vendredi 29 mars 2019

SOFIA Captures Cosmic Light Show of Star Formation

NASA & DLR - SOFIA Mission patch.

March 29, 2019

When massive stars — many times larger than our Sun— are born, they shine hot and bright before eventually exploding as supernovas. They release so much energy that they can affect the evolution of galaxies. But, unlike stars like our Sun, astronomers know much less about how these enormous stars form.

“Massive stars like this represent less than one percent of all stars, but they can affect the formation of their stellar siblings,” said Jim De Buizer, Universities Space Research Association senior scientist at the SOFIA Science Center. “Stars like our Sun have much quieter and humbler origins, and because there are so many of them, we understand their birth properties more thoroughly.”

To learn more, researchers used the Stratospheric Observatory for Infrared Astronomy, or SOFIA, to study a giant celestial cloud, called W51. Located almost 17,000 light years away and made mostly of hydrogen, it’s a place where rare, gigantic stars are forming. But they are born deep inside the cloud, invisible to the light our eyes can see. Using SOFIA’s airborne telescope and sensitive infrared camera, the research team peered inside the dense cloud. They captured a cosmic light show sparked by the forming stars, including many that have never been seen before.

Image above: A cosmic light show sparked by the formation of massive stars in the stellar nursery, called W51, glows over on a star field image (white) from the Sloan Digital Sky Survey. The oldest and most evolved massive star is in the upper left of the image, shown at the middle of yellowish bubble. The youngest generations are typically found in areas near the center of this figure, near the brightest ball at the slight left from the middle. Massive stars like these emit so much energy that they play a critical role in the evolution of our galaxy. Image Credits: NASA/SOFIA/Lim and De Buizer et al. and Sloan Digital Sky Survey.

The infrared camera, called Faint Object infraRed CAmera for the SOFIA Telescope, or FORCAST, has sensitive detectors and powerful magnification that let the researchers discover the enormous stars right after their birth. Learning how massive stars form in our Milky Way Galaxy helps scientists understand how these stars form in distant galaxies that are too far away to see in detail.

“This is the best resolution currently available using these wavelengths of infrared light,” said Wanggi Lim, Universities Space Research Association scientist at the SOFIA Science Center. “Not only does this reveal areas that we could not see before, but it’s critical to understanding the physical properties and relative age of the stars and their parental clouds.”

Researchers combined the SOFIA data with data from NASA’s Spitzer Space Telescope and Herschel Space Observatory to analyze the stars. They found that while they are all young, some are more evolved, and others are the youngest, most recently-created stars in the cloud. One may be exceptionally large — estimated to have the equivalent mass of 100 Suns. If future observations confirm it is indeed a single, colossal star, rather than multiple stellar siblings clustered together, it would be one of the most massive forming stars in our galaxy.

These are the first results from a survey that will reveal how young, massive stars are lighting up other parts of our Milky Way Galaxy.

SOFIA Boeing 747SP telescope door opening. Animation Credit: NASA

SOFIA, the Stratospheric Observatory for Infrared Astronomy, is a Boeing 747SP jetliner modified to carry a 106-inch diameter telescope. It is a joint project of NASA and the German Aerospace Center, DLR. NASA’s Ames Research Center in California’s Silicon Valley manages the SOFIA program, science and mission operations in cooperation with the Universities Space Research Association headquartered in Columbia, Maryland, and the German SOFIA Institute (DSI) at the University of Stuttgart. The aircraft is maintained and operated from NASA’s Armstrong Flight Research Center Hangar 703, in Palmdale, California.

Related links:

- Spitzer Space Telescope:

- Herschel Space Observatory:


Image (mentioned), Animation (mentioned), Text, Credits: NASA/Kassandra Bell.

Best regards,

NASA Astronauts Complete 215th Spacewalk at Station

ISS - Expedition 59 Mission patch / EVA - Extra Vehicular Activities patch.

March 29, 2019

Expedition 59 Flight Engineers Nick Hague and Christina Koch of NASA concluded their spacewalk at 2:27 p.m. EDT. During the six hour and 45-minute spacewalk, the two NASA astronauts successfully connected three newer, more powerful lithium-ion batteries to replace the previous six nickel-hydrogen batteries that provide power for one channel on one pair of the station’s solar arrays. The new batteries provide an improved and more efficient power capacity for operations.

The astronauts also did work to enable robotic specialists to remove one of the three new lithium ion batteries connected during last Friday’s spacewalk that is not charging properly and replace it with the two older nickel hydrogen batteries. The swap will restore a full power supply to that solar array power channel.

Image above: Spacewalker Nick Hague works to upgrade the International Space Station ‘s power storage capacity during today’s six hour and 45-minute spacewalk. Image Credit: NASA TV.

In addition, the astronauts also completed several tasks to prepare the worksite for future spacewalkers who will complete similar operations to upgrade the batteries for the set of solar arrays at the end of the port side of the station’s backbone structure known as the truss. Hague inspected the worksite interfaces for a portable foot restraint a spacewalker uses to anchor themselves during the battery upgrade work while Koch installed fabric handrails to help future spacewalkers move across the worksite.

This was the second spacewalk for Hague, who now has spent a total of 13 hours and 24 minutes spacewalking. It was the first spacewalk for Koch, who became the 14th female spacewalker.

Anne McClain and David Saint-Jacques of the Canadian Space Agency are scheduled to conduct another spacewalk April 8 to establish a redundant path of power to the Canadian-built robotic arm, known as Canadarm2, and install cables to provide for more expansive wireless communications coverage outside the orbital complex, as well as for enhanced hardwired computer network capability.

Image above: NASA astronaut Nick Hague is contrasted by the blackness of space during his first spacewalk on March 22, 2019. Image Credit: NASA TV.

Experts will discuss the work to be performed on the April 8 spacewalk during a news conference at 2 p.m. EDT Tuesday, April 2, at NASA’s Johnson Space Center in Houston. Live coverage of the briefing and spacewalks will air on NASA Television and the agency’s website. Participants in the briefing are Kenny Todd, International Space Station manager for Operations and Integration, Rick Henfling, spacewalk flight director, and John Mularski, lead spacewalk officer.

