Orbiter.ch Space News: 2018-05-27

samedi 2 juin 2018

NEOWISE Thermal Data Reveal Surface Properties of Over 100 Asteroids

NASA - NEOWISE Mission logo.

June 2, 2018

Nearly all asteroids are so far away and so small that the astronomical community only knows them as moving points of light. The rare exceptions are asteroids that have been visited by spacecraft, a small number of large asteroids resolved by NASA's Hubble Space Telescope or large ground-based telescopes, or those that have come close enough for radar imaging.

When seen by optical telescopes, these individual sources of reflected sunlight can provide some very valuable but also very basic information -- for example, the asteroid's orbit, a ballpark estimate of its size, sometimes an approximation of its shape, and perhaps an idea of its physical makeup. But to learn more about these elusive and important celestial objects requires a different type of instrument. An infrared sensor can, in the right circumstances, not only provide data on an asteroid's orbit and data that can be used to more accurately measure its size, but also chemical makeup and sometimes even its surface characteristics.

Image above: Analysis of asteroids like Lutetia was used in the Josef Hanuš-led paper on asteroid thermophysical modeling. Lutetia is a large main belt asteroid about 62 miles (100 kilometers) in diameter. Lutetia was visited by ESA's Rosetta spacecraft in 2010. Image Credits: ESA 2010 MPS.

NASA's Near-Earth Object Wide-field Infrared Survey Explorer, or NEOWISE, spacecraft, in orbit around Earth, uses asteroid-hunting thermal sensors that allow an infrared view of asteroids without the obscuring effects of Earth's atmosphere. In a paper published recently in the journal Icarus, researchers led by Josef Hanuš, a scientist at the Astronomical Institute of Charles University, Prague, have made an in-depth analysis of more than 100 asteroids that have come under the temperature-sensing gaze of NEOWISE. This analysis tripled the number of asteroids which have undergone detailed "thermophysical" modeling of asteroid properties that vary with temperature. The results provide a more accurate glimpse into the surface properties of main belt asteroids and also reinforce the capabilities of spaceborne infrared observatories to accurately assess the sizes of asteroids.

Value of this technique

Thermophysical modeling is a gold mine for asteroid researchers because it allows a more comprehensive analysis of the nature of asteroids. Not all asteroids are suitable for thermophysical modeling because the necessary raw data sets are not always available. But Hanuš's team found 122 asteroids that not only had NEOWISE data, but also detailed models of their rotation states (how fast an object rotates around its axis, and the orientation of the axis in space) and multi-faceted models of the asteroid's 3D shape.

"Using archived data from the NEOWISE mission and our previously derived shape models, we were able to create highly detailed thermophysical models of 122 main belt asteroids," said Hanuš, lead author of the paper. "We now have a better idea of the properties of the surface regolith and show that small asteroids, as well as fast rotating asteroids, have little, if any, dust covering their surfaces." (Regolith is the term for the broken rocks and dust on the surface.)

It could be difficult for fast-rotating asteroids to retain very fine regolith grains because their low gravity and high spin rates tend to fling small particles off their surfaces and into space. Also, it could be that fast-rotating asteroids do not experience large temperature changes because the sun's rays are more rapidly distributed across their surfaces. That would reduce or prevent the thermal cracking of an asteroid's surface material that could cause the generation of fine grains of regolith.

Hanuš's team also found that their detailed calculations for estimated sizes of the asteroids they studied were consistent with those of the same asteroids calculated by the NEOWISE team using simpler models.

"With the asteroids for which we were able to gather the most information from other sources, our calculations of their sizes were consistent with the radiometrically-derived values performed by the NEOWISE team," said Hanuš. "The uncertainties were within 10 percent between the two sets of results."

"This is an important example of how space-based infrared data can accurately characterize asteroids," said Alan Harris, a senior scientist at the German Aerospace Center (DLR) based in Berlin, Germany, who specializes in thermal modeling of asteroids but was not involved with the study. "NEOWISE is leading the way in demonstrating the value of space-based infrared observatories for asteroid and near-Earth object discovery and characterization, both vital to our understanding these important inhabitants of our solar system."

From WISE to NEOWISE

Originally called the Wide-field Infrared Survey Explorer (WISE), the spacecraft was launched in December 2009 to study galaxies, stars, and solar system bodies by imaging the entire sky in infrared light. It was placed in hibernation in 2011 after its primary astrophysics mission was completed. In September 2013, it was reactivated, renamed NEOWISE and assigned a new mission: to assist NASA's efforts to identify and characterize the population of near-Earth objects. NEOWISE also is characterizing more distant populations of asteroids and comets to provide information about their sizes and compositions.

NEOWISE asteroid chaser. Image Credits: NASA/JPL

NASA's Jet Propulsion Laboratory in Pasadena, California, manages and operates the NEOWISE mission for NASA's Planetary Defense Coordination Office within the 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 data processing takes place at IPAC at Caltech in Pasadena. Caltech manages JPL for NASA.

The thermophysical modeling paper accepted by Icarus is available at: https://arxiv.org/pdf/1803.06116.pdf

For more information about NEOWISE, visit:

https://www.nasa.gov/neowise and http://neowise.ipac.caltech.edu/

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

Images (mentioned), Text, Credits: NASA/JoAnna Wendel/JPL/DC Agle.

Greetings, Orbiter.ch

NASA CubeSats Steer Toward Mars

NASA - MarCO Mission patch.

June 2, 2018

NASA has achieved a first for the class of tiny spacecraft known as CubeSats, which are opening new access to space.

Over the past week, two CubeSats called MarCO-A and MarCO-B have been firing their propulsion systems to guide themselves toward Mars. This process, called a trajectory correction maneuver, allows a spacecraft to refine its path to Mars following launch. Both CubeSats successfully completed this maneuver; NASA's InSight spacecraft just completed the same process on May 22.

