cassini . The Cassini imaging team homepage is at http://ciclops.org and http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

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

Cheers, Orbiter.ch

Sweeping over the south pole of Mars

ESA - Mars Express Mission patch.

Sept. 10, 2015

An unusual observation by Mars Express shows a sweeping view over the planet’s south polar ice cap and across its ancient, cratered highlands.

The image was taken by the high-resolution stereo camera on ESA’s Mars Express on 25 February.

Mars south pole and beyond

During normal scientific imaging, the camera typically takes images pointing straight down towards the surface, from around the closest point to the planet along the spacecraft’s elliptical orbit at an altitude of about 300 km.

But in this unusual observation, known as a ‘broom calibration’ image, Mars Express turned such that its camera panned over the surface far above the planet, close to its furthest point along its orbit, in this case at around 9900 km.

Importantly, as well as affording an unusual wide view, this allows the camera to record a range of features at the same illumination conditions, allowing essential calibration of the camera’s sensors.

Towards the bottom of the image is the south polar ice cap, comprising frozen water and carbon dioxide ice. This feature changes in size and shape with the seasons; the main image presented here was captured during the south polar summer, but during winter the ice extends into the smooth regions that can be seen surrounding it.

The mid-section of the image corresponds to the planet’s ancient southern highlands – it is covered by a high density of impact craters of varying size and states of erosion, with many craters overlapping.

Numerous patterns of dark, dusty dune deposits are also visible, swept up by wind and accumulating in impact craters and troughs.

Mars south pole and beyond, topography

Towards the top left of the image a portion of the giant Hellas basin can be seen. This feature spans more than 2200 km across and plunges some 8 km below the surface.

Two prominent channels – Dao Vallis and Niger Vallis – can be seen breaching the basin rim, made out as thin, dark wiggly lines in the colour image.

Hazy patches seen in the upper part of the image are attributed to clouds, while a thin, delicate layer of atmosphere follows the curvature of the planet at the horizon.

Related links:

Looking at Mars: http://www.esa.int/Our_Activities/Space_Science/Mars_Express

High Resolution Stereo Camera: http://berlinadmin.dlr.de/Missions/express/indexeng.shtml

Behind the lens...: http://www.esa.int/Our_Activities/Space_Science/Mars_Express/Behind_the_lens

Frequently asked questions: http://www.esa.int/Our_Activities/Space_Science/Mars_Express/Frequently_asked_questions

ESA Planetary Science archive (PSA): http://www.rssd.esa.int/PSA

NASA Planetary Data System: http://pds-geosciences.wustl.edu/missions/mars_express/hrsc.htm

HRSC data viewer: http://hrscview.fu-berlin.de/

In depth:

Mars Express in depth: http://sci.esa.int/science-e/www/area/index.cfm?fareaid=9

Mars Express top 10 discoveries: http://sci.esa.int/jump.cfm?oid=51820

Images, Text, Credits: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO.

Greetings, Orbiter.ch

Dawn Takes a Closer Look at Occator

NASA - Dawn Mission patch.

Sep. 9, 2015

This image, made using images taken by NASA's Dawn spacecraft, shows Occator crater on Ceres, home to a collection of intriguing bright spots.

The bright spots are much brighter than the rest of Ceres' surface, and tend to appear overexposed in most images. This view is a composite of two images of Occator: one using a short exposure that captures the detail in the bright spots, and one where the background surface is captured at normal exposure.

The images were obtained by Dawn during the mission's High Altitude Mapping Orbit (HAMO) phase, from which the spacecraft imaged the surface at a resolution of about 450 feet (140 meters) per pixel.

For more information about Dawn mission, visit: http://www.nasa.gov/mission_pages/dawn/main/index.html

Image, Text, Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/Martin Perez.

Cheers, Orbiter.ch

NASA’s Space Cubes: Small Satellites Provide Big Payoffs

NASA logo.

Sep. 8, 2015

Good things really do come in small packages.

When we think of space satellites that assist with communications, weather monitoring and GPS here on Earth, we likely picture them as being quite large—many are as big as a school bus and weigh several tons. Yet there’s a class of smaller satellites that’s growing in popularity. These miniaturized satellites, known as nanosatellites or CubeSats, can fit in the palm of your hand and are providing new opportunities for space science.

“CubeSats are part of a growing technology that’s transforming space exploration,” said David Pierce, senior program executive for suborbital research at NASA Headquarters in Washington. “CubeSats are small platforms that enable the next generation of scientists and engineers to complete all phases of a complete space mission during their school career. While CubeSats have historically been used as teaching tools and technology demonstrations, today’s CubeSats have the potential to conduct important space science investigations as well.”