Space station crew members have conducted 215 spacewalks in support of assembly and maintenance of the orbiting laboratory. Spacewalkers have now spent a total of 56 days 4 hours and 24 minutes working outside the station.

Related links:

Expedition 59:

Space Station Research and Technology:

International Space Station (ISS):

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

Best regards,

Rocket Lab successfully launches R3D2 satellite for DARPA

Rocket Lab - DARPA / R3D2  Mission 5 patch.

March 29, 2019

Rocket Lab Electron R3D2 mission launch

A Rocket Lab Electron launch vehicle successfully lifted off from Launch Complex 1 on New Zealand’s Mahia Peninsula at 23:27, March 28th UTC (12:27, 29 March NZDT). The mission launched a prototype reflect array antenna to orbit for the Defense Advanced Research Projects Agency (DARPA). 

“Congratulations to our dedicated team for delivering another important and innovative asset to space – on time and on target. The unique requirements of this mission made Electron the perfect launch vehicle to lift R3D2 as a dedicated payload to a highly precise orbit,” said Rocket Lab founder and CEO Peter Beck. “Thank you to our mission partners. We look forward to continuing to provide frequent, reliable and rapidly-acquired launch services for innovative small satellites.”

Electron launches DARPA R3D2 mission

Rocket Lab was selected for the launch because of the company’s proven mission heritage and its ability support rapid acquisition of small satellite launch capabilities. Due to Rocket Lab’s streamlined acquisition practices, DARPA’s R3D2 mission was launched just over 18 months from conception – a significant reduction in traditional government launch acquisition timeframes.

With proven flight heritage from four orbital missions, Rocket Lab is the only fully commercial small satellite launch service provider in operation. The experienced Rocket Lab team has delivered 25 satellites to orbit, including innovative new space technologies that provide vital capabilities such as weather monitoring, Earth observation and Internet of Things connectivity. The R3D2 mission was Rocket Lab’s first of 2019, as the company heads into a busy year of launches booked for lift-off every four weeks. To support the small satellite industry’s highest launch cadence, Rocket Lab is currently producing one Electron launch vehicle every 30 days across its Huntington Beach, California, and Auckland, New Zealand, production facilities.

About the DARPA R3D2 payload:

DARPA’s R3D2 (Radio Frequency Risk Reduction Deployment Demonstration) spacecraft intends to space-qualify a prototype reflect array antenna to improve radio communications in small spacecraft. The 150kg spacecraft carried an antenna, made of a tissue-thin Kapton membrane, designed to pack tightly inside the small satellite for stowage during launch, before deploying to its full size of 2.25 meters in diameter in low Earth orbit. The design is intended to provide significant capability, typical of large spacecraft, in a much smaller package. The mission could lay the groundwork for a space-based internet by helping to validate emerging concepts for a resilient sensor and data transport layer in low Earth orbit – a capability that does not exist today.

About Electron:

The R3D2 mission was launched on an Electron launch vehicle, comprised of two fully carbon-composite stages, powered by a total of ten 3D printed and electric pump-fed Rutherford engines, designed and built in house by Rocket Lab at the company’s headquarters in Huntington Beach, California. The R3D2 payload was deployed to a circular orbit by Rocket Lab’s unique Kick Stage, an additional stage designed for precise orbital deployment and equipped with the ability to deorbit itself upon mission completion to leave no orbital debris behind.

Rocket Lab:

Defense Advanced Research Projects Agency (DARPA):

Images, Video, Text, Credits: Rocket Lab/DARPA/SciNews.


NASA's Cassini Finds Saturn's Rings Coat Tiny Moons

NASA - Cassini Mission to Saturn patch.

March 29, 2019

New findings have emerged about five tiny moons nestled in and near Saturn's rings. The closest-ever flybys by NASA's Cassini spacecraft reveal that the surfaces of these unusual moons are covered with material from the planet's rings - and from icy particles blasting out of Saturn's larger moon Enceladus. The work paints a picture of the competing processes shaping these mini-moons.

Image above: This graphic shows the ring moons inspected by NASA's Cassini spacecraft in super-close flybys. The rings and moons depicted are not to scale. Image Credits: NASA-JPL/Caltech.

"The daring, close flybys of these odd little moons let us peer into how they interact with Saturn's rings," said Bonnie Buratti of NASA's Jet Propulsion Laboratory in Pasadena, California. Buratti led a team of 35 co-authors that published their work in the journal Science on March 28. "We're seeing more evidence of how extremely active and dynamic the Saturn ring and moon system is."

The new research, from data gathered by six of Cassini's instruments before its mission ended in 2017, is a clear confirmation that dust and ice from the rings accretes onto the moons embedded within and near the rings.

Scientists also found the moon surfaces to be highly porous, further confirming that they were formed in multiple stages as ring material settled onto denser cores that might be remnants of a larger object that broke apart. The porosity also helps explain their shape: Rather than being spherical, they are blobby and ravioli-like, with material stuck around their equators.

"We found these moons are scooping up particles of ice and dust from the rings to form the little skirts around their equators," Buratti said. "A denser body would be more ball-shaped because gravity would pull the material in."

"Perhaps this process is going on throughout the rings, and the largest ring particles are also accreting ring material around them. Detailed views of these tiny ring moons may tell us more about the behavior of the ring particles themselves," said Cassini Project Scientist Linda Spilker, also at JPL.

Of the satellites studied, the surfaces of those closest to Saturn - Daphnis and Pan - are the most altered by ring materials. The surfaces of the moons Atlas, Prometheus and Pandora, farther out from Saturn, have ring material as well - but they're also coated with the bright icy particles and water vapor from the plume spraying out of Enceladus. (A broad outer ring of Saturn, known as the E ring, is formed by the icy material that fans out from Enceladus' plume.)

The key puzzle piece was a data set from Cassini's Visible and Infrared Mapping Spectrometer (VIMS), which collected light visible to the human eye and also infrared light of longer wavelengths. It was the first time Cassini was close enough to create a spectral map of the surface of the innermost moon Pan. By analyzing the spectra, VIMS was able to learn about the composition of materials on all five moons.

Image above: This montage of views from NASA's Cassini spacecraft shows three of the small, ring moons inspected during close flybys: Atlas, Daphnis and Pan. They're shown here at the same scale. Image Credits: NASA/JPL-Caltech/Space Science Institute.

