Tag: investigator (page 1 of 2)

High-Energy Cosmic Neutrinos Observed At The Geographic South Pole

An team of international experts has announced a new observation of high-energy neutrino particles using an instrument funded by the National Science Foundation (NSF). The particles from beyond our galaxy have been detected at the geographic South Pole, using a massive instrument buried deep in ice.The scientists from the IceCube Collaboration, a research team with headquarters at the Wisconsin IceCube Particle Astrophysics Center at the University of Wisconsin-Madison, pub [...]

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NASA Releases New Pictures of Ceres

Bright spots on Ceres continue to puzzle astronomersExcerpt from sciencetimes.com NASA has released the most brilliant images of Ceres to date, truly showcasing the surface of the dwarf planet located in the asteroid belt.  The new images could...

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Hubble Finds Giant Halo Around the Andromeda Galaxy





 Excerpt from hubblesite.org

Scientists using NASA's Hubble Space Telescope have discovered that the immense halo of gas enveloping the Andromeda galaxy, our nearest massive galactic neighbor, is about six times larger and 1,000 times more massive than previously measured. The dark, nearly invisible halo stretches about a million light-years from its host galaxy, halfway to our own Milky Way galaxy. This finding promises to tell astronomers more about the evolution and structure of majestic giant spirals, one of the most common types of galaxies in the universe.

"Halos are the gaseous atmospheres of galaxies. The properties of these gaseous halos control the rate at which stars form in galaxies according to models of galaxy formation," explained the lead investigator, Nicolas Lehner of the University of Notre Dame, Indiana. The gargantuan halo is estimated to contain half the mass of the stars in the Andromeda galaxy itself, in the form of a hot, diffuse gas. If it could be viewed with the naked eye, the halo would be 100 times the diameter of the full Moon in the sky. This is equivalent to the patch of sky covered by two basketballs held at arm's length.

The Andromeda galaxy, also known as M31, lies 2.5 million light-years away and looks like a faint spindle, about 6 times the diameter of the full Moon. It is considered a near-twin to the Milky Way galaxy.

Because the gas in Andromeda's halo is dark, the team looked at bright background objects through the gas and observed how the light changed. This is a bit like looking at a glowing light at the bottom of a pool at night. The ideal background "lights" for such a study are quasars, which are very distant bright cores of active galaxies powered by black holes. The team used 18 quasars residing far behind Andromeda to probe how material is distributed well beyond the visible disk of the galaxy. Their findings were published in the May 10, 2015, edition of The Astrophysical Journal.

Earlier research from Hubble's Cosmic Origins Spectrograph (COS)-Halos program studied 44 distant galaxies and found halos like Andromeda's, but never before has such a massive halo been seen in a neighboring galaxy. Because the previously studied galaxies were much farther away, they appeared much smaller on the sky. Only one quasar could be detected behind each faraway galaxy, providing only one light anchor point to map their halo size and structure. With its close proximity to Earth and its correspondingly large footprint on the sky, Andromeda provides a far more extensive sampling of a lot of background quasars.
"As the light from the quasars travels toward Hubble, the halo's gas will absorb some of that light and make the quasar appear a little darker in just a very small wavelength range," explains co-investigator J. Christopher Howk, also of Notre Dame. "By measuring the dip in brightness in that range, we can tell how much halo gas from M31 there is between us and that quasar."

The scientists used Hubble's unique capability to study the ultraviolet light from the quasars. Ultraviolet light is absorbed by Earth's atmosphere, which makes it difficult to observe with a ground-based telescope. The team drew from about 5 years' worth of observations stored in the Hubble data archive to conduct this research. Many previous Hubble campaigns have used quasars to study gas much farther away than — but in the general direction of — Andromeda, so a treasure trove of data already existed.