The pair of CubeSats that make up the Mars Cube One (MarCO) mission both launched on May 5, along with the InSight lander, which is headed toward a Nov. 26 touchdown on the Red Planet. They were designed to trail InSight on the way to Mars, aiming to relay back data about InSight as it enters the planet's atmosphere and attempts to land. The MarCOs were never intended to collect any science data; instead, they are a test of miniaturized communication and navigation technology that can blaze a path for future CubeSats sent to other planets.

Image above: An artist's concept of one of NASA's MarCO CubeSats. The twin MarCOs are the first CubeSats to complete a trajectory correction maneuver, firing their thrusters to guide themselves toward Mars. Image Credits: NASA/JPL-Caltech.

Both MarCO-A and B successfully completed a set of communications tests in the past couple of weeks, said John Baker, program manager for planetary SmallSats at NASA's Jet Propulsion Laboratory, Pasadena, California. JPL built both MarCO CubeSats and leads the mission.

"Our broadest goal was to demonstrate how low-cost CubeSat technology can be used in deep space for the first time," Baker said. "With both MarCOs on their way to Mars, we've already traveled farther than any CubeSat before them."

While MarCO-A corrected its course to Mars relatively smoothly, MarCO-B faced some unexpected challenges. Its maneuver was smaller due to a leaky thruster valve that engineers have been monitoring for the past several weeks. The leak creates small trajectory changes on its own. Engineers have factored in these nudges so that MarCO-B can still perform a trajectory correction maneuver. It will take several more weeks of tracking to refine these nudges so that MarCO-B can follow InSight on its cruise through space.

"We're cautiously optimistic that MarCO-B can follow MarCO-A," said Joel Krajewski of JPL, MarCO's project manager. "But we wanted to take more time to understand the underlying issues before attempting the next course-correction maneuver."

Once the MarCO team has analyzed data, they'll know the size of follow-on maneuvers. Several more course corrections will be needed to reach the Red Planet.

Should the CubeSats make it all the way to Mars, they will attempt to relay data to Earth about InSight's landing. InSight won't rely on either CubeSat for that data relay, however; that job will fall to NASA's Mars Reconnaissance Orbiter.

Related articles:

A Pale Blue Dot, As Seen by a CubeSat:
https://orbiterchspacenews.blogspot.com/2018/05/a-pale-blue-dot-as-seen-by-cubesat.html

Atlas V Lifts Off Carrying InSight Mission:
https://orbiterchspacenews.blogspot.com/2018/05/atlas-v-lifts-off-carrying-insight.html

Find more information about MarCO here: https://go.nasa.gov/marco_launch

Image (mentioned), Text, Credits: NASA/JPL/Andrew Good.

Greetings, Orbiter.ch

vendredi 1 juin 2018

Space Station Science Highlights: Week of May 28, 2018

ISS - Expedition 55 Mission patch.

June 1, 2018

Crew members aboard the International Space Station continued scientific activities this week, including work on new investigations that arrived last week aboard the Orbital ATK Cygnus resupply ship. These included observing nearly-frozen atoms, activating floating robot cameras, studying melt convection and more.

Image above: The Orbital ATK Cygnus resupply ship next to the Soyuz spacecraft, which will deliver NASA astronaut Scott Tingle and crewmates Anton Shkaplerov of the Russian space agency Roscosmos and Norishige Kanai of the Japan Aerospace Exploration Agency (JAXA) back to Earth this weekend. Image Credit: NASA.

In addition, NASA astronaut Scott Tingle and crewmates Anton Shkaplerov of the Russian space agency Roscosmos and Norishige Kanai of the Japan Aerospace Exploration Agency (JAXA) made final preparations for their return to Earth on June 3.

Here are more details on some of the science that happened last week aboard your orbiting laboratory:

Minimizing melt motion moves forward

Accelerations of the space station produce circular motions in fluids called melt convection, which affect flight experiments on crystal growth for semiconductor materials. Solidification Using a Baffle in Sealed Ampoules (SUBSA) tests an automatically moving baffle to minimize melt motion and identify its causes in order to advance understanding of the processes involved in semiconductor crystal growth in space.

Image above: The Solidification Using a Baffle in Sealed Ampoules (SUBSA) setup in the Microgravity Science Glovebox aboard the International Space Station. Image Credit: NASA.

Crew set up the SUBSA hardware this week, ran a calibration sample, and then began processing samples. High-definition video imaging allows monitoring of samples in real-time along with remote commanding of thermal control parameters.

Stone cold space science

The crew installed and configured the Cold Atom Laboratory (CAL) and began operation of a six-week checkout.

Animation above: CAL uses lasers and magnetic traps to slow down atoms until they are almost motionless, creating clouds of atoms ten billion times colder than deep space. In microgravity, scientists can observe these ultra-cold atoms for much longer than possible on the ground, which could help answer some big questions in modern physics. Animation Credit: NASA.

CAL uses lasers and magnetic traps to slow down atoms until they are almost motionless, creating clouds of atoms ten billion times colder than deep space. In microgravity, scientists can observe these ultra-cold atoms for much longer than possible on the ground, which could help answer some big questions in modern physics. Ultimately, results of this research could improve a number of different technologies, including sensors, quantum computers and atomic clocks used in spacecraft navigation.

Those samples don’t collect themselves

Crew member health remains an important area of research, with many of these investigations requiring astronauts to collect samples of their blood, urine or saliva. This week, crew collected saliva and other samples for the Microbial Tracking-2 (MT-2), which monitors microbes present on the space station in order to catalog and characterize potential disease-causing microorganisms. Crew stored the MT-2 samples inside a Minus Eighty Degree Celsius Laboratory Freezer for ISS (MELFI).

