Tag: Boulder (page 1 of 2)

New Horizons Spacecraft Captures Image of Pluto & Tiny Moons

An artist's concept shows the moon view of the Pluto system.

Excerpt from cbc.ca



NASA's Pluto-bound spacecraft can now see the dwarf planet's two tiniest known moons — both less than 30 kilometres wide.
Kerberos (which is 10 to 30 kilometres wide) and Styx (which is seven to 21 kilometres) are seen circling Pluto, along with the slightly larger moons Hydra and Nix, in an animated series of "family photos" captured by the New Horizons spacecraft between April 25 and May 1, and released by NASA Tuesday.


Pluto and its four smallest moons can all be seen in this "family photo" captured by the New Horizons spacecraft on April 27.


space animated GIF

"New Horizons is now on the threshold of discovery," said mission science team member John Spencer, from the Southwest Research Institute in Boulder, Colo., in a statement. "If the spacecraft observes any additional moons as we get closer to Pluto, they will be worlds that no one has seen before."

New Horizons is scheduled to make a close flyby of Pluto and its moons on July 14.



At the time the images were taken, the spacecraft was 89 million kilometres away. The glare from Pluto and its largest moon Charon, along with the light of background stars, were damped out using image processing.

Kerberos and Styx were discovered using the Hubble telescope in 2011 and 2012, respectively.

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The sun unleashes its biggest flare of the year




Excerpt from dailytimes.com.pk

The sun has unleashed its most powerful flare of the year causing radio blackouts throughout the Pacific region.

The enormous X-class solar flare peaked at 6:11pm ET yesterday from a sunspot called Active Region 2339 (AR2339).

Solar flares are powerful bursts of radiation that, when intense enough, can disturb the atmosphere in the layer where GPS and communications signals travel - and scientists say they could get more powerful in the future.

This latest flare is classified as an X2.7. X-class denotes the most intense flares, while the number provides more information about its strength.

Despite the recent radio blackouts, scientists say the flare is unlikely to cause any further major issues here on Earth.

‘Given the impulsive nature of this event, as well as the source location on the eastern limb of the sun, we are not expecting a radiation storm at Earth,’ scientists with the U.S. Space Weather Prediction Center (SWPC) in Boulder, Colorado.

‘We will be on the lookout for new imagery from the Nasa Soho [Solar and Heliospheric Observatory] mission to determine if there was an associated coronal mass ejection (CME) with this event,’ they added.

‘Given the same logic above, however, we do not expect there to be one that would impact Earth.’

Yesterday Kazunari Shibata, an astrophysicist from Kyoto University in Japan, said the sun has the potential to unleash a flare of such a magnitude that it would be larger than anything humans have ever seen.

At the Space Weather Workshop in Colorado, Shibata said ‘superflares,’ that contain energy 1,000 times larger than what we have seen could be on their way.

He said there is evidence of this happening every 800 to 5,000 years on Earth,

Scientists say such a solar ‘super-storm’ would pose a ‘catastrophic’ and ‘long-lasting’ threat to life on Earth.

A superflare would induce huge surges of electrical currents in the ground and in overhead transmission lines, causing widespread power outages and severely damaging critical electrical components.

The largest ever solar super-storm on record occurred in 1859 and is known as the Carrington Event, named after the English astronomer Richard Carrington who spotted the preceding solar flare.

This massive CME released about 1022 kJ of energy - the equivalent to 10 billion Hiroshima bombs exploding at the same time - and hurled around a trillion kilos of charged particles towards the Earth at speeds of up to 3000 km/s.

However, its impact on the human population was relatively benign as our electronic infrastructure at the time amounted to no more than about 124,000 miles (200,000 km) of telegraph lines.

Nasa has also released incredible footage showing the sun unleashing a huge lick of plasma that increased the star’s visible hemisphere by almost half.

The solar filament, which exploded on April 28 and 29, was suspended above the sun due to strong magnetic fields that pushed outwards.

Solar astronomers around the world had their eyes on this unusually large filament and kept track as it erupted.

Nasa’s animation involves images taken from the orbiting Solar and Heliospheric Observatory using its Large Angle Spectrometric Coronagraph.

The diameter of the animation is about 30 million miles (45 million km) at the distance of the sun, or half of the diameter of the orbit of Mercury.

The white circle in the centre of the round disk represents the size of the sun, which is being blocked by the telescope in order to see the fainter material around it.

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Puzzle of Moon’s origin resolved


It now seems more probable that a collision between two planets of similar composition led to the formation of the Moon.




