Tag: history (page 4 of 20)

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.

View Article Here Read More

Flawed Medical Research May Be Ruining Your Health & Your Life

Robert Oliva, Collective-EvolutionThere is a cancer eating at the core of medical research.You’ve most likely heard of medical reports touting the effectiveness of a diet plan, a new drug, a supplement, or medical procedure. You may have even decided on a course of action based on these findings, only to find out later that they have been refuted by new studies.Strikingly, the odds are that the studies that influenced your decision, and possibly the decision of your doctor, wer [...]

View Article Here Read More

Astronomers find baby blue galaxy close to dawn of time

NASA, ESA, P. OESCH AND I. MOMCHEVA (YALE UNIVERSITY), AND THE 3D-HST AND HUDF09/XDF TEAMS
Astronomers have discovered a baby blue galaxy that is the furthest away in distance and time - 13.1 billion years - that they’ve ever seen. Photo: Pascal Oesch and Ivelina Momcheva, NASA, European Space Agency via AP


Excerpt from smh.com.au

A team of astronomers peering deep into the heavens have discovered the earliest, most distant galaxy yet, just 670 million years after the Big Bang.

Astronomers have discovered a baby blue galaxy that is the furthest away in distance and time - 13.1 billion years - that they’ve ever seen.
Close-up of the blue galaxy

The findings, described in Astrophysical Journal Letters, reveal a surprisingly active, bright galaxy near the very dawn of the cosmos that could shed light on what the universe, now 13.8 billion years old, was really like in its young, formative years.

"We're actually looking back through 95 per cent of all time to see this galaxy," said study co-author Garth Illingworth, an astronomer at the University of California, Santa Cruz.

"It's really a galaxy in its infancy ... when the universe was in its infancy."

Capturing an image from a far-off light source is like looking back in time. When we look at the sun, we're seeing a snapshot of what it looked like eight minutes ago.

The same principle applies for the light coming from the galaxy known as EGS-zs8-1. We are seeing this distant galaxy as it existed roughly 13.1 billion years ago.

EGS-zs8-1 is so far away that the light coming from it is exceedingly faint. And yet, compared with other distant galaxies, it is surprisingly active and bright, forming stars at roughly 80 times the rate the Milky Way does today.

This precocious little galaxy has built up the mass equivalent to about 8 billion suns, more than 15 per cent of the mass of the Milky Way, even though it appears to have been in existence for a mere fraction of the Milky Way's more than 13 billion years.

"If it was a galaxy near the Milky Way [today], it would be this vivid blue colour, just because it's forming so many stars," Illingworth said.

One of the many challenges with looking for such faint galaxies is that it's hard to tell if they're bright and far, or dim and near. Astronomers can usually figure out which it is by measuring how much that distant starlight gets stretched, "redshifted", from higher-energy light such as ultraviolet down to optical and then infrared wavelengths. The universe is expanding faster and faster, so the further away a galaxy is, the faster it's going, and the more stretched, or "redder", those wavelengths of light will be.

The astronomers studied the faint light from this galaxy using NASA's Hubble and Spitzer space telescopes. But EGS-zs8-1 seemed to be too bright to be coming from the vast distances that the Hubble data suggested.

To narrow in, they used the MOSFIRE infrared spectrograph at the Keck I telescope in Hawaii to search for a particularly reliable fingerprint of hydrogen in the starlight known as the Lyman-alpha line. This fingerprint lies in the ultraviolet part of the light spectrum, but has been shifted to redder, longer wavelengths over the vast distance between the galaxy and Earth.

It's a dependable line on which to base redshift (and distance) estimates, Illingworth said - and with that settled, the team could put constraints on the star mass, star formation rate and formation epoch of this galaxy.

The telltale Lyman-alpha line also reveals the process through which the universe's haze of neutral hydrogen cleared up, a period called the epoch of reionisation. As stars formed and galaxies grew, their ultraviolet radiation eventually ionised the hydrogen and ended the "dark ages" of the cosmos.

Early galaxies-such as EGS-zs8-1 - are "probably the source of ultraviolet radiation that ionised the whole universe", Illingworth said.

Scientists have looked for the Lyman-alpha line in other distant galaxies and come up empty, which might mean that their light was still being blocked by a haze of neutral hydrogen that had not been ionised yet.

