Nasa's SOFIA finds water on sunlit surface of Moon

Nasa’s Stratospheric Observatory for Infrared Astronomy (SOFIA) – a telescope operating from an aircraft - has confirmed, for the first time, water on the sunlit surface of the Moon. This discovery indicates that water may be distributed across the lunar surface, and not limited to cold, shadowed places, Nasa revealed today.

SOFIA, a joint project of Nasa and the German Aerospace Centre. has detected water molecules (H2O) in Clavius Crater, one of the largest craters visible from Earth, located in the Moon’s southern hemisphere, the US space agency said. While previous observations of the Moon’s surface had detected some form of hydrogen, Nasa said, they were unable to distinguish between water and its close chemical relative, hydroxyl (OH). 

Data from this location reveal water in concentrations of 100 to 412 parts per million – roughly equivalent to a 12-ounce bottle of water – trapped in a cubic meter of soil spread across the lunar surface. The results are published in the latest issue of Nature Astronomy.

“We had indications that H2O – the familiar water we know – might be present on the sunlit side of the Moon,” said Paul Hertz, director of the Astrophysics Division in the Science Mission Directorate at NASA Headquarters in Washington. “Now we know it is there. This discovery challenges our understanding of the lunar surface and raises intriguing questions about resources relevant for deep space exploration.”

In comparison, the Sahara desert has 100 times the amount of water than what SOFIA detected in the lunar soil. Despite the small amounts, the discovery raises new questions about how water is created and how it persists on the harsh, airless lunar surface.

Since water is a precious resource in deep space and a key ingredient of life, Nasa is using its Artemis programme to study the presence of water on the Moon ahead of sending the first woman and next man to the lunar surface in 2024 with a view to establishing a sustainable human presence there by the end of the decade.

Under SOFIA’s results build on years of previous research examining the presence of water on the Moon. When the Apollo astronauts first returned from the Moon in 1969, it was thought to be completely dry. Orbital and impactor missions over the past 20 years, such as Nasa’s Lunar Crater Observation and Sensing Satellite, confirmed ice in permanently shadowed craters around the Moon’s poles.

Meanwhile, several spacecraft, including the Cassini mission and Deep Impact comet mission, as well as the Indian Space Research Organisation’s Chandrayaan-1 mission, and Nasa’s ground-based Infrared Telescope Facility, looked broadly across the lunar surface and found evidence of hydration in sunnier regions. Yet those missions were unable to definitively distinguish the form in which it was present – either H2O or OH.

“Prior to the SOFIA observations, we knew there was some kind of hydration,” said Casey Honniball, the lead author who published the results from her graduate thesis work at the University of Hawaii at Manoa in Honolulu. “But we didn’t know how much, if any, was actually water molecules – like we drink every day – or something more like drain cleaner.”

Scientists using Nasa’s telescope on an airplane, the Stratospheric Observatory for Infrared Astronomy, discovered water on a sunlit surface of the Moon for the first time. 

SOFIA is a modified Boeing 747SP aircraft that allows astronomers to study the solar system and beyond in ways that are not possible with ground-based telescopes. Molecular water, H2O, was found in Clavius Crater, one of the largest craters visible from Earth in the Moon’s southern hemisphere. This discovery indicates that water may be distributed across the lunar surface, and not limited to cold, shadowed places.

SOFIA offered a new means of looking at the Moon. Flying at altitudes of up to 45,000 feet, this modified Boeing 747SP jetliner with a 106-inch diameter telescope reaches above 99 per cent of the water vapor in Earth’s atmosphere to get a clearer view of the infrared universe. Using its Faint Object infraRed CAmera for the SOFIA Telescope (FORCAST), SOFIA was able to pick up the specific wavelength unique to water molecules, at 6.1 microns, and discovered a relatively surprising concentration in sunny Clavius Crater.

