jeudi 23 novembre 2017

Geneva scientist questioning dark matter







University of Geneva logo.

Nov. 23, 2017

André Maeder, professor at the University of Geneva, questions the theory of dark matter and dark energy.


Image above: André Maeder, Honorary Professor, Department of Astronomy, Faculty of Science, University of Geneva (UNIGE). (Photo: Screenshot RTS).

Dark matter and dark energy haunt the minds of physicists for a long time. These mysterious and elusive elements explain the movement of stars in galaxies and the acceleration of the expansion of the Universe. A researcher from Geneva questions this approach.

André Maeder, Honorary Professor in the Department of Astronomy of the Faculty of Science at the University of Geneva (UNIGE) believes that the commonly accepted model of the Big Bang followed by an expansion, which uses dark matter and black energy, does not take into account the "scale invariance of the vacuum".

This expression means that the vacuum and its properties do not change as a result of expansion or contraction. "When we add the hypothesis of the scale invariance of the void, we see a very very small term of outward acceleration that opposes the gravitational force," explained Maeder.

Low density media

On Earth, this term is insignificant, but in very sparse environments, like the edges of a galaxy or clusters of galaxies, it becomes relatively important, continued the professor. It thus makes it possible to account for the high speeds of stars on the borders of a galaxy.

He also explains why, in clusters made up of hundreds of galaxies, the movements observed are faster than what the visible mass would allow. Professor Maeder also finds that his model predicts the acceleration of the expansion of the Universe without any particle or ounce of dark energy being needed.


Image above: The M81 spiral galaxy, photographed by Subaru and Hubble telescopes. Image Credits: Roberto Colombari & Robert Gendler.

To be able to dispense with dark matter or dark energy to explain certain cosmological phenomena would constitute a scientific upheaval. For decades, researchers have been trying to identify dark matter through the establishment of very important means, such as at CERN, for example.

Encouraging beginnings

The hypothesis of André Maeder opens a way to raise issues and controversies, admits the UNIGE in a statement. The Geneva astronomer wants for the moment modest. The first confrontations with the observations are very encouraging, but nothing is ever acquired, he said.

The results of Dr. Maeder's research have been published in the journal The Astrophysical Journal.

University of Geneva, Astronomical Observatory - article: http://www.unige.ch/sciences/astro/en/news/natural-material-and-natural-energy-request/

University of Geneva: http://www.unige.ch/sciences/astro/en/

Images (mentioned), Text, Credits: Nxp/ATS/Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.ch

Weekly Recap from the Expedition Lead Scientist, week of November 6, 2017












ISS - Expedition 53 Mission patch.

Nov. 23, 2017

(Highlights: Week of November 6, 2017) - Crew members aboard the International Space Station contributed to research dedicated to topics ranging from human health to robotics to astrophysics.

NASA astronaut Mark Vande Hei set up the Airway Monitoring system in the US Laboratory module, Destiny, and powered on the Enhancement Unit and the Portable Pulmonary Function System (PFS) for a software upgrade from the ground. Using the PFS, Vande Hei later performed calibrations and conducted high and low nitric oxide (NO) measurements in Destiny. With dust particles present in the space station atmosphere, Airway Monitoring studies the occurrence and indicators of airway inflammation in crewmembers, using ultra-sensitive gas analyzers to analyze exhaled air. This could help to identify health impacts and support maintenance of crewmember well-being on future human spaceflight missions, such as to the moon and Mars, where crewmembers will have to be more self-sufficient in identifying and avoiding such conditions.


Image above: A view of Madagascar from the International Space Station. Image Credit: NASA.

At the start of the week, Vande Hei collected saliva samples and completed a questionnaire for the Japan Aerospace Exploration Agency (JAXA) Multi-Omics experiment. The samples will be placed into the Minus Eighty Degree Celsius Laboratory Freezer for ISS (MELFI). The Multi-omics investigation evaluates the impacts of space environment and prebiotics on astronauts’ immune function. It examines changes in gut microbiological composition, metabolite profiles, and the immune system.

At the end of the week, European Space Agency (ESA) astronaut Paolo Nespoli initiated the first of four sampling phases of the JAXA Probiotics investigation by collecting fecal samples and immediately stowing the samples into the MELFI. The sampling phases include fecal and saliva sample collections, a questionnaire, and a Probiotic capsule intake. Some species of harmful bacteria such as Salmonella grow stronger and more virulent in the microgravity environment of space. At the same time, the human immune system is weaker in space, leading to increased health risks. The objective of the Probiotics investigation is to study the impact of continuous consumption of probiotics on immune function and intestinal microbiota in astronauts under a closed microgravity environment.


Image above: Crew members tested out footpads that were designed by High School Students United with NASA to Create Hardware (HUNCH) students. The pads are designed to protect the tops of astronauts’ feet when they hook them under handrails as they move and work aboard the International Space Station. Image Credit: NASA.

This week, NASA astronaut Randy Bresnik created a photo panorama of the interior of the Japanese Experiment Module (JEM) to prepare for the Astrobee investigation. Astrobee is set to arrive in spring 2018, and consists of three self-contained, free flying robots and a docking station for use inside the station. The robots are designed to help scientists and engineers develop and test technologies for use in microgravity, to assist astronauts with routine chores and to give ground controllers additional eyes and ears on the space station. The autonomous robots, powered by fans and vision-based navigation, perform crew monitoring, sampling and logistics management.

At the start of the week, the AMS-02 laptop hard drive failed. Astronaut Joe Acaba replaced the drive and installed software. AMS-02 has collected and analyzed billions of cosmic ray events, and identified millions of these as electrons or positrons (anti-matter). Solving the origin of cosmic rays and antimatter increases understanding of our galaxy.


Image above: Documentation of the Airway Monitoring Kit following replacement of components from Resupply Kit 1. Image Credit: NASA.

The crew also worked on Microbial Tracking-2, Veg-03, Earth Imagery from ISS, Meteor, ISS HAM, Story Time from Space, Biochemical Profile, Fine Motor Skills, Lighting Effects, Space Headaches, ACE-T-6, and Two-Phase Flow investigations.

Related links:

Airway Monitoring: https://www.nasa.gov/mission_pages/station/research/experiments/1172.html

JAXA - Multi-Omics: https://www.nasa.gov/mission_pages/station/research/experiments/1949.html

Minus Eighty Degree Celsius Laboratory Freezer for ISS (MELFI): https://www.nasa.gov/mission_pages/station/research/experiments/58.html

JAXA - Probiotics: https://www.nasa.gov/mission_pages/station/research/experiments/2314.html

Astrobee: https://www.nasa.gov/astrobee

AMS-02: https://www.nasa.gov/mission_pages/station/research/experiments/742.html

Microbial Tracking-2: https://www.nasa.gov/mission_pages/station/research/experiments/1920.html

Veg-03: https://www.nasa.gov/mission_pages/station/research/experiments/1294.html

Earth Imagery from ISS: https://www.nasa.gov/mission_pages/station/research/experiments/2617.html

Meteor: https://www.nasa.gov/mission_pages/station/research/experiments/1323.html

ISS HAM: https://www.nasa.gov/mission_pages/station/research/experiments/346.html

Story Time from Space: https://www.nasa.gov/mission_pages/station/research/experiments/1287.html

Biochemical Profile: https://www.nasa.gov/mission_pages/station/research/experiments/1008.html

Fine Motor Skills: https://www.nasa.gov/mission_pages/station/research/experiments/1767.html

Lighting Effects: https://www.nasa.gov/mission_pages/station/research/experiments/2279.html

Space Headaches: https://www.nasa.gov/mission_pages/station/research/experiments/181.html

ACE-T-6: https://www.nasa.gov/mission_pages/station/research/experiments/1968.html

Two-Phase Flow: https://www.nasa.gov/mission_pages/station/research/experiments/1083.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/Michael Johnson/John Love, Lead Increment Scientist Expeditions 53 & 54.