Excerpt from nature.com


A nagging problem at the heart of the leading theory of how the Moon formed seems to have been explained away.

The ‘giant impact’ hypothesis, first proposed in the 1970s, suggests that the Moon was formed from the debris scattered when a Mars-sized planet slammed into the early Earth some 4.5 billion years ago. This fits well with what we know about the Moon, including its mass and lack of any significant iron core.

But the theory also implies that the Moon is made up mostly of impactor material. Since lunar and Earth rocks have such similar compositions, this suggests that Earth and the planet that smacked into it resembled each other too. They would have needed to be sister planets, with a relationship much closer than that of any other planetary bodies we have studied in our Solar System. The odds of this being possible were thought to be around a 1% chance, or “uncomfortably rare”, according to Robin Canup, a planetary researcher at the Southwest Research Institute in Boulder, Colorado1.

Better odds

Now it seems that the scenario is not so far-fetched, says Hagai Perets, an astrophysicist at the Israel Institute of Technology in Haifa. He and his colleagues performed simulations of the Solar System’s formation, to investigate how similar planets tend to be to their last giant impactor. They estimated that for 20% to 40% of collisions, the two bodies would be sufficiently similar to explain the Moon’s composition — considerably better odds. The findings are published in Nature2.

The planets would have closely resembled each other because of their similar distance from the Sun, meaning that they would have formed from the same kind of orbiting proto-planetary material. “The Earth and the Moon are not twins born from the same planet, but they are sisters in the sense that they grew up in the same environment,” says Perets.

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NASA puts Mars on back shelf, sets sight on asteroid mission

Excerpt from newsmaine.netNational Aeronautics and Space Administration (NASA) has always given priority to Mars mission but an announcement that NASA made showed that the agency will first begin work on an asteroid mission before it plans for Mars ...

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NASA’s Plan to Give the Moon a Moon


arm-capture_0




Excerpt from wired.com

It sounds almost like a late ’90s sci-fi flick: NASA sends a spacecraft to an asteroid, plucks a boulder off its surface with a robotic claw, and brings it back in orbit around the moon. Then, brave astronaut heroes go and study the space rock up close—and bring samples back to Earth.
Except it’s not a movie: That’s the real-life idea for the Asteroid Redirect Mission, which NASA announced today. Other than simply being an awesome space version of the claw arcade game (you know you really wanted that stuffed Pikachu), the mission will let NASA test technology and practice techniques needed for going to Mars.
The mission, which will cost up to $1.25 billion, is slated to launch in December 2020. It will take about two years to reach the asteroid (the most likely candidate is a quarter-mile-wide rock called 2008 EV5). The spacecraft will spend up to 400 days there, looking for a good boulder. After picking one—maybe around 13 feet in diameter—it will bring the rock over to the moon. In 2025, astronauts will fly NASA’s still-to-be-built Orion to dock with the asteroid-carrying spacecraft and study the rock up close.
Although the mission would certainly give scientists an up-close opportunity to look at an asteroid, its main purpose is as a testing ground for a Mars mission. The spacecraft will test a solar electronic propulsion system, which uses the power from solar panels to pump out charged particles to provide thrust. It’s slower than conventional rockets, but a lot more efficient. You can’t lug a lot of rocket fuel to Mars.
Overall, the mission gives NASA a chance at practicing precise navigation and maneuvering techniques that they’ll need to master for a Mars mission. Such a trip will also require a lot more cargo, so grabbing and maneuvering a big space rock is good practice. Entering lunar orbit and docking with another spacecraft would also be helpful, as the orbit might be a place for a deep-space habitat, a rendezvous point for astronauts to pick up cargo or stop on their way to Mars.
And—you knew this part was coming, Armageddon fans—the mission might teach NASA something about preventing an asteroid from striking Earth. After grabbing the boulder, the spacecraft will orbit the asteroid. With the added heft from the rock, the spacecraft’s extra gravity would nudge the asteroid, creating a slight change in trajectory that NASA could measure from Earth. “We’re not talking about a large deflection here,” says Robert Lightfoot, an associate administrator at NASA. But the idea is that a similar technique could push a threatening asteroid off a collision course with Earth.
NASA chose this mission concept over one that would’ve bagged an entire asteroid. In that plan, the spacecraft would’ve captured the space rock by enclosing it in a giant, flexible container. The claw concept won out because its rendezvous and soft-landing on the asteroid will allow NASA to test and practice more capabilities in preparation for a Mars mission, Lightfoot says. The claw would’ve also given more chances at grabbing a space rock, whereas it was all or nothing with the bag idea. “It’s a one-shot deal,” he says. “It is what it is when we get there.” But the claw concept offers some choices. “I’ve got three to five opportunities to pull one of the boulders off,” he says. Not bad odds. Better than winning that Pikachu