Once these samples are returned to Earth, they will be analyzed along with those collected pre- and post-flight, as well as environmental samples from surface and air locations on the station. This molecular analysis identifies specific microbes in order to understand the microbial flora diversity aboard the station and how it changes over time. Crew also collected samples for the Functional Immune and Probiotics investigations.

JAXA’s JEM Camera Robot floats free

The Japanese Experiment Module (JEM) Camera Robot, a free floating, remote-control panoramic camera, helps crews monitor operations aboard the JEM. It provides real-time video and image downloads to remote operators, freeing astronauts to use their hands for other tasks. Because it operates untethered, the camera also offers a view outside the visual field of other cameras in the JEM.

Image above: The JEM Robot Camera hovering in the Japanese Experiment Module (JEM) during activation. Image Credit: NASA.

Crew completed check-out of this hardware under various conditions in preparation for activating it in support of scientific activities.

Space to Ground: Handoff: 06/01/2018

Jovian Jet Stream

NASA - JUNO Mission logo.

June 1, 2018

See a jet stream speeding through Jupiter’s atmosphere in this new view taken by NASA’s Juno spacecraft. The jet stream, called Jet N2, was captured along the dynamic northern temperate belts of the gas giant planet. It is the white stream visible from top left to bottom right in the image.

The color-enhanced image was taken at 10:34 p.m. PST on May 23 (1:34 a.m. EST on May 24), as Juno performed its 13th close flyby of Jupiter. At the time the image was taken, the spacecraft was about 3,516 miles (5,659 kilometers) from the tops of the clouds of the planet at a northern latitude of 32.9 degrees.

Citizen scientists Gerald Eichstädt and Seán Doran created this image using data from the spacecraft’s JunoCam imager.

JunoCam's raw images are available for the public to peruse and process into image products at: http://www.missionjuno.swri.edu/junocam

More information about Juno is at:

https://www.nasa.gov/juno and http://missionjuno.swri.edu

Image, Text, Credits: NASA/Tony Greicius/JPL-Caltech/SwRI/MSSS/Gerald Eichstäd/Seán Doran.

Greetings, Orbiter.ch

From horizon to horizon: Celebrating 15 years of Mars Express

ESA - Mars Express Mission patch.

1 June 2018

Mars Express

Fifteen years ago, ESA’s Mars Express was launched to investigate the Red Planet. To mark this milestone comes a striking view of Mars from horizon to horizon, showcasing one of the most intriguing parts of the martian surface.

On 2 June 2003, the Mars Express spacecraft lifted off from Baikonur, Kazakhstan, on a journey to explore our red-hued neighbouring planet. In the 15 years since, it has become one of the most successful missions ever sent to Mars, as demonstrated by this image of the region known as the Tharsis province, shown here in its full glory.

Mammoth volcanoes, sweeping canyons, fractured ground: Tharsis is one of the most geologically interesting and oft-explored parts of the planet’s surface. Once an incredibly active region, displaying both volcanism and the shifting crustal plates of tectonics, it hosts most of the planet’s colossal volcanoes – the largest in the Solar System.

Mars from horizon to horizon

This view, taken by the High Resolution Stereo Camera aboard Mars Express in October 2017, shows Tharsis in all its glory.

It sweeps from the planet’s upper horizon — marked by the faint blue haze at the top of the frame — down across a web of pale fissures named Noctis Labyrinthus (a part of Valles Marineris stretching to the upper left corner of the image), Ascraeus and Pavonis Mons (two of Tharsis’ four great volcanoes at more than 20 km high), and finishes at the planet’s northern polar ice cap (in this perspective, North is to the lower left).

Sitting near Mars’ equator, Tharsis covers roughly a quarter of the martian surface and is thought to have a played an important role in the planet’s history. It straddles the boundary between Mars’ southern highlands and northern lowlands.

Elevation on Mars is defined relative to where the gravity is the same as the average at the martian equator. This serves as a type of ‘sea-level’, even though are no seas.

Most of Tharsis is higher than average, at between 2 and 10 km high. The province likely formed as mushroom-shaped plumes of molten rock (magma) swelled up beneath the viscous surface over time, creating seeping flows, magma chambers, and large, rocky provinces – like Tharsis – and feeding ongoing volcanism from below.

Location map of the Tharsis region on Mars

Tharsis is also connected to the formation of the famous Valles Marineris, which is some four times longer and deeper than the Great Canyon in Arizona, USA, and the most extensive canyon system discovered in the Solar System. This is partly visible as the dark tendrils to the upper left of the image.

As magma swelled up beneath the crust to create the Tharsis province, the tension caused some areas to rupture and fracture. Molten rock then flooded these fractures and destabilised and separated regions of the crust yet further, resulting in both the wide, substantial troughs and fissures that comprise modern-day Valles Marineris, and the web-like Noctis Labyrinthus that sits at the canyon system’s western end.

Captured in the new view are volcanoes Pavonis Mons (top right), Ascraeus Mons (just below), Alba Mons (to the bottom left), and a small sliver of Olympus Mons (to the lower right, continuing out of frame) in caramel hues; a view of the region with labels is provided here: (http://www.esa.int/spaceinimages/Images/2018/06/Mars_Express_view_of_Tharsis_labelled). The location of this slice of Mars’ surface is also shown in a context map of the planet and in a topographic context.

Topography of Tharsis region on Mars

This latter view shows higher areas of the surface in red and lower ones in blue-green, illustrating the difference in altitude between the northern and southern regions of Mars.

Mars Express has been revealing the beauty and variety of Mars for 15 years, and is still going strong.

