Alien or mummy? A screenshot of one of the 2 slides which have not yet been released to the public. Excerpt from mirror.co.uk Two photographs of a "dead alien" were unveiled at a big money event last night - and immediately dismissed as fake. A s...
Tag: model (page 2 of 7)
Heather Callaghan, ContributorWaking TimesNanotechnology – that is, metal oxide particles* such as titanium dioxide – are increasingly used in the commercial food supply, consumer goods, body care and in water treatment.The gut microbiome is today’s most appealing topic of science because it was previously unacknowledged by the medical community just how important gut health is to the human brain, hormones, immunity, mental health and more. Maintaining a h [...]
NASA's Dawn spacecraft visited Vesta for a year before continuing on to Ceres (Image: NASA/JPL-Caltech) Excerpt from gizmag.comNASA has released a browser-based application that allows citizen scientists to explore the surface of the asteroid V...
 |
| A photograph of the Annama meteorite fireball over Russia's Kola Peninsula. |
Excerpt from space.com
A crackling fireball that exploded over Russia last year appears to share an orbit with a huge asteroid discovered in October 2014, a new study reports.
The Kola fireball was spotted on April 19, 2014, as it lit up the night sky above the Kola Peninsula near the Finnish-Russian border. Its orbit is "disturbingly similar" to the asteroid 2014 UR116, slated to pass by the moon in 2017, the study authors said.
Camera observations by the Finnish Fireball Network, which monitors the sky for meteors and fireballs, and video from eyewitnesses helped scientists recreate the meteoroid's trajectory and hunt down meteorite fragments on the ground.
Josep Maria Trigo-Rodríguez, a researcher at the Institute of Space Sciences in Barcelona, Spain, led the international team of scientists who analyzed the meteorite's orbit. They calculated the fireball's size and path through Earth's atmosphere by examining its flight and the meteorite's final impact site. A computer model based on these figures was used to estimate the space rock's orbital path.
The 1,100-pound (500 kilogram) meteorite is an ordinary H5 chondrite, a type of stony meteorite responsible for 31 percent of Earth's impacts. The fragments are called the "Annama meteorite" because the meteorite fell near the Annama River in Russia.
The precise detective works suggests the fireball escaped from the innermost region of the asteroid belt, the study researchers reported. The rock has an elliptical orbit that is typical of the Apollo family of near-Earth orbiting asteroids, and it likely came from the same broad source region as the Lost City, Peekskill and Buzzard Coulee meteorites, the researchers said.
The researchers compared the Annama meteorite's orbit with known near-Earth asteroids (there are more than 1,500). Of 12 potential matches, by far the closest match was with the asteroid 2014 UR116, they said.
The findings were published April 7 in the journal Monthly Notices of the Royal Astronomical Society.
The new report does not suggest that asteroid 2014 UR116 flung the Annama meteorite directly at Earth. However, the two bodies could be related. Scientists think that streams of asteroid fragments — such as the remnants of interstellar collisions — can sail on nearly identical orbits. Tidal forces may stretch out these rocky debris patches over time. Asteroids may also fragment from the stress of passing near the planets, the researchers noted.
"The tidal effect on an asteroid, which rapidly rotates under the gravitational field of a planet, can fragment these objects or release large rocks from its surface, which could then become dangerous projectiles at a local scale, such as the one that fell in Chelyabinsk, Russia," Trigo-Rodríguez said in a statement.
Asteroid 2014 UR116, discovered by Russian scientists on Oct. 27, 2014, measures 1,312 feet (400 meters) across, but does not pose an impact danger to Earth, according to NASA.
An avowed paganist in a time of religious strife, Hypatia was also one of the first women to study math, astronomy and philosophy On the streets of Alexandria, Egypt, a mob led by Peter the Lector brutally murdered Hypatia, one of the last great thinkers of ancient Alexandria. (Mary Evans Picture Library / Alamy) By Sarah Zielinskismithsonian.com One day on the streets of Alexandria, Egypt, in the year 415 or 416, a mob of Christian zealots led by Peter the Lector accosted a wom [...]
Excerpt from techtimes.com Spacecraft are all shiny and new when they leave Earth but being up in space can do a number on them, resulting into bits and pieces of junk flying around. The European Space Agency's Clean Space initiative is looking to l...
 |
| March 9 Rosetta was 45 miles from Comet 67P/C-G when it photographed the comet’s head ringed with a halo of gas and dust. These jets extend from active areas of the comet’s surface and will become much more prominent over the next few months as the comet approaches the sun. |
Excerpt from dailytimesgazette.com
Astronomers have been on a mission to tail a slow moving comet in the outer space. Their mission started early last 2014, and they are getting better observations than they thought they would.