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Amazing Images of Comet 67P/Churyumov-Gerasimenko

Rosetta photo of Comet 67P/C-G.
Comet 67P/C-G is about as large as Central Park of Manhattan Island, New York

Excerpt from nytimes.com

By JONATHAN CORUM 


The European Space Agency’s Rosetta spacecraft caught up with Comet 67P/Churyumov-Gerasimenko last August, then dropped a lander onto the comet in November. Now Rosetta will follow the rubber-duck-shaped comet as it swings closer to the sun.
Scale in miles
Scale in km
Rosetta photo of Comet 67P/C-G.
1/2 MILE

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.
Rosetta photo of Comet 67P/C-G.
1/2 MILE

March 6 The comet’s head is angled down in this image of crisscrossing sunlit jets taken from 53 miles away.
Comet’s location when Rosetta was launched Rosetta launched in March 2004
Earth
Sun
Mars
Rendezvous
with Comet
67P/C-G
Orbit of
Jupiter
Rosetta today

Where is Rosetta? The Rosetta spacecraft took 10 years to match speed and direction with Comet 67P/C-G. The chase ended last August, and Rosetta will now follow the comet in its elliptical orbit as it moves closer to the sun. The spacecraft is no longer orbiting the comet because of increasing dust, but it is planning a series of close flybys.
Rosetta photo of Comet 67P/C-G.
1/2 MILE

March 6 Rosetta was 52 miles away when it looked up at the comet’s flat underbelly. The smooth plain at center covered with large boulders is named Imhotep.
Rosetta photo of Comet 67P/C-G.
1/2 MILE

Feb. 28 Rosetta captured a profile of the comet surrounded by curving jets of gas and dust from active regions. The spacecraft was 64 miles away.

Rosetta photo of Comet 67P/C-G.

Feb. 25–27 One day on Comet 67P/C-G is about 12 hours, the time it takes the comet to spin on its axis. The jets of gas and dust surrounding the comet are thought to curve from a combination of the comet’s rotation and the uneven gravity of its two-lobed structure.
Rosetta photo of Comet 67P/C-G.
1/2 MILE

Feb. 20 The comet’s sunlit underbelly casts a shadow obscuring the neck that joins the two lobes. Rosetta took this image from 74 miles away.
Rosetta photo of Comet 67P/C-G.
1 MILE

Feb. 18 Pale jets of gas and dust surround Comet 67P/C-G, seen from 123 miles away. Bright marks in the background are a mix of stars, camera noise and streaks from small particles ejected from the comet.
Rosetta photo of Comet 67P/C-G.
1/4 MILE
Panorama by The New York Times

Feb. 14 On Valentine’s Day, Rosetta made its first close flyby of the comet, passing within four miles of the surface. Here the spacecraft looks down on the large depression at the top of the comet’s head.

Rosetta photo of Comet 67P/C-G.
500 FEET

Feb. 14 An image of the comet’s underbelly taken six miles above the surface during the Valentine’s Day flyby. The smooth plain in the foreground is called Imhotep.

Rosetta photo of Comet 67P/C-G.
1/2 MILE

Feb. 9 The comet is upside down in this image from 65 miles away, and a fan-shaped jet of dust streams from the comet’s neck region.

Rosetta photo of Comet 67P/C-G.
1/2 MILE

Feb. 6 Jets of gas and dust extend from the comet’s neck and other sunlit areas in this image taken from 77 miles away.

Rosetta photo of Comet 67P/C-G.
1/4 MILE

Feb. 3 This close-up image of the comet’s neck was taken from 18 miles away, and was the last image taken from orbit around Comet 67P/C-G. Rosetta will continue to follow the comet, but will leave its gravity-bound orbit because of increasing dust and instead begin a series of flybys.

Rosetta photo of Comet 67P/C-G.
1/4 MILE

Jan. 31 The comet’s head, neck and back are sunlit in this image taken from 17 miles away. A prominent jet of gas and dust extends from an active region of the surface near the comet’s neck.