VIMS saw that the ring moons closest to Saturn appear the reddest, similar to the color of the main rings. Scientists don't yet know the exact composition of the material that appears red, but they believe it's likely a mix of organics and iron.

The moons just outside the main rings, on the other hand, appear more blue, similar to the light from Enceladus' icy plumes.

The six uber-close flybys of the ring moons, performed between December 2016 and April 2017, engaged all of Cassini's optical remote sensing instruments that study the electromagnetic spectrum. They worked alongside the instruments that examined the dust, plasma and magnetic fields and how those elements interact with the moons.

Questions remain, including what triggered the moons to form. Scientists will use the new data to model scenarios and could apply the insights to small moons around other planets and possibly even to asteroids.

"Do any of the moons of the ice giant planets Uranus and Neptune interact with their thinner rings to form features similar to those on Saturn's ring moons?" Buratti asked. "These are questions to be answered by future missions."

Cassini's mission ended in September 2017, when it was low on fuel. Mission controllers deliberately plunged Cassini into Saturn's atmosphere rather than risk crashing the spacecraft into the planet's moons. More science from the last orbits, known as the Grand Finale, will be published in the coming months.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's JPL, a division of Caltech in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. JPL designed, developed and assembled the Cassini orbiter. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the U.S. and several European countries.

More information about Cassini can be found here:

Images (mentioned), Text, Credits: NASA/JoAnna Wendel/JPL/Gretchen McCartney.


jeudi 28 mars 2019

Astronauts Ready After Robotics Sets Up Worksite for Friday Spacewalk

ISS - Expedition 59 Mission patch.

March 28, 2019

Astronauts Nick Hague and Christina Koch have configured their spacesuits and reviewed procedures for tomorrow’s spacewalk at the International Space Station. Robotics controllers also readied the Port-4 (P4) truss structure so the spacewalkers can continue battery swaps and power upgrades outside the orbital lab.

Hague and Koch will set their spacesuits to battery power Friday around 8:20 a.m. inside the Quest airlock. They will exit Quest to swap old nickel-hydrogen batteries with new lithium-ion batteries on the P4 truss. NASA TV will begin its live coverage of the scheduled 6.5-hour spacewalk Friday at 6:30 a.m.

Image above: NASA astronaut Nick Hague is tethered to the International Space Station during a six-hour, 39-minute spacewalk to upgrade the orbital complex’s power storage capacity. Image Credit: NASA TV.

Ground specialists in Mission Control remotely commanded the Canadarm2 robotic arm and its “robotic hand” Dextre to set up the P4 worksite throughout week. The fine-tuned robotics maneuvers transferred the batteries between an external pallet and the P4 worksite over several days.

NASA astronaut Anne McClain is tentatively scheduled to join Canadian Space Agency astronaut David Saint-Jacques on April 8 for another spacewalk. The spacewalkers will install truss jumpers to provide secondary power to the Canadarm2.

The International Space Station seen from Soyuz MS-08

Meanwhile, McClain collected her blood and urine samples today for ongoing human research. She spun the samples in a centrifuge and stowed them in a science freezer for later analysis. Saint-Jacques worked on computer electronics maintenance throughout the day.

Expedition 59 commander Oleg Kononenko and Alexey Ovchinin, both of Roscosmos, stayed focused on activities in the station’s Russian segment on Thursday. The duo spent the morning on life support maintenance before checking docked vehicle communications and photographing windows in the Zvezda service module.

NASA TV Broadcasts Live Spacewalk Coverage Friday Morning

Expedition 59 Flight Engineers Nick Hague and Christina Koch will exit the Quest airlock Friday for about 6.5 hours of battery swaps to upgrade the station’s power storage capacity. The duo will set their spacesuits to battery power about 8:20 a.m. EDT Friday signifying the start of their spacewalk. Coverage will begin its live coverage at 6:30 a.m.

Watch the spacewalk on NASA TV and on the agency’s website:

This will be the 215th spacewalk in support of space station assembly and maintenance. Hague will be designated extravehicular crew member 1 (EV 1), wearing the suit with red stripes. Koch will be designated extravehicular crew member 2 (EV 2), wearing the suit with no stripes.

Hague and Koch have configured their spacesuits and reviewed procedures for tomorrow’s spacewalk at the space station. Robotics controllers also readied the Port-4 (P4) truss structure so the spacewalkers can continue battery swaps and power upgrades outside the orbital lab.

Image above: NASA astronaut Anne McClain takes a “space-selfie” with her helmet visor up 260 miles above the Earth’s surface during a spacewalk on March 22, 2019. Image Credit: NASA TV.

This is the second battery replacement spacewalks this month. Hague and Koch will work on a second set of battery replacements on a different power channel in the same area of the station from the recent spacewalk on March 22.

During that spacewalk, NASA Flight Engineer Anne McClain and Hague replaced some nickel-hydrogen batteries with newer, more powerful lithium-ion batteries for the power channel on one pair of the station’s solar arrays. The batteries were transported to the station in September aboard the Japanese H-II Transfer Vehicle. The spacewalking work continues the overall upgrade of the station’s power system that began with similar battery replacement during spacewalks in January 2017.

Related links:

Expedition 59:


Quest airlock:

Canadarm2 robotic arm:

Zvezda service module:

Port-4 (P4) truss structure:

H-II Transfer Vehicle:

Human research:

Space Station Research and Technology:

International Space Station (ISS):

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

Best regards,

The Voyage to Interstellar Space

NASA - Voyager 1 & 2 Mission patch.

March 28, 2019

By all means, Voyager 1 and Voyager 2 shouldn’t even be here. Now in interstellar space, they are pushing the limits of spacecraft and exploration, journeying through the cosmic neighborhood, giving us our first direct look into the space beyond our star.

But when they launched in 1977, Voyager 1 and Voyager 2 had a different mission: to explore the outer solar system and gather observations directly at the source, from outer planets we had only seen with remote studies. But now, four decades after launch, they’ve journeyed farther than any other spacecraft from Earth; into the cold, quiet world of interstellar space.