But where did the giant halo come from? Large-scale simulations of galaxies suggest that the halo formed at the same time as the rest of Andromeda. The team also determined that it is enriched in elements much heavier than hydrogen and helium, and the only way to get these heavy elements is from exploding stars called supernovae. The supernovae erupt in Andromeda's star-filled disk and violently blow these heavier elements far out into space. Over Andromeda's lifetime, nearly half of all the heavy elements made by its stars have been expelled far beyond the galaxy's 200,000-light-year-diameter stellar disk.

What does this mean for our own galaxy? Because we live inside the Milky Way, scientists cannot determine whether or not such an equally massive and extended halo exists around our galaxy. It's a case of not being able to see the forest for the trees. If the Milky Way does possess a similarly huge halo, the two galaxies' halos may be nearly touching already and quiescently merging long before the two massive galaxies collide. Hubble observations indicate that the Andromeda and Milky Way galaxies will merge to form a giant elliptical galaxy beginning about 4 billion years from now.

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What astronomers learned when Messenger space probe crashed into Mercury



Excerpt from statecolumn.com


On April 30, NASA concluded an historic voyage known as the Mercury Surface, Space Environment, Geochemistry and Ranging mission. The mission came to an end when the spacecraft carrying analytical instruments, Messenger, crashed into the planet’s surface after consuming all of its fuel.
The mission was far from a waste, however, as NASA rarely expects to see the majority of the spacecraft they launch ever again. According to Discovery, The probe sent back a spectacular photo of the surface of Mercury, using the craft’s Narrow Angle Camera in tandem with the Mercury Dual Imaging System. The photo shows a mile-wide view of the nearby planet’s surface in 2.1 meters per pixel resolution.
Right after the probe delivered the photo to NASA’s Deep Space Network, which is a collection of global radio antennae that tracks data on the agency’s robotic missions around the solar system, the signal was lost in what scientists assume was the craft’s final contact with the closest planet to the sun.
The four-year mission came to an end when the craft could no longer maintain its orbit around the solar system’s innermost planet due to lack of fuel. Mercury is just 36 miles from the sun, compared to Earth, which is 93 million miles away from the center of the solar system. Mercury is a peculiar world, with both frigid and extremely hot temperatures. Messenger also revealed that Mercury has a magnetic field similar to that of Earth’s, created by the motion of metallic fluids within the planet’s core.
The main challenge the Messenger mission faced was getting the space probe into orbit around Mercury. Due to the planet’s proximity to the sun, it was extremely difficult for flight engineers to avoid its gravitational pull. In addition to the challenge of catching Mercury’s comparatively weak gravitational force, high temperatures also made things tricky. Messenger was equipped with a sunshield designed to protect the spaceship cool on the side that faced the sun. NASA engineers also attempted to chart a long, elliptical orbit around Mercury, giving Messenger time to cool off as it rounded the backside of the planet.
Messenger made over 4,000 orbits around Mercury between 2011 and 2015, many more than the originally planned one-year mission would allow.
With the close-up shots of Mercury’s surface provided by Messenger, NASA scientists were able to detect trace signals of magnetic activity in Mercury’s crust. Using clues from the number of impact craters on the surface, scientists figured that Mercury’s magnetized regions could be as old as 3.7 billion years. Astronomers count the craters on a planet in order to estimate its age – the logic being that younger surfaces should have fewer impact sites than older surfaces.
The data sent back by Messenger has caused astronomers to reconsider their understanding of Mercury’s magnetic history. They now date the beginning of magnetism on Mercury to about 700 million years after the planet was formed. They cannot say for sure, however, if the magnetic field has been consistently active over this timeframe.
According to Messenger guest investigator Catherine Johnson, geophysicist at the University of British Columbia in Vancouver, that it was possible the magnetic field has been active under constant conditions, though she suspects it might also oscillate over time, like Earth’s. Information for the time period between 4 billion years ago and present day is sparse, though Johnson added that additional research is in the pipeline.
Johnson was pleased, however, with the insight offered into Mercury’s formation provided by these new magnetic clues. Magnetism on a planetary scale typically indicates a liquid metal interior. Since Mercury is so tiny, scientists originally believed that its center would be solid, due to the rate of cooling. The presence of liquid in the planet’s center suggests other materials’ presence, which would lower the freezing point. This suggests that a totally solid core would be unlikely.
Mercury’s magnetic field offers valuable insight into the formation of the planet, the solar system, and even the universe. Magnetism on Mercury indicates that it has a liquid iron core, according to Messenger lead scientist Sean Solomon of Columbia University.

