samedi 9 avril 2016

Long March 2D launches the recoverable Shijian-10












CASC - China Aerospace Science and Technology Corporation logo.

April 9, 2016

Chinese Long March 2D rocket launches recoverable Shijian-10

China has launched the Shijian-10 recoverable satellite. The launch of Shijian-10 took place at 17:38 UTC on Tuesday April 5, 2016 using a Long March-2D launch vehicle from the 603 Launch Pad at the Jiuquan Satellite Launch Center’s LC43.

Microgravity experiments on Shijian-10, the 24th recoverable satellite of China, cover the fields of physical science and life science.

video
ShiJian-10 launch. Video Credits: CCTV/SciNews

The scientific purpose of the program is to promote the scientific research in the space microgravity environment by operating Shijian-10 at low Earth orbit for two weeks.

There are six experiments for fluid physics, three for combustion and eight for materials science in the field of physical science.

Also on board are three experiments for radiation biology, three for gravitational biology and four for biotechnology in the field of life science.

Shijian-10 spacecraft

The satellite also carries an experiment from the European Space Agency that consists of containers of highly pressurized crude oil will to help to improve our knowledge of oil reservoirs buried kilometers underground.

A full list and overview of the experiments can be found on this link:
https://forum.nasaspaceflight.com/index.php?topic=38110.msg1423581#msg1423581

Shijian-10 will operate on a 220 x 482 km orbit at 63 degrees orbital inclination. Mission duration is expected to be two weeks. The launch mass of the satellite is 3,600 kg.

For more information about China Aerospace Science and Technology Corporation (CASC), visit: http://english.spacechina.com/n16421/index.html

Images, Video (mentioned), Text, Credits: CASC/CCTV/NASA Spaceflight.com/Rui C. Barbosa.

Best regards, Orbiter.ch

vendredi 8 avril 2016

Saturn Spacecraft Not Affected by Hypothetical Planet 9










NASA - Cassini International logo.

April 8, 2016


Image above: Saturn as seen by NASA's Cassini spacecraft in 2008. Long-term tracking of the spacecraft's position has revealed no unexplained perturbations in Cassini's orbit.
Image Credits: NASA/JPL/Space Science Institute.

Contrary to recent reports, NASA's Cassini spacecraft is not experiencing unexplained deviations in its orbit around Saturn, according to mission managers and orbit determination experts at NASA's Jet Propulsion Laboratory in Pasadena, California.

Several recent news stories have reported that a mysterious anomaly in Cassini's orbit could potentially be explained by the gravitational tug of a theorized massive new planet in our solar system, lurking far beyond the orbit of Neptune. While the proposed planet's existence may eventually be confirmed by other means, mission navigators have observed no unexplained deviations in the spacecraft's orbit since its arrival there in 2004.

"An undiscovered planet outside the orbit of Neptune, 10 times the mass of Earth, would affect the orbit of Saturn, not Cassini," said William Folkner, a planetary scientist at JPL. Folkner develops planetary orbit information used for NASA's high-precision spacecraft navigation. "This could produce a signature in the measurements of Cassini while in orbit about Saturn if the planet was close enough to the sun. But we do not see any unexplained signature above the level of the measurement noise in Cassini data taken from 2004 to 2016."

A recent paper predicts that, if data tracking Cassini's position were available out to the year 2020, they might be used to reveal a "most probable" location for the new planet in its long orbit around the sun. However, Cassini's mission is planned to end in late 2017, when the spacecraft -- too low on fuel to continue on a longer mission -- will plunge into Saturn's atmosphere.

"Although we'd love it if Cassini could help detect a new planet in the solar system, we do not see any perturbations in our orbit that we cannot explain with our current models," said Earl Maize, Cassini project manager at JPL.

The Cassini-Huygens mission is a cooperative project of NASA, ESA and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate in Washington.

Related link:

http://www.aanda.org/articles/aa/pdf/2016/03/aa28227-16.pdf

Related article:

Caltech Researchers Find Evidence of a Real Ninth Planet:
http://orbiterchspacenews.blogspot.ch/2016/01/caltech-researchers-find-evidence-of.html

For more information about Cassini, visit:

http://www.nasa.gov/cassini

http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

http://saturn.jpl.nasa.gov

Image (mentioned), Text, Credits: NASA/JPL/Preston Dyches/Martin Perez.

Greetings, Orbiter.ch

Dragon Cargo Headed to Space Station Includes Habitat Prototype, Medical Research












SpaceX - Dragon CRS-8 Mission patch.

April 8, 2016


Image above: SpaceX's Falcon 9 carrying Dragon cargo spacecraft. Image Credit: NASA TV.

Tucked in the trunk of the latest commercial cargo spacecraft to head for the International Space Station is an expandable structure that has the potential to revolutionize work and life on the space station.

SpaceX's Dragon spacecraft is delivering almost 7,000 pounds of cargo, including the Bigelow Expandable Activity Module (BEAM), to the orbital laboratory following its launch on a Falcon 9 rocket at 4:43 p.m. EDT from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida.

video
SpaceX CRS-8 Launch

The mission is SpaceX’s eighth cargo delivery through NASA’s Commercial Resupply Services contract. Dragon's cargo will support dozens of the more than 250 science and research investigations taking place on the space station during Expeditions 47 and 48.

“The cargo will allow investigators to use microgravity conditions to test the viability of expandable space habitats, assess the impact of antibodies on muscle wasting, use protein crystal growth to aid the design of new disease-fighting drugs and investigate how microbes could affect the health of the crew and their equipment over a long duration mission,” said NASA Deputy Administrator Dava Newman.

Dragon will be grappled at 7 a.m. Sunday, April 10, by ESA (European Space Agency) astronaut Tim Peake, using the station's Candarm2 robotic arm, with help from NASA astronaut Jeff Williams.

video
SpaceX CRS-8 Falcon Rocket Successful Landing on Barge

BEAM will arrive in Dragon’s unpressurized trunk and, after about five days, will be removed and attached to the station. Expansion is targeted for the end of May. The module will expand to roughly 10 feet in diameter and 13 feet long. During its two-year test mission, astronauts will enter the module for a few hours several times a year to retrieve sensor data and assess conditions. Expandable habitats are designed to take up less room on a rocket, but provide greater volume for living and working in space once expanded. This first in situ test of the module will allow investigators to gauge how well the habitat protects against solar radiation, space debris and contamination.


Image above: The BEAM module will be attached to the rear port of the space station’s Node 3. After installation, the BEAM expands to roughly 13-feet-long and 10.5 feet in diameter. Image Credits: Bigelow Aerospace, LLC.