Rosetta photo of Comet 67P/C-G.
1/4 MILE

Jan. 16 The tail of the comet’s larger lobe points up, revealing a smooth plain named Imhotep at left. Rosetta was 18 miles away when it took this image.

Rosetta photo of Comet 67P/C-G.
1/4 MILE

Jan. 3 The smooth plain named Imhotep, at center right, lies on the comet’s flat underbelly, seen here from a distance of about 18 miles.

Rosetta photo of Comet 67P/C-G.
1/4 MILE
Cheops
IMHOTEP

Dec. 14, 2014 The large triangular boulder on the flat Imhotep plain is named Cheops, after the Egyptian pyramid. The spacecraft was about 12 miles from the comet when it took this image.

Rosetta photo of Comet 67P/C-G.
1/4 MILE

Dec. 10 Sunlight falls between the body and head of the comet, lighting up a large group of boulders in the smooth Hapi region of the comet’s neck. To the right of the boulders, the cliffs of Hathor form the underside of the comet’s head. Rosetta took this image from a distance of 12 miles.

Rosetta photo of Comet 67P/C-G.
1/4 MILE

Dec. 2 The round depression in the middle of the comet’s head is filled with shadow in this image taken 12 miles above the comet.

Rosetta photo of Comet 67P/C-G.
1/4 MILE

Nov. 22 An overexposed image of Comet 67P/C-G from 19 miles away shows faint jets of gas and dust extending from the sunlit side of the comet.

Philae photo from the surface of Comet 67P/C-G.

Nov. 12 Rosetta’s washing-machine sized lander Philae successfully touched down on the comet’s head. But anchoring harpoons failed and Philae bounced twice before going missing in the shadow of a cliff or crater (above). Without sunlight Philae quickly lost power, but might revive as the comet gets closer to the sun. On March 12, Rosetta resumed listening for radio signals from the missing lander.

Rosetta photo of Comet 67P/C-G.

Photo illustration by The New York Times

How big is the comet? The body of Comet 67P/C-G is about as long as Central Park. For images of Rosetta’s rendezvous and the Philae landing, see Landing on a Comet, 317 Million Miles From Home.

Sources: European Space Agency and the Rosetta mission. Images by ESA/Rosetta, except where noted. Some images are composite panoramas created by ESA, and most images were processed by ESA to bring out details of the comet’s activity.

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Does the Past Exist Yet? Evidence Suggests Your Past Isn’t Set in Stone


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Excerpt from robertlanza.com
By Robert Lanza 

Recent discoveries require us to rethink our understanding of history. “The histories of the universe,” said renowned physicist Stephen Hawking “depend on what is being measured, contrary to the usual idea that the universe has an objective observer-independent history.”

Is it possible we live and die in a world of illusions? Physics tells us that objects exist in a suspended state until observed, when they collapse in to just one outcome. Paradoxically, whether events happened in the past may not be determined until sometime in your future – and may even depend on actions that you haven’t taken yet.

In 2002, scientists carried out an amazing experiment, which showed that particles of light “photons” knew — in advance — what their distant twins would do in the future. They tested the communication between pairs of photons — whether to be either a wave or a particle. Researchers stretched the distance one of the photons had to take to reach its detector, so that the other photon would hit its own detector first. The photons taking this path already finished their journeys — they either collapse into a particle or don’t before their twin encounters a scrambling device.
Somehow, the particles acted on this information before it happened, and across distances instantaneously as if there was no space or time between them. They decided not to become particles before their twin ever encountered the scrambler. It doesn’t matter how we set up the experiment. Our mind and its knowledge is the only thing that determines how they behave. Experiments consistently confirm these observer-dependent effects.

More recently (Science 315, 966, 2007), scientists in France shot photons into an apparatus, and showed that what they did could retroactively change something that had already happened. As the photons passed a fork in the apparatus, they had to decide whether to behave like particles or waves when they hit a beam splitter. 
Later on – well after the photons passed the fork – the experimenter could randomly switch a second beam splitter on and off. It turns out that what the observer decided at that point, determined what the particle actually did at the fork in the past. At that moment, the experimenter chose his history.

Of course, we live in the same world. Particles have a range of possible states, and it’s not until observed that they take on properties. So until the present is determined, how can there be a past? According to visionary physicist John Wheeler (who coined the word “black hole”), “The quantum principle shows that there is a sense in which what an observer will do in the future defines what happens in the past.” Part of the past is locked in when you observe things and the “probability waves collapse.” But there’s still uncertainty, for instance, as to what’s underneath your feet. If you dig a hole, there’s a probability you’ll find a boulder. Say you hit a boulder, the glacial movements of the past that account for the rock being in exactly that spot will change as described in the Science experiment.