Alongside myriad striking views such as this, the spacecraft has produced global maps tracing the planet’s geologic activity, water, volcanism, and minerals, and provided enough data to construct thousands of 3D images of the surface. It has studied immense volcanoes, canyons, polar ice caps, and ancient impact craters; probed the sub-surface with radar; and explored the martian atmosphere, finding signs of ozone and methane, fleeting cloud layers, and mighty dust storms. The spacecraft has witnessed charged particles escaping to space, and examined Mars’ moons Phobos and Deimos. It has successfully identified dried-up river valleys, traces of catastrophic floods, and buried glaciers.

The past 15 years of observations from Mars Express have significantly contributed to the newly emerging picture of Mars as a once-habitable planet, with warmer and wetter epochs that may have once acted as oases for ancient martian life. These findings have paved the way for missions dedicated to hunting for signs of life on the planet, such as ESA and Roscosmos’s two-mission ExoMars programme: ExoMars returns first images from new orbit: https://orbiterchspacenews.blogspot.com/2018/04/exomars-returns-first-images-from-new.html

Meanwhile, on board Mars Express, an innovative software patch has recently rejuvenated the spacecraft.

After the successful activation of new software loaded on the spacecraft on 16 April, followed by a series of in-flight tests, Mars Express resumed science operations on 27 April. The new software, developed by ESA, was needed to compensate for the potential old-age run-down of the satellite's six gyroscopes, which measure how much Mars Express rotates about any of its three axes. Since 16 May, the spacecraft has been operating with its gyros mostly switched off. Fine-tuning of the new software will take place over the coming months.

This implementation is a major operational milestone for the mission, as it gives Mars Express an extended lifeline, possibly through the mid-2020s.

Related links:

Mars Express: http://www.esa.int/Our_Activities/Space_Science/Mars_Express

Mars Express overview: http://www.esa.int/Our_Activities/Space_Science/Mars_Express_overview

Mars Express 10 year brochure: https://esamultimedia.esa.int/multimedia/publications/BR-312/

Mars Express in-depth: http://sci.esa.int/marsexpress

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

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

HRSC at DLR: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10364/548_read-400/#/gallery/657

Mars Webcam: http://blogs.esa.int/vmc

Images, Text, Credits: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO/NASA/Viking/MGS/MOLA Science Team.

Greetings, Orbiter.ch

jeudi 31 mai 2018

Crew to Swap Command Before Return to Earth

ISS - Expedition 55 Mission patch.

May 31, 2018

Three Expedition 55 crew members are returning to Earth Sunday, but first the Commander will hand over control of the International Space Station in a ceremony Friday afternoon. In the meantime, the crew managed to continue ongoing space research and station maintenance.

Image above: The six member Expedition 55 crew poses for a portrait in the Japanese Kibo laboratory module. Clockwise from left are Flight Engineers Norishige Kanai, Ricky Arnold, Drew Feustel, Oleg Artemyev and Scott Tingle. In the center is International Space Station Commander Anton Shkaplerov. Image Credit: NASA.

Cosmonaut Anton Shkaplerov, who has been leading the station crew since February, will turn over command of the orbital laboratory to NASA astronaut Drew Feustel during the traditional Change of Command Ceremony at 2:25 p.m. EDT Friday live on NASA TV.

Next, the International Space Station Program turns its attention to the undocking Sunday at 5:16 a.m. of Shkaplerov with crewmates Scott Tingle and Norishige Kanai inside the Soyuz MS-07 spacecraft. The trio will parachute to a landing in Kazakhstan at 8:40 a.m. (6:40 p.m. Kazakh time) after 168 days in space. NASA TV begins it live coverage starting at 1:30 a.m. when the crew says farewell and closes the hatches to their Soyuz vehicle.

Image above: Flying over South Pacific Ocean, seen by EarthCam on ISS, speed: 27'598 Km/h, altitude: 407,31 Km, image captured by Roland Berga (on Earth in Switzerland) from International Space Station (ISS) using ISS-HD Live application with EarthCam's from ISS on May 31, 2018 at 22:20 UTC. Image Credits: Orbiter.ch Aerospace/Roland Berga.

Feustel worked throughout Thursday installing improved communications gear inside Europe’s Columbus lab module. Flight Engineer Ricky Arnold strapped himself into an exercise bike to research how exercising in microgravity affects the human body.

Related links:

Exercising in microgravity: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=644

NASA TV: https://www.nasa.gov/multimedia/nasatv/index.html

Expedition 55: https://www.nasa.gov/mission_pages/station/expeditions/expedition55/index.html

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Text, Credits: NASA/Mark Garcia/Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.ch

Dawn Mission: New Orbit, New Opportunities

NASA - Dawn Mission patch.

May 31, 2018

Image above: This picture is one of the first images returned by Dawn in more than a year, as Dawn moves to its lowest-ever and final orbit around Ceres. Dawn captured this view on May 16, 2018 from an altitude of about 270 miles (440 kilometers). Image Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

NASA’s Dawn spacecraft is maneuvering to its lowest-ever orbit for a close-up examination of the inner solar system’s only dwarf planet.

In early June, Dawn will reach its new, final orbit above Ceres. Soon after, it will begin collecting images and other science data from an unprecedented vantage point. This orbit will be less than 30 miles (50 kilometers) above the surface of Ceres -- 10 times closer than the spacecraft has ever been.

Dawn will collect gamma ray and neutron spectra, which help scientists understand variations in the chemical makeup of Ceres’ uppermost layer. That very low orbit also will garner some of Dawn’s closest images yet.

The transfer from Dawn’s previous orbit to its final one is not as simple as making a lane change. Dawn’s operations team worked for months to plot the course for this second extended mission of the veteran spacecraft, which is propelled by an ion engine. Engineers mapped out more than 45,000 possible trajectories before devising a plan that will allow the best science observations.