Best regards, Orbiter.ch

mercredi 22 novembre 2017

Muscle Research and Science Cargo Work Ahead of Thanksgiving












ISS - Expedition 53 Mission patch.

November 22, 2017

The six-member Expedition 53 crew heads into Thanksgiving observing how living in space affects the human body and packing the Cygnus cargo craft. The orbital crewmates are also preparing for next month’s arrival of the SpaceX Dragon resupply ship.

Veteran space station residents Paolo Nespoli and Sergey Ryazanskiy were back inside the Columbus lab module today examining what microgravity is doing to their leg muscles. The duo took turns strapping themselves in a unique exercise chair and attaching electrodes to their knees. Next, the pair used magnetic resonance imaging and ultrasound devices to observe the changes taking place in their legs in space.


Image above: Flight Engineer Mark Vande Hei swaps out a payload card from the TangoLab-1 facility and places it into the TangoLab-2 facility. Image Credit: NASA.

NASA astronaut Joe Acaba transferred the TangoLab-1 multi-use science facility into the Cygnus space freighter for a demonstration today. TangoLab-1 is being tested inside Cygnus to determine the viability of using a cargo craft as a laboratory while docked at the International Space Station.

The next cargo craft to visit the station will be the SpaceX Dragon when it launches Dec. 4 aboard the Falcon 9 rocket from Florida. Flight Engineer Mark Vande Hei trained today for the rendezvous and capture of Dragon when it arrives two days after its launch. Dragon will carry new science experiments to explore the Sun’s impact on Earth and improve the accuracy of a new diabetes implant device.

Related links:

Leg muscles: https://www.nasa.gov/mission_pages/station/research/experiments/738.html

Sun’s impact on Earth: https://www.nasa.gov/goddard/tsis-1

New diabetes implant device: https://www.nasa.gov/mission_pages/station/research/experiments/2636.html

Expedition 53: https://www.nasa.gov/mission_pages/station/expeditions/expedition53/index.html

Cygnus cargo craft: https://blogs.nasa.gov/spacestation/2017/11/14/cygnus-installed-on-station-with-new-science-experiments/

SpaceX Dragon: http://www.nasa.gov/spacex

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's TSIS-1 Keeps an Eye on Sun's Power Over Ozone












ISS - International Space Station logo.

Nov. 21, 2017

High in the atmosphere, above weather systems, is a layer of ozone gas. Ozone is Earth’s natural sunscreen, absorbing the Sun’s most harmful ultraviolet radiation and protecting living things below. But ozone is vulnerable to certain gases made by humans that reach the upper atmosphere. Once there, they react in the presence of sunlight to destroy ozone molecules.

Currently, several NASA and National Oceanic and Atmospheric Administration (NOAA) satellites track the amount of ozone in the upper atmosphere and the solar energy that drives the photochemistry that creates and destroys ozone. NASA is now ready to launch a new instrument to the International Space Station that will provide the most accurate measurements ever made of sunlight as seen from above Earth’s atmosphere — an important component for evaluating the long-term effects of ozone-destroying chemistry. The Total and Spectral solar Irradiance Sensor (TSIS-1) will measure the total amount of sunlight that reaches the top of Earth's atmosphere and how that light is distributed between different wavelengths, including ultraviolet wavelengths that we cannot sense with our eyes, but are felt by our skin and harmful to our DNA.


Image above: Light can be split into many wavelengths and a rainbow illustrates this in visible light. Each color is a different wavelength of light. NASA’s TSIS- 1 will see more than 1,000 wavelength bands of sunlight reaching the top of the atmosphere, including light we cannot sense with our eyes. Image Credits: Copyright Matthew Almon Roth (via Creative Commons).

This is not the first time NASA has measured the total light energy from the Sun. TSIS-1 succeeds previous and current NASA missions to monitor incoming sunlight with technological upgrades that should improve stability, provide three times better accuracy and lower interference from other sources of light, according to Candace Carlisle, TSIS-1 project manager at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

“We need to measure the full spectrum of sunlight and the individual wavelengths to evaluate how the Sun affects Earth’s atmosphere,” said Dong Wu, TSIS-1 project scientist at Goddard.

TSIS-will see more than 1,000 wavelength bands from 200 to 2400 nanometers. The visible part of the spectrum our eyes see goes from about 390 nanometers (blue) to 700 nanometers (red). A nanometer is one billionth of a meter.

“Each color or wavelength of light affects Earth’s atmosphere differently,” Wu said.

TSIS-1 will see different types of ultraviolet (UV) light, including UV-B and UV-C. Each plays a different role in the ozone layer. UV-C rays are essential in creating ozone. UV-B rays and some naturally occurring chemicals regulate the abundance of ozone in the upper atmosphere. The amount of ozone is a balance between these natural production and loss processes. In the course of these processes, UV-C and UV-B rays are absorbed, preventing them from reaching Earth's surface and harming living organisms. Thinning of the ozone layer has allowed some UV-B rays to reach the ground.


Image above: Antarctic ozone hole, Oct. 10, 2017: Purple and blue represent areas of low ozone concentrations in the atmosphere; yellow and red are areas of higher concentrations. Carbon tetrachloride (CCl4), which was once used in applications such as dry cleaning and as a fire-extinguishing agent, was regulated in 1987 under the Montreal Protocol along with other chlorofluorocarbons that destroy ozone and contribute to the ozone hole over Antarctica. Image Credits: NASA's Goddard Space Flight Center.

In the 1970s, scientists theorized that certain human-made chemicals found in spray cans, air conditioners and refrigerators could throw off the natural balance of ozone creation and depletion and cause an unnatural depletion of the protective ozone. In the 1980s, scientists observed ozone loss consistent with the concentrations of these chemicals and confirmed this theory.

Ozone loss was far more severe than expected over the South Pole during the Antarctic spring (fall in the United States), a phenomenon that was named “the Antarctic ozone hole.” The discovery that human-made chemicals could have such a large effect on Earth’s atmosphere brought world leaders together. They created an international commitment to phase out ozone-depleting chemicals called the Montreal Protocol, which was universally ratified in 1987 by all countries that participate in the United Nations, and has been updated to tighten constraints and account for additional ozone depleting chemicals.


Image above: The picture on the left shows a calm sun from October 2010. The right side, from October 2012, shows a much more active and varied solar atmosphere as the sun moves closer to peak solar activity, or solar maximum. NASA's Solar Dynamics Observatory (SDO) captured both images. Image Credits: NASA's Goddard Space Flight Center/SDO.