But it's hard to say with just isolated examples, Illingworth pointed out. If scientists can survey many galaxies from different points in the universe's very early history, they can have a better sense of how reionisation may have progressed.

"We're trying to understand how many galaxies do have this line - and that gives us some measure of when the universe itself was reionised," Illingworth said.

"One [galaxy] is interesting, but it's when you have 50 that you can really say something about what galaxies were really like then."
As astronomers push the limits of current telescopes and await the completion of NASA's James Webb Space Telescope, set for launch in 2018, scientists may soon find more of these galaxies even closer to the birth of the universe than this new record breaker.

"You don't get to be record holder very long in this business," Illingworth said, "which is good because ultimately we are trying to learn about the universe. So more is better."

View Article Here Read More

Nuclear Experimentation Year 70 – Playing With Madness

Ethan Indigo Smith, ContributorThe recent “news” on the nuclear situation in Iran brings to light the madhouse of cards on which the postmodern world is built. Or rather, it would bring the madness to light if the major media outlets of the world were not bought up and sold out to the military industrial complex, and therefore completely misinformed on the actions and dangers of the nuclear experimentation industry.The story is not just about [...]

View Article Here Read More

Ancient Signs in the Sky: Did a Meteorite Change the Course of Christianity 2,000 Years Ago?


Detail, The Conversion of St. Paul. Paul and companions are knocked to the ground during the profound event.

Excerpt from ancient-origins.net

Did an ancient meteor have such a life-changing impact on witnesses of the day that it shaped a religion and altered the course of history? Astronomers theorize that the dramatic flash and boom that converted Paul the Apostle may have been an exploding meteor.

In the Christian Bible, it is written that a man named Saul experienced an event so extreme that it changed his views in an instant, and he became one of the most influential evangelists in early Christianity.

Saul was said to have been a vehement persecutor of the followers of Jesus and was traveling in search of disciples of Jesus for punishment. It is written in the fifth book of the New Testament, Acts of the Apostles, that Saul was on the road to Damascus, Syria, when a bright light appeared in the sky. So intense was the light that he was blinded for three days. What he heard was described as a great thunderous sound, or a divine voice. He and his companions are said to have been knocked to the ground by the force of the event. The experience was so profound that Saul changed his name to Paul, took up missionary journeys across the Mediterranean, and became instrumental in spreading Christianity.

The Conversion of Saint Paul – Paul and his companions are knocked to the ground by a resounding boom and brilliant light. Did a meteor cause this ancient event?
The Conversion of Saint Paul – Paul and his companions are knocked to the ground by a resounding boom and brilliant light. Did a meteor cause this ancient event? 


William Hartmann, co-founder of the Planetary Science Institute in the U.S. has connected Paul’s experience with similar accounts of exploding meteors, such as the well-recorded Chelyabinsk meteor which broke up over Russia in 2013, injuring over 1,500 people. The eyewitness descriptions and physical reactions to meteors or fireballs in the sky seem to parallel what is recorded about Paul.

Meteor trail over Chelyabinsk, Russia.
Meteor trail over Chelyabinsk, Russia. Wikimedia Commons


If true, then it’s possible that an act of nature may have been contributory in the spread and evolution of Christianity in its early days, and therefore shaped the course of history.

In a study published in the journal Meteoritics and Planetary Science, Hartmann cites major events like the meteors or asteroids over Chelyabinsk, Russia and Tunguska, Siberia as offering “opportunities to compare reactions of modern eyewitnesses to eyewitness accounts of possible ancient fireball events.” There are consistencies among the many accounts suggesting the biblical descriptions of Paul’s experience closely match known modern events, reports NewScientist.

In the biblical accounts, Paul was blinded for three days due to the intense light from the sky; it was “brighter than the sun, shining round me,” according to the text. This matches the Chelyabinsk meteor, as it was calculated to be shining around three times as bright as the sun. The blazing fireball made shadows move around the ground as it travelled.

Paul and his companions were said to have been knocked to the earth, and this also corresponds to the shockwave generated by the powerful Chelyabinsk meteor as it blasted out windows, knocked people off their feet, shook cars and buildings, and collapsed roofs.
The divine voice is said to have either boomed like thunder, or questioned Paul’s behavior (the exact sound is debated). Meteors create great, explosive booms and roars which can be scary or painful even for those who know what they’re experiencing.

