Top 5 Lists of the greatest mysteries of this world and beyond…
We’re better off with the knowledge gained from experiments like the Large Hadron Collider and the Trinity and Starfish Prime atomic bomb explosions, but what if they had gone wrong?
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New findings include Hubble Space Telescope images that show decade-old shells of ionized gas racing away from the largest star at a million miles an hour, and new 3-D models that reveal never-before-seen features of the stars’ interactions.
Eta Carinae is a binary system containing the most luminous and massive star within 10,000 light-years. A long-term study led by astronomers at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, combined data from NASA satellites, ground-based observing campaigns and theoretical modeling to produce the most comprehensive picture of Eta Carinae to date. New findings include Hubble Space Telescope images that show decade-old shells of ionized gas racing away from the largest star at a million miles an hour, and new 3-D models that reveal never-before-seen features of the stars’ interactions.
Located about 7,500 light-years away in the southern constellation of Carina, Eta Carinae comprises two massive stars whose eccentric orbits bring them unusually close every 5.5 years. Both produce powerful gaseous outflows called stellar winds, which enshroud the stars and stymy efforts to directly measure their properties. Astronomers have established that the brighter, cooler primary star has about 90 times the mass of the sun and outshines it by 5 million times. While the properties of its smaller, hotter companion are more contested, Goddard’s Ted Gull and his colleagues think the star has about 30 solar masses and emits a million times the sun’s light.
At closest approach, or periastron, the stars are 140 million miles (225 million kilometers) apart, or about the average distance between Mars and the sun. Astronomers observe dramatic changes in the system during the months before and after periastron. These include X-ray flares, followed by a sudden decline and eventual recovery of X-ray emission; the disappearance and re-emergence of structures near the stars detected at specific wavelengths of visible light; and even a play of light and shadow as the smaller star swings around the primary.
During the past 11 years, spanning three periastron passages, the Goddard group has developed a model based on routine observations of the stars using ground-based telescopes and multiple NASA satellites. According to this model, the interaction of the two stellar winds accounts for many of the periodic changes observed in the system. The winds from each star have markedly different properties: thick and slow for the primary, lean and fast for the hotter companion. The primary’s wind blows at nearly 1 million mph and is especially dense, carrying away the equivalent mass of our sun every thousand years. By contrast, the companion’s wind carries off about 100 times less material than the primary’s, but it races outward as much as six times faster.
The images and video on this page include periastron observations from NASA’s Rossi X-ray Timing Explorer, the X-Ray Telescope aboard NASA’s Swift, the Hubble Space Telescope’s STIS instrument, and computer simulations.
A ghostly never-before-seen fish with wing-like fins has set a new depth record for fish. The previously-unknown snailfish was filmed 8143m under the sea.
A ghostly never-before-seen fish with wing-like fins has set a new depth record for fish. During a recent trip to the Mariana Trench in the Pacific Ocean, the deepest place on Earth, the previously-unknown snailfish was filmed several times floating along the dark sea floor, reaching a record low of 8143 metres below the surface (see video above).
The unusual fish, spotted on the expedition, which was led by Jeff Drazen andPatty Fryer of the University of Hawaii, has a different body shape from other known varieties of snailfish. It boasts broad, translucent fins, stringy appendages and an eel-like tail that allows it to glide smoothly.
Snailfish are known to thrive at extreme depths: another variety, Pseudoliparis amblystomopsis, previously held the undisputed record for deepest-living fish at 7703 metres. Handling the intense pressure of the deep sea is a challenge for most animals because it impedes muscles and nerves and bends proteins out of shape, disrupting the working of enzymes required for life.
In 1999, Paul Yancey from Whitman College in Washington, who was also on the recent trip, discovered that a chemical called trimethylamine oxide, or TMAO, which helps regulate the concentration of dissolved substances in cells,prevents proteins from warping in deep-living fish. Levels of TMAO were found to be higher in deeper-dwelling species and individuals. But there is a limit to the amount of the chemical that a cell can hold, which should also constrain how low fish can go.