Crew members experience significant decreases in bone density and muscle mass during long-duration spaceflight without appropriate nutrition and exercise. One life science investigation on its way to the orbiting laboratory will assess myostatin inhibition as a means of preventing skeletal muscle atrophy and weakness in mice exposed to long-duration spaceflight. Drugs tested on the space station could progress to human clinical trials back on Earth to validate their effectiveness for future space missions.

Dragon also will deliver Microchannel Diffusion, a study of fluids at the nanoscale, or atomic, level. Nanofluidic sensors could measure the air in the space station, or be used to deliver drugs to specific places in the body. The laws that govern flow through nanoscale channels are not well understood, and this investigation simulates those interactions by studying them at the larger microscopic level. This type of research is possible only on the space station, where Earth’s gravity is not strong enough to interact with the molecules in a sample, so they behave more like they would at the nanoscale. Knowledge gleaned from the investigation may have implications for drug delivery and particle filtration, as well as future technological applications for space exploration.

Another experiment onboard Dragon is a protein crystal growth investigation focused on drug design and development. Growing protein crystals in microgravity can help researchers avoid some of the obstacles inherent to protein crystallization on Earth, such as sedimentation. One investigation will study the effect of microgravity on the co-crystallization of a membrane protein to determine its three-dimensional structure. This will enable scientists to chemically target and inhibit, with “designer” compounds, an important human biological pathway thought to be responsible for several types of cancer.

SpaceX Dragon cargo spacecraft. Image Credit: NASA

To learn more about the dozens of science experiments headed to the space station, watch the science briefing “What’s on Board”: https://www.youtube.com/watch?v=cq_Kl0IGHH0

The spacecraft is scheduled to depart the space station May 11 for a splashdown in the Pacific Ocean, west of Baja California, bringing almost 3,500 pounds of science, hardware and spacewalking tools back to Earth for further study, including biological samples from NASA’s one-year mission.

The International Space Station is a convergence of science, technology and human innovation that demonstrates new technologies and makes research breakthroughs not possible on Earth. The space station has been continuously occupied since November 2000. In that time, it has been visited by more than 200 people and a variety of international and commercial spacecraft. The space station remains the springboard to NASA's next great leap in exploration, including future missions to an asteroid and Mars.

Related link:

Bigelow Expandable Activity Module (BEAM): http://bigelowaerospace.com/beam/

For more information about SpaceX's mission, visit: http://www.nasa.gov/spacex

For more information about the International Space Station, visit: http://www.nasa.gov/station

Images (mentioned), Video, Text, Credits: NASA/Tabatha Thompson/Karen Northon/SpaceX/NASA TV/JSC/Dan Huot.

Greetings, Orbiter.ch

NASA’s SDO Spies an Elongated Coronal Hole












NASA - Solar Dynamics Observatory patch.

April 8, 2016

video
NASA's SDO Spies an Elongated Coronal Hole. Video Credits: NASA/SDO

A long coronal hole can be seen right down the middle of the sun in this video captured by NASA’s Solar Dynamics Observatory on March 23-25, 2016. Coronal holes are areas on the sun where the solar magnetic field extends up and out into interplanetary space, sending solar material speeding out in a high-speed stream of solar wind. Scientists study these fast solar wind streams because they sometimes interact with Earth’s magnetic field, creating what’s called a geomagnetic storm, which can expose satellites to radiation and interfere with communications signals. This video was captured in extreme ultraviolet wavelengths of 193 angstroms – a type of light that is typically invisible to our eyes, but is colorized here in bronze.

For more information about Solar Dynamics Observatory (SDO), visit: http://www.nasa.gov/mission_pages/sdo/main/index.html

Video (mentioned), Text, Credits: NASA’s Goddard Space Flight Center/Steele Hill/Sarah Frazier/Rob Garner.

Greetings, Orbiter.ch

Searching for Far Out and Wandering Worlds












NASA - Kepler Space Telescope patch.

April 7, 2016

Astronomers have made great strides in discovering planets outside of our solar system, termed "exoplanets." In fact, over the past 20 years more than 5,000 exoplanets have been detected beyond the eight planets that call our solar system home.

The majority of these exoplanets have been found snuggled up to their host star completing an orbit (or year) in hours, days or weeks, while some have been found orbiting as far as Earth is to the sun, taking one Earth year to circle. But, what about those worlds that orbit much farther out, such as Jupiter and Saturn, or, in some cases, free-floating exoplanets that are on their own and have no star to call home? In fact, some studies suggest that there may be more free-floating exoplanets than stars in our galaxy.


Animation above: As an exoplanet passes in front of a more distant star, its gravity causes the trajectory of the starlight to bend, and in some cases, results in a brief brightening of the background star as seen by a telescope. The artistic animation illustrates this effect. This phenomenon of gravitational microlensing enables scientists to search for exoplanets that are too distant and dark to detect any other way. Image Animation Credits: NASA Ames/JPL-Caltech/T. Pyle.

This week, NASA's K2 mission, the repurposed mission of the Kepler space telescope, and other ground-based observatories, have teamed up to kick-off a global experiment in exoplanet observation. Their mission: survey millions of stars toward the center of our Milky Way galaxy in search of distant stars' planetary outposts and exoplanets wandering between the stars.

While today's planet-hunting techniques have favored finding exoplanets near their sun, the outer regions of a planetary system have gone largely unexplored. In the exoplanet detection toolkit, scientists have a technique well suited to search these farthest outreaches and the space in between the stars. This technique is called gravitational microlensing.

Gravitational Microlensing

For this experiment, astronomers rely on the effect of a familiar fundamental force of nature to help detect the presence of these far out worlds -- gravity. The gravity of massive objects such as stars and planets produces a noticeable effect on other nearby objects.

But gravity also influences light, deflecting or warping the direction of light that passes close to massive objects. This bending effect can make gravity act as a lens, concentrating light from a distant object, just as a magnifying glass can focus the light from the sun. Scientists can take advantage of the warping effect by measuring the light of distant stars, looking for a brightening that might be caused by a massive object, such as a planet, that passes between a telescope and a distant background star. Such a detection could reveal an otherwise hidden exoplanet.


Image above: In a global experiment in exoplanet observation, the K2 mission and Earth-based observatories on six continents will survey millions of stars toward the center of our Milky Way galaxy. Image Credits: NASA Ames/W. Stenzel and JPL-Caltech/R. Hurt.

"The chance for the K2 mission to use gravity to help us explore exoplanets is one of the most fantastic astronomical experiments of the decade," said Steve Howell, project scientist for NASA's Kepler and K2 missions at NASA's Ames Research Center in California's Silicon Valley. "I am happy to be a part of this K2 campaign and look forward to the many discoveries that will be made."

This phenomenon of gravitational microlensing -- "micro" because the angle by which the light is deflected is small -- is the effect for which scientists will be looking during the next three months. As an exoplanet passes in front of a more distant star, its gravity causes the trajectory of the starlight to bend, and in some cases results in a brief brightening of the background star as seen by the observatory.