Dawn orbiting Ceres. Image Credits: NASA/JPL-Caltech

Dawn was launched in 2007 and has been exploring the two largest bodies in the main asteroid belt, Vesta and Ceres, to uncover new insights into our solar system. It entered Ceres’ orbit in March 2015.

“The team is eagerly awaiting the detailed composition and high-resolution imaging from the new, up-close examination,” said Dawn’s Principal Investigator Carol Raymond of NASA’s Jet Propulsion Laboratory, Pasadena, California. “These new high-resolution data allow us to test theories formulated from the previous data sets and discover new features of this fascinating dwarf planet.”

More detailed information about Dawn’s planned orbit is in Marc Rayman’s Dawn Journal. Rayman is Dawn’s mission director and chief engineer: https://www.jpl.nasa.gov/blog/columns/dawn-journal/

More information about the Dawn mission is available at the following sites:

https://www.nasa.gov/dawn

https://dawn.jpl.nasa.gov

The Dawn mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. JPL is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.

For a complete list of mission participants, visit: https://dawn.jpl.nasa.gov/mission

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

Greetings, Orbiter.ch

Exposed Bedrock on the Red Planet's Hale Crater

NASA - Mars Reconnaissance Orbiter (MRO) patch.

May 31, 2018

This image from MRO, NASA's Mars Reconnaissance Orbiter, shows the Red Planet's Hale Crater, a large impact crater (more than 62 miles, or 100 kilometers, across) with a suite of interesting features such as active gullies, active recurring slope lineae (long markings that are dark or bright) and extensive icy ejecta flows. There are also exposed diverse (colorful) bedrock units.

Mars Reconnaissance Orbiter (MRO): http://www.nasa.gov/mission_pages/MRO/main/index.html

Image, Text, Credit: NASA/Yvette Smith/JPL-Caltech/Univ. of Arizona.

Greetings, Orbiter.ch

Cosmic collision lights up the darkness

ESA - Hubble Space Telescope logo.

31 May 2018

Peculiar galaxy NGC 3256

Though it resembles a peaceful rose swirling in the darkness of the cosmos, NGC 3256 is actually the site of a violent clash. This distorted galaxy is the relic of a collision between two spiral galaxies, estimated to have occurred 500 million years ago. Today it is still reeling in the aftermath of this event.

Located about 100 million light-years away in the constellation of Vela (The Sails), NGC 3256 is approximately the same size as our Milky Way and belongs to the Hydra-Centaurus Supercluster. It still bears the marks of its tumultuous past in the extended luminous tails that sprawl out around the galaxy, thought to have formed 500 million years ago during the initial encounter between the two galaxies, which today form NGC 3256. These tails are studded with young blue stars, which were born in the frantic but fertile collision of gas and dust.

Wide-field image of NGC 3256 (ground-based image)

When two galaxies merge, individual stars rarely collide because they are separated by such enormous distances, but the gas and dust of the galaxies do interact — with spectacular results. The brightness blooming in the centre of NGC 3256 gives away its status as a powerful starburst galaxy, host to vast amounts of infant stars born into groups and clusters. These stars shine most brightly in the far infrared, making NGC 3256 exceedingly luminous in this wavelength domain. Because of this radiation, it is classified as a Luminous Infrared Galaxy.

NGC 3256 has been the subject of much study due to its luminosity, its proximity, and its orientation: astronomers observe its face-on orientation, that shows the disc in all its splendour. NGC 3256 provides an ideal target to investigate starbursts that have been triggered by galaxy mergers. It holds particular promise to further our understanding of the properties of young star clusters in tidal tails.

Zoom-in on NGC 3256

As well as being lit up by over 1000 bright star clusters, the central region of NGC 3256 is also home to crisscrossing threads of dark dust and a large disc of molecular gas spinning around two distinct nuclei — the relics of the two original galaxies. One nucleus is largely obscured, only unveiled in infrared, radio and X-ray wavelengths.

These two initial galaxies were gas-rich and had similar masses, as they seem to be exerting roughly equal influence on each other. Their spiral disks are no longer distinct, and in a few hundred million years time, their nuclei will also merge and the two galaxies will likely become united as a large elliptical galaxy.

Pan on NGC 3256

NGC 3256 was previously imaged through fewer filters by the NASA/ESA Hubble Space Telescope as part of a large collection of 59 images of merging galaxies, released for Hubble’s 18th anniversary on 24th April 2008.
More information

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

Links:

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

NGC 3256 observed in 2008: https://www.spacetelescope.org/images/heic0810ar/

Hubble Space Telescope (HST): https://www.spacetelescope.org/

Image, Text, Credits: Hubble/NASA/ESA/Mathias Jäger/Digitized Sky Survey 2; Acknowledgement: Davide De Martin/Videos: ESA/Hubble, NASA, Digitized Sky Survey 2. Acknowledgement: Davide De Martin/Music: John Dyson.

Best regards, Orbiter.ch

mercredi 30 mai 2018

Crew Juggles Science, Departure Preps and Spacewalk Work

ISS - Expedition 55 Mission patch.

May 30, 2018

International Space Station Commander Anton Shkaplerov will lead fellow Expedition 54-55 crewmates Scott Tingle and Norishige Kanai back to Earth early Sunday morning. The trio will undock from the Rassvet module inside the Soyuz MS-07 spacecraft on Sunday at 5:16 a.m. Just three and a half hours later the homebound crew will parachute to a landing in Kazakhstan after 168 days in space. NASA TV will broadcast live the undocking and landing activities.

Three more crew members are waiting in Kazakhstan to replace the Expedition 54-55 crew. Soyuz MS-09 Commander Sergey Prokopyev will launch with Expedition 56-57 Flight Engineers Serena Auñón-Chancellor and Alexander Gerst on June 6 from Kazakhstan on a two-day ride to their new home in space.