Voyager spacecraft travel in interstellar space. Animation Credits: NASA/JPL

Originally designed to measure the properties of the giant planets, the instruments on both spacecraft have spent the past few decades painting a picture of the propagation of solar events from our Sun. And the Voyagers' new mission focuses not only on effects on space from within our heliosphere — the giant bubble around the Sun filled up by the constant outflow of solar particles called the solar wind — but from outside of it. Though they once helped us look closer at the planets and their relationship to the Sun, they now give us clues about the nature of interstellar space as the spacecraft continue their journey.

The environment they explore is colder, subtler and more tenuous than ever before, and yet the Voyagers continue on, exploring and measuring the interstellar medium, a smorgasbord of gas, plasma and particles from stars and gas regions not originating from our system. Three of the spacecraft's 10 instruments are the major players that study how space inside the heliosphere differs from interstellar space. Looking at this data together allows scientist to piece together our best-yet picture of the edge of the heliosphere and the interstellar medium. Here are the stories they tell.

The Magnetometer

Image above: Illustration of NASA’s Voyager spacecraft, with the Magnetometer (MAG) instrument and its boom displayed. Image Credits: NASA’s Goddard Space Flight Center/Jet Propulsion Laboratory/Mary Pat Hrybyk-Keith.

On the Sun Spot, we have been exploring the various instruments on Voyager 2 one at a time, and analyzing how scientists read the individual sets of data sent to Earth from the far-reaching spacecraft. But one instrument we have not yet talked about is Voyager 2’s Magnetometer, or MAG for short.

During the Voyagers' first planetary mission, the MAG was designed to investigate the magnetospheres of planets and their moons, determining the physical mechanics and processes of the interactions of those magnetic fields and the solar wind. After that mission ended, the Voyager spacecraft studied the magnetic field of the heliosphere and beyond, observing the magnetic reach of the Sun and the changes that occur within that reach during solar activity.

Getting the magnetic data as we travel further into space requires an interesting trick. Voyager spins itself around, in a calibration maneuver that allows Voyager to differentiate between the spacecraft's own magnetic field — that goes along for the ride as it spins — and the magnetic fields of the space it’s traveling through.

The initial peek into the magnetic field beyond the Sun’s influence happened when Voyager 1 crossed the heliopause in 2012. Scientists saw that within the heliosphere, the strength of the magnetic field was quite variable, changing and jumping as Voyager 1 moved through the heliosphere. These changes are due to solar activity. But once Voyager 1 crossed into interstellar space, that variability was silenced. Although the strength of the field was similar to what it was inside the heliosphere, it no longer had the variability associated with the Sun’s outbursts.

Graphic above: Magnetometer (MAG) data taken from Voyager 1 during its transition into interstellar space in 2012. Graphic Credits: NASA’s Goddard Space Flight Center/Jet Propulsion Laboratory.

This graph shows the magnitude, or the strength, of the magnetic field around the heliopause from January 2012 out to May 2014. Before encountering the heliopause, marked by the orange line, the magnetic strength fluctuates quite a bit. After a bumpy ride through the heliopause in 2012, the magnetic strength stops fluctuating and begins to stabilize in 2013, once the spacecraft is far enough out into the interstellar medium.

In November 2018, Voyager 2 also crossed the heliopause and similarly experienced quite the bumpy ride out of the heliopause. Scientists are excited to see how its journey differs from its twin spacecraft.

Scientists are still working through the MAG data from Voyager 2, and are excited to see how Voyager 2’s journey differed from Voyager 1.

The Cosmic Ray Subsystem

Image above: Illustration of NASA’s Voyager spacecraft, with the Cosmic Ray Subsystem (CRS) highlighted. Image Credits: NASA’s Goddard Space Flight Center/Jet Propulsion Laboratory/Mary Pat Hrybyk-Keith.

Much like the MAG, the Cosmic Ray Subsystem — called CRS — was originally designed to measure planetary systems. The CRS focused on the compositions of energetic particles in the magnetospheres of Jupiter, Saturn, Uranus and Neptune. Scientists used it to study the charged particles within the solar system and their distribution between the planets. Since it passed the planets, however, the CRS has been studying the heliosphere’s charged particles and — now — the particles in the interstellar medium.

The CRS measures the count rate, or how many particles detected per second. It does this by using two telescopes: the High Energy Telescope, which measures high energy particles (70MeV) identifiable as interstellar particles, and the Low Energy Telescope, which measures low-energy particles (5MeV) that originate from our Sun. You can think of these particles like a bowling ball hitting a bowling pin versus a bullet hitting the same pin — both will make a measurable impact on the detector, but they're moving at vastly different speeds. By measuring the amounts of the two kinds of particles, Voyager can provide a sense of the space environment it’s traveling through.

Graphic above: Scientists compared data from Voyager 1 with its 2012 crossing of the heliopause to watch for clue for when Voyager 2 would cross. In November 2018, the first clues came from the Cosmic Ray Subsystem! Graphic Credits: NASA’s Jet Propulsion Laboratory/NASA Headquarters/Patrick Koehn.

These graphs show the count rate — how many particles per second are interacting with the CRS on average each day — of the galactic ray particles measured by the High Energy Telescope (top graph) and the heliospheric particles measured by the Low Energy Telescope (bottom graph). The line in red shows the data from Voyager 1, time shifted forward 6.32 years from 2012 to match up with the data from Voyager around November 2018, shown in blue.

CRS data from Voyager 2 on Nov. 5, 2018, showed the interstellar particle count rate of the High Energy Telescope increasing to count rates similar to what Voyager 1 saw then leveling out. Similarly, the Low Energy Telescope shows a severe decrease in heliospheric originating particles. This was a key indication that Voyager 2 had moved into interstellar space. Scientists can keep watching these counts to see if the composition of interstellar space particles changes along the journey.

The Plasma Instrument

Image above: Illustration of NASA’s Voyager spacecraft, with the Plasma Science Instrument (PLS) displayed. Image Credits: NASA’s Goddard Space Flight Center/Jet Propulsion Laboratory/Mary Pat Hrybyk-Keith.

The Plasma Science instrument, or PLS, was made to measure plasma and ionized particles around the outer planets and to measure the solar wind’s influence on those planets. The PLS is made up of four Faraday cups, an instrument that measures the plasma as it passes through the cups and calculates the plasma’s speed, direction and density.