The lensing events caused by a free-floating exoplanet last on the order of a day or two, making the continuous gaze of the Kepler spacecraft an invaluable asset for this technique.

video
Using Starlight to Find Wanderling Worlds

"We are seizing the opportunity to use Kepler's uniquely sensitive camera to sniff for planets in a different way," said Geert Barentsen, research scientist at Ames.

The ground-based observatories will record simultaneous measurements of these brief events. From their different vantage points, space and Earth, the measurements can determine the location of the lensing foreground object through a technique called parallax.

"This is a unique opportunity for the K2 mission and ground-based observatories to conduct a dedicated wide-field microlensing survey near the center of our galaxy," said Paul Hertz, director of the astrophysics division in NASA's Science Mission Directorate at the agency's headquarters in Washington. "This first-of-its-kind survey serves as a proof of concept for NASA's Wide-Field Infrared Survey Telescope (WFIRST), which will launch in the 2020s to conduct a larger and deeper microlensing survey. In addition, because the Kepler spacecraft is about 100 million miles from Earth, simultaneous space- and ground-based measurements will use the parallax technique to better characterize the systems producing these light amplifications."

To understand parallax, extend your arm and hold up your thumb. Close one eye and focus on your thumb and then do the same with the other eye. Your thumb appears to move depending on the vantage point. For humans to determine distance and gain depth perception, the vantage points, our eyes, use parallax.

Flipping the Spacecraft

The Kepler spacecraft trails Earth as it orbits the sun and is normally pointed away from Earth during the K2 mission. But this orientation means that the part of the sky being observed by the spacecraft cannot generally be observed from Earth at the same time, since it is mostly in the daytime sky.

To allow simultaneous ground-based observations, flight operations engineers at Ball Aerospace and the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder will perform a maneuver turning the spacecraft around to point the telescope in the forward velocity vector. So, instead of looking toward where it's been, the spacecraft will look in the direction of where it's going.

Kepler Space Telescope. Image Credits: NASA/JPL

This alignment will also yield a viewing opportunity of Earth and the moon as they cross the spacecraft's field of view. On April 14 at 11:50 a.m. PDT (18:50 UT), Kepler will record a full frame image. The result of that image will be released to the public archive in June once the data has been downloaded and processed. Kepler measures the change in brightness of objects and does not resolve color or physical characteristics of an observed object.

Observing from Earth

To achieve the objectives of this important path-finding research and community exercise in anticipation of WFIRST, approximately two-dozen ground-based observatories on six continents will observe in concert with K2. Each will contribute to various aspects of the experiment and will help explore the distribution of exoplanets across a range of stellar systems and distances.

These results will aid in our understanding of planetary system architectures, as well as the frequency of exoplanets throughout our galaxy.

For a complete list of participating observatories, reference the paper that defines the experiment: Campaign 9 of the K2 mission.

During the roughly 80-day observing period or campaign, astronomers hope to discover more than 100 lensing events, ten or more of which may have signatures of exoplanets occupying relatively unexplored regimes of parameter space.

Ames manages the Kepler and K2 missions for NASA's Science Mission Directorate. NASA's Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

Related links:

NASA's K2 mission: http://orbiterchspacenews.blogspot.ch/2016/03/nasas-k2-mission-kepler-space.html

Campaign 9 of the K2 mission: http://arxiv.org/abs/1512.09142

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

Images (mentioned), Animation (mentioned), Video, Text, Credits: NASA/Ames Research Center/Michele Johnson/JPL/Whitney Clavin.

Greetings, Orbiter.ch

jeudi 7 avril 2016

Icy ‘Spider’ on Pluto












NASA - New Horizons Mission logo.

April 7, 2016


Image above: Pluto’s unusual spider-like feature consists of at least six extensional fractures that converge to a point. Individual fractures can reach hundreds of miles long and appear to expose a reddish subsurface layer. Image Credits: NASA/JHUAPL/SwRI.

Sprawling across Pluto’s icy landscape is an unusual geological feature that resembles a giant spider.

“Oh, what a tangled web Pluto’s geology weaves,” said Oliver White, a member of the New Horizons geology team from NASA Ames Research Center, Moffett Field, California. “The pattern these fractures form is like nothing else we’ve seen in the outer solar system, and shows once again that anywhere we look on Pluto, we see something different.”

As shown in the enhanced color image above – obtained by NASA’s New Horizons spacecraft on July 14, 2015 – this feature consists of at least six extensional fractures (indicated by white arrows) converging to a point near the center. The longest fractures are aligned roughly north-south, and the longest of all, the informally named Sleipnir Fossa, is more than 360 miles (580 kilometers) long. The fracture aligned east-west is shorter and is less than 60 miles (100 kilometers) long.  To the north and west, the fractures extend across the mottled, rolling plains of the high northern latitudes, and to the south, they intercept and cut through the bladed terrain informally named Tartarus Dorsa.

Curiously, the spider’s “legs” noticeably expose red deposits below Pluto’s surface.


Image above: Location of the spider-like feature at the eastern edge of Pluto's encounter hemisphere, as captured by NASA’s New Horizons spacecraft on July 14, 2015. Image Credits: NASA/JHUAPL/SwRI.

New Horizons scientists think fractures seen elsewhere on Pluto – which tend to run parallel to one another in long belts – are caused by global-scale extension of Pluto’s water–ice crust.  The curious radiating pattern of the fractures forming the “spider” may instead be caused by a focused source of stress in the crust under the point where the fractures converge – for example, due to material welling up from under the surface.  The spider somewhat resembles radially fractured centers on Venus called novae, seen by NASA’s Magellan spacecraft, as well as the Pantheon Fossae formation, seen by NASA’s MESSENGER spacecraft on Mercury.

This image was obtained by New Horizons’ Ralph/Multispectral Visible Imaging Camera (MVIC).  The image resolution is approximately 2,230 feet (680 meters) per pixel.  It was obtained at a range of approximately 21,100 miles (33,900 kilometers) from Pluto, about 45 minutes before New Horizons’ closest approach on July 14, 2015.

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

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

Greetings, Orbiter.ch

Tiny Cubesat Tracks Worldwide Air Traffic






ESA - European Space Agency logo.

7 April 2016

Since its launch six months ago, a satellite small enough to fit in an airline passenger’s carry-on bag has been tracking aircraft in flight across the entire globe.

Built for ESA by GomSpace in Denmark, the GomX-3 CubeSat was ejected from the International Space Station on 5 October 2015, along with a Danish student satellite.

Aircraft detections from GomX-3

“CubeSats are based on standardised 10 cm cubic units,” explains Roger Walker, overseeing ESA’s technology CubeSat effort. “Being small and low-cost, they make ideal platforms for rapidly flight testing experimental technologies.

