Orbiter.ch Space News

mardi 28 avril 2020

NASA’s Swift Mission Tallied Water From Interstellar Comet Borisov

NASA - Swift Mission patch.

April 28, 2020

For the first time, NASA’s Neil Gehrels Swift Observatory tracked water loss from an interstellar comet as it approached and rounded the Sun. The object, 2I/Borisov, traveled through the solar system in late 2019.

“Borisov doesn't fit neatly into any class of solar system comets, but it also doesn’t stand out exceptionally from them,” said Zexi Xing, a graduate student at the University of Hong Kong and Auburn University in Alabama who led the research. “There are known comets that share at least one of its properties.”

Swift Tracks Water From Interstellar Comet Borisov

Video above: Watch how NASA’s Neil Gehrels Swift Observatory tracked water production by interstellar comet 2I/Borisov as it sped through the solar system. On average, Borisov produced enough water to fill a standard bathtub in 10 seconds. It shares many traits with solar system comets, which may mean that comets form similarly in different planetary systems. Video Credits: NASA's Goddard Space Flight Center.

Comets are frozen clumps of gases mixed with dust, often called “dirty snowballs.” Scientists estimate hundreds of billions of them may orbit the Sun. Based on Borisov’s speed and computed path, however, it must have come from outside the solar system. The comet is only the second known interstellar visitor, discovered two years after the first object, named ‘Oumuamua, zipped through the solar system.

Amateur astronomer Gennady Borisov discovered the comet on August 30, four months before it made its closest approach to the Sun. The early identification gave multiple space- and ground-based observatories time for detailed follow-up observations. In October, scientists using the Apache Point Observatory in Sunspot, New Mexico, detected the first hint of water from the comet. In the following months, NASA’s Hubble Space Telescope snapped images of Borisov as the comet sped along at around 100,000 miles (161,000 kilometers) per hour.

As a comet approaches the Sun, frozen material on its surface — such as carbon dioxide — warms and begins converting to gas. When it gets within 230 million miles (370 million kilometers) of the Sun, water vaporizes. Xing and her colleagues confirmed the presence of water from Borisov and measured its fluctuations using ultraviolet light.

When sunlight breaks apart water molecules, one of the fragments is hydroxyl, a molecule composed of one oxygen and one hydrogen atom. Swift detects the fingerprint of UV light emitted by hydroxyl using its Ultraviolet/Optical Telescope (UVOT). Between September and February, Xing’s team made six observations of Borisov with Swift. They saw a 50% increase in the amount of hydroxyl — and therefore water — Borisov produced between Nov. 1 and Dec. 1, which was just seven days from the comet’s closest brush with the Sun.

Animation above: NASA's Neil Gehrels Swift Observatory’s Ultraviolet/Optical Telescope captured six snapshots of Borisov as it traveled through the solar system. This GIF shows the UV images, with Borisov in the center. Animation Credit: NASA's Goddard Space Flight Center.

At peak activity, Borisov shed eight gallons (30 liters) of water per second, enough to fill a bathtub in about 10 seconds. During its trip through the solar system, the comet lost nearly 61 million gallons (230 million liters) of water — enough to fill over 92 Olympic-size swimming pools. As it moved away from the Sun, Borisov’s water loss dropped off — and did so more rapidly than any previously observed comet. Xing said this could have been caused by a variety of factors, including surface erosion, rotational change and even fragmentation. In fact, data from Hubble and other observatories show that chunks of the comet broke off in late March.

“We’re really happy that Swift’s rapid response time and UV capabilities captured these water production rates,” said co-author Dennis Bodewits, an associate professor of physics at Auburn. “For comets, we express the amount of other detected molecules as a ratio to the amount of water. It provides a very important context for other observations."

Swift’s water production measurements also helped the team calculate that Borisov’s minimum size is just under half a mile (0.74 kilometer) across. The team estimates at least 55% of Borisov’s surface — an area roughly equivalent to half of Central Park — was actively shedding material when it was closest to the Sun. That’s at least 10 times the active area on most observed solar system comets. Borisov also differs from solar system comets in other aspects. For example, astronomers working with Hubble and the Atacama Large Millimeter/submillimeter Array, a radio telescope in Chile, discovered Borisov produced the highest levels of carbon monoxide ever seen from a comet at that distance from the Sun.