Earlier this year, along with Alan Jamieson from the University of Aberdeen, UK, Yancey calculated that the depth limit for fish, based on TMAO, should be about 8200 metres, which neatly matched real observations. And the new discovery gets even closer to the mark. “The new depth record for fish is still within the 8200 metres we predicted,” says Yancey.
NASA scientist and colleagues have identified and mapped how patterns in nighttime light intensity change during major holiday seasons around the world.
Even from space, holidays shine bright.
With a new look at daily data from the NOAA/NASA Suomi National Polar-orbiting Partnership (Suomi NPP) satellite, a NASA scientist and colleagues have identified how patterns in nighttime light intensity change during major holiday seasons – Christmas and New Year’s in the United States and the holy month of Ramadan in the Middle East.
Around many major U.S. cities, nighttime lights shine 20 to 50 percent brighter during Christmas and New Year’s when compared to light output during the rest of the year, as seen in the satellite data. In some Middle Eastern cities, nighttime lights shine more than 50 percent brighter during Ramadan, compared to the rest of the year.
Suomi NPP, a joint NASA/National Oceanic and Atmospheric Administration (NOAA) mission, carries an instrument called the Visible Infrared Imaging Radiometer Suite (VIIRS). VIIRS can observe the dark side of the planet – and detect the glow of lights in cities and towns worldwide. In 2012, NOAA scientists released “Earth at Night” maps, created from VIIRS data. These well-known images are composites – based on monthly long-term averages of data collected on nights with no clouds or moonlight.
The new analysis of holiday lights uses an advanced algorithm, developed atNASA’s Goddard Space Flight Center in Greenbelt, Maryland, that filters out moonlight, clouds and airborne particles in order to isolate city lights on a daily basis. The data from this algorithm provide high-quality satellite information on light output across the globe, allowing scientists to track when – and how brightly – people illuminate the night.
Christmas and New Year’s in the United States
In the United States, the lights started getting brighter on “Black Friday,” the day after Thanksgiving, and continued through New Year’s Day, said Miguel Román, a research physical scientist at NASA Goddard and member of the Suomi NPP Land Discipline Team, who co-led this research. He and his colleagues examined the light output in 2012 and 2013 in 70 U.S. cities, as a first step in determining patterns in urban energy use – a key factor in greenhouse gas emissions.
In most suburbs and outskirts of major cities, light intensity increased by 30 to 50 percent. Lights in the central urban areas did not increase as much as in the suburbs, but still brightened by 20 to 30 percent.
“It’s a near ubiquitous signal. Despite being ethnically and religiously diverse, we found that the U.S. experiences a holiday increase that is present across most urban communities,” Román said. “These lighting patterns are tracking a national shared tradition.”
Because snow reflects so much light, the researchers could only analyze snow-free cities. They focused on the U.S. West Coast from San Francisco and Los Angeles, and cities south of a rough imaginary line from St. Louis to Washington, D.C. The team also examined lighting patterns across 30 major towns in Puerto Rico, known for its vibrant nocturnal celebrations and for having one of the longest Christmas holiday periods.
“Overall, we see less light increases in the dense urban centers, compared to the suburbs and small towns where you have more yard space and single-family homes,” said Eleanor Stokes, a NASA Jenkins Graduate Fellow and Ph.D. candidate at Yale University’s School of Forestry and Environmental Studies, New Haven, Connecticut, who co-led the study with Román.
These new results, illustrating holidays in lights, were presented at the American Geophysical Union’s Fall Meeting in San Francisco.
Ramadan in the Middle East
The idea to look at holiday light-use patterns stemmed from one of the first analyses of the new daily lights algorithm, Román said. Colleagues from NASA Goddard and Yale were looking data of Cairo in 2012 and noticed a large discrepancy.
“‘Either you have something going on with your data that’s wrong, or there’s a real signal there that you have to look into,'” Román recalls them saying. When the team investigated the satellite record, they found that the large increase in light output in Egypt’s capital corresponded with the holy month of Ramadan. During Ramadan, Muslims fast during the day, pushing meals and many social gatherings, markets, commerce and more to nighttime hours.