The plasma instrument on Voyager 1 was damaged during a fly-by of Saturn and had to be shut off long before Voyager 1 exited the heliosphere, making it unable to measure the interstellar medium’s plasma properties. With Voyager 2's crossing, scientists will get the first-ever plasma measurements of the interstellar medium.

Scientists predicted that interstellar plasma measured by Voyager 2 would be higher in density but lower in temperature and speed than plasma inside the heliosphere. And in November 2018, the instrument saw just that for the first time. This suggests that the plasma in this region is getting colder and slower, and, like cars slowing down on a freeway, is beginning to pile up around the heliopause and into the interstellar medium.

And now, thanks to Voyager 2’s PLS, we have a never-before-seen perspective on our heliosphere: The plasma velocity from Earth to the heliopause.

Graphic above: With Voyager 2 crossing the heliopause, scientists now have a new view of solar wind plasma across the heliosphere. Graphic Credits: NASA's Jet Propulsion Laboratory/ Michigan Institute of Technology/John Richardson.

These three graphs tell an amazing story, summarizing a journey of 42 years in one plot. The top section of this graph shows the plasma velocity, how fast the plasma across the heliosphere is moving, against the distance out from Earth. The distance is in astronomical units; one astronomical unit is the average distance between the Sun and Earth, about 93 million miles. For context, Saturn is 10 AU from Earth, while Pluto is about 40 AU away.

The heliopause crossing happened at 120 AU, when the velocity of plasma coming out from the Sun drops to zero (seen on the top graph), and the outward flow of the plasma is diverted — seen in the increase in the two bottom graphs, which show the upwards and downward speeds (the normal velocity, middle graph) and the sideways speed of the solar wind (the tangential velocity, bottom graph) of the solar wind plasma, respectively. This means as the solar wind begins to interact with the interstellar medium, it is pushed out and away, like a wave hitting the side of a cliff. 

Looking at each instrument in isolation, however, does not tell the full story of what interstellar space at the heliopause looks like. Together, these instruments tell a story of the transition from the turbulent, active space within our Sun's influence to the relatively calm waters on the edge of interstellar space.

The MAG shows that the magnetic field strength decreases sharply in the interstellar medium. The CRS data shows an increase in interstellar cosmic rays, and a decrease in heliospheric particles. And finally, the PLS shows that there’s no longer any detectable solar wind.

Now that the Voyagers are outside of the heliosphere, their new perspective will provide new information about the formation and state of our Sun and how it interacts with interstellar space, along with insight into how other stars interact with the interstellar medium.

Voyager 1 and Voyager 2 are providing our first look at the space we would have to pass through if humanity ever were to travel beyond our home star — a glimpse of our neighborhood in space. 

Related links:

Video: "NASA Science Live: Going Interstellar":

Explore Voyager 2 data on "The Sun Spot" blog:


Images (mentioned), Graphics (mentioned), Animation (mentioned), Text, Credits: NASA/Rob Garner/Goddard Space Flight Center, by Susannah Darling.


Dark dust devil tracks on Mars

ESA - Mars Express Mission patch.

28 March 2019

The winds of Mars are responsible for myriad features across the planet’s surface – including the dark dunes and wispy, filament-like streaks seen in this image from ESA’s Mars Express.

Dust devils in Chalcoporos Rupes

The intriguing features shown here are ‘dust devil’ tracks: as the Sun heats up the martian ground during the day, vortices form that lift warm air from near the surface, whipping up dust as they do so, shaping and sculpting it into swirling, column-shaped, tornado-like whirlwinds (click here for videos of dust devils made by NASA's Mars rover Spirit).

These dust devils range across the entire planet, lifting the top, brighter layer of dust from the surface, and leaving darker paths in their wake. They are most often seen in the martian spring and summer, lasting for a few months at most before their tracks become obscured by dust that has been buffeted around by storms and winds.

Mars Express

These Mars Express images show a curving, looping, crisscrossing web of dust devil tracks in the southern hemisphere of the planet, around an escarpment feature known as Chalcoporos Rupes. This area is covered in a thick layer of dust and is not unfrequently home to wind-related activity.

Context view

Areas of Mars that most regularly see dust devils include Amazonis Planitia, Argyre Planitia, Hellas Basin, and two impact craters that lie close to the region shown here: Proctor and Russell.

Proctor, Russell, and Chalcoproros Rupes are based in Mars’ Noachis quadrangle, an area so thickly pockmarked with impact craters that it is thought to be one of the oldest parts of the planet.

Both the craters visible in this frame boast dense, dark, eye-catching patches of rippling sand dunes, while the surrounding terrain is decorated with a broad web of dunes and signs of past dust devil activity.

Topographic view of Chalcoporos Rupes

Martian dust devils are similar to those seen on Earth in especially dry, arid, desert landscapes – but they are far larger. They can tower up to eight kilometres high on the Red Planet, creating paths that are hundreds of metres wide and stretch out for a few kilometres.

Their colossal size makes them highly effective at carrying dust high up into Mars’ atmosphere – in fact, these devils may lift as much material as a martian global dust storm does at its peak.

Perspective view

Such dust storms are immense and impressive. Mars Express captured signs of a burgeoning storm near Mars’ north pole in April of last year, highlighting an intense boundary between the planet’s usual, calm, ochre-hued surface and an incoming wall of dust clouds – and this was a somewhat modest dust storm compared to those that blanket the entirety of Mars and rage on for months.

Dust devils have been seen often on Mars, both by Mars Express and other missions – including the ESA-Roscosmos ExoMars Trace Gas Orbiter, which recently imaged an impressive pattern of dust devil tracks in the Terra Sabaea region of Mars that may be the result of hundreds or even thousands of small martian tornadoes coming together and leaving their mark on the planet’s surface.

Chalcoporos Rupes in 3D

The Trace Gas Orbiter will be joined by a rover – recently named Rosalind Franklin – and a surface science platform, due to launch in 2020. These will allow the ExoMars mission to explore the Red Planet in even greater detail in coming years.

Related links:

Mars Express:

ESA-Roscosmos ExoMars:

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


Hubble Captures Rare Active Asteroid

ESA - Hubble Space Telescope logo.