CubeSat Launch Initiative announcement. Image Credit: NASA

CubeSats are built to standard specifications of 1 unit (U), which is equal to 10x10x10 centimeters (about 4x4x4 inches). CubeSats can be 1U, 2U, 3U or 6U in size, weighing about 3 pounds per U. They often are launched into orbit as auxiliary payloads aboard rockets, significantly reducing costs.

Because of the smaller payload and lower price tag, CubeSat technology allows for experimentation. “There’s an opportunity to embrace some risk,” said Janice Buckner, program executive of NASA’s Small Innovative Missions for Planetary Exploration (SIMPLEx) program. “These mini experiments complement NASA’s larger assets.”

Another advantage of the “smaller is bigger” concept is it’s more inclusive. The low cost and relatively short delivery time from concept to launch – typically 2-3 years – allows students and a growing community of citizen scientists and engineers to contribute to NASA’s space exploration goals, part of the White House’s Maker Initiative. By providing hands-on opportunities for students and teachers, NASA helps attract and retain students in science, technology, engineering and math disciplines, strengthening NASA’s and the nation’s future workforce.

This inclusiveness also applies to geography. In 2014 NASA announced the expansion of its CubeSat Launch Initiative, with the goal of launching 50 small satellites from 50 states within five years. To date NASA has selected CubeSats from 30 states, 17 of which have already been launched. Two more -- Alaska and Maryland -- are slated to go to space later this year, including the first ever CubeSat launched by an elementary school.

In April 2015 the SIMPLEx program requested proposals for interplanetary CubeSat investigations, with a panel of NASA and other scientists and engineers reviewing 22 submissions. Two were chosen—one led by a postdoctoral research scientist and the other a university professor. NASA Headquarters, Planetary Science Division, also selected three technology developments for possible future planetary missions: one to   expand NASA’s ability to analyze Mars’ atmosphere, one to investigate the hydrogen cycle at the moon and one to view a small near-Earth asteroid. Each selected team will receive one year of funding to bring their respective technologies to a higher level of readiness. To be considered for flight, teams must demonstrate progress in a future mission proposal competition.

CubeSats deployed from the International Space Station (ISS). Image Credit: NASA

The CubeSat investigations selected for a planetary science mission opportunity are:

- Lunar Polar Hydrogen Mapper (LunaH-Map), a 6U-class CubeSat that will enter a polar orbit around the moon with a low altitude (3-7 miles) centered on the lunar south pole. LunaH-Map carries two neutron spectrometers that will produce maps of near-surface hydrogen. LunaH-Map will map hydrogen within craters and other permanently shadowed regions throughout the south pole. Postdoc Craig Hardgrove from Arizona State University (ASU), Tempe, Arizona, is the principal investigator. ASU will manage the project.

- CubeSat Particle Aggregation and Collision Experiment (Q-PACE) is a 2U-class, thermos-sized, CubeSat that will explore the fundamental properties of low-velocity particle collision in a microgravity environment, in an effort to better understand the mechanics of early planet development. Josh Colwell from the University of Central Florida (UCF), Orlando, Florida, is the principal investigator, and UCF will manage the project.

The proposals selected for further technology development are:

- The Mars Micro Orbiter (MMO) mission, which uses a 6U-class Cubesat to measure the Martian atmosphere in visible and infrared wavelengths from Mars orbit. Michael Malin of Malin Space Science Systems, San Diego, California, is the principal investigator.

- Hydrogen Albedo Lunar Orbiter (HALO) is a propulsion-driven 6U-class CubeSat that will answer critical questions about the lunar hydrogen cycle and the origin of water on the lunar surface by examining the reflected hydrogen in the moon’s solar wind. The principal investigator is Michael Collier of NASA’s Goddard Space Flight Center, Greenbelt, Maryland.

- Diminutive Asteroid Visitor using Ion Drive (DAVID) is a 6U-class CubeSat mission that will investigate an asteroid much smaller than any studied by previous spacecraft missions and will be the first NASA mission to investigate an Earth-crossing asteroid. Geoffrey Landis of NASA’s Glenn Research Center, Cleveland, Ohio, is the principal investigator.

“These selections will enable the next generation of planetary scientists and engineers to use revolutionary new mission concepts that have the potential to return extraordinary science,” said Buckner. “CubeSats are going to impact the future of planetary exploration.”

Related links:

CubeSat Launch Initiative: http://www.nasa.gov/directorates/heo/home/CubeSats_initiative/#.VemjYxFVhBc

CubeSats: http://www.nasa.gov/cubesats/

Images (mentioned), Text, Credits: NASA/Brian Dunbar.

Greetings, Orbiter.ch