Swift

Borisov does have some traits in common with solar system comets, though. Its rise in water production as it approached the Sun was similar to previously observed objects. Xing and her team also found that other molecules in Borisov’s chemical inventory — and their abundances — are similar to home-grown comets. For example, with respect to hydroxyl and cyanogen — a compound composed of carbon and nitrogen — Borisov produced a small amount of diatomic carbon, a molecule made of two carbon atoms, and amidogen, a molecule derived from ammonia. About 25% to 30% of all solar system comets share that trait.

But Borisov’s combined characteristics defy placement in any single known comet family. Scientists are still pondering what this means for comet development in other planetary systems.

The team’s results were published in the April 27, 2020, issue of The Astrophysical Journal Letters and are available online: https://iopscience.iop.org/article/10.3847/2041-8213/ab86be

Swift was developed to study gamma-ray bursts, the most luminous explosions in the universe. But for the last decade, Bodewits has used it to learn more about comets as they traverse the solar system. Most UV light is absorbed by Earth’s atmosphere, so scientists must look for hydroxyl’s signature from space. And because Swift has a flexible observing strategy and rapid reaction time, it can perform long-term monitoring of interesting new targets. The first five observations of Borisov were composed of UVOT snapshots taken over 12 hours, and the last was a series of images captured over 24 hours.

“The team did not envision that the mission would contribute so much to our understanding of planetary science when it was being built,” said Swift Principal Investigator S. Bradley Cenko at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “But it’s a nice example of people coming up with creative and powerful ways to use the capabilities that are out there to do unexpected and exciting science.”

Goddard manages the Swift mission in collaboration with Penn State in University Park, the Los Alamos National Laboratory in New Mexico and Northrop Grumman Innovation Systems in Dulles, Virginia. Other partners include the University of Leicester and Mullard Space Science Laboratory in the United Kingdom, Brera Observatory and the Italian Space Agency in Italy.

Related links:

Ultraviolet/Optical Telescope (UVOT): https://swift.gsfc.nasa.gov/about_swift/uvot_desc.html

Hubble Space Telescope (HST): https://www.nasa.gov/mission_pages/hubble/main/index.html

Data from Hubble: http://www.astronomerstelegram.org/?read=13613

Swift: http://www.nasa.gov/mission_pages/swift/main/index.html

Comets: http://www.nasa.gov/comets

Image, Animation (mentioned), Video (mentioned), Text, Credits: NASA/GSFC/Jeannette Kazmierczak/Claire Andreoli.

Best regards, Orbiter.ch

Hubble Watches Comet ATLAS Disintegrate Into More Than Two Dozen Pieces

NASA - Hubble Space Telescope patch.

April 28, 2020

These two Hubble Space Telescope images of comet C/2019 Y4 (ATLAS), taken on April 20 and 23, 2020, provide the sharpest views yet of the breakup of the fragile comet.

Hubble identified about 30 fragments on April 20, and 25 pieces on April 23. They are all enveloped in a sunlight-swept tail of cometary dust. "Their appearance changes substantially between the two days, so much so that it's quite difficult to connect the dots," said David Jewitt, professor of planetary science and astronomy at UCLA, Los Angeles, and leader of one of two teams that photographed the doomed comet with Hubble. "I don't know whether this is because the individual pieces are flashing on and off as they reflect sunlight, acting like twinkling lights on a Christmas tree, or because different fragments appear on different days."

Image above: These two Hubble Space Telescope images of comet C/2019 Y4 (ATLAS), taken on April 20 (left) and April 23, 2020, provide the sharpest views yet of the breakup of the solid nucleus of the comet. Hubble's eagle-eye view identifies as many as 30 separate fragments. Hubble distinguishes pieces that are roughly the size of a house. Before the breakup, the entire nucleus of the comet may have been the length of one or two football fields. Astronomers aren't sure why this comet broke apart. The comet was approximately 91 million miles (146 million kilometers) from Earth when the images were taken. Image Credits: NASA, ESA, STScI and D. Jewitt (UCLA).