28 March 2019

Thanks to an impressive collaboration bringing together data from ground-based telescopes, all-sky surveys and space-based facilities — including the NASA/ESA Hubble Space Telescope — a rare self-destructing asteroid called 6478 Gault has been observed.

Asteroid 6478 Gault

Clear images from the NASA/ESA Hubble Space Telescope have provided researchers with new insight into asteroid Gault’s unusual past. The object is 4–9 kilometres wide and has two narrow, comet-like tails of debris that tell us that the asteroid is slowly undergoing self-destruction. Each tail is evidence of an active event that released material into space.

Gault was discovered in 1988. However, this observation of two debris tails is the first indication of the asteroid’s instability. This asteroid one of only a handful to be caught disintegrating by a process known as a YORP torque. When sunlight heats an asteroid, the infrared radiation that escapes from its warmed surface carries off both heat and momentum. This creates a small force that can cause the asteroid to spin faster. If this centrifugal force eventually overcomes gravity, the asteroid becomes unstable. Landslides on the object can release rubble and dust into space, leaving behind a tail of debris, as seen here with asteroid Gault.

“This self-destruction event is rare”, explained Olivier Hainaut (European Southern Observatory, Germany). “Active and unstable asteroids such as Gault are only now being detected by means of new survey telescopes that scan the entire sky, which means asteroids such as Gault that are misbehaving cannot escape detection any more.”

Gault within the solar system

Astronomers estimate that among the 800,000 known asteroids that occupy the Asteroid Belt between Mars and Jupiter, YORP disruptions occur roughly once per year. The direct observation of this activity by the Hubble Space Telescope has provided astronomers with a special opportunity to study the composition of asteroids. By researching the material that this unstable asteroid releases into space, astronomers can get a glimpse into the history of planet formation in the early ages of the Solar System.

Understanding the nature of this active and self-destructive object has been a collaborative effort involving researchers and facilities around the world. The asteroid’s debris tail was first detected by the University of Hawaiʻi/NASA ATLAS (Asteroid Terrestrial-Impact Last Alert System) telescopes in the Hawaiian Islands on 5 January 2019. Upon review of archival data from ATLAS and UH/NASA Pan-STARRS (Panoramic Survey Telescope and Rapid Response System), it was found that the object’s larger tail of debris had been observed earlier in December 2018. Shortly thereafter, in January 2019, a second, shorter tail was seen by various telescopes, including the Isaac Newton, William Herschel, and ESA OGS Telescopes in La Palma and Tenerife, Spain; the Himalayan Chandra Telescope in India; and the CFHT in Hawaiʻi. Subsequent analysis of these observations suggested that the two events that produced these debris trails occurred around 28 October and 30 December 2018, respectively. These tails will only be visible for only a few months, after which the dust will have dispersed into interplanetary space.

Follow-up observations were then made by various ground-based telescopes. These data were used to deduce a two-hour rotation period for Gault, which is very close to the critical speed at which material will begin to tumble and slide across the asteroid’s surface before drifting off into space.

Pan across the Gault asteroid

“Gault is the best ‘smoking-gun’ example of a fast rotator right at the two-hour limit”, explained lead author Jan Kleyna (University of Hawaiʻi, USA). “It could have been on the brink of instability for 10 million years. Even a tiny disturbance, like a small impact from a pebble, might have triggered the recent outbursts.”

Hubble’s sharp imaging provided valuable detail regarding the asteroid’s activity. From the narrow width of the streaming tails, researchers inferred that the release of material took place in short episodes lasting from a few hours to a couple of days. From the absence of excess dust in the immediate vicinity of the asteroid, they concluded that the asteroid’s activity was not caused by a collision with another massive object. Researchers hope that further observations will provide even more insight into this rare and curious object.

Hubble Space Telescope (HST)

The team’s results have been accepted for publication in The Astrophysical Journal Letters:

More information:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

The research team’s work is presented in the scientific paper “The Sporadic Activity of (6478) Gault: A YORP driven event?”, which will be published in The Astrophysical Journal Letters.

ATLAS (Asteroid Terrestrial-impact Last Alert System) is an asteroid impact early warning system being developed by the University of Hawai’i and funded by NASA. It consists of two telescopes, 100 miles apart, which automatically scan the whole sky several times every night looking for moving objects.

The international team of astronomers in this study consists of Jan T. Kleyna (University of Hawai’i Institute for Astronomy, USA), Olivier R. Hainaut(European Southern Observatory, Germany), Karen J. Meech (University of Hawai’i Institute for Astronomy, USA), Henry H. Hsieh (Planetary Science Institute, USA, & Academia Sinica Institute of Astronomy and Astrophysics, Taiwan), Alan Fitzsimmons (Queen’s University Belfast Astrophysics Research Centre, UK), Marco Micheli (European Space Agency Near Earth Object Coordination Centre, Italy, & National Institute for Astrophysics - Osservatorio Astronomico di Roma, Italy), Jacqueline V. Keane (University of Hawai’i Institute for Astronomy, USA), Larry Denneau (University of Hawai’i Institute for Astronomy, USA), John Tonry (University of Hawai’i Institute for Astronomy, USA), Aren Heinze (University of Hawai’i Institute for Astronomy, USA), Bhuwan C. Bhatt(Indian Institute for Astrophysics, India), Devendra K. Sahu (Indian Institute for Astrophysics, India),

Detlef Koschny (European Space Agency European Space Research and Technology Centre, the Netherlands & Near Earth Object Coordination Centre, Italy, & Technical University of Munich, Germany), Ken W. Smith (Queen’s University Belfast Astrophysics Research Centre, UK), Harald Ebeling (University of Hawai’i Institute for Astronomy, USA), Robert Weryk (University of Hawai’i Institute for Astronomy, USA), Heather Flewelling (University of Hawai’i Institute for Astronomy, USA), and Richard J. Wainscoat (University of Hawai’i Institute for Astronomy, USA).