A decade after the ratification of the Montreal Protocol, the amount of human-made ozone-destroying chemicals in the atmosphere peaked and began a slow decline. However, it takes decades for these chemicals to completely cycle out of the upper atmosphere, and the concentrations of these industrially produced molecules are not all decreasing as expected, while additional, new compounds are being created and released.

More than three decades after ratification, NASA satellites have verified that ozone losses have stabilized and, in some specific locations, have even begun to recover due to reductions in the ozone-destroying chemicals regulated under the Montreal Protocol.

As part of their work in monitoring the recovery of the ozone hole, scientists use computer models of the atmosphere that simulate the physical, chemical and weather processes in the atmosphere. These atmospheric models can then take input from ground and satellite observations of various atmospheric gases, both natural and human-produced, to help predict ozone layer recovery. They test the models by simulating past changes and then compare the results with satellite measurements to see if the simulations match past outcomes. To run the best possible simulation, the models also need accurate measurements of sunlight across the spectrum.

"Atmospheric models need accurate measurements of sunlight across the ultraviolet spectrum to model the ozone layer correctly,” said Peter Pilewskie, TSIS-1 lead scientist at the Laboratory for Atmospheric and Space Physics in Boulder, Colorado. Scientists have learned that variations in UV radiance produce significant changes in the results of the computer simulations.


Image above: TSIS-1 will be affixed to the International Space Station in December 2017 TSIS-1 operates like a sun flower: it follows the Sun, from the ISS sunrise to its sunset, which happens every 90 minutes. At sunset, it rewinds, recalibrates and waits for the next sunset. Image Credits: Courtesy NASA/LASP.

Overall, solar energy output varies by approximately 0.1 percent — or about 1 watt per square meter between the most and least active part of an 11-year solar cycle. The solar cycle is marked by the alternating high and low activity periods of sunspots, dark regions of complex magnetic activity on the Sun's surface. While UV light represents a tiny fraction of the total sunlight that reaches the top of Earth's atmosphere, it fluctuates much more, anywhere from 3 to 10 percent, a change that in turn causes small changes in the chemical composition and thermal structure of the upper atmosphere.

That's where TSIS-1 comes in. “[TSIS] measurements of the solar spectrum are three times more accurate than previous instruments," said Pilewskie. Its high quality measurements will allow scientists to fine tune their computer models and produce better simulations of the ozone layer's behavior — as well as other atmospheric processes influenced by sunlight, such as the movement of winds and weather that are.

TSIS-1 joins a fleet of NASA’s Earth-observing missions that monitor nearly every aspect of the Earth system, watching for any changes in our environment that could harm life.

For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future by deploying space based sensors like TSIS-1. NASA’s Goddard Space Flight Center has overall responsibility for the development and operation of TSIS-1 on International Space Station as part of the Earth Systematic Missions program. The Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder, under contract with NASA, is responsible for providing the TSIS-1 measurements and ensuring their availability to the scientific community.

Related links:

Climate: https://www.nasa.gov/subject/3127/climate

Earth: https://www.nasa.gov/topics/earth/index.html

Ozone: https://www.nasa.gov/ozone

Science Instruments: https://www.nasa.gov/topics/technology/science-instruments/index.html

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

Images (mentioned), Text, Credits: NASA/Rob Garner/Goddard Space Flight Center, by Rani Gran.

Greetings, Orbiter.ch

mardi 21 novembre 2017

NASA Telescope Studies Quirky Comet 45P











NASA logo.

Nov. 21, 2017

When comet 45P zipped past Earth early in 2017, researchers observing from NASA’s Infrared Telescope Facility, or IRTF, in Hawai’i gave the long-time trekker a thorough astronomical checkup. The results help fill in crucial details about ices in Jupiter-family comets and reveal that quirky 45P doesn’t quite match any comet studied so far.

Like a doctor recording vital signs, the team measured the levels of nine gases released from the icy nucleus into the comet’s thin atmosphere, or coma. Several of these gases supply building blocks for amino acids, sugars and other biologically relevant molecules. Of particular interest were carbon monoxide and methane, which are so hard to detect in Jupiter-family comets that they’ve only been studied a few times before.


Image above: Comet 45P/Honda-Mrkos-Pajdušáková is captured using a telescope on December 22 from Farm Tivoli in Namibia, Africa. Image Credit: Gerald Rhemann.

The gases all originate from the hodgepodge of ices, rock and dust that make up the nucleus. These native ices are thought to hold clues to the comet’s history and how it has been aging.

“Comets retain a record of conditions from the early solar system, but astronomers think some comets might preserve that history more completely than others,” said Michael DiSanti, an astronomer at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the new study in the Astronomical Journal.

The comet—officially named 45P/Honda-Mrkos-Pajdušáková—belongs to the Jupiter family of comets, frequent orbiters that loop around the Sun about every five to seven years. Much less is known about native ices in this group than in the long-haul comets from the Oort Cloud.

To identify native ices, astronomers look for chemical fingerprints in the infrared part of the spectrum, beyond visible light. DiSanti and colleagues conducted their studies using the iSHELL high-resolution spectrograph recently installed at IRTF on the summit of Maunakea. With iSHELL, researchers can observe many comets that used to be considered too faint.

The spectral range of the instrument makes it possible to detect many vaporized ices at once, which reduces the uncertainty when comparing the amounts of different ices. The instrument covers wavelengths starting at 1.1 micrometers in the near-infrared (the range of night-vision goggles) up to 5.3 micrometers in the mid-infrared region.

iSHELL also has high enough resolving power to separate infrared fingerprints that fall close together in wavelength. This is particularly necessary in the cases of carbon monoxide and methane, because their fingerprints in comets tend to overlap with the same molecules in Earth’s atmosphere.

“The combination of iSHELL’s high resolution and the ability to observe in the daytime at IRTF is ideal for studying comets, especially short-period comets,” said John Rayner, director of the IRTF, which is managed for NASA by the University of Hawai’i.

While observing for two days in early January 2017—shortly after 45P’s closest approach to the Sun—the team made robust measurements of water, carbon monoxide, methane and six other native ices. For five ices, including carbon monoxide and methane, the researchers compared levels on the sun-drenched side of the comet to the shaded side. The findings helped fill in some gaps but also raised new questions.

The results reveal that 45P is running so low on frozen carbon monoxide, that it is officially considered depleted. By itself, this wouldn’t be too surprising, because carbon monoxide escapes into space easily when the Sun warms a comet. But methane is almost as likely to escape, so an object lacking carbon monoxide should have little methane. 45P, however, is rich in methane and is one of the rare comets that contains more methane than carbon monoxide ice.

It’s possible that the methane is trapped inside other ice, making it more likely to stick around. But the researchers think the carbon monoxide might have reacted with hydrogen to form methanol. The team found that 45P has a larger-than-average share of frozen methanol.

When this reaction took place is another question—one that gets to the heart of comet science. If the methanol was produced on grains of primordial ice before 45P formed, then the comet has always been this way. On the other hand, the levels of carbon monoxide and methanol in the coma might have changed over time, especially because Jupiter-family comets spend more time near the Sun than Oort Cloud comets do.

“Comet scientists are like archaeologists, studying old samples to understand the past,” said Boncho Bonev, an astronomer at American University and the second author on the paper. “We want to distinguish comets as they formed from the processing they might have experienced, like separating historical relics from later contamination.”