“This 3-unit GomX-3 is ESA’s very first technology CubeSat to fly. We were able to make it operational within only 96 hours of its release from the Space Station, with a wide variety of tests taking place during the following months.”

GomX-3’s distinctive helical antenna has detected millions of signals from aircraft, building a detailed map of global aviation traffic.

GomX-3

These signals are regularly broadcast from aircraft, giving flight information such as speed, position and altitude. All aircraft entering European airspace are envisaged to provide such automatic surveillance in the coming years.

ESA’s 2013-launched Proba-V first confirmed the feasibility of detection from orbit, opening up the prospect of a global aircraft monitoring system incorporating remote regions not covered by ground-based air traffic control.

GomX-3 also carries a miniaturised X-band transmitter, developed by Syrlinks in France, which has demonstrated the rapid download of data.

CubeSats ejected

In addition, the CubeSat is measuring radio signals emitted by telecom satellites to assess their overall transmission efficiency and how their signal quality changes with respect to distance from their target footprints.

“GomX-3 has in contrast to many other CubeSats demonstrated three-axis control, so it can be pointed as required, whether downwards or upwards, to an accuracy of 3º,” explains Roger.  

 “A success in terms of planning, speed of development and technical achievements, GomX-3 has now completed its planned six-month technology demonstration mission and continues to operate normally.

“With its orbit naturally decaying from atmospheric drag, the satellite is predicted to reenter and burn up in September of this year.”

GomX-3 being built

GomX-3 was supported by ESA through its General Support Technology Programme, aimed at convert promising engineering concepts into spaceworthy products.

Further ESA technology CubeSats are set for launch later this year. Meanwhile, GomSpace is developing a follow-up 6-unit CubeSat called GomX-4B, also supported by ESA, scheduled for launch in the second half of 2017.  

Related link:

ESA technology CubeSats: http://www.esa.int/Our_Activities/Space_Engineering_Technology/Technology_CubeSats

Images, Text, Credits: ESA/GomSpace/NASA/davidgerhardt.com.

Greetings, Orbiter.ch

The colour-changing comet












ESA - Rosetta Mission patch.

7 April 2016

Rosetta’s comet has been seen changing colour and brightness in front of the ESA orbiter’s eyes, as the Sun’s heat strips away the older surface to reveal fresher material.

Rosetta’s Visible and InfraRed Thermal Imaging Spectrometer, VIRTIS, began to detect these changes in the sunlit parts of Comet 67P/Churyumov–Gerasimenko – mostly the northern hemisphere and equatorial regions – in the months immediately following the spacecraft’s arrival in August 2014.

The colour-changing comet

A new paper, published in the journal Icarus, reports on the early findings of this study, up to November 2014, during which time Rosetta was operating between 100 km to within 10 km of the comet nucleus. At the same time, the comet itself moved along its orbit closer to the Sun, from about 542 million km to 438 million km.

VIRTIS monitored the changes in light reflected from the surface over a wide range of visible and infrared wavelengths, as an indicator of subtle changes in the composition of the comet’s outermost layer.

When it arrived, Rosetta found an extremely dark body, reflecting about 6% of the visible light falling on it. This is because the majority of the surface is covered with a layer of dark, dry, dust made out of mixture of minerals and organics.

Some surfaces are slightly brighter, some slightly darker, indicating differences in composition. Most of the surface is slightly reddened by organic-rich material, while the occasional ice-rich material shows up as somewhat bluer.

Comet on 19 September 2014 – NavCam

Even when Rosetta first rendezvoused with the comet far from the Sun, ices hidden below the surface were being gently warmed, sublimating into gas, and escaping, lifting some of the surface dust away and contributing to the comet’s coma and tail.

VIRTIS shows that as the ‘old’ dust layers were slowly ejected, fresher material was gradually exposed. This new surface was both more reflective, making the comet brighter, and richer in ice, resulting in bluer measurements.

On average, the comet’s brightness changed by about 34%. In the Imhotep region, it increased from 6.4% to 9.7% over the three months of observations.

“The overall trend seems to be that there is an increasing water-ice abundance in the comet’s surface layers that results in a change in the observed spectral signatures. In that respect, it’s like the comet is changing colour in front of our eyes,” says Gianrico Filacchione, lead author of the study.

“This evolution is a direct consequence of the activity occurring on and immediately beneath the comet’s surface. The partial removal of the dust layer caused by the start of gaseous activity is the probable cause of the increasing abundance of water ice at the surface.”

Imhotep mosaic

“The surface properties are really dynamic, changing with the distance from the Sun and with the levels of comet activity,” adds Fabrizio Capaccioni, VIRTIS principal investigator.

“We’ve started analysing the subsequent datasets and can already see that the trend continues in the observations made beyond November 2014.”

“The evolution of surface properties with activity has never been observed by a cometary mission before and is a major science objective of the Rosetta mission,” says Matt Taylor, ESA’s Rosetta Project Scientist.

“It is great to see science papers being published directly addressing this topic and we’re looking forward to seeing how things have changed over the entire mission.”

Notes for Editors:

“The global surface composition of 67P/CG nucleus by Rosetta/VIRTIS. 1) Pre-landing phase,” by G. Filacchione et al. is published in Icarus: http://dx.doi.org/10.1016/j.icarus.2016.02.055

A follow-up paper is in preparation covering the period November 2014 to May 2015.

Related links:

Where is Rosetta?: http://sci.esa.int/where_is_rosetta/

For more information about Rosetta mission, visit: http://www.esa.int/Our_Activities/Space_Science/Rosetta

Rosetta overview: http://www.esa.int/Our_Activities/Space_Science/Rosetta_overview

Rosetta in depth: http://sci.esa.int/rosetta

Rosetta at Astrium: http://www.astrium.eads.net/en/programme/rosetta-1go.html

Rosetta at DLR: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10394/

Ground-based comet observation campaign: http://www.rosetta-campaign.net/home

Rosetta factsheet: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_factsheet

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

Images, Text, Credits: ESA/Matt Taylor/Markus Bauer/INAF-IAPS/Fabrizio Capaccioni/Gianrico Filacchione/Spacecraft: ESA/ATG medialab; Data: ESA/Rosetta/VIRTIS/INAF-IAPS/OBS DE PARIS-LESIA/DLR; G. Filacchione et al (2016)/Rosetta/NAVCAM/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA.

Best regards, Orbiter.ch

mercredi 6 avril 2016

Computer-Simulated Image of a Supermassive Black Hole












NASA patch.

April 6, 2016


This computer-simulated image shows a supermassive black hole at the core of a galaxy. The black region in the center represents the black hole’s event horizon, where no light can escape the massive object’s gravitational grip. The black hole’s powerful gravity distorts space around it like a funhouse mirror. Light from background stars is stretched and smeared as the stars skim by the black hole.