Images of Hubble:

Hubblesite release:

The science paper by J. Kleyna et al.:

NASA/ESA Hubble Space Telescope (HST):

Image, Animation, Text, Credits: NASA, ESA, NASA, ESA, K. Meech and J. Kleyna (University of Hawaii), O. Hainaut (European Southern Observatory), L. Calçada/Videos: ESA/Hubble, L. Calçada / Meech and J. Kleyna (University of Hawaii), O. Hainaut (European Southern Observatory)/Music: James Creasey — Space Drone (


The JAXA Space Exploration Hub Center Co-Produces Results on Remote and Automatic Control to Build Lunar Base

JAXA - Japan Aerospace Exploration Agency logo.

March 28, 2019

National Research and Development Agency Japan Aerospace Exploration Agency (President: Hiroshi Yamakawa, hereafter JAXA) and Kajima Corporation (President and Representative Director: Yoshikazu Oshimi) have promoted research and development on the remote construction system by coordination of remote and automatic control. * The project got started in 2016 with the participation of schools; Shibaura Institute of Technology, The University of Electro-Communications and Kyoto University. With application in view to remotely controlled construction of a lunar base, the experiment conducted at the Kajima Seisho Experiment Site, Odawara, Kanagawa, of two kinds of the automated construction functionality has produced some results.

*Remote construction system by coordination of remote and automatic control: A joint research theme of the JAXA Space Exploration Innovation Hub Center.

Computer generated images of remotely operated construction of lunar base

Research Background

Remote control is a feasible method to build a human base off of Earth, on the moon and Mars in the future. Compensation of the considerable delay caused by sending any command to construction machinery from Earth has been an issue, however, along with others such as productivity and efficiency. On Earth, too, the same technologies are in need to deal with a predicted shortage of adept human resources in the construction industry, which has conventionally been human labor oriented. Since 2015, A4CSEL, developed by Kajima Corporation to automate construction machinery has been on site. The research took off by the parties of five – JAXA, Kajima Corporation and three schools as technologies of A4CSEL can be used to realize the remote construction functionality in space by coordination of remote and automatic control.

Research Overview

Remote, autonomous control to build a human lunar base will require the following steps;
①     Site preparation work for the module for human habitation
②     Excavation that meets the required depth
③     Installation of the module
④     Shielding the module with the surface material to protect it from meteoroids and radiation

Remote Construction of Manned Lunar Base

A seven-ton class earth mover has been modified with onboard survey instruments and an automatic operation control console. The instruments that the tractor and backhoe are installed with autonomously measure the position and direction of its own, making it both remotely and automatically operable.

In addition to full automation, this research is designed to acquire the following to establish remote construction functionality by coordination of remote and automatic control;

- Operational support to compensate for delays: remote control functionality that could compensate for considerable communication delays for 3 to 8 seconds without undermining the operation and stability of the remotely controlled machinery

- Motion recognition that adapts to environment: autonomous operation that opts for plausible solution in variable space topography due to communication delays

- Coordination of multiple construction machines: interference avoidance that facilitates synchronization of several operations

Various commands have been executed – the routine operation is repeated, driving over specified distances is automated, and operations requiring fine tuning are controlled remotely. The operational process has shown feasibility of the unmanned technologies to build a lunar base.

Autonomously operated tractor and backhoe

Future Directions for Research

Research and development continues to advance the obtained results and to improve the functions and performance of the system. Practical technologies are to be sought for to estimate position on the Moon and Mars where Global Navigation Satellite System (GNSS) is unavailable, and to precisely recognize and navigate terrains, and to ensure the system stability in the uncertain cosmic communication environment.

This ongoing joint research has been carried out as part of the Japan Science and Technology Agency Support program to start up an innovation hub center.

Related links:

Kajima Corporation:


Images, Text, Credits: Japan Aerospace Exploration Agency (JAXA)/National Research and Development Agency/Kajima Corporation.

Best regards,

mercredi 27 mars 2019

'Space Butterfly' Is Home to Hundreds of Baby Stars

NASA - Spitzer Space Telescope patch.

March 27, 2019

Image above: Officially known as W40, this red butterfly in space is a nebula, or a giant cloud of gas and dust. The "wings" of the butterfly are giant bubbles of gas being blown from the inside out by massive stars. Image Credits: NASA/JPL-Caltech.

What looks like a red butterfly in space is in reality a nursery for hundreds of baby stars, revealed in this infrared image from NASA's Spitzer Space Telescope. Officially named Westerhout 40 (W40), the butterfly is a nebula — a giant cloud of gas and dust in space where new stars may form. The butterfly's two "wings" are giant bubbles of hot, interstellar gas blowing from the hottest, most massive stars in this region.

Besides being beautiful, W40 exemplifies how the formation of stars results in the destruction of the very clouds that helped create them. Inside giant clouds of gas and dust in space, the force of gravity pulls material together into dense clumps. Sometimes these clumps reach a critical density that allows stars to form at their cores. Radiation and winds coming from the most massive stars in those clouds — combined with the material spewed into space when those stars eventually explode — sometimes form bubbles like those in W40. But these processes also disperse the gas and dust, breaking up dense clumps and reducing or halting new star formation.

The material that forms W40's wings was ejected from a dense cluster of stars that lies between the wings in the image. The hottest, most massive of these stars, W40 IRS 1a, lies near the center of the star cluster. W40 is about 1,400 light-years from the Sun, about the same distance as the well-known Orion nebula, although the two are almost 180 degrees apart in the sky. They are two of the nearest regions in which massive stars — with masses upwards of 10 times that of the Sun — have been observed to be forming.

Another cluster of stars, named Serpens South, can be seen to the upper right of W40 in this image. Although both Serpens South and the cluster at the heart of W40 are young in astronomical terms (less than a few million years old), Serpens South is the younger of the two. Its stars are still embedded within their cloud but will someday break out to produce bubbles like those of W40. Spitzer has also produced a more detailed image of the Serpens South cluster.

A mosaic of Spitzer's observation of the W40 star-forming region was originally published as part of the Massive Young stellar clusters Study in Infrared and X-rays (MYStIX) survey of young stellar objects.

The Spitzer picture is composed of four images taken with the telescope's Infrared Array Camera (IRAC) during Spitzer's prime mission, in different wavelengths of infrared light: 3.6, 4.5, 5.8 and 8.0 μm (shown as blue, green, orange and red). Organic molecules made of carbon and hydrogen, called polycyclic aromatic hydrocarbons (PAHs), are excited by interstellar radiation and become luminescent at wavelengths near 8.0 microns, giving the nebula its reddish features. Stars are brighter at the shorter wavelengths, giving them a blue tint. Some of the youngest stars are surrounded by dusty disks of material, which glow with a yellow or red hue.