The team is now on the case to figure out how typical their results might be among similar comets. 45P was the first of five such short-period comets that are available for study in 2017 and 2018. On the heels of 45P were comets 2P/Encke and 41P/Tuttle-Giacobini-Kresak. Due next summer and fall is 21P/Giacobini–Zinner, and later will come 46P/Wirtanen, which is expected to remain within 10 million miles (16 million kilometers) of Earth throughout most of December 2018.

“This research is groundbreaking,” said Faith Vilas, the solar and planetary research program director at the National Science Foundation, or NSF, which helped support the study. “This broadens our knowledge of the mix of molecular species coexisting in the nuclei of Jovian-family comets, and the differences that exist after many trips around the Sun.”

“We’re excited to see this first publication from iSHELL, which was built through a partnership between NSF, the University of Hawai’i, and NASA,” said Kelly Fast, IRTF program scientist at NASA Headquarters. “This is just the first of many iSHELL results to come.”

More information about NASA’s IRTF: http://irtfweb.ifa.hawaii.edu/

More information about comets: https://www.nasa.gov/comets

Image (mentioned), Text, Credits: NASA/Karl Hille/Goddard Space Flight Center, by Elizabeth Zubritsky.

Greetings, Orbiter.ch

lundi 20 novembre 2017

BEAM Prepped for Cargo, CubeSats Deployed and Leg Muscles Scanned












ISS - Expedition 53 Mission patch.

November 20, 2017

An experimental module attached to the International Space Station is being prepared for upcoming cargo operations. Tiny research satellites were also ejected from the orbital lab while a pair of Expedition 53 crew members scanned their leg muscles today.

BEAM, officially called the Bigelow Expandable Activity Module, is being outfitted this week for future stowage operations. Excess gear, including inflation tanks and dynamic sensors, used during its initial expansion back in May of 2016 is being removed to make room for new cargo. BEAM’s old gear and trash will now be stowed in the Cygnus resupply craft for disposal early next month.


Image above: A deployer mechanism attached to the outside of the Japanese Kibo lab module ejects a CubeSat into Earth orbit. Image Credit: NASA.

The Kibo lab module from the Japan Aerospace Exploration Agency was the site for the deployment of several CubeSats Monday morning. A mechanism attached to the outside of Kibo ejected the CubeSats that will orbit Earth and provide insights into antibiotic resistance, astrophysics and “space weather.” More CubeSats will be deployed Tuesday.

Flight Engineers Paolo Nespoli and Sergey Ryazanskiy spent Monday exploring how the lack of gravity affects leg muscles. Nespoli strapped himself into a specialized exercise chair and attached electrodes to his leg with assistance from Ryazanskiy. The Sarcolab-3 experiment uses measurements from an ultrasound device and magnetic resonance imaging to observe impacts to the muscles and tendons of a crew member.

Related links:

Bigelow Expandable Activity Module (BEAM): https://www.nasa.gov/content/bigelow-expandable-activity-module

Cygnus resupply craft: http://orbiterchspacenews.blogspot.ch/2017/11/robotic-arm-reaches-out-and-grapples.html

Antibiotic resistance: https://www.nasa.gov/centers/ames/engineering/projects/ecamsat

Astrophysics: https://www.jpl.nasa.gov/cubesat/missions/asteria.php

Space weather: https://www.nasa.gov/mission_pages/station/research/experiments/2518.html

Sarcolab-3: https://www.nasa.gov/mission_pages/station/research/experiments/738.html

Expedition 53: https://www.nasa.gov/mission_pages/station/expeditions/expedition53/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

Behold! Observing the Sun












NASA - Solar Dynamics Observatory (SDO) patch.

Nov. 20, 2017


A broad hole in the corona was the Sun's dominant feature November 7-9, 2017, as shown in this image from NASA's Solar Dynamics Observatory. The hole is easily recognizable as the dark expanse across the top of the Sun and extending down in each side. Coronal holes are magnetically open areas on the Sun that allow high-speed solar wind to gush out into space. They always appear darker in extreme ultraviolet. This one was likely the source of bright aurora that shimmered for numerous observers, with some reaching down even to Nebraska.

SDO (Solar Dynamics Observatory): http://www.nasa.gov/mission_pages/sdo/main/index.html

Image, Text, Credits:NASA/Yvette Smith/GSFC/Solar Dynamics Observatory.

Greetings, Orbiter.ch

ESO Observations Show First Interstellar Asteroid is Like Nothing Seen Before












ESO - European Southern Observatory logo.

20 November 2017

VLT reveals dark, reddish and highly-elongated object

Artist’s impression of the interstellar asteroid `Oumuamua

For the first time ever astronomers have studied an asteroid that has entered the Solar System from interstellar space. Observations from ESO’s Very Large Telescope in Chile and other observatories around the world show that this unique object was traveling through space for millions of years before its chance encounter with our star system. It appears to be a dark, reddish, highly-elongated rocky or high-metal-content object. The new results appear in the journal Nature on 20 November 2017.

Combined deep image of `Oumuamua from the VLT and other telescopes (annotated)

On 19 October 2017, the Pan-STARRS 1 telescope in Hawai`i picked up a faint point of light moving across the sky. It initially looked like a typical fast-moving small asteroid, but additional observations over the next couple of days allowed its orbit to be computed fairly accurately. The orbit calculations revealed beyond any doubt that this body did not originate from inside the Solar System, like all other asteroids or comets ever observed, but instead had come from interstellar space. Although originally classified as a comet, observations from ESO and elsewhere revealed no signs of cometary activity after it passed closest to the Sun in September 2017. The object was reclassified as an interstellar asteroid and named 1I/2017 U1 (`Oumuamua) [1].

The Orbit of ‘Oumuamua

“We had to act quickly,” explains team member Olivier Hainaut from ESO in Garching, Germany. “`Oumuamua had already passed its closest point to the Sun and was heading back into interstellar space.”

ESO’s Very Large Telescope was immediately called into action to measure the object’s orbit, brightness and colour more accurately than smaller telescopes could achieve. Speed was vital as `Oumuamua was rapidly fading as it headed away from the Sun and past the Earth’s orbit, on its way out of the Solar System. There were more surprises to come.

Combined deep image of ‘Oumuamua from the VLT and other telescopes (unannotated)

Combining the images from the FORS instrument on the VLT using four different filters with those of other large telescopes, the team of astronomers led by Karen Meech (Institute for Astronomy, Hawai`i, USA) found that `Oumuamua varies dramatically in brightness by a factor of ten as it spins on its axis every 7.3 hours.

Artist’s impression of the interstellar asteroid `Oumuamua

Karen Meech explains the significance: “This unusually large variation in brightness means that the object is highly elongated: about ten times as long as it is wide, with a complex, convoluted shape. We also found that it has a dark red colour, similar to objects in the outer Solar System, and confirmed that it is completely inert, without the faintest hint of dust around it.”

Light curve of interstellar asteroid `Oumuamua

These properties suggest that `Oumuamua is dense, possibly rocky or with high metal content, lacks significant amounts of water or ice, and that its surface is now dark and reddened due to the effects of irradiation from cosmic rays over millions of years. It is estimated to be at least 400 metres long.