“Without a thick atmosphere, water on the sunlit lunar surface should just be lost to space,” said Honniball, who is now a postdoctoral fellow at Nasa’s Goddard Space Flight Center in Greenbelt, Maryland. “Yet somehow we’re seeing it. Something is generating the water, and something must be trapping it there.”

Several forces could be at play in the delivery or creation of this water. Micrometeorites raining down on the lunar surface, carrying small amounts of water, could deposit the water on the lunar surface upon impact. Another possibility is there could be a two-step process whereby the Sun’s solar wind delivers hydrogen to the lunar surface and causes a chemical reaction with oxygen-bearing minerals in the soil to create hydroxyl. Meanwhile, radiation from the bombardment of micrometeorites could be transforming that hydroxyl into water.

How the water then gets stored – making it possible to accumulate – also raises some intriguing questions. The water could be trapped into tiny beadlike structures in the soil that form out of the high heat created by micrometeorite impacts. Another possibility is that the water could be hidden between grains of lunar soil and sheltered from the sunlight – potentially making it a bit more accessible than water trapped in beadlike structures.

For a mission designed to look at distant, dim objects such as black holes, star clusters, and galaxies, SOFIA’s spotlight on Earth’s nearest and brightest neighbor was a departure from business as usual. The telescope operators typically use a guide camera to track stars, keeping the telescope locked steadily on its observing target. But the Moon is so close and bright that it fills the guide camera’s entire field of view. With no stars visible, it was unclear if the telescope could reliably track the Moon. To determine this, in August 2018, the operators decided to try a test observation.

“It was, in fact, the first time SOFIA has looked at the Moon, and we weren’t even completely sure if we would get reliable data, but questions about the Moon’s water compelled us to try,” said Naseem Rangwala, SOFIA’s project scientist at Nasa's Ames Research Center in California's Silicon Valley. “It’s incredible that this discovery came out of what was essentially a test, and now that we know we can do this, we’re planning more flights to do more observations.”

SOFIA’s follow-up flights will look for water in additional sunlit locations and during different lunar phases to learn more about how the water is produced, stored, and moved across the Moon. The data will add to the work of future Moon missions, such as Nasa’s Volatiles Investigating Polar Exploration Rover (VIPER), to create the first water resource maps of the Moon for future human space exploration.

In the same issue of Nature Astronomy, scientists have published a paper using theoretical models and Nasa's Lunar Reconnaissance Orbiter data, pointing out that water could be trapped in small shadows, where temperatures stay below freezing, across more of the Moon than currently expected. The results can be found here. 

“Water is a valuable resource, for both scientific purposes and for use by our explorers,” said Jacob Bleacher, chief exploration scientist for Nasa’s Human Exploration and Operations Mission Directorate. “If we can use the resources at the Moon, then we can carry less water and more equipment to help enable new scientific discoveries.”SOFIA is a joint project of Nasa and the German Aerospace Center. Ames manages the SOFIA programme, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft is maintained and operated by Nasa’s Armstrong Flight Research Center Building 703, in Palmdale, California. Source: https://www.domain-b.com/