To confirm that the nighttime signal was not merely an instrument artifact, they examined three consecutive years worth of data from 2012 through the fall of 2014. They found that the peaks in light use closely tracked the Islamic calendar, as Ramadan shifted earlier in the summer.
But not all Middle Eastern cities responded the same as Cairo. Light use in Saudi Arabian cities, such as Riyadh and Jeddah, increased by about 60 to 100 percent through the month of Ramadan. Light use in Turkish cities, however, increased far less. Some regions in Syria, Iraq and Lebanon did not have an increase in light output, or even demonstrated a moderate decrease, possibly due to unstable electrical grids or conflict in the region.
“Even within majority Muslim populations, there are a lot of variations,” Stokes said. “What we’ve seen is that these lighting patterns track cultural variation within the Middle East.”
With the high resolution provided by VIIRS, that variation even appears at the neighborhood level. Román and Stokes used data from Cairo to divide the city’s neighborhoods into different socioeconomic groups, based on available records of voting patterns, access to public sanitation, and literacy rates. Some of the poorest and most devout areas observed Ramadan without significant increases in light use throughout the month, choosing – whether for cultural or financial reasons – to leave their lights off at night. But during the Eid al-Fitr celebration that marks of the end of Ramadan, light use soared across all study groups, as all the neighborhoods appeared to join in the festivities. This is telling researchers that energy is providing services that enable social and cultural activities, Stokes said, and thus energy decision-making patterns are reflecting social and cultural identities.
“Whether you’re rich or poor, or religious or not, everybody in Egypt is celebrating the Eid, or the end of Ramadan,” Román said. This demonstrates that the drivers of demand for energy services aren’t just controlled by individual factors, like price; they are also influenced by the beliefs, statuses, and routines of a city’s inhabitants, he added.
Understanding Energy Decisions
“Having a daily global dynamic dataset of nighttime lights is a new way for researchers to understand the broad societal forces impacting energy decisions,” Stokes said. And with the Intergovernmental Panel on Climate Change noting that greenhouse gas reductions are going to come from energy efficiency and conservation, scientists and policy makers will need to better understand the driving forces behind energy use.
“More than 70 percent of greenhouse gas emissions come from urban areas,” Román said. “If we’re going to reduce these emissions, then we’ll have to do more than just use energy-efficient cars and appliances. We also need to understand how dominant social phenomena, the changing demographics of urban centers, and socio-cultural settings affect energy-use decisions.”
The VIIRS data also provide a new way of looking at how people use cities, from an energy perspective, Román said. Earth-observing satellites like the Landsat series have mapped the footprints and the built infrastructure within urban boundaries for decades – but the presence of buildings doesn’t reveal whether people are actually using them. The new daily dynamic data is a step in that direction, he said.
“What’s really difficult to do is to try and track people’s activity patterns and to understand how this shapes the demand for energy services,” Román said. “We can now see pieces of these patterns from space – when, where and how often we turn on the lights.”
For more information about the Suomi NPP satellite and VIIRS monthly city lights produced at NOAA, visit:
www.nasa.gov/NPP
http://www.ngdc.noaa.gov/eog/viirs.html
A moving view, like a trippy morphing spiral, is enough to make a hummingbird unstable. Little is known about how birds use senses to control flight.
If a sipping hummingbird starts to wobble when near a flower, it’s probably not because its nectar has been spiked. A moving view, like a trippy morphing spiral, seems to be enough to make it lose its stability (see video above).
To investigate how Anna’s hummingbirds control their body position, Douglas Altshuler and his team at the University of British Columbia in Canada set up a hummingbird bar in front of a screen with moving patterns. The group found that even minimal background movement affected the birds’ hovering, causing them to wobble back and forth while feeding or to jam their bills in too far, depending on the direction of motion.
Given that the birds’ natural environment is full of moving elements, it is surprising how sensitive they are to movement in their visual field, says the team. Little is known about how birds use their senses to control flight.
The effect, however, doesn’t stop hummingbirds from being spectacular aerial acrobats: Anna’s hummingbirds can shake faster than any other vertebrate and dive at record-breaking speeds.