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Pluto images reveal intriguing bright spot near pole

Excerpt from  latimes.comCheck out the best images yet of the dwarf planet Pluto.The moving images of Pluto and its Texas-sized moon Charon you see below were taken by NASA's New Horizons spacecraft, which has spent nine years on a high-speed j...

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The Messenger of fate: NASA spacecraft smashes into planet Mercury

Excerpt from usatoday.comIts fuel tanks empty and its options gone, NASA's Messenger spacecraft smashed into planet Mercury on Thursday afternoon after valiantly fighting off the inevitable.Engineers calculated that the spacecraft, traveling a scorc...

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Guiding Our Search for Life on Other Earths


The James Webb Telescope


Excerpt from space.com

A telescope will soon allow astronomers to probe the atmosphere of Earthlike exoplanets for signs of life. To prepare, astronomer Lisa Kaltenegger and her team are modeling the atmospheric fingerprints for hundreds of potential alien worlds. Here's how:
The James Webb Space Telescope, set to launch in 2018, will usher a new era in our search for life beyond Earth. With its 6.5-meter mirror, the long-awaited successor to Hubble will be large enough to detect potential biosignatures in the atmosphere of Earthlike planets orbiting nearby stars.
And we may soon find a treasure-trove of such worlds. The forthcoming exoplanet hunter TESS (Transiting Exoplanet Survey Satellite), set to launch in 2017, will scout the entire sky for planetary systems close to ours. (The current Kepler mission focuses on more distant stars, between 600 and 3,000 light-years from Earth.) 

Astronomer Lisa Kaltenegger




While TESS will allow for the brief detection of new planets, the larger James Webb will follow up on select candidates and provide clues about their atmospheric composition. But the work will be difficult and require a lot of telescope time.
"We're expecting to find thousands of new planets with TESS, so we'll need to select our best targets for follow-up study with the Webb telescope," says Lisa Kaltenegger, an astronomer at Cornell University and co-investigator on the TESS team.
To prepare, Kaltenegger and her team at Cornell's Institute for Pale Blue Dots are building a database of atmospheric fingerprints for hundreds of potential alien worlds. The models will then be used as "ID cards" to guide the study of exoplanet atmospheres with the Webb and other future large telescopes.
Kaltenegger described her approach in a talk for the NASA Astrobiology Institute's Director Seminar Series last December.
"For the first time in human history, we have the technology to find and characterize other worlds," she says. "And there's a lot to learn."

Detecting life from space  

In its 1990 flyby of Earth, the Galileo spacecraft took a spectrum of sunlight filtered through our planet's atmosphere. In a 1993 paper in the journal Nature, astronomer Carl Sagan analyzed that data and found a large amount of oxygen together with methane — a telltale sign of life on Earth. These observations established a control experiment for the search of extraterrestrial life by modern spacecraft.
"The spectrum of a planet is like a chemical fingerprint," Kaltenegger says. "This gives us the key to explore alien worlds light years away."
Current telescopes have picked up the spectra of giant, Jupiter-like exoplanets. But the telescopes are not large enough to do so for smaller, Earth-like worlds. The James Webb telescope will be our first shot at studying the atmospheres of these potentially habitable worlds.
Some forthcoming ground-based telescopes — including the Giant Magellan Telescope (GMT), planned for completion in 2020, and the European Extremely Large Telescope (E-ELT), scheduled for first light in 2024 — may also be able to contribute to that task. [The Largest Telescopes on Earth: How They Compare]
And with the expected discovery by TESS of thousands of nearby exoplanets, the James Webb and other large telescopes will have plenty of potential targets to study. Another forthcoming planet hunter, the Planetary Transits and Oscillations of stars (PLATO), a planned European Space Agency mission scheduled for launch around 2022-2024, will contribute even more candidates.
However, observation time for follow-up studies will be costly and limited.
"It will take hundreds of hours of observation to see atmospheric signatures with the Webb telescope," Kaltenegger says. "So we'll have to pick our targets carefully."