Read More........→October 30, 2020

A New Way To See The High-Energy Sky

Credit: HAWC Collaboration

University of Maryland (UMD) physicists pioneered development of observatory that has located new high-energy sources in the universe and provided more detail on known sources in first year of full operation. HAWC observations show that a previously known gamma ray source in the Milky Way galaxy, TeV J1930+188, which is probably due to a pulsar wind nebula, is far more complicated than originally thought. Where researchers previously identified a single gamma ray source, HAWC identified several hot spots. The United States and Mexico constructed the High Altitude Water Cherenkov (HAWC) Gamma-ray Observatory to observe some of the most energetic phenomena in the known universe--the aftermath when massive stars die, glowing clouds of electrons around rapidly spinning neutron stars, and supermassive black holes devouring matter and spitting out powerful jets of particles. These violent explosions produce high-energy gamma rays and cosmic rays, which can travel large distances--making it possible to see objects and events far outside our own galaxy. Today, scientists operating HAWC released a new survey of the sky made from the highest energy gamma rays ever observed. The new sky map, which uses data collected since the observatory began running at full capacity last March, offers a deeper understanding of high-energy processes taking place in our galaxy and beyond. "HAWC gives us a new way to see the high-energy sky," said Jordan Goodman, professor of physics at the University of Maryland, and U.S. lead investigator and spokesperson for the HAWC collaboration. "This new data from HAWC shows the galaxy in unprecedented detail, revealing new high-energy sources and previously unseen details about existing sources." HAWC researchers presented the new observation data and sky map April 18, 2016, at the American Physical Society meeting. They also participated in a press conference at the meeting. The new sky map shows many new gamma ray sources within our own Milky Way galaxy. Because HAWC observes 24 hours per day and year-round with a wide field-of-view and large area, the observatory boasts a higher energy reach especially for extended objects. In addition, HAWC can uniquely monitor for gamma ray flares by sources in our galaxy and other active galaxies, such as Markarian 421 and Markarian 501. This is a view of two-thirds of the entire sky with very-high-energy gamma rays observed by HAWC. Many sources are clearly visible in our own Milky Way galaxy, as well as two other galaxies: Markarian 421 and Markarian 501. Some well-known constellations are shown as a reference. The center of the Milky Way is located toward

Credit: HAWC Collaboration

Sagittarius. One of HAWC's new observations provides a better understanding of the high-energy nature of the Cygnus region--a northern constellation lying on the plane of the Milky Way. A multitude of neutron stars and supernova remnants call this star nursery home. HAWC scientists observed previously unknown objects in the Cygnus region and identified objects discovered earlier with sharper resolution. In a region of the Milky Way where researchers previously identified a single gamma ray source named TeV J1930+188, HAWC identified several hot spots, indicating that the region is more complicated than previously thought. "Studying these objects at the highest energies can reveal the mechanism by which they produce gamma rays and possibly help us unravel the hundred-year-old mystery of the origin of high-energy cosmic rays that bombard Earth from space," said Goodman. HAWC--located 13,500 feet above sea level on the slopes of Mexico's Volcán Sierra Negra--contains 300 detector tanks, each holding 50,000 gallons of ultrapure water with four light sensors anchored to the floor. When gamma rays or cosmic rays reach Earth's atmosphere they set off a cascade of charged particles, and when these particles reach the water in HAWC's detectors, they produce a cone-shaped flash of light known as Cherenkov radiation. The effect is much like a sonic boom produced by a supersonic jet, because the particles are traveling slightly faster than the speed of light in water when they enter the detectors. The complete array of HAWC detector tanks is seen here in Dec. 2014.

Credit: HAWC Collaboration

The light sensors record each flash of Cherenkov radiation inside the detector tanks. By comparing nanosecond differences in arrival times at each light sensor, scientists can reconstruct the angle of travel for each particle cascade. The intensity of the light indicates the primary particle's energy, and the pattern of detector hits can distinguish between gamma rays and cosmic rays. With 300 detectors spread over an area equivalent to more than three football fields, HAWC "sees" these events in relatively high resolution. "Unlike traditional telescopes, with HAWC we have now an instrument that surveys two-thirds of the sky at the highest energies, day and night," said Andrés Sandoval, Mexico spokesperson for HAWC. HAWC exhibits 15-times greater sensitivity than its predecessor--an observatory known as Milagro that operated near Los Alamos, New Mexico, and ceased taking data in 2008. In eight years of operation, Milagro found new sources of high-energy gamma rays, detected diffuse gamma rays from the Milky Way galaxy and discovered that the cosmic rays hitting earth had an unexpected non-uniformity. "HAWC will collect more data in the next few years, allowing us to reach even higher energies," said Goodman. "Combining HAWC observations with data from other instruments will allow us to extend the reach of our understanding of the most violent processes in the universe." Contacts and sources:Abby Robinson, University of Maryland (UMD) Source: http://www.ineffableisland.com/

Read More........→April 25, 2016

Gravitational waves detected for the first time

Credits: R. Hurt/Caltech-JPL

In a historical scientific landmark, researchers have announced the first detection of gravitational waves, as predicted by Einstein's general theory of relativity 100 years ago. This major discovery opens a new era of astronomy.