To the ancients the incredible and unfamiliar natural celestial events were interpreted through cultural understandings of the day – which is to say, they were considered divine or damning.

The Chelyabinsk meteor gave off small amounts of radiation, enough to cause sunburn and temporary blindness in witnesses. Harmann suggests that Paul could have suffered photokeratitis, a temporary blindness from intense ultraviolet radiation, and this explains the return of his sight after healing.

Paul having his sight restored after being blinded by a celestial light that might have been a meteor.
Paul having his sight restored after being blinded by a celestial light that might have been a meteor. 


Hartmann told NewScientist, “Everything they are describing in those three accounts in the book of Acts are exactly the sequence you see with a fireball.”

IBTimes writes that the Acts of Apostles text describes three events of bright lights “from heaven” which took place around Damascus during the 30s B.C. If meteorites can be found in Syria, and accurately dated to the relevant timeframes, it might give support to the published theories.

Hartmann’s research aim is not to discredit Christianity, but to demonstrate how the interpretation of ancient events may have shaped how we exist today, spiritually and culturally.

This wouldn’t be the first meteorite in history to have potentially inspired worship or acted as an agent of change. In antiquity meteorites were seen as messages from the gods, or profound omens, and many cultures saw fallen meteorites as religious icons to be worshiped or as objects of protection. Jewelry and art has also been created from the space rocks.

Each year devout Muslims make the pilgrimage to Mecca in Saudi Arabia, circling the Kaaba, or black stone, and give a nod or a kiss to the meteorite that is said to rest inside the Grand Mosque. The worship of the Black Stone goes back to pre-Islamic shrines, when Semitic cultures used unusual stones to signify sites of reverence. According to Muslim belief, the stone originates from the time of Adam and the Islamic prophet Muhammad set the Black Stone in place after it fell from the skies.

A 1315 illustration inspired by the story of Muhammad and the Meccan clan elders lifting the Black Stone into place. Was the black stone a meteor from space?
A 1315 illustration inspired by the story of Muhammad and the Meccan clan elders lifting the Black Stone into place. Was the black stone a meteor from space?


In a more modern example, after the dramatic Chelyabinsk event over Russia in 2013, the ‘Church of the Meteorite’ was set up, and the followers hold rites on the shores of Lake Chebarkul where pieces of the space rock fell.

Some scientists regard the Conversion of Paul theory as speculation, but seem to welcome further evidence.
Bill Cooke, head of NASA's Meteoroid Environment Office told NewScientist, “It’s well recorded that extraterrestrial impacts have helped to shape the evolution of life on this planet. If it was a Chelyabinsk fireball that was responsible for Paul’s conversion, then obviously that had a great impact on the growth of Christianity.”

Indeed, “Some scholars call Paul the second founder of Christianity” says Justin Meggitt, religious historian at the University of Cambridge. Without the fireball, and without Paul’s conversion, perhaps Christianity would be different than it is today.
“Christianity probably would be very different without him,” Meggitt concludes.

Illumination from 1450 depicting Paul's conversion – the bright light and sound come from the sky. The event was said to change Paul, and may have changed history.
Illumination from 1450 depicting Paul's conversion – the bright light and sound come from the sky. The event was said to change Paul, and may have changed history. Public Domain
Featured Image: Detail, The Conversion of St. Paul. Paul and companions are knocked to the ground during the profound event.

View Article Here Read More

Lab for genetic modification of human embryos just $2,000 away – report


Reuters / Christian Charisius



Reuters

With the right expertise in molecular biology, one could start a basic laboratory to modify human embryos using a genome-editing computer technique all for a couple thousand dollars, according to a new report.

Genetic modification has received heightened scrutiny recently following last week’s announcement that Chinese researchers had, for the first time, successfully edited human embryos’ genomes. 
The team at Sun Yat-Sen University in Guangzhou, China, used CRISPR (clustered regularly interspaced palindromic repeats), a technique that relies on “cellular machinery” used by bacteria in defense against viruses. 

This machinery is copied and altered to create specific gene-editing complexes, which include the wonder enzyme Cas9. The enzyme works its way into the DNA and can be used to alter the molecule from the inside. The combination is attached to an RNA guide that takes the gene-editing complex to its target, telling Cas9 where to operate. 

Use of the CRISPR technique is not necessarily relegated to the likes of cash-flush university research operations, according to a report by Business Insider. 