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

More information on Spitzer can be found at its website: and

Image (mentioned), Animation, Text, Credits: NASA/Tony Greicius/JPL/Calla Cofield.


Spacewalks Preps and More Brain Research At Station Today

ISS - Expedition 59 Mission patch.

March 27, 2019

Two days away from the second International Space Station spacewalk of 2019 and the Expedition 59 crew is studying the human brain and an astronaut’s wake-sleep cycle in space.

Flight Engineers Nick Hague and Christina Koch will exit the Quest airlock Friday for about 6.5 hours of battery swaps to upgrade the station’s power storage capacity. The duo will set their spacesuits to battery power about 8:20 a.m. EDT Friday signifying the start of their spacewalk. NASA TV will begins its live coverage at 6:30 a.m.

Image above: NASA astronauts Christina Koch (left) and Nick Hague are fitted in U.S. spacesuits and check out spacewalk cameras inside the Quest airlock. Image Credit: NASA.

While Hague and Koch were organizing their spacewalk tools today, the duo had time to research how blood flows to the brain in microgravity. Koch took Doppler waveform measurements of her arterial blood pressure for the Cerebral Autoregulation study. Hague then closed out the brain blood-flow experiment and stowed its gear in the Kibo lab module.

Astronaut David Saint-Jacques of the Canadian Space Agency was back on spacesuit duty today cleaning cooling loops, checking tools and readying the SAFER jetpacks. He later worked on a wearable device, the Actiwatch Spectrum (AWS), which measures an astronaut’s daily wake-sleep cycle, or circadian rhythm. The AWS provides doctors insights into sleep quality, sleep onset and ambient light quality aboard the orbital lab.

International Space Station (ISS). Image Credit: NASA

NASA astronaut Anne McClain also assisted with the spacesuit work today checking the SAFER jet packs and reconfiguring the U.S. spacesuits. She also worked on a science freezer and trashed obsolete ultrasonic hardware designed to detect pressure leaks.

Related links:

Expedition 59:



Cerebral Autoregulation:

Kibo lab module:

Actiwatch Spectrum (AWS):

Science freezer:

Space Station Research and Technology:

International Space Station (ISS):

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

Best regards,

Tests Prove Out Orion Safety Systems From Liftoff to Splashdown

NASA - Orion CV logo.

March 27, 2019

Engineers completed two key tests the week of March 18 to help ensure NASA’s Orion spacecraft is ready from liftoff to splashdown for missions to the Moon. Teams successfully tested one of the motors on Orion’s Launch Abort System responsible for taking the crew to safety in an emergency during launch, and completed testing at sea for the qualification of the system used to upright Orion after it lands in the ocean.

At its facility in Elkton, Maryland, Northrop Grumman hot fired a motor for Orion’s launch abort system. The attitude control motor is responsible for orienting the crew module for landing in the event that Orion’s ride to space experiences a failure during launch or ascent. The motor is essential because it helps stabilize Orion and control its trajectory as it moves away from the rocket. During the 30-second test, the motor produced more than 7,000 pounds of thrust from eight valves. This test was the first in a series of evaluations aimed at qualifying the attitude control motor for crewed missions.

Image above: The attitude control motor fires during a test at Northrop Grumman’s facility in Elkton, MD. Image Credit: Northrop Grumman.

Orion’s launch abort system is positioned on top of the crew module and is designed to protect astronauts during their trip to space. It can activate within milliseconds to pull the crew module to safety if needed. It consists of three solid rocket motors: the abort motor that pulls the crew module away from a rocket, the attitude control motor that can steer Orion in any direction upon command, and the jettison motor that ignites to separate the launch abort system from the spacecraft so that Orion is free to deploy its parachutes to assist with landing.

Ensuring crew safety continues throughout the mission, including systems used to assist with returning astronauts to land. Off the coast of Atlantic Beach, North Carolina, engineers tested the crew module uprighting system (CMUS) to ensure the capsule can be oriented right-side up once it returns from its deep space missions.

When Orion splashes down in the ocean, it can settle in one of two positions. In the most ideal scenario, the capsule is oriented with the heat shield in the water and its windows and hatches out of the water. The crew module also could land with the top submerged in the water, and the heat shield facing the sky. The CMUS deploys a series of five, bright orange airbags to flip the capsule right side up in the event the Orion lands upside down. It takes less than four minutes for the system to upright the capsule to help protect the astronauts inside that are returning home from future deep space missions.

Image above: NASA tested Orion’s crew module uprighting system off the Coast of North Carolina in March 2018. Image Credit: NASA.

In a perfect post-mission landing situation, all five of Orion’s airbags will deploy to reorient the capsule, and while this is the most likely scenario for capsule recovery, NASA aims to be ready for any situation. Several tests performed with a mockup of the Orion crew capsule demonstrated that even if one of the airbags failed to inflate, the CMUS would still be able to perform as intended.

The system was previously tested in the Neutral Buoyancy Lab, a giant pool at NASA’s Johnson Space Center in Houston, primarily used for astronaut training, as well as off the coast of Galveston, Texas. Engineers also wanted to test the uprighting system in more challenging waves, similar to those where Orion is expected to land, and partnered with the Coast Guard to test the CMUS in the Atlantic Ocean.

Engineers experimented with four different CMUS configurations over several days of testing. These tests verified the system’s ability to perform in varying wave conditions, and demonstrated how the CMUS would protect the crew in a wide range of landing scenarios.

“Performing full-scale integrated testing like this at-sea is very complex. The recent CMUS accomplishments were the result of years of work and planning on this critical system needed to enable safe crew recovery of future Orion missions,” said Tara Radke, Orion Integrated Landing and Recovery System manager. “I’m grateful to our dedicated team for their support that made these tests all a huge success.”

With the success of both tests, the Orion team is well on its way to verify Orion is ready for missions to the Moon and beyond.

Related links:

Orion Spacecraft:

Moon to Mars:

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