For the first time, scientists have directly observed "ripples" in the fabric of spacetime called gravitational waves, arriving at the Earth from a cataclysmic event in the distant universe. This confirms a major prediction of Einstein’s 1915 general theory of relativity and opens an unprecedented new window onto the cosmos. The observation was made at 09:50:45 GMT on 14th September 2015, when two black holes collided. However, given the enormous distance involved and the time required for light to reach us, this event actually occurred some 1.3 billion years ago, during the mid-Proterozoic Eon. For context, this is so far back that multicellular life here on Earth was only just beginning to spread. The signal came from the Southern Celestial Hemisphere, in the rough direction of (but much further away than) the Magellanic Clouds. The two black holes were spinning together as a binary pair, turning around each other several tens of times a second, until they eventually collided at half the speed of light. These objects were 36 and 29 times the mass of our Sun. As their event horizons merged, they became one – like two soap bubbles in a bath. During the fraction of a second that this happened, three solar masses were converted to gravitational waves, and for a brief instant the event hit a peak power output 50 times

The gravitational waves were detected by both of the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington, USA. The LIGO Observatories are funded by the National Science Foundation (NSF), and were conceived, built, and are operated by Caltech and MIT. The discovery was published yesterday in the journal Physical Review Letters.

that of the entire visible universe. Prof. Stephen Hawking told BBC News: "Gravitational waves provide a completely new way of looking at the Universe. The ability to detect them has the potential to revolutionise astronomy. This discovery is the first detection of a black hole binary system and the first observation of black holes merging. Apart from testing General Relativity, we could hope to see black holes through the history of the Universe. We may even see relics of the very early Universe during the Big Bang at some of the most extreme energies possible." "There is a Nobel Prize in it – there is no doubt," said Prof. Karsten Danzmann, from the Max Planck Institute for Gravitational Physics and Leibniz University in Hannover, Germany, who collaborated on the study. In an interview with the BBC, he claimed the significance of this discovery is on a par with the determination of the structure of DNA. "It is the first ever direct detection of gravitational waves; it's the first ever direct detection of black holes and it is a confirmation of General Relativity because the property of these black holes agrees exactly with what Einstein predicted almost exactly 100 years ago." "We found a beautiful signature of the merger of two black holes and it agrees exactly – fantastically – with the numerical solutions to Einstein equations ...

LIGO measurement of gravitational waves at the Hanford (left) and Livingston (right) detectors, compared to the theoretical predicted values.By Abbott et al. [CC BY 3.0]