"This is really exciting — both because such events are super cool to watch and because they do not happen very often. Most comets that fragment are too dim to see. Events at such scale only happen once or twice a decade," said the leader of a second Hubble observing team, Quanzhi Ye, of the University of Maryland, College Park.

The results are evidence that comet fragmentation is actually fairly common, say researchers. It might even be the dominant mechanism by which the solid, icy nuclei of comets die. Because this happens quickly and unpredictably, astronomers remain largely uncertain about the cause of fragmentation. Hubble's crisp images may yield new clues to the breakup. Hubble distinguishes pieces as small as the size of a house. Before the breakup, the entire nucleus may have been no more than the length of two football fields.

One idea is that the original nucleus spun itself into pieces because of the jet action of outgassing from sublimating ices. Because such venting is probably not evenly dispersed across the comet, it enhances the breakup. "Further analysis of the Hubble data might be able to show whether or not this mechanism is responsible," said Jewitt. "Regardless, it's quite special to get a look with Hubble at this dying comet."

The comet was discovered on Dec. 29, 2019, by the ATLAS (Asteroid Terrestrial-impact Last Alert System) robotic astronomical survey system based in Hawaii. This NASA-supported survey project for Planetary Defense operates two autonomous telescopes that look for Earth-approaching comets and asteroids.

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

The comet brightened quickly until mid-March, and some astronomers anticipated that it might be visible to the naked eye in May to become one of the most spectacular comets seen in the last 20 years.

However, the comet abruptly started to get dimmer instead of brighter. Astronomers speculated that the icy core may be fragmenting, or even disintegrating. ATLAS' fragmentation was confirmed by amateur astronomer Jose de Queiroz, who was able to photograph around three pieces of the comet on April 11.

The disintegrating comet was approximately 91 million miles (146 million kilometers) from Earth when the latest Hubble observations were taken. If any of it survives, the comet will make its closest approach to Earth on May 23 at a distance of about 72 million miles (116 million kilometers), and eight days later it will skirt past the Sun at 25 million miles (40 million kilometers).

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

Related links:

Comets: http://www.nasa.gov/comets

Hubble Space Telescope: https://www.nasa.gov/mission_pages/hubble/main/index.html

Animation (mentioned), Image (mentioned), Text, Credits: NASA/Rob Garner/GSFC/Claire Andreoli/STSI/Ray Villard/UCLA/David Jewitt/University of Maryland/Quanzhi Ye.

Greetings, Orbiter.ch

Small Asteroid to Safely Fly by Earth

Asteroid Watch logo.

April 28, 2020

A relatively small asteroid, about 4 to 8 meters in diameter, will fly safely past Earth just before 3pm today, Apr. 28 (Eastern U.S. time). NASA is tracking the object, but orbit calculations ruled out any chance that the near-Earth object could pose a threat to our planet.

“Small asteroids like 2020 HS7 safely pass by Earth a few times per month,” said Lindley Johnson, Planetary Defense Officer and Program Executive for the Planetary Defense Coordination Office at NASA Headquarters in Washington, DC. “At its closest approach 2020 HS7 will pass Earth by a distance of about 23,000 miles/36,400 km. It poses no threat to our planet, and even if it were on a collision path with Earth it is small enough that it would be disintegrated by our Earth’s atmosphere.”

Near-Earth asteroid

Near-Earth asteroid 2020 HS7, estimated to be 13 to 24 feet (4 to 8 meters) in size, will safely pass Earth at 2:51 p.m. EDT on Apr. 28 (6:51 UTC).

What is a near-Earth object?

Near-Earth objects (NEOs) are asteroids and comets that orbit the Sun, but their orbits bring them into Earth’s neighborhood – within 30 million miles of Earth’s orbit.