The comet, Comet 67P, would take 12.4 hours to complete one rotation in the circular path it’s moving in. Controllers of Rosetta are noticing that the icy ball approximately a second every day before it completes a rotation. The flight director of Rosetta – Andrea Accomazzo, said that, “The gas jets coming out of the comet, are acting like thrusters and are slowing down the comet.”
During the Royal Aeronautical Society in London earlier this week, the European Space Agency officially revealed some juicy details on how their team learned to maneuver Rosetta to fly precisely around the massive astral body. Comet 67P is said to weigh 10-billion tons with 4-km size in width.
The controllers and navigators use the landmark-method on the comet to understand its rotation. The team is moving around the outer space relying only on the information provided by the model. Both the model and information guides them in accurately projecting the trajectory of the satellite in the best position.
As they were trying out the model, the ESA team noticed that the landmarks were not following the usual track at the expected time.
During September 2014, the team were determined and very convinced that comet’s rotation period lengthen by 33 milliseconds per day. At present, the comet is approaching the Sun. As it does, it releases great volumes of gas and dust as a result of the so-called Spin-Down effect; further lengthening the rotation period to a second per day.
Accomazzo clarified that Comet 67P is not going to slow down in a slow motion. But its current speed allows them achieve the great magnitude of accuracy in navigating the spacecraft around the comet.
Rosetta made significant observations of the comet last December and January as it moves like an orbit within 30 km distance from the comet. However, this movement is no longer going to happen because Rosetta has retreated from the comet as the gas and dust are being released.
But it does them well as Accomazzo said that, “The aerodynamic effects are now more and more important. The jets are getting stronger and stronger… To give you an idea, these gases come out of the comet for a few kilometers and are moving at 800 meters per second. We definitely have to take this into account. We are a big spacecraft with 64 square meter s of solar panels. We’re like a big sail.”
The trackers were confused during the recent weeks because they have mistaken the dust particles for stars. It was due to the fact that the dusts in the atmosphere were moving around the comet.
Now, Rosetta is using its propulsion system to move in a hyperbolic orbital rotation around Comet 67P. It approaches the comet no closer than 60 to 70 km. With the slowdown of the comet, the ESA team is planning to fly closer.
They were estimating a flight as close as 20 km to get a better look at the surface of the comet and find their lost landing probe, Philae. They lost contact with the robotic probe since November 12 due to lost battery power only days after it successfully landed on the comet.
The slowdown gives them an opportunity to search for Philae. As it moves closer to the Sun, lighting conditions are definitely better than their previous runs. The controllers are now calling onto Philae using radio shout outs.
Philae is solar powered so the team hopes that enough solar energy falls on the panels awaking the probe. But one problem still persist, “The problem is that even if Philae hears Rosetta, it has to have enough charge to turn on its radio transmitter.”
The flight director is quite doubtful if Philae will be awakening. Andrea suggested, “I put it at 50-50, but I will be the happiest person in the world if it happens,”
Their mission achieved great progress and observation of a comet. The team is wishing for better things as the 67P slow down leaving them with more advantage
Excerpt from mashable.com Thanks to a rare, severe geomagnetic storm, the Northern Lights may be visible on Tuesday night in areas far to the south of its typical home in the Arctic. The northern tier of the U.S., from Washington State to Michiga...
Excerpt from smithsonianmag.com
In the hunt for alien life, our first glimpse of extraterrestrials may be in the rainbow of colors seen coming from the surface of an exoplanet.
That's the deceptively simple idea behind a study led by Siddharth Hegde at the Max Planck Institute for Astronomy in Germany. Seen from light-years away, plants on Earth give our planet a distinctive hue in the near-infrared, a phenomenon called red edge. That's because the chlorophyll in plants absorbs most visible light waves but starts to become transparent to wavelengths on the redder end of the spectrum. An extraterrestrial looking at Earth through a telescope could match this reflected color with the presence of oxygen in our atmosphere and conclude there is life here.
 |
| Eight of the 137 microorganism samples used to measure biosignatures for the catalog of reflection signatures of Earth life forms. In each panel, the top is a regular photograph of the sample and the bottom is a micrograph, a version of the top image zoomed-in 400 times. |
Plants, though, have only been around for 500 million years—a relative blip in our planet's 4.6-billion-year history. Microbes dominated the scene for some 2.5 billion years in the past, and some studies suggest they will rule the Earth again for much of its future. So Hegde and his team gathered 137 species of microorganisms that all have different pigments and that reflect light in specific ways. By building up a library of the microbes' reflectance spectra—the types of colors those microscopic critters reflect from a distance—scientists examining the light from habitable exoplanets can have a plethora of possible signals to search for, the team argues this week in the Proceedings of the National Academy of Sciences.