it looked too beautiful to be true." "Scientists have been looking for gravitational waves for decades – but we’ve only now been able to achieve the incredibly precise technologies needed to pick up these very, very faint echoes from across the universe," said Danzmann. "This discovery would not have been possible without the efforts and the technologies developed by the Max Planck, Leibniz Universität, and UK scientists working in the GEO collaboration." Researchers at the LIGO Observatories were able to measure tiny and subtle disturbances the waves made to space and time as they passed through the Earth, with machines detecting changes just fractions of the width of an atom. At each observatory, the two-and-a-half-mile (4-km) long L-shaped LIGO interferometer uses laser light split into two beams that travel back and forth along tubes kept at a near-perfect vacuum. The beams are used to monitor the distance between mirrors precisely positioned at the ends of the arms. According to Einstein’s theory, the distance between the mirrors will change by an infinitesimal amount when gravitational waves pass by the detector. A change in the lengths of the arms smaller than one-ten-thousandth the diameter of a proton can be detected; equivalent to a human hair's diameter over three light years from Earth. "The Advanced LIGO detectors are a tour de force of science and technology, made possible by a truly exceptional international team of technicians, engineers, and scientists," says David Shoemaker of MIT. "We are very proud that we finished this NSF-funded project on time and on budget." "We spent years modelling the gravitational-wave emission from one of the most extreme events in the universe: pairs of massive black holes orbiting with each other and then merging. And that’s exactly the kind of signal we detected!" says Prof. Alessandra Buonanno, director at the Max Planck Institute for Gravitational Physics in Potsdam. "With this discovery, we humans are embarking on a marvellous new quest: the quest to explore the warped side of the universe – objects and phenomena that are made from warped spacetime," says Kip Thorne, Feynman Professor of Theoretical Physics at Caltech. "Colliding black holes and gravitational waves are our first beautiful examples." Advanced LIGO is among the most sensitive instruments ever built. During its next observing stage, it is expected to detect five more black hole mergers and to detect around 40 binary star mergers each year, in addition to an unknown number of more exotic gravitational wave sources, some of which may not be anticipated by current theory. Source: Futurtimeline.net

Read More........→February 15, 2016

NASA camera reveals 'dark side' of moon

Washington: From nearly 1.6 lakh km away, a NASA camera has captured a stunning view of the far side of the moon as it moved in front of the sun-lit side of Earth last month. The images show the fully illuminated “dark side” of the moon that is never visible from Earth. The lunar far side lacks the large and dark basaltic plains (called maria) that are so prominent on the Earth-facing side. A thin sliver of shadowed area of moon is visible on its right side. "It is surprising how much brighter Earth is than the moon. Our planet is a truly brilliant object in dark space compared to the lunar surface,” said said Adam Szabo, project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The images were captured by NASA's Earth Polychromatic Imaging Camera (EPIC), a four megapixel CCD camera and telescope aboard the Deep Space Climate Observatory (DSCOVR) satellite orbiting 1 million miles (1.6 lakh km) from Earth. EPIC maintains a constant view of the fully-illuminated Earth as it rotates, providing scientific observations of ozone, vegetation, cloud height and aerosols in the atmosphere. The far side of the moon was not seen until 1959 when the Soviet Luna 3 spacecraft returned the first images. Since then, several NASA missions have imaged the lunar far side in great detail. The same side of the moon always faces an earthbound observer because the moon is tidally locked to Earth. That means its orbital period is the same as its rotation around its axis. Once EPIC begins regular observations next month, NASA will post daily colour images of Earth to a dedicated public website. About twice a year, the camera will capture the moon and Earth together as the orbit of DSCOVR crosses the orbital plane of the moon. Source: ummid.com, Image: flickr.com