All Known Asteroids in the Solar System (1999-2018)

These objects are relatively unchanged remnant debris from the solar system’s formation some 4.6 billion years ago. Most of the rocky asteroids originally formed in the warmer inner solar system between the orbits of Mars and Jupiter, while comets, composed mostly of water ice with embedded dust particles, formed in the cold outer solar system.

Who searches for near-Earth objects?

NASA’s Near-Earth Object (NEO) Observations Program finds, tracks and monitors near-Earth asteroids and comets. Astronomers supported by the program use telescopes to follow up the discoveries to make additional measurements, as do many observatories all over the world. The Center for Near-Earth Object Studies, based at NASA’s Jet Propulsion Laboratory, also uses these data to calculate high-precision orbits for all known near-Earth objects and predict future close approaches by them to Earth, as well as the potential for any future impacts.

NASA Science Live: Asteroid Close Approach

How do we calculate the orbit of a near-Earth object?

Scientists determine the orbit of an asteroid by comparing measurements of its position as it moves across the sky to the predictions of a computer model of its orbit around the Sun. The more observations that are used and the longer the period over which those observations are made, the more accurate the calculated orbit and the predictions that can be made from it.

Near-Earth asteroid 2020 HS7 orbit

How many near-Earth objects have been discovered so far?

At the start of 2019, the number of discovered NEOs totaled more than 19,000, and it has increased to22,776 at the time of this writing. An average of 30 new discoveries are added each week. More than 95 percent of these objects were discovered by NASA-funded surveys since 1998, when NASA initially established its NEO Observations Program and began tracking and cataloguing them.

Pan Starrs Telescope

Related links:

NASA Planetary Defense: https://www.nasa.gov/planetarydefense

NASA Center for Near-Earth Object Studies: https://cneos.jpl.nasa.gov/

International Astronomical Union (IAU) Minor Planet Center: https://www.minorplanetcenter.net/iau/mpc.html

Twitter: NASA Asteroid Watch: https://twitter.com/AsteroidWatch

Planetary Defense Coordination Office: https://www.nasa.gov/planetarydefense/overview

Near-Earth Object (NEO) Observations Program: https://www.nasa.gov/planetarydefense/neoo

Asteroids: https://www.nasa.gov/mission_pages/asteroids/main/index.html

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

Greetings, Orbiter.ch

lundi 27 avril 2020

Study Improving Fiber Optics; Cosmonauts Relaxing After Cargo Mission

ISS - Expedition 63 Mission patch.

April 27, 2020

The International Space Station provides an orbiting research platform that benefits not only human health, but also industry and technology. Expedition 63 Commander Chris Cassidy kicked off a physics study today that explores space manufacturing.

Cassidy began his workday in the U.S. Destiny laboratory module configuring the Microgravity Science Glovebox (MSG) for the Space Fibers physics investigation. The study is using the MSG to test techniques for manufacturing fiber optic cables superior to those produced on Earth.

Image above: Expedition 63 Commander Chris Cassidy services botany research hardware in Europe’s Columbus laboratory module. Image Credit: NASA.

Gravity degrades the performance of fiber optic cables produced on Earth. Space Fibers may enable the manufacturing and commercialization of cables with greater transparency and higher transmission rates than on Earth.

The NASA commander then spent Monday afternoon on regularly scheduled maintenance for the COLBERT treadmill in the station’s Tranquility module. Cassidy greased the treadmill’s axles, tightened belts and replaced components.

International Space Station (ISS). Animation Credit: NASA

NASA CubeSat Will Shine a Laser Light on the Moon's Darkest Craters

Artemis Program logo.

April 27, 2020

As astronauts explore the Moon during the Artemis program, they may need to make use of the resources that already exist on the lunar surface. Take water, for instance: Because it's a heavy and therefore expensive resource to launch from Earth, our future explorers might have to seek out ice to mine. Once excavated, it can be melted and purified for drinking and used for rocket fuel. But how much water is there on the Moon, and where might we find it?

This is where NASA's Lunar Flashlight comes in. About the size of a briefcase, the small satellite — also known as a CubeSat — aims to detect naturally occurring surface ice believed to be at the bottom of craters on the Moon that have never seen sunlight.