Image above: The city of Perth, Garden Island and Rottnest Island are pictured as the International Space Station began an orbital pass across the coast of Western Australia. Image Credit: NASA.

The following week after the crew swap activities, NASA astronauts Ricky Arnold and Drew Feustel will go out on their third spacewalk together this year. The duo will install new high definition cameras and route cables on the Harmony module during the 6.5-hour spacewalk planned for June 14. Tingle is readying some of the gear today that will be installed during that spacewalk.

Finally, Feustel and Arnold spent a little over half their day today setting up the new Cold Atom Lab (CAL). The duo installed the scientific gear in the Destiny lab module, connected cables and inspected fiber optics before powering up the low temperature research device. The CAL will chill atoms to temperatures barely above absolute zero allowing scientists to observe quantum behaviors not possible on Earth.

Related links:

Cold Atom Lab (CAL): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7396

Expedition 55: https://www.nasa.gov/mission_pages/station/expeditions/expedition55/index.html

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

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

Best regards, Orbiter.ch

NASA Dives Deep into the Search for Life

NASA logo.

May 30, 2018

Off the coast of Hawaii’s Big Island and more than 3,000 feet beneath the ocean surface lie the warm, bubbling springs of a volcano — a deep-sea location that may hold lessons for the search for extraterrestrial life.

Artist rendering showing an interior cross-section of the crust of Enceladus, which shows how hydrothermal activity may be causing the plumes of water at the moon’s surface. Image Credits: NASA-GSFC/SVS, NASA/JPL-Caltech/Southwest Research Institute.

Here, NASA and its partners are blending ocean and space exploration, with a project called SUBSEA, short for Systematic Underwater Biogeochemical Science and Exploration Analog. Lessons learned in both fields will be mutually beneficial and could help design future science-focused missions across the solar system.

Saturn’s moon Enceladus and Jupiter’s moon Europa are thought to have liquid oceans and hydrothermal activity under icy crusts. Locations on Earth with key similarities to future deep-space destinations are called analog environments. SUBSEA’s target, the springs emerging from a volcano forming the next Hawaiian island, called the Lō`ihi seamount, is an analog for these ocean worlds.

When NASA’s Cassini mission to Saturn discovered a plume of water erupting from beneath the icy surface of Enceladus, the characteristics of the plume told scientists what conditions might be like on the sea floor. This included the temperature, pressure and composition, and suggested the presence of hydrothermal activity. Scientists think these moons are good places to look for potential life, because water interacting with rock on their sea floors could yield chemical reactions that would make microbial metabolism possible.

Image above: Dramatic jets of ice, water vapor and organic compounds spray from the south pole of Saturn's moon Enceladus in this image captured by NASA's Cassini spacecraft in November 2009. Image Credits: NASA/JPL-Caltech/Space Science Institute.

Lō`ihi is an especially good place to test predictions about seafloor hydrothermal systems and their ability to support life. Previous research focused more on locations where tectonic plates come together, but the Lō`ihi seamount involves molten magma erupting from the middle of one of these plates. This is the type of volcanic activity scientists think could be similar to seafloor volcanoes that may exist on Europa and Enceladus. The zones where plates meet may actually be too hot to provide a realistic representation of hydrothermal activity on the moons of Jupiter and Saturn.

Throughout the 2018 SUBSEA expedition aboard the vessel Nautilus, the team’s scientists from NASA, the National Oceanic and Atmospheric Administration and various academic institutions will study the conditions around Lō`ihi’s seafloor springs across a range of pressures and temperatures. What they learn here will increase our understanding of the potential for conditions that could support life forms on other ocean worlds.

Learn more:

Systematic Underwater Biogeochemical Science and Exploration Analog (SUBSEA): https://www.nasa.gov/ames/subsea

Images (mentioned), Text, Credits: NASA/Abigail Tabor.

Best regards, Orbiter.ch

Black Hole Bounty Captured in the Center of the Milky Way

NASA - Chandra X-ray Observatory patch.

May 30, 2018

Astronomers have discovered evidence for thousands of black holes located near the center of our Milky Way galaxy using data from NASA's Chandra X-ray Observatory.

This black hole bounty consists of stellar-mass black holes, which typically weigh between five to 30 times the mass of our Sun. These newly identified black holes were found within three light years — a relatively short distance on cosmic scales — of the supermassive black hole at our Galaxy's center known as Sagittarius A* (Sgr A*).

Theoretical studies of the dynamics of stars in galaxies have indicated that a large population of stellar mass black holes — as many as 20,000 — could drift inward over the eons and collect around Sgr A*. This recent analysis using Chandra data is the first observational evidence for such a black hole bounty.

A black hole by itself is invisible. However, a black hole — or neutron star — locked in close orbit with a star will pull gas from its companion (astronomers call these systems "X-ray binaries"). This material falls into a disk and heats up to millions of degrees and produces X-rays before disappearing into the black hole. Some of these X-ray binaries appear as point-like sources in the Chandra image.

Chandra X-Ray Observatory: https://www.nasa.gov/mission_pages/chandra/main/index.html

Image, Text, Credits: NASA/Yvette Smith/Chandra X-Ray Observatory.

Greetings, Orbiter.ch

A Crowded Neighbourhood

ESO - European Southern Observatory logo.

30 May 2018

The rich region around the Tarantula Nebula in the Large Magellanic Cloud

Glowing brightly about 160 000 light-years away, the Tarantula Nebula is the most spectacular feature of the Large Magellanic Cloud, a satellite galaxy to our Milky Way. The VLT Survey Telescope at ESO’s Paranal Observatory in Chile has imaged this region and its rich surroundings in exquisite detail. It reveals a cosmic landscape of star clusters, glowing gas clouds and the scattered remains of supernova explosions. This is the sharpest image ever of this entire field.