Geneticist George Church, who runs a top CRISPR research program at the Harvard Medical School, said the technique could be employed with expert knowledge and about half of the money needed to pay for an average annual federal healthcare plan in 2014 -- not to mention access to human embryos. 

"You could conceivably set up a CRISPR lab for $2,000,” he said, according to Business Insider. 

Other top researchers have echoed this sentiment. 

"Any scientist with molecular biology skills and knowledge of how to work with [embryos] is going to be able to do this,” Jennifer Doudna, a biologist at the University of California, Berkeley, recently told MIT Tech Review, which reported that Doudna co-discovered how to edit genetic code using CRISPR in 2012. 

Last week, the Sun Yat-Sen University research team said it attempted to cure a gene defect that causes beta-thalassemia (a genetic blood disorder that could lead to severe anemia, poor growth, skeletal abnormalities and even death) by editing the germ line. For that purpose they used a gene-editing technique based on injecting non-viable embryos with a complex, which consists of a protective DNA element obtained from bacteria and a specific protein. 

"I suspect this week will go down as a pivotal moment in the history of medicine," wrote science journalist Carl Zimmer for National Geographic.


Response to the new research has been mixed. Some experts say the gene editing could help defeat genetic diseases even before birth. Others expressed concern. 

“At present, the potential safety and efficacy issues arising from the use of this technology must be thoroughly investigated and understood before any attempts at human engineering are sanctioned, if ever, for clinical testing,” a group of scientists, including some who had worked to develop CRISPR, warned in Science magazine. 

Meanwhile, the director of the US National Institutes for Health (NIH) said the agency would not fund such editing of human embryo genes. 

“Research using genomic editing technologies can and are being funded by NIH,” Francis Collins said Wednesday. “However, NIH will not fund any use of gene-editing technologies in human embryos. The concept of altering the human germline in embryos for clinical purposes ... has been viewed almost universally as a line that should not be crossed.”

Although the discovery of CRISPR sequences dates back to 1987 – when it was first used to cure bacteria of viruses – its successes in higher animals and humans were only achieved in 2012-13, when scientists achieved a revolution by combining the resulting treatment system with Cas9 for the first time. 


On April 17, the MIT’s Broad Institute announced that has been awarded the first-ever patent for working with the Crisp-Cas9 system. 

The institute’s director, Eric Lander, sees the combination as “an extraordinary, powerful tool. The ability to edit a genome makes it possible to discover the biological mechanisms underlying human biology.”

The system’s advantage over other methods is in that it can also target several genes at the same time, working its way through tens of thousands of so-called 'guide' RNA sequences that lead them to the weapon to its DNA targets. 

Meanwhile, last month in the UK, a healthy baby was born from an embryo screened for genetic diseases, using karyomapping, a breakthrough testing method that allows doctors to identify about 60 debilitating hereditary disorders.

View Article Here Read More

Hubble’s Other Telescope And The Day It Rocked Our World

The Hooker 100-inch reflecting telescope at the Mount Wilson Observatory, just outside Los Angeles. Edwin Hubble's chair, on an elevating platform, is visible at left. A view from this scope first told Hubble our galaxy isn't the only one.
The Hooker 100-inch reflecting telescope at the Mount Wilson Observatory, just outside Los Angeles. Edwin Hubble's chair, on an elevating platform, is visible at left. A view from this scope first told Hubble our galaxy isn't the only one.
Courtesy of The Observatories of the Carnegie Institution for Science Collection at the Huntington Library, San Marino, Calif.


Excerpt from hnpr.org

The Hubble Space Telescope this week celebrates 25 years in Earth's orbit. In that time the telescope has studied distant galaxies, star nurseries, planets in our solar system and planets orbiting other stars.

But, even with all that, you could argue that the astronomer for whom the telescope is named made even more important discoveries — with far less sophisticated equipment.

A young Edwin Hubble at Mount Wilson's 100-inch telescope circa 1922, ready to make history.i
A young Edwin Hubble at Mount Wilson's 100-inch telescope circa 1922, ready to make history.
Edwin Hubble Papers/Courtesy of Huntington Library, San Marino, Calif.


In the 1920s, Edwin Hubble was working with the 100-inch Hooker telescope on Mount Wilson, just outside Los Angeles. At the time, it was the largest telescope in the world.