Image above: This artist's concept shows the Lunar Flashlight spacecraft, a six-unit CubeSat designed to search for ice on the Moon's surface using special lasers. The spacecraft will use its near-infrared lasers to shine light into shaded polar regions on the Moon, while an onboard reflectometer will measure surface reflection and composition. Image Credits: NASA/JPL-Caltech.

"Although we have a pretty good idea there's ice inside the coldest and darkest craters on the Moon, previous measurements have been a little bit ambiguous," said Barbara Cohen, principal investigator of the mission at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Scientifically, that's fine, but if we're planning on sending astronauts there to dig up the ice and drink it, we have to be sure it exists."

Managed by NASA's Jet Propulsion Laboratory in Southern California, the spacecraft is a technology demonstration: It will seek to achieve several technological firsts, including being the first mission to look for water ice using lasers. It will also be the first planetary spacecraft to use a "green" propellant, a new kind of fuel that is safer to transport and store than the commonly used spacecraft propellant hydrazine.

"A technology demonstration mission like Lunar Flashlight, which is lower cost and fills a specific gap in our knowledge, can help us better prepare for an extended NASA presence on the Moon as well as test key technologies that may be used in future missions," said John Baker, Lunar Flashlight project manager at JPL.

Peering Into the Shadows

Over the course of two months, Lunar Flashlight will swoop low over the Moon's South Pole to shine its lasers into permanently shadowed regions and probe for surface ice. Found near the North and South Poles, these dark craters are thought to be "cold traps" that accumulate molecules of different ices, including water ice. The molecules may have come from comet and asteroid material impacting the lunar surface and from solar wind interactions with the lunar soil.

"The Sun moves around the crater horizon but never actually shines into the crater," said Cohen, whose team includes scientists at the University of California, Los Angeles, John Hopkins Applied Physics Laboratory and the University of Colorado. "Because these craters are so cold, these molecules never receive enough energy to escape, so they become trapped and accumulate over billions of years."

Lunar Flashlight's four-laser reflectometer will use near-infrared wavelengths that are readily absorbed by water to identify any accumulations of ice on the surface. Should the lasers hit bare rock as they shine into the South Pole's permanently shadowed regions, their light will reflect back to the spacecraft, signaling a lack of ice. But if the light is absorbed, it would mean these dark pockets do indeed contain ice. The greater the absorption, the more widespread ice may be at the surface.

While the CubeSat can provide information only about the presence of ice on the surface, and not below it, Lunar Flashlight seeks to fill a critical gap in our understanding of how much water ice these regions possess. "We will also be able to compare the Lunar Flashlight data with the great data that we already have from other Moon-orbiting missions to see if there are correlations in signatures of water ice, thereby giving us a global view of surface ice distribution," added Cohen.

The mission is detailed in a new paper published in the April 2020 issue of IEEE Aerospace and Electronic Systems Magazine: https://doi.org/10.1109/MAES.2019.2950746

Lunar Flashlight is funded by the Small Spacecraft Technology program within NASA's Space Technology Mission Directorate. The program is based at NASA's Ames Research Center in California's Silicon Valley. It will be one of 13 secondary payloads aboard the Artemis I mission, the first integrated flight test of NASA's Deep Space Exploration Systems, including the Orion spacecraft and Space Launch System (SLS) rocket launching from the newly upgraded Exploration Ground Systems at Kennedy Space Center in Florida.

Under the Artemis program, astronauts and robots will explore more of the Moon than ever before. Robotic missions begin with commercial lunar deliveries in 2021, humans return in 2024, and the agency will establish sustainable lunar exploration by the end of the decade. We will use what we learn on the Moon to prepare to send astronauts to Mars.

To learn more about Lunar Flashlight, visit: https://www.jpl.nasa.gov/missions/lunar-flashlight/

To learn more about NASA's Artemis lunar exploration program, visit: https://www.nasa.gov/artemis

Space Technology Mission Directorate: https://www.nasa.gov/directorates/spacetech/home/index.html

Image (mentioned), Text, Credits: NASA/Tony Greicius/Clare Skelly/JPL/Ian J. O'Neill.