Giant Magellan Telescope
Set to see its first light in 2021, The Giant Magellan Telescope will be the world’s largest telescope.

Getting a head start

To guide that process, Kaltenegger and her team are putting together a database of atmospheric fingerprints of potential alien worlds. "The models are tools that can teach us how to observe and help us prioritize targets," she says.
To start, they have modeled the chemical fingerprint of Earth over geological time. Our planet's atmosphere has evolved over time, with different life forms producing and consuming various gases. These models may give astronomers some insight into a planet's evolutionary stage.
Other models take into consideration the effects of a host of factors on the chemical signatures — including water, clouds, atmospheric thickness, geological cycles, brightness of the parent star, and even the presence of different extremophiles.
"It's important to do this wide range of modeling right now," Kaltenegger said, "so we're not too startled if we detect something unexpected. A wide parameter space can allow us to figure out if we might have a combination of these environments."
She added: "It can also help us refine our modeling as fast as possible, and decide if more measurements are needed while the telescope is still in space. It's basically a stepping-stone, so we don't have to wait until we get our first measurements to understand what we are seeing. Still, we'll likely find things we never thought about in the first place."
 

A new research center

The spectral database is one of the main projects undertaken at the Institute for Pale Blue Dots, a new interdisciplinary research center founded in 2014 by Kaltenegger. The official inauguration will be held on May 9, 2015.
"The crux of the institute is the characterization of rocky, Earth-like planets in the habitable zone of nearby stars," Kaltenergger said. "It's a very interdisciplinary effort with people from astronomy, geology, atmospheric modeling, and hopefully biology."
She added: "One of the goal is to better understand what makes a planet a life-friendly habitat, and how we can detect that from light years away. We're on the verge of discovering other pale blue dots. And with Sagan's legacy, Cornell University is a really great home for an institute like that."

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New Light on Our Accelerating Universe –"Not as Fast as We Thought"

 A Type Ia supernova, SN1994D, is shown exploding in lower left corner of the image at the top of the page of the galaxy NGC 4526 taken by the Hubble Space Telescope. (High-Z Supernova Search Team, HST, NASA)Excerpt from dailygalaxy.com Cer...

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Circular thinking: Stonehenge’s origin is subject of new theory




Excerpt from theguardian.com

Whether it was a Druid temple, an astronomical calendar or a centre for healing, the mystery of Stonehenge has long been a source of speculation and debate. Now a dramatic new theory suggests that the prehistoric monument was in fact “an ancient Mecca on stilts”.

The megaliths would not have been used for ceremonies at ground level, but would instead have supported a circular wooden platform on which ceremonies were performed to the rotating heavens, the theory suggests.

Julian Spalding, an art critic and former director of some of the UK’s leading museums, argues that the stones were foundations for a vast platform, long since lost – “a great altar” raised up high towards the heavens and able to support the weight of hundreds of worshippers.

“It’s a totally different theory which has never been put forward before,” Spalding told the Guardian. “All the interpretations to date could be mistaken. We’ve been looking at Stonehenge the wrong way: from the earth, which is very much a 20th-century viewpoint. We haven’t been thinking about what they were thinking about.”

Since Geoffrey of Monmouth wrote in the 12th century that Merlin had flown the stones from Ireland, theories on Stonehenge, from plausible to absurd, have abounded. In the last decade alone, the monument has been interpreted as “the prehistoric Lourdes” where people brought the sick to be healed by the power of the magic bluestones from Wales and as a haunted place of the dead contrasting with seasonal feasts for the living at nearby Durrington Walls. 