"No one had looked at the wide range of diverse life on Earth and asked how we could potentially spot such life on other planets, and include life from extreme environments on Earth that could be the 'norm' on other planets," Lisa Kaltenegger, a co-author on the study, says via email. "You can use it to model an Earth that is different and has different widespread biota and look how it would appear to our telescopes."
To make sure they got enough diversity, the researchers looked at temperate-dwelling microbes as well as creatures that live in extreme environments like deserts, mineral springs, hydrothermal vents or volcanically active areas.
While it might seem that alien life could take a huge variety of forms—for instance, something like the silicon-based Horta from Star Trek—it's possible to narrow things down if we restrict the search to life as we know it. First, any life-form that is carbon-based and uses water as a solvent isn't going to like the short wavelengths of light far in the ultraviolet, because this high-energy UV can damage organic molecules. At the other end of the spectrum, any molecule that alien plants (or their analogues) use to photosynthesize won't be picking up light that's too far into the infrared, because there's not enough energy at those longer wavelengths.
In addition, far-infrared light is hard to see through an Earth-like atmosphere because the gases block a lot of these waves, and whatever heat the planet emits will drown out any signal from surface life. That means the researchers restricted their library to the reflected colors we can see when looking at wavelengths in the visible part of the spectrum, the longest wavelength UV and short-wave infrared.
The library won't be much use if we can't see the planets' surfaces in the first place, and that's where the next generation of telescopes comes in, Kaltenegger says. The James Webb Space Telescope, scheduled for launch in 2018, should be able to see the spectra of relatively small exoplanet atmospheres and help scientists work out their chemical compositions, but it won't be able to see any reflected spectra from material at the surface. Luckily, there are other planned telescopes that should be able to do the job. The European Extremely Large Telescope, a 40-meter instrument in Chile, will be complete by 2022. And NASA's Wide Field Infrared Survey Telescope, which is funded and in its design stages, should be up and running by the mid-2020s.
Another issue is whether natural geologic or chemical processes could look like life and create a false signal. So far the pigments from life-forms look a lot different from those reflected by minerals, but the team hasn't examined all the possibilities either, says Kaltenegger. They hope to do more testing in the future as they build up the digital library, which is now online and free for anyone to explore at biosignatures.astro.cornell.edu.
Excerpt from autotrader.com By Josh Sadlier Seems like the only thing automakers want to talk about these days is how their cars suddenly get great fuel economy. Given this relentless chatter, it's tempting to conclude that mos...
 |
| Astronomers in Brazil have discovered a cluster of stars forming at the edge of the Milky Way, according to a press release from the Royal Astronomical Society. |
Excerpt from news.discovery.com
This is unusual because it was believed that stars generally take form closer to the center of our spiral-shaped galaxy, rather than from its swirling, spiral arms, which are thousands of light-years away. These two clusters of stars — named Camargo 438 and 439 — were seen in a cloud at the galaxy’s outskirts.
Denilso Camargo, an astronomer at the Federal University of Rio Grande do Sul in Porto Alegre, Brazil, led a team that analyzed data from NASA’s orbiting Wide-Field Infrared Survey Explorer (WISE) observatory. They zeroed in on dense clumps of gas in so-called giant molecular clouds(GMCs) that are known to generate stars. GMCs are mainly located in the inner part of the galactic disc.
The new star clusters lie about 16,000 light-years away from the main disk of the Milky Way galaxy. How did they form there? The scientists aren’t yet sure but Camargo theorizes that one of two scenarios could have led to the stars’ formation.
In the first scenario, called the “chimney model,” supernovas could have flung the gas and dust that formed the cloud out of the Milky Way. Another explanation is the material could have drifted in from outside the galaxy.
“Our work shows that the space around the Galaxy is a lot less empty that we thought,” said Camargo. “The new clusters of stars are truly exotic.”
Camargo’s team published their results in the journal Monthly
Excerpt from csmonitor.com
Thanks to a phenomenon known as gravitational lensing, the Hubble Space Telescope has captured four images of the same supernova explosion.