Astronomers have uncovered a near-record breaking supermassive black hole, weighing 17 billion suns, in an unlikely place: in the center of a galaxy in a sparsely populated area of the universe. The observations, made by NASA’s Hubble Space Telescope and the Gemini Telescope in Hawaii, may indicate that these monster objects may be more common than once thought.

Until now, the biggest supermassive black holes – those roughly 10 billion times the mass of our sun – have been found at the cores of very large galaxies in regions of the universe packed with other large galaxies. In fact, the current record holder tips the scale at 21 billion suns and resides in the crowded Coma galaxy cluster that consists of over 1,000 galaxies.

Related article:

Astronomers have uncovered a near-record breaking supermassive black hole:
http://orbiterchspacenews.blogspot.ch/2016/04/behemoth-black-hole-found-in-unlikely.html

Image Credit: NASA, ESA, and D. Coe, J. Anderson, and R. van der Marel (STScI)/Sarah Loff.

Greetings, Orbiter.ch

Behemoth black hole found in an unlikely place












ESA - Hubble Space Telescope logo.

6 April 2016

NGC 1600

Astronomers have uncovered one of the biggest supermassive black holes, with the mass of 17 billion Suns, in an unlikely place: the centre of a galaxy that lies in a quiet backwater of the Universe. The observations, made with the NASA/ESA Hubble Space Telescope and the Gemini Telescope in Hawaii, indicate that these monster objects may be more common than once thought. The results of this study are released in the journal Nature.

Until now, the biggest supermassive black holes — those having more than 10 billion times the mass of our Sun — have only been found at the cores of very large galaxies in the centres of massive galaxy clusters. Now, an international team of astronomers using the NASA/ESA Hubble Space Telescope has discovered a supersized black hole with a mass of 17 billion Suns in the centre of the rather isolated galaxy NGC 1600.

NGC 1600 is an elliptical galaxy which is located not in a cluster of galaxies, but in a small group of about twenty. The group is located 200 million light-years away in the constellation Eridanus. While finding a gigantic supermassive black hole in a massive galaxy within a cluster of galaxies is to be expected, finding one in an average-sized galaxy group like the one surrounding NGC 1600 is much more surprising.

“Even though we already had hints that the galaxy might host an extreme object in the centre, we were surprised that the black hole in NGC 1600 is ten times more massive than predicted by the mass of the galaxy,” explains lead author of the study Jens Thomas from the Max Planck-Institute for Extraterrestrial Physics, Germany.

Ground-based view of NGC 1600

Based on previous Hubble surveys of supermassive black holes, astronomers had discovered a correlation between a black hole’s mass and the mass of its host galaxy’s central bulge of stars: the larger the galaxy bulge, the more massive the black hole is expected to be. “It appears from our finding that this relation does not work so well with extremely massive black holes,” says Thomas. “These monster black holes account for a much larger fraction of the host galaxy’s mass than the previous correlations would suggest.”

Finding this extremely massive black hole in NGC 1600 leads astronomers to ask whether these objects are more common than previously thought. “There are quite a few galaxies the size of NGC 1600 that reside in average-size galaxy groups,” explains co-author Chung-Pei Ma, an astronomer from the University of California, Berkeley, USA, and head of the MASSIVE Survey [1]. “We estimate that these smaller groups are about fifty times more abundant than large, dense galaxy clusters. So the question now is: is this the tip of an iceberg? Maybe there are a lot more monster black holes out there.”

It is assumed that this black hole grew by merging with another supermassive black hole from another galaxy. It may then have continued to grow by gobbling up gas funneled to the core of the galaxy by further galaxy collisions. Thus may also explain why NGC 1600 resides in a sparsely populated region of the Universe and why it is at least three times brighter than its neighbours.

As the supermassive black hole is currently dormant, astronomers were only able to find it and estimate its mass by measuring the velocities of stars close to it, using the Gemini North 8-metre telescope on Mauna Kea, Hawaii. Using these data the team discovered that stars lying about 3000 light-years from the core are moving as if there had been many more stars in the core in the distant past. This indicates that most of the stars in this region have been kicked out from the centre of the galaxy.

video
Hubble and the sunrise over Earth

Archival Hubble images, taken with the Near Infrared Camera and Multi-Object Spectrometer (NICMOS), support the idea that the two merging supermassive black holes in the distant past gave stars the boot. The NICMOS images revealed that the galaxy’s core is unusually faint, indicating a lack of stars close to the galactic centre. “We estimate that the mass of stars tossed out of the central region of NGC 1600 is equal to 40 billion Suns,” concludes Thomas. “This is comparable to ejecting the entire disc of our Milky Way galaxy.”

Notes:

[1] The MASSIVE Survey, which began in 2014, measures the mass of stars, dark matter, and the central black hole of the 100 most massive, nearby galaxies, those larger than 300 billion solar masses and within 350 million light-years of Earth. Among its goals are to find the descendants of luminous quasars that may be sleeping unsuspected in large nearby galaxies and to understand how galaxies form and grow supermassive black holes.

More information:

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

The study “A 17-billion-solar-mass black hole in a group galaxy with a diffuse core” appeared in the journal Nature.

The international team of astronomers in this study consists of J. Thomas (Max Planck Institute for Extraterrestrial Physics, Germany), C.-P. Ma (University of California, Berkeley, USA), N. McConnell (Dominion Astrophysical Observatory, Canada), J. Greene (Princeton University, USA), J. Blakeslee (Dominion Astrophysical Observatory, Canada), and R. Janish (University of California, Berkeley, USA).

Related links:

Near Infrared Camera and Multi-Object Spectrometer (NICMOS): http://www.spacetelescope.org/about/general/instruments/nicmos/

Links:

Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/

Link to hubblesite release: http://hubblesite.org/newscenter/archive/releases/2016/12/

Link to the release of the Max Planck Institute for Extraterrestrial Physics: http://www.mpe.mpg.de/6537551/news-20160406

Link to science paper: http://www.spacetelescope.org/static/archives/releases/science_papers/heic1607a.pdf

Images, Video, Text, Credits: NASA/ESA/Hubble/Mathias Jäger/Digital Sky Survey 2/Max Planck Institute for Extraterrestrial Physics/Jens Thomas.


Best regards, Orbiter.ch

Mars Longevity Champion Launched 15 Years Ago











NASA - 2001 Mars Odyssey logo.

April 6, 2016


Image above: At 11:02 a.m. EDT on April 7, 2001, crowds watch a Boeing Delta II rocket lift off from Cape Canaveral Air Force Station, Florida, carrying NASA's 2001 Mars Odyssey spacecraft into space on its seven-month journey to Mars. Image Credit: NASA.