Read More........→August 08, 2015

Carbon Glow of Galaxies At 'Cosmic Dawn' Observed

When galaxies first assembled, during a period often referred to as 'Cosmic Dawn,' most of the space between the stars was filled with a mixture of hydrogen and helium produced in the Big Bang. As subsequent generations of massive stars ended their brief but brilliant lives as supernovas, they seeded the interstellar medium with a fine dust of heavy elements, mostly carbon, silicon, and oxygen, which are forged in their nuclear furnaces. Astronomers study the elements scattered between the stars to learn about the internal workings of galaxies, their motion and chemistry. To date, however, attempts to detect the telltale radio signature of carbon in the very early Universe have been thwarted, perhaps -- as some have speculated -- by the need to allow a few billion years more for stars to manufacture sufficient quantities to be observed across such vast cosmic distances. New observations with the Atacama Large Millimeter/submillimeter Array (ALMA), however, readily detected the first faint traces of carbon atoms permeating the interstellar atmospheres of so-called normal galaxies, seen only one billion years after the Big Bang. This suggests that even though normal galaxies in the very early Universe were already brimming with carbon, they were not nearly as chemically evolved as similar galaxies observed just a few billion years later. In these later galaxies most of the ionized carbon has condensed into dust grains -- simple organic molecules like carbon monoxide (CO). The ALMA data for four of these galaxies is show in relation to objects in the COSMOS field taken with the Hubble Space Telescope shown above. 'Astronomers are trying to better understand how we went from the primordial gas of the Big Bang to the heavy atoms and complex molecules we see in galaxies throughout the Universe today,' said Peter Capak, an astronomer with the California Institute of Technology in Pasadena and lead author on a study appearing in the journal Nature. 'Before ALMA, there was no way to directly sample these very young, very distant galaxies because any radio emission from carbon would have simply been too weak to detect.' ALMA, with its unprecedented sensitivity, was able to detect the faint millimeter 'glow' of ionized carbon in the interstellar atmospheres of nine very distant, very young galaxies seen when the Universe was only seven percent of its current age. Atoms like carbon can become ionized by the powerful ultraviolet radiation emitted by bright, massive stars. 'The particular spectral signature of ionized carbon has long been considered a potentially powerful tool to study the enrichment of galaxies with elements heavier than hydrogen and helium. It's also a unique probe of early galaxy dynamics,' said co-author Chris Carilli with theNational Radio Astronomy Observatory in Socorro, N.M. 'The results from this paper clearly demonstrate this potential and portend a great future for these kinds of studies.' Since carbon has an affinity for other elements, binding to make simple and complex organic molecules, it doesn't remain in an unbound, ionized state for very long. It is therefore typically found in much lower concentrations when compared with other heavy elements in the interstellar medium. This makes ionized carbon an excellent tracer of relatively young unevolved galaxies. 'The fact that we see carbon in this peculiar state reveals that the concentrations of other heavier elements in the interstellar medium are relatively low,' said Capak. 'This is in stark contrast to galaxies just two billion years later, which are teeming with a dust of heavy elements and present a much lower concentration of ionized carbon.' The astronomers also used the data in these same observations as an intergalactic speed camera, and were able to clock the interstellar gas in these galaxies careening up to 380 kilometers per second. 'This is a measurement that was previously impossible for such distant galaxies,' noted Capak. 'It opens up a new window into understanding how the first galaxies assembled and evolved.' The velocities observed by ALMA are similar to those seen in normal, star-forming galaxies a few billion years later and even today in the nearby Universe. The ALMA data also show that the mass of each of these distant galaxies is between 10-100 billion times the mass of the Sun, which is comparable to the mass of the Milky Way. These results surprised astronomers because they had assumed normal galaxies in the early Universe would be less energetic and have lower masses than those observed at later epochs. Instead, the ALMA data reveal that the early Universe was capable of creating what we now consider to be normal-size galaxies. The difference in chemistry and the conspicuous lack of dust, however, indicate that they are in a very immature stage of evolution. For their research, the astronomers selected nine typical star-forming galaxies about 13 billion light-years away. The galaxies were selected from the Cosmic Evolution Survey (COSMOS) and their distances were determined with the Deep Extragalactic Imaging Multi-Object Spectrograph (DEIMOS) on the W. M. Keck-II Observatory in Hawaii. ALMA, located in the Atacama Desert of Chile, is able to detect the faint millimeter-wavelength radiation emitted by atoms and molecules in space. Earlier studies of galaxies at this extreme distance failed to detect this same signature because they focused on atypical galaxies undergoing merger, which may have masked the faint signal from ionized carbon. The new ALMA observations, which were achieved with only a portion of the array in less than 20 minutes of observations on each source, offer promise that subsequent observations with ALMA's full complement of antennas will present an even clearer picture of the assembly of galaxies and their chemical compositions. The Daily Galaxy via National Radio Astronomy Observatory, Image credit: ALMA (NRAO/ESO/NAOJ), P. Capak; B. Saxton (NRAO/AUI/NSF), NASA/ESA Hubble , Source: Article

Read More........→July 16, 2015