For the first time, a cosmic magnifying glass has allowed scientists to see the same star explosion four times, possibly offering a revealing glimpse into these explosive stellar deaths and the nature of the accelerating universe.
Astronomers using the Hubble Space Telescope have captured four images of a supernova explosion in deep space thanks to a galaxy located between Earth and the massive star explosion. You can see how Hubble saw the supernova in this NASA video. The galaxy cluster warped the fabric of space and time around it — like a bowling ball placed on a bed sheet — allowing scientists to see the supernova in four images.
"It was predicted 50 years ago that a supernova could be gravitationally lensed like this, but it's taken a long time for someone to find an example," lead study author Patrick Kelly, an astronomer at the University of California, Berkeley told Space.com. "It's fun to have been able to find the first one."
The supernova, which was discovered on Nov. 11, 2014, is located about 9.3 billion light-years away from Earth, near the edge of the observable universe. The researchers have named the distant supernova SN Refsdal in honor of the late Norwegian astrophysicist Sjur Refsdal, a pioneer of gravitational lensing studies. Due to gravitational lensing, "the supernova appears 20 times brighter than its normal brightness," study co-author Jens Hjorth, head of the Dark Cosmology Centre at the Niels Bohr Institute at the University of Copenhagen, said in a statement.
The lensing galaxy, which is about 5 billion light-years from Earth, is part of a large cluster of galaxies known MACS J1149.6+2223. In 2009, astronomers discovered that this cluster was the source of the largest known image of a spiral galaxy ever seen through a gravitational lens.
The four images of the supernova each appeared separately over the course of a few weeks. This is because light can take various paths around and through a gravitational lens, arriving at Earth at different times.
Using gravity as a lens
Gravity is created when matter warps the fabric of reality. The greater the mass of an object, the more space-time curves around that object and the stronger its gravitational pull, the discovery enshrined in Einstein's theory of general relativity, which celebrates its centennial this year.
As a result, gravity can also bend light like a lens, meaning objects see n behind powerful gravitational fields, such as those of massive galaxies, are magnified. Gravitational lensing was first discovered in 1979, and today gravitational lenses can help astronomers see features otherwise too distant and faint to detect with even the largest telescopes.
"These gravitational lenses are like a natural magnifying glass. It's like having a much bigger telescope," Kelly said in a statement. "We can get magnifications of up to 100 times by looking through these galaxy clusters."
When light is far from a gravitationally lensing mass, or if the gravitationally lensing mass is not especially large, only "weak lensing" occurs, barely distorting the light. However, when the light comes from almost exactly behind the gravitationally lensing mass, "strong lensing" can happen.
When a strongly lensed object occupies a large patch of space — for instance, if it's a galaxy — it can get smeared into an "Einstein ring" surrounding a gravitationally lensing mass. However, strong lensing of small, pointlike items — for instance, super-bright objects known as quasars — often produces multiple images surrounding the gravitationally lensing mass, resulting in a so-called "Einstein cross."
The observations of SN Refsdal mark the first time astronomers on Earth have witnessed strong lensing of a supernova, with four images of an exploding star arrayed as an Einstein cross.
An expanding universe
These new findings could help scientists measure the accelerating rate at which the universe is expanding, researchers say.
A computer model of the lensing cluster suggests the scientists missed chances to see the lensed supernova 50 and 10 years ago. However, the model also suggests more images of the explosion will repeat again within the next 10 years.
The timing of when all these images of the supernova arrive depends on the gravitational pull of the matter generating the gravitational lens. So, by measuring those times, the researchers hope to map how visible normal matter and invisible dark matter is distributed in the lensing galaxy.
Dark matter is currently one of the greatest mysteries in science, a poorly understood substance thought to make up five-sixths of all matter in the universe. A better understanding of how dark matter is behaving in this gravitationally lensing cluster might help shed light on the material's nature, Kelly said.
Analyzing when the images arrive could also help scientists pinpoint the rate at which the universe is expanding. Although there are already several ways to measure the cosmic expansion rate, "there has been a lot of heated debate between different methods, so it'd be interesting to see how this new technique might affect the area," Kelly said. "It's always nice to have completely independent measurements of the same quantity."
The scientists detailed their findings in the March 6 issue of the journal Science.
This work is licensed under a Creative Commons Attribution 4.0
International License.
unless otherwise marked.
Terms of Use | Privacy Policy
— Up ↑ —
Comments