The NASA spacecraft that was launched 15 years ago this week carried the name 2001 Mars Odyssey and the hopes for reviving a stymied program of exploring the Red Planet.

Back-to-back failures of two Mars missions launched in 1999 had prompted an overhaul of NASA's Mars plans. It worked: Not only has Odyssey itself operated successfully longer than any other spacecraft ever sent to Mars, but during Odyssey's lifespan so far, all six subsequent NASA missions sent to Mars have also succeeded.

A Delta II launch vehicle lifted Odyssey from Cape Canaveral Air Force Station, Florida, on April 7, 2001. When the spacecraft reached Mars on Oct. 24, 2001, it fired its main engine to enter orbit. A three-month "aerobraking" phase followed, using carefully controlled dips into the upper atmosphere of Mars to adjust the size and shape of the orbit in preparation for systematic mapping of the Red Planet.


Image above: Morning clouds fill Coprates Chasma on Mars in this Nov. 25, 2015, image from the THEMIS camera on NASA's Mars Odyssey. No orbiter systematically observed Mars in morning sunlight before 2015. The clouds appear blue because ice particles in them scatter blue light more strongly than other colors. Image Credits: NASA/JPL-Caltech/Arizona State University.

The year of the launch and arrival played into NASA naming the mission 2001 Mars Odyssey as a tribute to the vision and spirit of space exploration portrayed in the works of science-fiction author Arthur C. Clarke, including the best-seller "2001: A Space Odyssey." Clarke (1917-2008) endorsed the mission's naming before the launch.

Odyssey completed its prime mission in 2004. With repeated mission extensions, it became the longevity champion of Mars spacecraft in December 2010.

"Every day for more than five years, Odyssey has been extending its record for how long a spacecraft can keep working at Mars," said Odyssey Project Manager David Lehman of NASA's Jet Propulsion Laboratory, Pasadena, California. "The spacecraft is remarkably healthy, and we have enough fuel to last for several more years."

Lockheed Martin Space Systems, Denver, built the Odyssey spacecraft and collaborates with JPL in mission operations.

"In addition to the quality of this spacecraft, the careful way it is operated has been crucial to how it has stayed so productive so long," said Odyssey Project Scientist Jeffrey Plaut of JPL. "Odyssey was designed for a four-year mission. We're in the 15th year, and it keeps doing everything we ask it to do."

Some of Odyssey's important findings were accomplished within the first year after launch. One suite of instruments found evidence for water ice close to the surface in large areas of Mars. Another investigation measured the natural radiation environment on the way from Earth to Mars and in orbit around Mars, gaining information vital for design of human missions in what has become NASA's Journey to Mars.

Artist's view of the NASA's 2001 Mars Odyssey spacecraft. Image Credits: NASA/JPL

Odyssey's longevity has enabled other feats, such as complete global mapping of Mars both in daytime light and in nighttime infrared emissions.

Each full year of changing seasons on Mars lasts about 26 months, so Odyssey has observed the planet through more than six Martian years. These observations have revealed some seasonal patterns that repeat each year and other seasonal events, such as large dust storms, which differ significantly from year to year.

Just in the past year, Odyssey's orbit has put the spacecraft in position to observe Mars in early-morning light. Previously, the spacecraft flew over ground that was either in afternoon lighting or pre-dawn darkness. Maneuvers in 2014 and 2015 were designed to alter the geometry of the orbit with respect to the sun. The new geometry enables studies of morning clouds and fogs and comparison of ground temperatures in the morning to temperatures of the same sites in the afternoon and pre-dawn.

In addition to its direct contributions to planetary science, Odyssey provides important support for other missions in NASA's Journey to Mars through communication relay service and observations of candidate landing sites. More than 90 percent of the data received from NASA's Spirit and Opportunity rovers has been relayed via Odyssey. Relay support for NASA's Curiosity Mars rover is shared between the Mars Reconnaissance Orbiter and Odyssey.

For more information about Odyssey, visit: http://mars.jpl.nasa.gov/odyssey

Images (mentioned), Text, Credits: NASA/Dwayne Brown/Laurie Cantillo/Tony Greicius/JPL/Guy Webster.

Best regards, Orbiter.ch

mardi 5 avril 2016

Asteroid-Hunting Spacecraft Delivers a Second Year of Data








NASA - NEOWISE Mission logo.

April 5, 2016

video
Two Years of NEOWISE Asteroid Data

Video above: NASA's asteroid-hunting NEOWISE survey uses infrared to detect and characterize asteroids and comets. Since December 2013, NEOWISE has discovered 72 near-Earth objects and characterized 439 others. Video Credit: NASA.

NASA's Near-Earth Object Wide-field Survey Explorer (NEOWISE) mission has released its second year of survey data.  The spacecraft has now characterized a total of 439 NEOs since the mission was re-started in December 2013.  Of these, 72 were new discoveries.

Near-Earth Objects (NEOs) are comets and asteroids that have been nudged by the gravitational attraction of the giant planets in our solar system into orbits that allow them to enter Earth's neighborhood. Eight of the objects discovered in the past year have been classified as potentially hazardous asteroids (PHAs), based on their size and how closely their orbits approach Earth.

With the release to the public of its second year of data, NASA’s NEOWISE spacecraft completed another milestone in its mission to discover, track and characterize the asteroids and comets that approach closest to Earth.

Since beginning its survey in December 2013, NEOWISE has measured more than 19,000 asteroids and comets at infrared wavelengths. More than 5.1 million infrared images of the sky were collected in the last year. A new movie, based on the data collected, depicts asteroids and comets observed so far by NEOWISE.

"By studying the distribution of lighter- and darker-colored material, NEOWISE data give us a better understanding of the origins of the NEOs, originating from either different parts of the main asteroid belt between Mars and Jupiter or the icier comet populations," said James Bauer, the mission’s deputy principal investigator at NASA's Jet Propulsion Laboratory in Pasadena, California.

Originally called the Wide-field Infrared Survey Explorer (WISE), the spacecraft was launched in December 2009. It was placed in hibernation in 2011 after its primary mission was completed. In September 2013, it was reactivated, renamed NEOWISE and assigned a new mission: to assist NASA's efforts to identify the population of potentially hazardous near-Earth objects. NEOWISE also is characterizing previously known asteroids and comets to provide information about their sizes and compositions.

"NEOWISE discovers large, dark, near-Earth objects, complementing our network of ground-based telescopes operating at visible-light wavelengths.  On average, these objects are many hundreds of meters across," said Amy Mainzer of JPL, NEOWISE principal investigator.  NEOWISE has discovered 250 new objects since its restart, including 72 near-Earth objects and four new comets.