Greetings, Orbiter.ch

Modern Alchemy – Turning Metal into Glass

ISS - International Space Station logo.

April 27, 2020

Metals and glass don't seem to have anything in common. Glass is generally transparent and fragile while metals are opaque and extremely strong; but under the right conditions, metals can form glass, and when they do, what results is an opaque, durable, scratch- and corrosion-resistant material that is often stronger than steel. Metallic glass is so versatile it can be used in iPhone cases, the lubricant-free gears of Moon rovers, and electrical transformers. Recently, experiments on the International Space Station that NASA’s Space Life and Physical Sciences Research and Applications (SLPSRA) division funded have revealed aspects of metallic glass formation that could open the door to even greater possibilities.

Current research in the field is focused on determining which metals form the best glass and how that glass can be used. The three most commonly used metals are zirconium, palladium, and iron, in that order, and the big questions in metallic glass research are:

1)    Will the metal turn into a glass?
2)    At what temperature will that transformation happen?
3)    What will the properties of the glass be?
4)    Can it be used for practical applications?

Until now, physicists tried to answer those questions by looking at what occurs at the temperature at which a molten metal actually transitions into a glass as it cools down. That transition point is called the glass transition temperature (Tg). What scientist Ken Kelton and his colleagues at Washington University at St. Louis discovered during their research project on the International Space Station is that the transition process actually starts while the metal is still a liquid, at a much higher temperature than Tg, and that by measuring how thick (viscous) the liquid is at that higher temperature, we can determine whether a glass will form and what some of its properties will be.

(Above) Graphic representation of an atom, consists of a positively charged nucleus surrounded and neutralized by negatively charged electrons revolving in orbits at varying distances from the nucleus.

Kelton and his team performed two identical experiments that compared the temperatures at which liquid metals crystallized when they cooled down on the space station to the temperatures at which they crystallized when they cooled down on Earth. Gravity causes gases or liquids that are less dense than their surroundings to rise and those that are more dense to sink. This gentle motion creates what’s called gravitational stirring. That doesn’t happen in the microgravity environment of the space station, so the researchers wanted to see if the lack of gravitational stirring changed the liquids’ crystallization behavior. Microgravity makes it possible to measure things much more precisely than we can on Earth, so the team was confident any differences in the results would be accurate.

In addition, the team’s experiments were performed in the space station’s Electromagnetic Levitation Facility (EML), which suspends liquids in space using electromagnetic energy. EML facilities on Earth require so much power to break the hold of gravity and levitate the sample that they induce stirring. Recently, a feature was added to the space station EML that allows scientists to measure the electrical resistance of metallic liquids in the levitation chamber. No EML facility on Earth’s surface has this feature, and it made the most exciting findings of the team’s work possible.

The experiments produced two results the researchers didn't expect. The first is that the glass transition process starts far above Tg in liquid metals and the second is that, unlike other substances, above a certain temperature the electrical resistance in liquid metals doesn't increase when the temperature gets higher. Here's how that works.

Most of us are familiar with the fact that when you heat pancake syrup it becomes thinner and pours more easily. This occurs because heat makes the syrup molecules move faster. When the syrup cools, it becomes thicker because the molecules move more slowly. Electrical resistance operates something like this.

Image above: Prof. Kenneth Kelton of Washington University in St. Louis, MO, (L) and Dr. Michael Robinson of NASA's Marshall Space Flight Center (MSFC) examine a titanium-iron silicate (TiFeSiO) sample processed in MSFC's Electrostatic Levitator (ESL) Facility (background).

The classic model of an atom (Illustration) is a nucleus of protons and neutrons with electrons orbiting the nucleus. When an atom is on its own, all of its electrons stay with it; but in metals, whether they are solid or liquid, the outer set of electrons (called the valence electrons) merge together into what is called “the electron sea.” They are shared by all the other atoms and, when properly stimulated from the outside, form an electron stream or electrical current.