Animation of `Oumuamua passing through the Solar System

Preliminary orbital calculations suggested that the object had come from the approximate direction of the bright star Vega, in the northern constellation of Lyra. However, even travelling at a breakneck speed of about 95 000 kilometres/hour, it took so long for the interstellar object to make the journey to our Solar System that Vega was not near that position when the asteroid was there about 300 000 years ago. `Oumuamua may well have been wandering through the Milky Way, unattached to any star system, for hundreds of millions of years before its chance encounter with the Solar System.

Animation of `Oumuamua passing through the Solar System (annotated)

Astronomers estimate that an interstellar asteroid similar to `Oumuamua passes through the inner Solar System about once per year, but they are faint and hard to spot so have been missed until now. It is only recently that survey telescopes, such as Pan-STARRS, are powerful enough to have a chance to discover them.

“We are continuing to observe this unique object,” concludes Olivier Hainaut, “and we hope to more accurately pin down where it came from and where it is going next on its tour of the galaxy. And now that we have found the first interstellar rock, we are getting ready for the next ones!”

Animation of artist's concept of `Oumuamua

Notes:

[1] The Pan-STARRS team’s proposal to name the interstellar objet was accepted by the International Astronomical Union, which is responsible for granting official names to bodies in the Solar System and beyond. The name is Hawaiian and more details are given here http://www.minorplanetcenter.org/mpec/K17/K17V17.html. The IAU also created a new class of objects for interstellar asteroids, with this object being the first to receive this designation. The correct forms for referring to this object are now: 1I, 1I/2017 U1, 1I/`Oumuamua and 1I/2017 U1 (`Oumuamua). Note that the character before the O is an okina. So, the name should sound like H O u  mu a mu a. Before the introduction of the new scheme, the object was referred to as A/2017 U1.

More information:

This research was presented in a paper entitled “A brief visit from a red and extremely elongated interstellar asteroid”, by K. Meech et al., to appear in the journal Nature on 20 November 2017.

The team is composed of Karen J. Meech (Institute for Astronomy, Honolulu, Hawai`i, USA [IfA]) Robert Weryk (IfA), Marco Micheli (ESA SSA-NEO Coordination Centre, Frascati, Italy; INAF–Osservatorio Astronomico di Roma, Monte Porzio Catone, Italy), Jan T. Kleyna (IfA) Olivier Hainaut (ESO, Garching, Germany), Robert Jedicke (IfA) Richard J. Wainscoat (IfA) Kenneth C. Chambers (IfA) Jacqueline V. Keane (IfA), Andreea Petric (IfA), Larry Denneau (IfA), Eugene Magnier (IfA), Mark E. Huber (IfA), Heather Flewelling (IfA), Chris Waters (IfA), Eva Schunova-Lilly (IfA) and Serge Chastel (IfA).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, 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 by 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:

Research paper in Nature: https://www.eso.org/public/archives/releases/sciencepapers/eso1737/eso1737a.pdf

Photos of the VLT: http://www.eso.org/public/images/archive/category/paranal/

ESO’s Very Large Telescope (VLT): http://www.eso.org/public/teles-instr/paranal-observatory/vlt/

FORS instrument: http://www.eso.org/instruments/fors1/

International Astronomical Union: https://www.iau.org/

Pan-STARRS 1 telescope in Hawai: https://en.wikipedia.org/wiki/Pan-STARRS

Images, Text, Credits: ESO/Richard Hook/Olivier Hainaut/M. Kornmesser/Institute for Astronomy
Honolulu/Karen Meech et al./Videos: ESO, M. Kornmesser, L.Calcada. Music: Azul Cobalto.

Best regards, Orbiter.ch

Solar System’s First Interstellar Visitor Dazzles Scientists










Asteroid Watch logo.

Nov. 20, 2017

Astronomers recently scrambled to observe an intriguing asteroid that zipped through the solar system on a steep trajectory from interstellar space—the first confirmed object from another star.


Image above: Artist’s concept of interstellar asteroid 1I/2017 U1 (‘Oumuamua) as it passed through the solar system after its discovery in October 2017. The aspect ratio of up to 10:1 is unlike that of any object seen in our own solar system. Image Credits: European Southern Observatory/M. Kornmesser.

Now, new data reveal the interstellar interloper to be a rocky, cigar-shaped object with a somewhat reddish hue. The asteroid, named ‘Oumuamua by its discoverers, is up to one-quarter mile (400 meters) long and highly-elongated—perhaps 10 times as long as it is wide. That aspect ratio is greater than that of any asteroid or comet observed in our solar system to date. While its elongated shape is quite surprising, and unlike asteroids seen in our solar system, it may provide new clues into how other solar systems formed.

The observations and analyses were funded in part by NASA and appear in the Nov. 20 issue of the journal Nature. They suggest this unusual object had been wandering through the Milky Way, unattached to any star system, for hundreds of millions of years before its chance encounter with our star system.

“For decades we’ve theorized that such interstellar objects are out there, and now – for the first time – we have direct evidence they exist,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate in Washington. “This history-making discovery is opening a new window to study formation of solar systems beyond our own.”

Immediately after its discovery, telescopes around the world, including ESO’s Very Large Telescope in Chile and other observatories around the world were called into action to measure the object’s orbit, brightness and color. Urgency for viewing from ground-based telescopes was vital to get the best data.

Combining the images from the FORS instrument on the ESO telescope using four different filters with those of other large telescopes, a team of astronomers led by Karen Meech of the Institute for Astronomy in Hawaii found that ‘Oumuamua varies in brightness by a factor of ten as it spins on its axis every 7.3 hours. No known asteroid or comet from our solar system varies so widely in brightness, with such a large ratio between length and width. The most elongated objects we have seen to date are no more than three times longer than they are wide.  

“This unusually big variation in brightness means that the object is highly elongated: about ten times as long as it is wide, with a complex, convoluted shape,” said Meech. We also found that it had a reddish color, similar to objects in the outer solar system, and confirmed that it is completely inert, without the faintest hint of dust around it.”

These properties suggest that ‘Oumuamua is dense, comprised of rock and possibly metals, has no water or ice, and that its surface was reddened due to the effects of irradiation from cosmic rays over hundreds of millions of years.

A few large ground-based telescopes continue to track the asteroid, though it’s rapidly fading as it recedes from our planet. Two of NASA’s space telescopes (Hubble and Spitzer) are tracking the object the week of Nov. 20. As of Nov. 20, ‘Oumuamua is travelling about 85,700 miles per hour (38.3 kilometers per second) relative to the Sun. Its location is approximately 124 million miles (200 million kilometers) from Earth -- the distance between Mars and Jupiter – though its outbound path is about 20 degrees above the plane of planets that orbit the Sun. The object passed Mars’s orbit around Nov. 1 and will pass Jupiter’s orbit in May of 2018. It will travel beyond Saturn’s orbit in January 2019; as it leaves our solar system, ‘Oumuamua will head for the constellation Pegasus.

Hubble Space Telescope (HST). Animation Credits: NASA/ESA

Observations from large ground-based telescopes will continue until the object becomes too faint to be detected, sometime after mid-December. NASA’s Center for Near-Earth Object Studies (CNEOS) continues to take all available tracking measurements to refine the trajectory of 1I/2017 U1 as it exits our solar system.