The site pored over by archaeologists for centuries still produces surprises, including the outline of stones now missing, which appeared in the parched ground in last summer’s drought and showed that the monument was not left unfinished as some had believed, but was once a perfect circle.

Spalding, who is not an archaeologist, believes that other Stonehenge theorists have fallen into error by looking down instead of up. His evidence, he believes, lies in ancient civilisations worldwide. As far afield as China, Peru and Turkey, such sacred monuments were built high up, whether on manmade or natural sites, and in circular patterns possibly linked to celestial movements.

He said: “In early times, no spiritual ceremonies would have been performed on the ground. The Pharaoh of Egypt and the Emperor of China were always carried – as the Pope used to be. The feet of holy people were not allowed to touch the ground. We’ve been looking at Stonehenge from a modern, earth-bound perspective.”
“All the great raised altars of the past suggest that the people who built Stonehenge would never have performed celestial ceremonies on the lowly earth,” he went on. “That would have been unimaginably insulting to the immortal beings, for it would have brought them down from heaven to bite the dust and tread in the dung.”

Spalding’s theory has not met with universal approval. Prof Vincent Gaffney, principal investigator on the Stonehenge Hidden Landscapes Project at Bradford University, said he held “a fair degree of scepticism” and Sir Barry Cunliffe, a prehistorian and emeritus professor of European archaeology at Oxford University, said: “He could be right, but I know of no evidence to support it”.
The archaeologist Aubrey Burl, an authority on prehistoric stone circles, said: “There could be something in it. There is a possibility, of course. Anything new and worthwhile about Stonehenge is well worth looking into, but with care and consideration.”

On Monday Spalding publishes his theories in a new book, titled Realisation: From Seeing to Understanding – The Origins of Art. It explores our ancestors’ understanding of the world, offering new explanations of iconic works of art and monuments.

Stonehenge, built between 3000 and 2000BC, is England’s most famous prehistoric monument, a UNESCO World Heritage site on Salisbury Plain in Wiltshire that draws more than 1 million annual visitors. It began as a timber circle, later made permanent with massive blocks of stone, many somehow dragged from dolerite rock in the Welsh mountains. Spalding believes that ancient worshippers would have reached the giant altar by climbing curved wooden ramps or staircases.

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MAVEN mission finds early surprises in Martian atmosphere

Excerpt from chroniclebulletin.com University of Colorado-led Mars mission has observed two unexpected phenomena in the Martian atmosphere, unveiled Wednesday at the 46th Lunar and Planetary Science Conference in Texas.NASA describes the finds by MA...

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Incredible pictures show best views of Mercury’s scorched surface and ice-filled craters




A heat map of Mercury's surface
In this heat map red represents the areas of Mercury's surface where temperatures are up to 126C





Excerpt from express.co.uk


The detailed shots were taken by Nasa's Mercury Messenger spacecraft which is orbiting close to the planet and will crash into it once it runs out of fuel.

The spacecraft will hit into Mercury's surface on April 30 after almost four years exploring the planet closest to the Sun.

The images were revealed at the 46th Lunar and Planetary Science Conference (LPSC) in Texas.

Dr Nancy Chabot, the instrument scientist for Messenger's Mercury Dual Imaging System, said: "We're seeing into these craters that don't see the Sun, at higher resolution than was ever possible before."

One shot taken by Messenger shows deep craters on the face of Mercury.

The planet's lack of atmosphere means any space debris that hits the planet leaves large craters.

The Fuller crater on MercuryNASA
The 16mile-wide Fuller crater is among those seen in much more detail on Mercury

We're seeing into these craters that don't see the Sun, at higher resolution than was ever possible before
Dr Nancy Chabot
These are so deep that sunlight does not penetrate all the way down.