Artist's view of NEOWISE spacecraft. Image Credits: NASA/JPL

NASA's Jet Propulsion Laboratory in Pasadena, California, manages the NEOWISE mission for NASA's Science Mission Directorate in Washington. The Space Dynamics Laboratory in Logan, Utah, built the science instrument. Ball Aerospace & Technologies Corp. of Boulder, Colorado, built the spacecraft. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

For more information about NEOWISE, visit: http://www.nasa.gov/neowise

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

Images (mentioned), Text, Credits: NASA/Dwayne Brown/Tony Greicius/JPL/DC Agle.

Best regards, Orbiter.ch

John Grunsfeld Announces Retirement from NASA











NASA logo.

April 5, 2016


Image above: In this March 2002 image, John Grunsfeld, former astronaut and associate administrator of NASA's Science Mission Directorate, is shown in space shuttle Columbia's cargo bay. Image Credit: NASA.

John Grunsfeld will retire from NASA April 30, capping nearly four decades of science and exploration with the agency. His tenure includes serving as astronaut, chief scientist, and head of NASA’s Earth and space science activities.

Grunsfeld has directed NASA’s Science Mission Directorate as associate administrator since 2012, managing more than 100 science missions -- many of which have produced groundbreaking science, findings and discoveries.

“John leaves an extraordinary legacy of success that will forever remain a part of our nation’s historic science and exploration achievements," said NASA Administrator Charlie Bolden. “Widely known as the ‘Hubble Repairman,’ it was an honor to serve with him in the astronaut corps and watch him lead NASA's science portfolio during a time of remarkable discovery. These are discoveries that have rewritten science textbooks and inspired the next generation of space explorers."

Geoff Yoder, currently the directorate’s deputy, will serve as acting associate administrator until a successor is named.

“After exploring strange new worlds and seeking out new life in the universe, I can now boldly go where I’ve rarely gone before – home,” said Grunsfeld. “I’m grateful to have had this extraordinary opportunity to lead NASA science, and know that the agency is well-positioned to make the next giant leaps in exploration and discovery.”

Notable science achievements under Grunsfeld’s leadership include the Curiosity rover Mars landing in 2012 – and its remarkable discoveries about the habitability of ancient Mars – and the July 2015 New Horizons Pluto flyby, completing the initial reconnaissance of the solar system.

Grunsfeld managed numerous missions to protect and study our home planet, including the Deep Space Climate Observatory, Orbiting Carbon Observatory-2, and Global Precipitation Measurement spacecraft, in addition to numerous Earth science aircraft campaigns. These and other projects have laid the foundation for future missions to better understand how Earth is changing.

Grunsfeld has also been a strong advocate for research with suborbital rockets, high-altitude balloon flights and CubeSats, to enable great science and train the next generation of explorers.

Preparations are well underway for a host of other missions and activities that will continue Grunsfeld’s work. These include the first U.S. mission to return a sample of an asteroid, the first mission to look for signs of life on Jupiter’s moon Europa, a mission to study the sun closer than ever before, participating in a national space weather strategy, and constructing the next rover to Mars, scheduled to launch in 2020.

Additionally, NASA’s fleet of robotic spacecraft are exploring the solar system and beyond, revealing the workings and beauty of the universe, while discovering thousands of new worlds. This pioneering work will continue with the launch of the James Webb Space Telescope in 2018, and the Wide-Field Infrared Survey Telescope.

Grunsfeld, a fierce proponent of science education and five-time space shuttle astronaut, was the lead spacewalker during the last Hubble Space Telescope servicing flight in 2009, which successfully upgraded the observatory to the apex of its scientific capability. He’s also the last human to touch the iconic telescope. In April 2015, Hubble celebrated 25 years of operations, vastly outperforming its planned lifetime of 15 years. In 2015, Grunsfeld was inducted into the U.S. Astronaut Hall of Fame.

Related link:

Deep Space Climate Observatory: http://www.nesdis.noaa.gov/DSCOVR/index.html

For Grunsfeld’s NASA biography, visit: http://www.nasa.gov/about/highlights/grunsfeld_biography.html

Image (mentioned), Text, Credits: NASA/Dwayne Brown/Laurie Cantillo/Karen Northon.

Greetings, Orbiter.ch

NASA’s New Horizons Fills Gap in Space Environment Observations












NASA - New Horizons Mission logo.

April 5, 2016

When NASA's New Horizons sped past Pluto on July 14, 2015, it took the best-ever pictures of the rocky world’s surface, giving us new insight into its geology, composition and atmosphere. These stunning images are the most famous result of New Horizons, but the spacecraft also sent back over three years’ worth of measurements of the solar wind – the constant flow of solar particles that the sun flings out into space – from a region that has been visited by only a few spacecraft.  

This unprecedented set of observations give us a peek into an almost entirely unexplored part of our space environment – filling a crucial gap between what other missions see closer to the sun and what the Voyager spacecraft see further out. A new study to appear in The Astrophysical Journal Supplement lays out New Horizons’ observations of the solar wind ions that it encountered on its journey.


Image above: Space environment data collected by New Horizons over a billion miles of its journey to Pluto will play a key role in testing and improving models of the space environment throughout the solar system. This visualization is one example of such a model: It shows the simulated space environment out to Pluto a few months before New Horizons’ closest approach. Drawn over the model is the path of New Horizons up to 2015, as well as the current direction of the two Voyager spacecraft – which are currently at three or four times New Horizons’ distance from the sun. The solar wind that New Horizons encountered will reach the Voyager spacecraft about a year later. Image Credits: NASA's Goddard Space Flight Center Scientific Visualization Studio, the Space Weather Research Center (SWRC) and the Community-Coordinated Modeling Center (CCMC), Enlil and Dusan Odstrcil (GMU).

Not only does the New Horizons data provide new glimpses of the space environment of the outer solar system, but this information helps round out our growing picture of the sun’s influence on space, from near-Earth effects to the boundary where the solar wind meets interstellar space. The new data shows particles in the solar wind that have picked up an initial burst of energy, an acceleration boost that kicks them up just past their original speed. These particles may be the seeds of extremely energetic particles called anomalous cosmic rays. When these super-fast, energetic rays travel closer to Earth, they can pose a radiation hazard to astronauts. Further away, at lower energies, the rays are thought to play a role at shaping the boundary where the solar wind hits interstellar space – the region of our solar system that Voyager 2 is currently navigating and observing.

Studying the Solar Wind

Though space is about a thousand times emptier than even the best laboratory vacuums on Earth, it’s not completely devoid of matter – the sun’s constant outflow of solar wind fills space with a thin and tenuous wash of particles, fields, and ionized gas known as plasma. This solar wind, along with other solar events like giant explosions called coronal mass ejections, influences the very nature of space and can interact with the magnetic systems of Earth and other worlds. Such effects also change the radiation environment through which our spacecraft – and, one day, our astronauts headed to Mars – travel.