Taking advantage of the capacities of the VLT Survey Telescope (VST) at ESO’s Paranal Observatory in Chile, astronomers captured this very detailed new image of the Tarantula Nebula and its numerous neighbouring nebulae and star clusters. The Tarantula, which is also known as 30 Doradus, is the brightest and most energetic star-forming region in the Local Group of galaxies.

Tarantula Nebula region in the constellation of Doradus

The Tarantula Nebula, at the top of this image, spans more than 1000 light-years and is located in the constellation of Dorado (The Dolphinfish) in the far southern sky. This stunning nebula is part of the Large Magellanic Cloud, a dwarf galaxy that measures about 14 000 light-years across. The Large Magellanic Cloud is one of the closest galaxies to the Milky Way.

At the core of the Tarantula Nebula lies a young, giant star cluster called NGC 2070, a starburst region whose dense core, R136, contains some of the most massive and luminous stars known. The bright glow of the Tarantula Nebula itself was first recorded by French astronomer Nicolas-Louis de Lacaille in 1751.

The rich region around the Tarantula Nebula in the Large Magellanic Cloud (annotated)

Another star cluster in the Tarantula Nebula is the much older Hodge 301, in which at least 40 stars are estimated to have exploded as supernovae, spreading gas throughout the region. One example of a supernova remnant is the superbubble SNR N157B, which encloses the open star cluster NGC 2060. This cluster was first observed by British astronomer John Herschel in 1836, using an 18.6-inch reflector telescope at the Cape of Good Hope in South Africa. On the outskirts of the Tarantula Nebula, on the lower right-hand side, it is possible to identify the location of the famous supernova SN 1987A [1].

Moving to the left-hand side of the Tarantula Nebula, one can see a bright open star cluster called NGC 2100, which displays a brilliant concentration of blue stars surrounded by red stars. This cluster was discovered by Scottish astronomer James Dunlop in 1826 while working in Australia, using his self-built 9-inch (23-cm) reflecting telescope.

Zooming in on the Tarantula Nebula

At the centre of the image is the star cluster and emission nebula NGC 2074, another massive star-forming region discovered by John Herschel. Taking a closer look one can spot a dark seahorse-shaped dust structure — the “Seahorse of the Large Magellanic Cloud”. This is a gigantic pillar structure roughly 20 light-years long — almost five times the distance between the Sun and the nearest star, Alpha Centauri. The structure is condemned to disappear over the next million years; as more stars in the cluster form, their light and winds will slowly blow away the dust pillars.

Obtaining this image was only possible thanks to the VST’s specially designed 256-megapixel camera called OmegaCAM. The image was created from OmegaCAM images through four different coloured filters, including one designed to isolate the red glow of ionised hydrogen [2].

Notes:

[1] SN 1987A was the first supernova to be observed with modern telescopes and the brightest since Kepler’s Star in 1604. SN 1987A was so intense that it blazed with the power of 100 million suns for several months following its discovery on 23 February 1987.

[2] The H-alpha emission line is a red spectral line created when the electron inside a hydrogen atom loses energy. This happens in hydrogen around hot young stars when the gas becomes ionised by the intense ultraviolet radiation and electrons subsequently recombine with protons to form atoms again. The ability of OmegaCAM to detect this line allows astronomers to characterise the physics of giant molecular clouds where new stars and planets form.

More information:

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It has 15 Member States: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile and with Australia as a strategic partner. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its world-leading Very Large Telescope Interferometer as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. ESO is also a major partner in two facilities on Chajnantor, APEX and ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky”.

Links:

ESOcast 162 Light: A Crowded Neighbourhood: https://www.eso.org/public/videos/eso1816a/

VLT Survey Telescope (VST): http://www.eso.org/public/teles-instr/surveytelescopes/vst/

ESO’s Paranal Observatory: http://www.eso.org/public/teles-instr/paranal-observatory/

OmegaCAM: https://www.eso.org/sci/facilities/paranal/instruments/omegacam.html

Images, Text, Credits: ESO/Richard Hook/IAU and Sky & Telescope/Video: ESO/Digitized Sky Survey 2/Nick Risinger (skysurvey.org)/Robert Gendler (http://www.robgendlerastropics.com/). Music: John Dyson.

Greetings, Orbiter.ch

mardi 29 mai 2018

Crew Unloading Cygnus While New Trio Preps for Launch

ISS - Expedition 55 Mission patch.

May 29, 2018

The Expedition 55 crew is unloading the Orbital ATK Cygnus space freighter today ahead of next week’s crew swap at the International Space Station. On top of the cargo transfers and crew departure activities, the orbital residents are also running space experiments to benefit humans on Earth and astronauts in space.

Image above: Flying over South Pacific Ocean, seen by EarthCam on ISS, speed: 27'603 Km/h, altitude: 408,73 Km, image captured by Roland Berga (on Earth in Switzerland) from International Space Station (ISS) using ISS-HD Live application with EarthCam's from ISS on May 10, 2018 at 21:00 UTC. Image Credits: Orbiter.ch Aerospace/Roland Berga.

NASA Flight Engineer Scott Tingle has been working inside Cygnus today unpacking station hardware and research gear delivered just last week. He removed science kits and spacewalking gear and stowed them throughout the orbital lab.

Tingle finally wrapped up his workday with his homebound crewmates Commander Anton Shkaplerov and Flight Engineer Norishige Kanai preparing for their June 3 return to Earth. The trio packed personal items and other gear inside the Soyuz MS-07 spacecraft that will parachute the crew to a landing in Kazakhstan after 168 days in space.