This remarkable object was discovered Oct. 19 by the University of Hawaii’s Pan-STARRS1 telescope, funded by NASA’s Near-Earth Object Observations (NEOO) Program, which finds and tracks asteroids and comets in Earth’s neighborhood. NASA Planetary Defense Officer Lindley Johnson said, “We are fortunate that our sky survey telescope was looking in the right place at the right time to capture this historic moment. This serendipitous discovery is bonus science enabled by NASA’s efforts to find, track and characterize near-Earth objects that could potentially pose a threat to our planet.” 

Preliminary orbital calculations suggest that the object came from the approximate direction of the bright star Vega, in the northern constellation of Lyra. However, it took so long for the interstellar object to make the journey – even at the speed of about 59,000 miles per hour (26.4 kilometers per second) -- that Vega was not near that position when the asteroid was there about 300,000 years ago.

While originally classified as a comet, observations from ESO and elsewhere revealed no signs of cometary activity after it slingshotted past the Sun on Sept. 9 at a blistering speed of 196,000 miles per hour (87.3 kilometers per second).

The object has since been reclassified as interstellar asteroid 1I/2017 U1 by the International Astronomical Union (IAU), which is responsible for granting official names to bodies in the solar system and beyond. In addition to the technical name, the Pan-STARRS team dubbed it ‘Oumuamua (pronounced oh MOO-uh MOO-uh), which is Hawaiian for “a messenger from afar arriving first.”

Astronomers estimate that an interstellar asteroid similar to ‘Oumuamua passes through the inner solar system about once per year, but they are faint and hard to spot and have been missed until now. It is only recently that survey telescopes, such as Pan-STARRS, are powerful enough to have a chance to discover them.

“What a fascinating discovery this is!” said Paul Chodas, manager of the Center for Near-Earth Object Studies at NASA’s Jet Propulsion Laboratory, Pasadena, California. “It’s a strange visitor from a faraway star system, shaped like nothing we’ve ever seen in our own solar system neighborhood.”

For more on NASA’s Planetary Defense Coordination Office:

https://www.nasa.gov/planetarydefense

To watch a NASA Planetary Defense video on International Asteroid Day:

https://www.youtube.com/watch?v=VYO-mpoC8_s

Click here for interstellar asteroid FAQs:

https://www.nasa.gov/planetarydefense/faq/interstellar

ESO’s Very Large Telescope: http://www.eso.org/public/teles-instr/paranal-observatory/vlt/

NASA’s Center for Near-Earth Object Studies (CNEOS): https://cneos.jpl.nasa.gov/

NASA’s Near-Earth Object Observations (NEOO): https://cneos.jpl.nasa.gov/about/search_program.html

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

Greetings, Orbiter.ch

Recurring Martian Streaks: Flowing Sand, Not Water?












NASA - Mars Reconnaissance Orbiter (MRO) patch.

Nov. 20, 2017


Image above: This inner slope of a Martian crater has several of the seasonal dark streaks called "recurrent slope lineae," or RSL, that a November 2017 report interprets as granular flows, rather than darkening due to flowing water. The image is from the HiRISE camera on NASA's Mars Reconnaissance Orbiter. Image Credits: NASA/JPL-Caltech/UA/USGS.

Dark features on Mars previously considered evidence for subsurface flowing of water are interpreted by new research as granular flows, where grains of sand and dust slip downhill to make dark streaks, rather than the ground being darkened by seeping water.

Continuing examination of these still-perplexing seasonal dark streaks with a powerful camera on NASA's Mars Reconnaissance Orbiter (MRO) shows they exist only on slopes steep enough for dry grains to descend the way they do on faces of active dunes.

The findings published today in Nature Geoscience argue against the presence of enough liquid water for microbial life to thrive at these sites. However, exactly how these numerous flows begin and gradually grow has not yet been explained. Authors of the report propose possibilities that include involvement of small amounts of water, indicated by detection of hydrated salts observed at some of the flow sites.

These features have evoked fascination and controversy since their 2011 discovery, as possible markers for unexpected liquid water or brine on an otherwise dry planet. They are dark streaks that extend gradually downhill in warm seasons, then fade away in winter and reappear the next year. On Earth, only seeping water is known to have these behaviors, but how they form in the dry Martian environment remains unclear.

Many thousands of these Martian features, collectively called "recurring slope lineae" or RSL, have been identified in more than 50 rocky-slope areas, from the equator to about halfway to the poles.

"We've thought of RSL as possible liquid water flows, but the slopes are more like what we expect for dry sand," said Colin Dundas of the U.S. Geological Survey's Astrogeology Science Center in Flagstaff, Arizona. "This new understanding of RSL supports other evidence that shows that Mars today is very dry."

Dundas is lead author of the report, which is based on observations with the High Resolution Imaging Science Experiment (HiRISE) camera on MRO. The data include 3-D models of slope steepness using pairs of images for stereo information. Dundas and co-authors examined 151 RSL features at 10 sites.

The RSL are almost all restricted to slopes steeper than 27 degrees. Each flow ends on a slope that matches the dynamic "angle of repose" seen in the slumping dry sand of dunes on Mars and Earth. A flow due to liquid water should readily extend to less steep slopes.

"The RSL don't flow onto shallower slopes, and the lengths of these are so closely correlated with the dynamic angle of repose, it can't be a coincidence," said HiRISE Principal Investigator Alfred McEwen at the University of Arizona, Tucson, a co-author of the new report.

The seasonal dark streaks have been thought of as possible evidence for biologically significant liquid water -- sufficient water for microbial life -- though explaining how so much liquid water could exist on the surface in Mars' modern environment would be challenging. A granular-flow explanation for RSL fits with the earlier understanding that the surface of modern Mars, exposed to a cold, thin atmosphere, lacks flowing water. A 2016 report also cast doubt on possible sources of underground water at RSL sites. Liquid water on today's Mars may be limited to traces of dissolved moisture from the atmosphere and thin films, which are challenging environments for life as we know it.

However, RSL remain puzzling. Traits with uncertain explanations include their gradual growth, their seasonal reappearance, their rapid fading when inactive, and the presence of hydrated salts, which have water molecules bound into their crystal stucture.

Mars Reconnaissance Orbiter (MRO). Image Credits: NASA/JPL-Caltech

The new report describes possible connections between these traits and how RSL form. For example, salts can become hydrated by pulling water vapor from the atmosphere, and this process can form drops of salty water. Seasonal changes in hydration of salt-containing grains might result in some trigger mechanism for RSL grainflows, such as expansion, contraction, or release of some water. Darkening and fading might result from changes in hydration. If atmospheric water vapor is a trigger, then a question is why the RSL appear on some slopes but not others.

"RSL probably form by some mechanism that is unique to the environment of Mars," McEwen said, "so they represent an opportunity to learn about how Mars behaves, which is important for future surface exploration."

"Full understanding of RSL is likely to depend upon on-site investigation of these features," said MRO Project Scientist Rich Zurek of NASA's Jet Propulsion Laboratory, Pasadena, California. "While the new report suggests that RSL are not wet enough to favor microbial life, it is likely that on-site investigation of these sites will still require special procedures to guard against introducing microbes from Earth, at least until they are definitively characterized. In particular, a full explanation of how these enigmatic features darken and fade still eludes us. Remote sensing at different times of day could provide important clues."