New Horizons measured this space environment for over a billion miles of its journey, from just beyond the orbit of Uranus to its encounter with Pluto.

“The instrument was only scheduled to power on for annual checkouts after the Jupiter flyby in 2007,” said Heather Elliott, a space scientist at the Southwest Research Institute in San Antonio, Texas, and lead author on the study. “We came up with a plan to keep the particle instruments on during the cruise phase while the rest of the spacecraft was hibernating and started observing in 2012.”


Animation above: Space environment data collected by New Horizons over a billion miles of its journey to Pluto will play a key role in testing and improving models of the space environment throughout the solar system. This visualization is one example of such a model: It shows the simulated space environment out to Pluto a few months before New Horizons’ closest approach. Animation Credits: NASA's Goddard Space Flight Center Scientific Visualization Studio, the Space Weather Research Center (SWRC) and the Community-Coordinated Modeling Center (CCMC), Enlil and Dusan Odstrcil (GMU).

This plan yielded three years of near-continuous observations of the space environment in a region of space where only a handful of spacecraft have ever flown, much less captured detailed measurements.

“This region is billions of cubic miles, and we have a handful of spacecraft that have passed through every decade or so,” said Eric Christian, a space scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who studies what's called the heliosphere – the region of our solar system dominated by the solar wind – but was not involved with this study. “We learn more from every one.”

Since the sun is the source of the solar wind, events on the sun are the primary force that shapes the space environment. Shocks in the solar wind – which can create space weather, such as auroras, on worlds with magnetic fields – are created either by fast, dense clouds of material called coronal mass ejections, or CMEs, or by the collision of two different-speed solar wind streams. These individual features are discernible in the inner solar system – but New Horizons didn’t see the same level of detail.

The New Horizons data show that the space environment in the outer solar system has less detailed structure than space closer to Earth, since smaller structures tend to be worn down or clump together as they travel outwards, creating fewer – but bigger – features.

“At this distance, the scale size of discernible structures increases, since smaller structures are worn down or merge together,” said Elliott. “It’s hard to predict if the interaction between smaller structures will create a bigger structure, or if they will flatten out completely.”


Image above: New Horizons collected data on the space environment nearly continuously from early 2012 through its flyby of Pluto, shown here in an image mosaic from the spacecraft, on July 14, 2015, shedding new light on space in a relatively unexplored part of the solar system. Image Credits: NASA/JHUAPL/SwRI.

Subtler signs of the sun’s influence are also harder to spot in the outer solar system. Characteristics of the solar wind – including speed, density, and temperature – are shaped by the region of the sun it flows from. As the sun and its different wind-producing regions rotate, patterns form. New Horizons didn't see patterns as defined as they are when closer to the sun, but nevertheless it did spot some structure.

“Speed and density average together as the solar wind moves out,” said Elliott. “But the wind is still being heated by compression as it travels, so you can see evidence of the sun’s rotation pattern in the temperature even in the outer solar system.”

Finding the Origins of Space Radiation Hazards

The New Horizons observations also show what may be the starting seeds of the extremely energetic particles that make up anomalous cosmic rays. Anomalous cosmic rays are observed near Earth and can contribute to radiation hazard for astronauts, so scientists want to better understand what causes them.

The seeds for these energetic, super-fast particles may also help shape the boundary where the solar wind meets interstellar space. Anomalous cosmic rays have been observed by the two Voyager spacecraft out near these boundaries, but only in their final stages, leaving questions as to the exact location and mechanism of their origins.


Image above: This figure shows solar wind observations measured by New Horizons from Jan. 1 to Aug. 25, 2015. This measurement of seed particles for anomalous cosmic rays in the solar wind is completely new in this region of space and is key for interpreting Voyager data further out in the interstellar boundary region. Points closer to the top of the graph correspond to higher-energy particles, and red and yellow colors show a larger number of particles hitting the detector. The particle instruments were shut down during certain spacecraft operations and trajectory maneuvers, resulting in brief data gaps. Image Credits: NASA/New Horizons/SwRI.

“The Voyagers can’t measure these seed particles, only the outcome,” said Christian. “So with New Horizons going into that region, this blank patch in the observations is being filled in with data.”

Filling in such a blank patch will help scientists better understand the way such particles move and affect the space environment around them, helping to interpret what Voyager is seeing on its journey.

Comparing New Horizons to Observations and Models

Since New Horizons is one of the very few spacecraft that has explored the space environment in the outer solar system, lack of corroborating data meant that a key part of Elliott's work was simply calibrating the data. Her work was supported by the Heliophysics Research and Analysis program.

She calibrated the observations with pointing information from New Horizons, the results of extensive tests on the laboratory version of the instrument, and comparison with data from the inner solar system. NASA’s Advanced Composition Explorer, or ACE, and NASA’s Solar and Terrestrial Relations Observatory, or STEREO, for example, observe the space environment near Earth’s orbit, allowing scientists to capture a snapshot of solar events as they head towards the edges of the solar system. But because the space environment in the outer solar system is relatively unexplored, it wasn’t clear how those events would develop. The only previous information on space in this region was from Voyager 2, which traveled through roughly the same region of space as New Horizons, although about a quarter of a century earlier.

Artist's view of New Horizons approach Pluto. Image Credit: NASA

“There are similar characteristics between what was seen by New Horizons and Voyager 2, but the number of events is different,” said Elliott. “Solar activity was much more intense when Voyager 2 traveled through this region.”

Now, with two data sets from this region, scientists have even more information about this distant area of space. Not only does this help us characterize the space environment better, but it will be key for scientists testing models of how the solar wind propagates throughout the solar system. In the absence of a constant sentinel measuring the particles and magnetic fields in space near Pluto, we rely on simulations – not unlike terrestrial weather simulations – to model space weather throughout the solar system. Before New Horizons passed Pluto, such models were used to simulate the structure of the solar wind in the outer solar system. With a calibrated data set in hand, scientists can compare the reality to the simulations and improve future models.

Related Links:

Southwest Research Institute's press release: http://www.swri.org/9what/releases/2016/new-horizons-solar-wind-pluto.htm

Feature story: "NASA Visualizes Space Environment Near Pluto": http://www.nasa.gov/feature/goddard/nasa-releases-new-visualization-of-space-environment-at-pluto

NASA's New Horizons website: https://www.nasa.gov/mission_pages/newhorizons/main/index.html

Academic paper: "New Horizons Solar Wind Around Pluto (SWAP) Observations of the Solar Wind From 11-33 AU": http://arxiv.org/abs/1601.07156

Images (mentioned), Animation (mentioned), Text, Credits: NASA’s Goddard Space Flight Center/Sarah Frazier/Rob Garner.

Best regards, Orbiter.ch