On a chilly evening, I climb up to the dome of that telescope with operator Nik Arkimovich and ask him to show me where Hubble would sit when he was using the telescope. Arkimovich points to a platform near the top of the telescope frame.

"He's got an eyepiece with crosshairs on it," Arkimovich explains. The telescope has gears and motors that let it track a star as it moves across the sky. "He's got a paddle that allows him to make minor adjustments. And his job is to keep the star in the crosshairs for maybe eight hours."

"It's certainly much, much easier today," says John Mulchaey, acting director of the observatories at Carnegie Institution of Science. "Now we sit in control rooms. The telescopes operate brilliantly on their own, so we don't have to worry about tracking and things like this."

Today, astronomers use digital cameras to catch the light from stars and other celestial objects. In Hubble's day, Mulchaey says, they used glass plates.

"At the focus of the telescope you would put a glass plate that has an emulsion layer on it that is actually sensitive to light," he says. At the end of an observing run, the plates would be developed, much like the film in a camera.

The headquarters of the Carnegie observatories is at the foot of Mount Wilson, in the city of Pasadena. It's where Hubble worked during the day.

A century's worth of plates are stored here in the basement. Mulchaey opens a large steel door and ushers me into a room filled with dozens of file cabinets.

"Why don't we go take a look at Hubble's famous Andromeda plates," Mulchaey suggests.

The plates are famous for a reason: They completely changed our view of the universe. Mulchaey points to a plate mounted on a light stand.

"This is a rare treat for you," he says. "This plate doesn't see the light of day very often."


This glass side of a photographic plate shows where Hubble marked novas. The red VAR! in the upper right corner marks his discovery of the first Cepheid variable star — a star that told him the Andromeda galaxy isn't part of our Milky Way.i
This glass side of a photographic plate shows where Hubble marked novas. The red VAR! in the upper right corner marks his discovery of the first Cepheid variable star — a star that told him the Andromeda galaxy isn't part of our Milky Way.
Courtesy of the Carnegie Observatories 
To the untrained eye, there's nothing terribly remarkable about the plate. But Mulchaey says what it represents is the most important discovery in astronomy since Galileo.

The plate shows the spiral shape of the Andromeda galaxy. Hubble was looking for exploding stars called novas in Andromeda. Hubble marked these on the plate with the letter "N."

"The really interesting thing here," Mulchaey says, "is there's one with the N crossed out in red — and he's changed the N to VAR with an exclamation point."

Hubble had realized that what he was seeing wasn't a nova. VAR stands for a type of star known as a Cepheid variable. It's a kind of star that allows you to make an accurate determination of how far away something is. This Cepheid variable showed that the Andromeda galaxy isn't a part of our galaxy.

At the time, most people thought the Milky Way was it — the only galaxy in existence.

"And what this really shows is that the universe is much, much bigger than anybody realizes," Mulchaey says.
It was another blow to our human conceit that we are the center of the universe.

Hubble went on to use the Mount Wilson telescope to show the universe was expanding, a discovery so astonishing that Hubble had a hard time believing it himself.

If Hubble could make such important discoveries with century-old equipment, it makes you wonder what he might have turned up if he'd had a chance to use the space telescope that bears his name.

View Article Here Read More

NASA wants your vote on Ceres’ mysterious bright spots

NASA wants your vote on Ceres’ bright spots

The nature of the bright spots has yet to be elucidated.




Excerpt from thespacereporter.com

NASA’s Jet Propulsion Laboratory has set up a website at which members of the public can register their votes as to the identify of the strange and unexpected bright spots seen on Ceres by the Dawn probe. Although Dawn will study the spots in much greater detail in the near future, having just assumed its first scientific orbit, in the meantime the nature of spots in anyone’s guess. This author voted for “ice”.

It seems ice is the most popular possibility so far, with 33 percent of the vote. The next most popular choice is “other”, with 28 percent. “Volcano” and “geyser” both have 11 percent, “salt deposit” has nine percent, and “rock” has eight percent.

At about 590 miles in diameter, Ceres is the largest body in the asteroid belt between the orbits of Mars and Jupiter. Dawn had imaged Ceres’s surface throughout its approach. Dawn entered orbit of Ceres on March 6, the first spacecraft to orbit a dwarf planet. From 2011 to 2012, Dawn also orbited the asteroid Vesta, the second-most massive body in the asteroid belt. Having studied both Vesta and Ceres, Dawn is the first spacecraft in history to orbit two extraterrestrial objects. Dawn’s investigations of Vesta and Ceres will shed light on the early evolution of our solar system; both bodies represent incipient planets, gravitationally perturbed early in their formation.