The University of Arizona operates HiRISE, which was built by Ball Aerospace & Technologies Corp., Boulder, Colorado. JPL, a division of Caltech in Pasadena, California, manages the MRO Project for the NASA Science Mission Directorate in Washington. Lockheed Martin Space Systems of Denver built the orbiter and supports its operations.

Related link:

NASA's Mars Reconnaissance Orbiter (MRO): https://mars.nasa.gov/mro/

Images (mentioned), Text, Credits: NASA/Laurie Cantillo/Dwayne Brown/JPL/Guy Webster/U.S. Geological Survey/Jennifer LaVista.

Greetings, Orbiter.ch

samedi 18 novembre 2017

NASA Detects Solar Flare Pulses at Sun and Earth












NASA - Solar Dynamics Observatory (SDO) patch.

Nov. 18, 2017

When our Sun erupts with giant explosions — such as bursts of radiation called solar flares — we know they can affect space throughout the solar system as well as near Earth. But monitoring their effects requires having observatories in many places with many perspectives, much the way weather sensors all over Earth can help us monitor what’s happening with a terrestrial storm.

By using multiple observatories, two recent studies show how solar flares exhibit pulses or oscillations in the amount of energy being sent out. Such research provides new insights on the origins of these massive solar flares as well as the space weather they produce, which is key information as humans and robotic missions venture out into the solar system, farther and farther from home.

The first study spotted oscillations during a flare — unexpectedly — in measurements of the Sun’s total output of extreme ultraviolet energy, a type of light invisible to human eyes. On Feb. 15, 2011, the Sun emitted an X-class solar flare, the most powerful kind of these intense bursts of radiation. Because scientists had multiple instruments observing the event, they were able to track oscillations in the flare’s radiation, happening simultaneously in several different sets of observations.


Animation above: NASA’s Solar Dynamics Observatory captured these images of an X-class flare on Feb. 15, 2011. Animation Credits: NASA's Goddard Space Flight Center/SDO.

“Any type of oscillation on the Sun can tell us a lot about the environment the oscillations are taking place in, or about the physical mechanism responsible for driving changes in emission,” said Ryan Milligan, lead author of this first study and solar physicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the University of Glasgow in Scotland. In this case, the regular pulses of extreme ultraviolet light indicated disturbances — akin to earthquakes — were rippling through the chromosphere, the base of the Sun’s outer atmosphere, during the flare.

What surprised Milligan about the oscillations was the fact that they were first observed in extreme ultraviolet data from NOAA’s GOES — short for Geostationary Operation Environmental Satellite, which resides in near-Earth space. The mission studies the Sun from Earth’s perspective, collecting X-ray and extreme ultraviolet irradiance data — the total amount of the Sun’s energy that reaches Earth’s atmosphere over time.

This wasn’t a typical data set for Milligan. While GOES helps monitor the effects of solar eruptions in Earth’s space environment — known collectively as space weather — the satellite wasn’t initially designed to detect fine details like these oscillations.

When studying solar flares, Milligan more commonly uses high-resolution data on a specific active region in the Sun’s atmosphere to study the physical processes underlying flares. This is often necessary in order to zoom in on events in a particular area — otherwise they can easily be lost against the backdrop of the Sun’s constant, intense radiation.

“Flares themselves are very localized, so for the oscillations to be detected above the background noise of the Sun’s regular emissions and show up in the irradiance data was very striking,” Milligan said.

There have been previous reports of oscillations in GOES X-ray data coming from the Sun’s upper atmosphere, called the corona, during solar flares. What’s unique in this case is that the pulses were observed in extreme ultraviolet emission at frequencies that show they originated lower, in the chromosphere, providing more information about how a flare’s energy travels throughout through the Sun’s atmosphere.

To be sure the oscillations were real, Milligan and his colleagues checked corresponding data from other Sun-observing instruments on board NASA’s Solar Dynamics Observatory or SDO, for short: one that also collects extreme ultraviolet irradiance data and another that images the corona in different wavelengths of light. They found the exact same pulses in those data sets, confirming they were a phenomenon with its source at the Sun. Their findings are summarized in a paper published in The Astrophysical Journal Letters on Oct. 9, 2017.

These oscillations interest the scientists because they may be the result of a mechanism by which flares emit energy into space — a process we don’t yet fully understand. Additionally, the fact that the oscillations appeared in data sets typically used to monitor larger space patterns suggests they could play a role in driving space weather effects.

In the second study, scientists investigated a connection between solar flares and activity in Earth’s atmosphere. The team discovered that pulses in the electrified layer of the atmosphere — called the ionosphere — mirrored X-ray oscillations during a July 24, 2016, C-class flare. C-class flares are of mid-to-low intensity, and about 100 times weaker than X-flares.

How Solar Flares Affect Earth

Video above: A team of scientists investigated a connection between solar flares and Earth’s atmosphere. They discovered pulses in the electrified layer of the atmosphere — called the ionosphere — mirrored X-ray oscillations during a July 24, 2016, flare. Video Credits: NASA’s Goddard Space Flight Center/Genna Duberstein.

Stretching from roughly 30 to 600 miles above Earth’s surface, the ionosphere is an ever-changing region of the atmosphere that reacts to changes from both Earth below and space above. It swells in response to incoming solar radiation, which ionizes atmospheric gases, and relaxes at night as the charged particles gradually recombine.

In particular, the team of scientists — led by Laura Hayes, a solar physicist who splits her time between NASA Goddard and Trinity College in Dublin, Ireland, and her thesis adviser Peter Gallagher — looked at how the lowest layer of the ionosphere, called the D-region, responded to pulsations in a solar flare.

“This is the region of the ionosphere that affects high-frequency communications and navigation signals,” Hayes said. “Signals travel through the D-region, and changes in the electron density affect whether the signal is absorbed, or degraded.”

The scientists used data from very low frequency, or VLF, radio signals to probe the flare’s effects on the D-region. These were standard communication signals transmitted from Maine and received in Ireland. The denser the ionosphere, the more likely these signals are to run into charged particles along their way from a signal transmitter to its receiver. By monitoring how the VLF signals propagate from one end to the other, scientists can map out changes in electron density.

Pooling together the VLF data and X-ray and extreme ultraviolet observations from GOES and SDO, the team found the D-region’s electron density was pulsing in concert with X-ray pulses on the Sun. They published their results in the Journal of Geophysical Research on Oct. 17, 2017.

“X-rays impinge on the ionosphere and because the amount of X-ray radiation coming in is changing, the amount of ionization in the ionosphere changes too,” said Jack Ireland, a co-author on both studies and Goddard solar physicist. “We’ve seen X-ray oscillations before, but the oscillating ionosphere response hasn’t been detected in the past.”

Solar Dynamics Observatory (SDO). Image Credit: NASA

Hayes and her colleagues used a model to determine just how much the electron density changed during the flare. In response to incoming radiation, they found the density increased as much as 100 times in just 20 minutes during the pulses — an exciting observation for the scientists who didn’t expect oscillating signals in a flare would have such a noticeable effect in the ionosphere. With further study, the team hopes to understand how the ionosphere responds to X-ray oscillations at different timescales, and whether other solar flares induce this response.