Back on Earth, Soyuz MS-09 Commander Sergey Prokopyev and Flight Engineers Serena Auñón-Chancellor and Alexander Gerst are in final training in Kazakhstan ahead of their June 6 launch to the space station. The Expedition 56-57 trio will orbit Earth for two days before docking to the Rassvet module to begin a six-month stay in space.

Image above: The next three crew members to launch to the space station and their backups pose for a portrait at the Cosmonaut Hotel in Baikonur, Kazakhstan. From left are Expedition 56-57 crew members Alexander Gerst, Sergei Prokopyev and Serena Auñón-Chancellor with back up crew members Anne McClain, Oleg Kononenko and David Saint-Jacques. Image Credits: Roscosmos/NASA.

NASA astronauts Ricky Arnold and Drew Feustel, who are staying in space until Oct. 4, familiarized themselves today with the new Cold Atom Lab’s hardware and installation procedures. The device, delivered last week on Cygnus, will research what happens to atoms exposed to temperatures less than a billionth of a degree above absolute zero.

The two later split up as Arnold set up thermal hardware that will help scientists understand the processes involved in semiconductor crystal growth. Feustel moved on and began uninstalling a plant biology facility, the European Modular Cultivation System (EMCS), which has finalized its research operations. The EMCS will now be readied for return to Earth aboard the next SpaceX Dragon cargo craft.

Related links:

Orbital ATK: https://www.nasa.gov/orbital

Expedition 55: https://www.nasa.gov/mission_pages/station/expeditions/expedition55/index.html

Cold Atom Lab: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7396

European Modular Cultivation System (EMCS): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=336

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Text, Credits: NASA/Mark Garcia/Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.ch

Astronomers Spot a Distant and Lonely Neutron Star

NASA - Chandra X-ray Observatory patch.

May 29, 2018

Astronomers have discovered a special kind of neutron star for the first time outside of the Milky Way galaxy, using data from NASA's Chandra X-ray Observatory and the European Southern Observatory's Very Large Telescope (VLT) in Chile.

Neutron stars are the ultra dense cores of massive stars that collapse and undergo a supernova explosion. This newly identified neutron star is a rare variety that has both a low magnetic field and no stellar companion.

The neutron star is located within the remains of a supernova – known as 1E 0102.2-7219 (E0102 for short) – in the Small Magellanic Cloud, located 200,000 light years from Earth.

This new composite image of E0102 allows astronomers to learn new details about this object that was discovered more than three decades ago. In this image, X-rays from Chandra are blue and purple, and visible light data from VLT’s Multi Unit Spectroscopic Explorer (MUSE) instrument are bright red. Additional data from the Hubble Space Telescope are dark red and green.

Oxygen-rich supernova remnants like E0102 are important for understanding how massive stars fuse lighter elements into heavier ones before they explode. Seen up to a few thousand years after the original explosion, oxygen-rich remnants contain the debris ejected from the dead star’s interior. This debris (visible as a green filamentary structure in the combined image) is observed today hurtling through space after being expelled at millions of miles per hour.

Chandra observations of E0102 show that the supernova remnant is dominated by a large ring-shaped structure in X-rays, associated with the blast wave of the supernova. The new MUSE data revealed a smaller ring of gas (in bright red) that is expanding more slowly than the blast wave. At the center of this ring is a blue point-like source of X-rays. Together, the small ring and point source act like a celestial bull’s eye.

The combined Chandra and MUSE data suggest that this source is an isolated neutron star, created in the supernova explosion about two millennia ago. The X-ray energy signature, or “spectrum,” of this source is very similar to that of the neutron stars located at the center of two other famous oxygen-rich supernova remnants: Cassiopeia A (Cas A) and Puppis A. These two neutron stars also do not have companion stars.

The lack of evidence for extended radio emission or pulsed X-ray radiation, typically associated with rapidly rotating highly-magnetized neutron stars, indicates that the astronomers have detected the X-radiation from the hot surface of an isolated neutron star with low magnetic fields. About ten such objects have been detected in the Milky Way galaxy, but this is the first one detected outside our galaxy.

Chandra X-ray Observatory

But how did this neutron star end up in its current position, seemingly offset from the center of the circular shell of X-ray emission produced by the blast wave of the supernova? One possibility is that the supernova explosion did occur near the middle of the remnant, but the neutron star was kicked away from the site in an asymmetric explosion, at a high speed of about two million miles per hour. However, in this scenario, it is difficult to explain why the neutron star is, today, so neatly encircled by the recently discovered ring of gas seen at optical wavelengths.

Another possible explanation is that the neutron star is moving slowly and its current position is roughly where the supernova explosion happened. In this case, the material in the optical ring may have been ejected either during the supernova explosion, or by the doomed progenitor star up to a few thousand years before.

A challenge for this second scenario is that the explosion site would be located well away from the center of the remnant as determined by the extended X-ray emission. This would imply a special set of circumstances for the surroundings of E0102: for example, a cavity carved by winds from the progenitor star before the supernova explosion, and variations in the density of the interstellar gas and dust surrounding the remnant.

Future observations of E0102 at X-ray, optical, and radio wavelengths should help astronomers solve this exciting new puzzle posed by the lonely neutron star.

A paper describing these results was published in the April issue of Nature Astronomy, and is available online. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations.

For more Chandra images, multimedia and related materials, visit: http://www.nasa.gov/chandra

Nature Astronomy: https://arxiv.org/abs/1803.01006

Image, Animation, Credits: X-ray (NASA/CXC/ESO/F.Vogt et al); Optical (ESO/VLT/MUSE & NASA/STScI). Text, Credits: NASA/Jennifer Harbaugh/NASA Marshall Space Flight Center/Molly Porter/Chandra X-ray Center/Megan Watzke.

Best regards, Orbiter.ch