“The approach imaging campaign has completed successfully by giving us a preliminary, tantalizing view of the world Dawn is about to start exploring in detail. It has allowed us to start asking some new and intriguing questions,” said Marc Rayman, Dawn’s mission director and chief engineer at the JPL, in a separate NASA statement.

View Article Here Read More

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."

View Article Here Read More

Study: 70% of People on Antidepressants Don’t Have Depression

Mike Barrett, Natural SocietyIf sales for antidepressants such as Zoloft, Lexapro, or Prozac tell us anything, it’s that depression is sweeping the nation. But a new study questions the validity of most of these sales. The study has found that the majority of individuals on antidepressants – a whopping 69% – do not even meet the criteria for clinical depression. These individuals are likely just experiencing normal sadness and hardships that most of u [...]

View Article Here Read More

NASA submarine to Study Planet Saturn Moon Titan’s Sea





dailysciencejournal.com 

An animated and dramatic 3D video released by NASA has revealed the international space agency plans of exploring the depths of largest sea on the Titan, Kraken Mare.

NASA is planning to launch a submarine in the Kraken Mare Sea with an aim of studying the depth.

Titan is one of the 62 moons of the planet Saturn. Titan has its own and interesting atmosphere compared to other 61. 



Click to zoom


A spacecraft named Cassini has been trying to study the Titan’s atmosphere since 2004. Most of the area of the moon Titan is covered by large bodies of methane and ethane in liquid form.

The submarine will definitely help more compared to Cassini spacecraft to measure and map the shorelines or sea.

While releasing the video the scientists from NASA has stated that the submarine will definitely help in exploring the history of the moon’s climatic conditions and could provide major breakthroughs among the discoveries made till date.

View Article Here Read More

Citizen Scientists Find Green Blobs in Hubble Galaxy Shots





Excerpt from wired.com

In 2007, A Dutch schoolteacher named Hanny var Arkel discovered a weird green glob of gas in space. Sifting through pictures of galaxies online, as part of the citizen science project Galaxy Zoo, she saw a cloud, seemingly glowing, sitting next to a galaxy. Intrigued, astronomers set out to find more of these objects, dubbed Hanny’s Voorwerp (“Hanny’s object” in Dutch). Now, again with the help of citizen scientists, they’ve found 19 more of them, using the Hubble space telescope to snap the eight haunting pictures in the gallery above.



Since var Arkel found the first of these objects, hundreds more volunteers have swarmed to help identify parts of the universe in the Galaxy Zoo gallery. To find this new set, a couple hundred volunteers went through nearly 16,000 pictures online (seven people went through all of them), clicking yes/no/maybe as to whether they saw a weird green blob. Astronomers followed up on the galaxies they identified using ground-based telescopes, and confirmed 19 new galaxies surrounded by green gas.



What causes these wispy tendrils of gas to glow? Lurking at the center of each of these galaxies is a supermassive black hole, millions to billions times as massive as the sun, with gravity so strong that even light can’t escape them. As nearby gas and dust swirls into the black hole, like water circling a drain, that material heats up, producing lots of radiation—including powerful ultraviolet. Beaming out from the galaxy, that ultraviolet radiation strikes nearby clouds of gas, left over from past collisions between galaxies. And it makes the clouds glow an eerie green. “A lot of these bizarre forms we’re seeing in the images arise because these galaxies either interacted with a companion or show evidence they merged with a smaller galaxy,” says William Keel, an astronomer at the University of Alabama, Tuscaloosa.



The eight in this gallery, captured with Hubble, are especially weird. That’s because the quasar, the black-hole engine that’s supposed to be churning out the ultraviolet radiation, is dim—too dim, in fact, to be illuminating the green gas. Apparently, the once-bright quasar has faded. But because that UV light takes hundreds of thousands of years to travel, it can continue to illuminate the gas long after its light source has died away.  