“This is an exciting result, showing Earth’s atmosphere is more closely linked to solar X-ray variability than previously thought,” Hayes said. “Now we plan to further explore this dynamic relationship between the Sun and Earth’s atmosphere.” 
Both of these studies took advantage of the fact that we are increasingly able to track solar activity and space weather from a number of vantage points. Understanding the space weather that affects us at Earth requires understanding a dynamic system that stretches from the Sun all the way to our upper atmosphere — a system that can only be understood by tapping into a wide range of missions scattered throughout space.

Related links:

September 2017’s Intense Solar Activity Viewed from Space: https://www.nasa.gov/feature/goddard/2017/september-2017s-intense-solar-activity-viewed-from-space

NASA’s ICON Explores the Boundary Between Earth and Space: https://www.nasa.gov/feature/goddard/2017/nasa-s-icon-explores-the-boundary-between-earth-and-space/

Journal of Geophysical Research:
On Oct. 9, 2017:
http://iopscience.iop.org/article/10.3847/2041-8213/aa8f3a/meta
On Oct. 17, 2017:
http://onlinelibrary.wiley.com/doi/10.1002/2017JA024647/abstract

NOAA’s GOES: https://www.nasa.gov/content/goes/

NASA’s Solar Dynamics Observatory or SDO: http://nasa.gov/sdo

Animation (mentioned), Image (mentioned), Video (mentioned), Text, Credits: NASA/Rob Garner.

Greetings, Orbiter.ch

Astronauts Take on Science, Plumbing and Cargo Duties












ISS - Expedition 53 Mission patch.

Nov. 18, 2017

Expedition 53 checked out a specialized microscope and worked on the International Space Station’s toilet today. More supplies and hardware are also being offloaded from the newly-arrived Cygnus cargo craft.

Commander Randy Bresnik opened up the Fluids Integrated Rack this morning to take a look at its Light Microscopy Module (LMM), an advanced space microscope. He was troubleshooting the device and swapping out its cables. The LMM provides a facility to examine the microscopic properties of different types of fluids in microgravity.


Image above: The six-member Expedition 53 crew poses for a portrait inside the Japanese Kibo laboratory module with the VICTORY art spacesuit that was hand-painted by cancer patients in Russia and the United States. On the right (from top to bottom) are European Space Agency astronaut Paolo Nespoli, cosmonaut Sergey Ryazanskiy of Roscosmos and Expedition 53 Commander Randy Bresnik of NASA.

European Space Agency Paolo Nespoli worked on space plumbing throughout the day in the station’s restroom, the Waste and Hygiene Compartment (WHC). The veteran station resident removed and replaced valves and sensors in the WHC as part regular preventative maintenance.

More crew supplies and research gear are being unloaded from Cygnus today to outfit the crew and continue ongoing space science experiments. NASA astronaut Joe Acaba was unpacking food, batteries and computer gear for stowage throughout the station. The second-time station resident was also removing Genes in Space gear and blood sample kits for upcoming science work.

Related links:

Light Microscopy Module (LMM): https://www.nasa.gov/mission_pages/station/research/experiments/541.html

Genes in Space: https://www.nasa.gov/mission_pages/station/research/experiments/2524.html

Expedition 53: https://www.nasa.gov/mission_pages/station/expeditions/expedition53/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, Text, Credits: NASA/Mark Garcia.

Best regards, Orbiter.ch

NASA Launches NOAA Weather Satellite to Improve Forecasts












ULA - Delta II / JPSS-1 Mission poater.

Nov. 18, 2017


Image above: At Vandenberg Air Force Base's Space Launch Complex 2, the Delta II rocket engines roar to life. The 1:47 a.m. PST (4:47 a.m. EST), liftoff begins the Joint Polar Satellite System-1, or JPSS-1, mission. JPSS is the first in a series four next-generation environmental satellites in a collaborative program between NOAA and NASA.

NASA has successfully launched for the National Oceanic and Atmospheric Administration (NOAA) the first in a series of four highly advanced polar-orbiting satellites, equipped with next-generation technology and designed to improve the accuracy of U.S. weather forecasts out to seven days.

The Joint Polar Satellite System-1 (JPSS-1) lifted off on a United Launch Alliance Delta II rocket from Vandenberg Air Force Base, California, at 1:47 a.m. PST Saturday.

Approximately 63 minutes after launch the solar arrays on JPSS-1 deployed and the spacecraft was operating on its own power. JPSS-1 will be renamed NOAA-20 when it reaches its final orbit. Following a three-month checkout and validation of its five advanced instruments, the satellite will become operational.

NASA Launches NOAA Weather Satellite to Improve Forecasts

“Launching JPSS-1 underscores NOAA’s commitment to putting the best possible satellites into orbit, giving our forecasters -- and the public -- greater confidence in weather forecasts up to seven days in advance, including the potential for severe, or impactful weather,” said Stephen Volz, director of NOAA’s Satellite and Information Service.

JPSS-1 will join the joint NOAA/NASA Suomi National Polar-orbiting Partnership satellite in the same orbit and provide meteorologists with observations of atmospheric temperature and moisture, clouds, sea-surface temperature, ocean color, sea ice cover, volcanic ash, and fire detection. The data will improve weather forecasting, such as predicting a hurricane’s track, and will help agencies involved with post-storm recovery by visualizing storm damage and the geographic extent of power outages.

“Emergency managers increasingly rely on our forecasts to make critical decisions and take appropriate action before a storm hits,” said Louis W. Uccellini, director of NOAA’s National Weather Service. “Polar satellite observations not only help us monitor and collect information about current weather systems, but they provide data to feed into our weather forecast models.”

JPSS-1 has five instruments, each of which is significantly upgraded from the instruments on NOAA’s previous polar-orbiting satellites. The more-detailed observations from JPSS will allow forecasters to make more accurate predictions. JPSS-1 data will also improve recognition of climate patterns that influence the weather, such as El Nino and La Nina.

JPSS-1 satellite

The JPSS program is a partnership between NOAA and NASA through which they will oversee the development, launch, testing and operation all the satellites in the series. NOAA funds and manages the program, operations and data products. NASA develops and builds the instruments, spacecraft and ground system and launches the satellites for NOAA. JPSS-1 launch management was provided by NASA’s Launch Services Program based at the agency's Kennedy Space Center in Florida.

“Today’s launch is the latest example of the strong relationship between NASA and NOAA, contributing to the advancement of scientific discovery and the improvement of the U.S. weather forecasting capability by leveraging the unique vantage point of space to benefit and protect humankind,” said Sandra Smalley, director of NASA’s Joint Agency Satellite Division.

Ball Aerospace designed and built the JPSS-1 satellite bus and Ozone Mapping and Profiler Suite instrument, integrated all five of the spacecraft’s instruments and performed satellite-level testing and launch support. Raytheon Corporation built the Visible Infrared Imaging Radiometer Suite and the Common Ground System. Harris Corporation built the Cross-track Infrared Sounder. Northrop Grumman Aerospace Systems built the Advanced Technology Microwave Sounder and the Clouds and the Earth's Radiant Energy System instrument.

To learn more about the JPSS-1 mission, visit:

http://www.jpss.noaa.gov/ and https://www.nesdis.noaa.gov/jpss-1

Images, Video, Text, Credits: NASA/Sean Potter.

Greetings, Orbiter.ch