Researchers have suggested that would allow ice carried by asteroids to remain there without melting.

While another image taken from Mercury's north polar region shows a heat map of the surface where red represents temperatures up to 126C.

In the shot the vast majority of the planet's surface is red which shows its scorchingly hot surface temperatures.

Sean Solomon, a principal investigator for the mission, added: "We’re able to see at close range portions of the planet we haven’t seen in such detail before."

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We’re About To Learn A Lot More About Area 51

Excerpt from huffingtonpost.comWhen the National Atomic Testing Museum of Las Vegas opened its "Area 51: Myth or Reality" exhibit two years ago, it became an instant hit. It wasn't just the only place that had a comprehensive knowledge of Area 51 -...

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Dawn Enters Orbit Around Dwarf Planet Ceres ~ Video

Ceres Dawn




Dwarf Planet Ceres

Excerpt from spacenews.com

NASA’s Dawn spacecraft arrived in orbit around the dwarf planet Ceres March 6, completing a journey of nearly seven and a half years and five billion kilometers.  In a statement, NASA’s Jet Propulsion Laboratory said Dawn entered orbit about 61,000 kilometers above Ceres at 7:39 am EST March 6, sending a signal to Earth about an hour later confirming it was in orbit and in good health.  “We feel exhilarated,” Dawn principal investigator Chris Russell said in the statement. “We have much to do over the next year and a half, but we are now on station with ample reserves, and a robust plan to obtain our science objectives.”

Dawn will gradually spiral down to its initial science orbit, 13,500 kilometers above Ceres, by April. Later in its mission Dawn will move gradually closer to the surface, eventually moving into an orbit of 375 kilometers.  The Dawn spacecraft, built by Orbital ATK, launched on a United Launch Alliance Delta 2 rocket in September 2007. After making a gravity assist flyby of Mars in February 2009, it entered orbit around the large main-belt asteroid Vesta in July 2011. It remained there for more than a year, using its ion thrusters to leave orbit in September 2012 to head to Ceres. 

Ceres, the largest object in the main asteroid belt between the orbits of Mars and Jupiter, was the first asteroid discovered by astronomers, in 1801. The International Astronomical Union designated Ceres a “dwarf planet” in 2006, a new category of objects that also includes the former planet Pluto.


Click to zoom
Dawn will gradually spiral down to its initial science orbit, 13,500 kilometers above Ceres, by April. Later in its mission Dawn will move gradually closer to the surface, eventually moving into an orbit of 375 kilometers.
The Dawn spacecraft, built by Orbital ATK, launched on a United Launch Alliance Delta 2 rocket in September 2007. After making a gravity assist flyby of Mars in February 2009, it entered orbit around the large main-belt asteroid Vesta in July 2011. It remained there for more than a year, using its ion thrusters to leave orbit in September 2012 to head to Ceres.
Ceres, the largest object in the main asteroid belt between the orbits of Mars and Jupiter, was the first asteroid discovered by astronomers, in 1801. The International Astronomical Union designated Ceres a “dwarf planet” in 2006, a new category of objects that also includes the former planet Pluto.
- See more at: http://spacenews.com/dawn-enters-orbit-around-ceres/#sthash.yoclEQI4.dpuf
WASINGTON — NASA’s Dawn spacecraft arrived in orbit around the dwarf planet Ceres March 6, completing a journey of nearly seven and a half years and five billion kilometers.
In a statement, NASA’s Jet Propulsion Laboratory said Dawn entered orbit about 61,000 kilometers above Ceres at 7:39 am EST March 6, sending a signal to Earth about an hour later confirming it was in orbit and in good health.
“We feel exhilarated,” Dawn principal investigator Chris Russell said in the statement. “We have much to do over the next year and a half, but we are now on station with ample reserves, and a robust plan to obtain our science objectives.”
- See more at: http://spacenews.com/dawn-enters-orbit-around-ceres/#sthash.yoclEQI4.dpuf

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