Hubble finds phantom objects close to dead quasars

That glowing gas can tell astronomers a lot about the quasar that brought it to light. “What I’m so excited about is the fact that we can use them to do archaeology,” says Gabriela Canalizo, an astronomer at the University of California, Riverside, who wasn’t part of the new research. Because the streaks of gas are so vast, stretching up to tens of thousands of light years, the way they glow reveals the history of the radiation coming from the quasar. As the quasar fades, so will the gas’s glow, with the regions of gas closer to the quasar dimming first. By analyzing how the glow dwindles with distance from the quasar, astronomers can determine how fast the quasar is fading. “This was something we’ve never been able to do,” Canalizo says.

Measuring how fast the quasar fades allows astronomers to figure out exactly what’s causing it to turn off in the first place. “What makes them dim is running out of material to eat,” Canalizo says. That could happen if the quasar is generating enough radiation to blow away all the gas and dust surrounding the black hole—the same gas and dust that feeds it. Without a steady diet, the quasar is powerless to produce radiation. Only if more gas happens to make its way toward the black hole can the quasar turn on again. The glowing gas can provide details of this process, and if other mechanisms are at play.

With more powerful telescopes, astronomers will likely find many more. Hanny’s Verwoort, it turns out, may not be that weird after all.

View Article Here Read More

Shortest Total Lunar Eclipse of the Century Visible Early Saturday


 


Excerpt from space.com 
By Calia Cofield 

Don't forget to look skyward in the early hours of Saturday morning (April 4), to catch a glimpse of the shortest total lunar eclipse of the century.

The moon will be completely swallowed by Earth's shadow for just 4 minutes and 43 seconds on Saturday morning, according to NASA officials. During that time, the moon may change from its normal grayish hue to a deep, blood red. The total eclipse begins at 6:16 a.m. EDT (1016 GMT). You can watch a live webcast of the eclipse on the Slooh Observatory website, Slooh.com, or here at Space.com courtesy of Slooh, starting at 6 a.m. EDT (1000 GMT).
That color change can make for a dramatic display, especially for humans in the distant past, NASA officials said. 


"For early humans, [a lunar eclipse] was a time when they were concerned that life might end, because the moon became blood red and the light that the moon provided at night might have been taken away permanently," Mitzi Adams, an astronomer at NASA's Marshall Space Flight Center in Huntsville, Alabama, said during a news conference today (April 3). "But fortunately, [the light] always returned." 

The April 4 eclipse is the third in a series of four total lunar eclipses — known as a lunar tetrad — visible in the United States. Each of the eclipses is separated by about 6 months. The final installment of this four-eclipse series will occur on Sept. 28. Saturday's lunar eclipse follows closely behind the total solar eclipse that took place on March 20.

Earth's shadow has an outer ring, called the penumbra, and an inner core, called the umbra. Where the moon passes into the penumbra, it appears dark, as if a bite had been taken out of it. When the moon passes though the umbra, it turns a deep, red color.

A total lunar eclipse occurs when the moon is totally submerged in the umbra. On Saturday, the moon will begin to enter the umbra at about 6:16 a.m. EDT (1016 GMT) but will not be completely covered by the shadow until about 7:57 EDT (1157 GMT), after the moon has set in most locations east of the Mississippi River.

While the total eclipse will last less than five minutes, the moon will be partially submerged in the umbra for about one hour and 40 minutes. The dark shadow of the penumbra will first be visible on the moon's surface starting at about 5:35 a.m. EDT (0935 GMT), according to Sky and Telescope magazine.

Viewers west of the Mississippi River will be able to see the total lunar eclipse, starting at about 4:57 a.m. PDT (1157 GMT). Skywatchers in Hawaii and western Alaska will be able to watch the entire eclipse, from the moon's entrance to its exit from the penumbra.

Viewing Guide for Total Lunar Eclipse, April 4, 2015
This world maps shows the regions where the April 4 total lunar eclipse will be visible. The best viewing locations are in the Pacific Ocean.

This weekend's eclipse is extremely short because the moon is only passing through the outskirts of the umbra. (The shortest total lunar eclipse in recorded history, according to Adams, was in 1529 and lasted only 1 minute and 41 seconds).

The eclipse will not be visible in Europe or most of Africa. The partial eclipse will be visible in all except the easternmost parts of South America. The best viewing locations for the total eclipse will be in the Pacific region, including eastern Australia, New Zealand and other parts of Oceania.

View Article Here Read More
Older posts Newer posts

Creative Commons License
This work is licensed under a
Creative Commons Attribution 4.0
International License
.
unless otherwise marked.

Terms of Use | Privacy Policy



Up ↑