Think of a crowd of people. If they are standing still and you want to move through the crowd, it’s easy to do because you can walk in the spaces between the people. If they’re moving, however, it’s harder to get through the crowd because you can’t plan your route; and if they’re moving very fast, you start bumping into them and losing your balance. This is electrical resistance.

Atoms move faster when they’re heated, so an electron stream trying to get through a heated liquid or solid has a hard time because it keeps running into rapidly moving atoms. These collisions and impediments are what cause electrical resistance, and the higher the temperature, the more resistance there is.

International Space Station (ISS). Image Credit: NASA

What Kelton and his colleagues found was that, when some metal alloys are heated and become liquids, the electrical resistance doesn’t change much as the temperature increases. What surprised them was that, above certain temperatures, the electrical resistance of these metallic liquids doesn’t change at all! They don’t know why this happens, but they intend to find out. The answer could have a big impact on how we make things, especially things that have to withstand the extreme temperature swings and harsh conditions of space.

These two discoveries – that you can predict glass formation and type by measuring a molten metal's viscosity at temperatures far above Tg and that temperature doesn't affect electrical resistance at these temperatures – give physicists different places to set to work and a whole new set of phenomena to explore. Luckily for us, most of those phenomena will translate into practical applications that will make our lives easier. They may also translate into new materials that could improve long-term space travel. Who knows where we might end up when the universe is the limit.

Related link:

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

Stay informed on other exciting SLPSRA research initiatives:
https://www.nasa.gov/directorates/heo/slpsra

Images (mentioned) Graphic (mentioned), Text, Credits: NASA/Carlyle Webb.

Greetings, Orbiter.ch

dimanche 26 avril 2020

Mysterious lights cross the Swiss sky

STARLINK Constellation logo.

April 26, 2020

Several people were arrested by a strange string of stars moving in the sky Thursday evening. They are neither UFOs nor shooting stars.

STARLINK Train in the Swiss sky

"Strange lights" or "a long shooting star". Numerous testimonies have reported mysterious streaks of lights Thursday evening in the Swiss sky. Nothing paranormal behind this unusual phenomenon: it is actually the Starlink satellites of SpaceX, the American space company owned by the entrepreneur Elon Musk and the engineer Gwynne Shotwell.

When to see satellites

The Find Starlink website will let you know when they will pass over your location. For example, they will be visible again this evening at 9:59 p.m. for a few minutes.

STARLINK Train

Swiss residents captured the moment in photos and videos. Since May 2019, the date of the start of the deployment, there are nearly 360 of them circling the earth like a chain of lights and causing a sensation around the world.

Mysterious lights cross the Swiss sky

Musk's satellite network (42,000 satellites) should allow the United States and the rest of the world to have faster internet access from mid-2020. By 2021, almost the entire world will be able to access the Internet by satellite.

Striped sky - The Starlink Situation - Sky & Telescope

However, SpaceX is not the only project for a internet satellites, Amazon and Facebook have the same ambitions. What causes an uproar among astronomers who denounce pollution of the night sky, already that the light pollution of urbanizations pose a lot of problems for them, now the sky will be "zebra" by these satellites during observations of celestial bodies over long time of photos (long exposures) of these stars because the image will be completely "striped" and unusable for astronomical observations.

Joins the world wide Petition against this sky pollution by multi-billionaire companies!

Related article:

Panic wind among astronomers
https://orbiterchspacenews.blogspot.com/2019/05/panic-wind-among-astronomers.html

Related links:

IDA - International Dark-Sky Association: https://www.darksky.org/

Petition STOP! SpaceX Starlink from Spoiling Outer Space for Humanity:
https://www.change.org/p/stop-spacex-starlink-from-spoiling-outer-space-for-humanity

Find Starlink: https://findstarlink.com/

SpaceX: https://www.spacex.com/

Images, Animation, Video, Text, Credits: SCL/LOM/Sky & Telescope/Orbiter.ch Aerospace/Roland berga.

Best regards, Orbiter.ch