But what about dinosaur fossils? Fossils are really no different than anything else in nature. For instance, the carbon atoms in your body are “fossils” created in the heart of exploding supernova stars. 
Bottom line: reality begins and ends with the observer. “We are participators,” Wheeler said “in bringing about something of the universe in the distant past.” Before his death, he stated that when observing light from a quasar, we set up a quantum observation on an enormously large scale. It means, he said, the measurements made on the light now, determines the path it took billions of years ago.

Like the light from Wheeler’s quasar, historical events such as who killed JFK, might also depend on events that haven’t occurred yet. There’s enough uncertainty that it could be one person in one set of circumstances, or another person in another. Although JFK was assassinated, you only possess fragments of information about the event. But as you investigate, you collapse more and more reality. According to biocentrism, space and time are relative to the individual observer – we each carry them around like turtles with shells.

History is a biological phenomenon — it’s the logic of what you, the animal observer experiences. You have multiple possible futures, each with a different history like in the Science experiment. Consider the JFK example: say two gunmen shot at JFK, and there was an equal chance one or the other killed him. This would be a situation much like the famous Schrödinger’s cat experiment, in which the cat is both alive and dead — both possibilities exist until you open the box and investigate.

“We must re-think all that we have ever learned about the past, human evolution and the nature of reality, if we are ever to find our true place in the cosmos,” says Constance Hilliard, a historian of science at UNT. Choices you haven’t made yet might determine which of your childhood friends are still alive, or whether your dog got hit by a car yesterday. In fact, you might even collapse realities that determine whether Noah’s Ark sank. “The universe,” said John Haldane, “is not only queerer than we suppose, but queerer than we can suppose.”

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Scientists: Enceladus may have warm water ocean with ingredients for life


Enceladus ocean
This artist's impression of the interior of Saturn's moon Enceladus shows that interactions between hot water and rock occur at the floor of the subsurface ocean -- the type of environment that might be friendly to life, scientists say. (NASA/JPL-Caltech)



Excerpt from latimes.com

Scientists say they’ve discovered evidence of a watery ocean with warm spots hiding beneath the surface of Saturn’s icy moon Enceladus. The findings, described in the journal Nature, are the first signs of hydrothermal activity on another world outside of Earth – and raise the chances that Enceladus has the potential to host microbial life.

Scientists have wondered about what lies within Enceladus at least since NASA’s Cassini spacecraft caught the moon spewing salty water vapor out from cracks in its frozen surface. Last year, a study of its gravitational field hinted at a 10-kilometer-thick regional ocean around the south pole lying under an ice crust some 30 to 40 kilometers deep.

Another hint also emerged about a decade ago, when Cassini discovered tiny dust particles escaping Saturn’s system that were nanometer-sized and rich in silicon.

“It’s a peculiar thing to find particles enriched with silicon,” said lead author Hsiang-Wen Hsu, a planetary scientist at the University of Colorado, Boulder. In Saturn’s moons and among its rings, water ice dominates, so these odd particles clearly stood out.

The scientists traced these particles’ origin to Saturn’s E-ring, which lies between the orbits of the moons Mimas and Titan and whose icy particles are known to come from Enceladus. So Hsu and colleagues studied the grains to understand what was going on inside the gas giant’s frigid satellite.   
Rather than coming in a range of sizes, these particles were all uniformly tiny – just a few nanometers across. Studying the spectra of these grains, the scientists found that they were made of silicon dioxide, or silica. That’s not common in space, but it’s easily found on Earth because it’s a product of water interacting with rock. 

Knowing how silica interacts in given conditions such as temperature, salinity and alkalinity, the scientists could work backward to determine what kind of environment creates these unusual particles.

A scientist could do the same thing with a cup of warm coffee, Hsu said.

“You put in the sugar and as the coffee gets cold, if you know the relation of the solubility of sugar as a function of temperature, you will know how hot your coffee was,” Hsu said. “And applying this to Enceladus’s ocean, we can derive a minimum [temperature] required to form these particles.”

The scientists then ran experiments in the lab to determine how such silica particles came to be. With the particles’ particular makeup and size distribution, they could only have formed under very specific circumstances, the study authors found, determining that the silica particles must have formed in water that had less than 4% salinity and that was slightly alkaline (with a pH of about 8.5 to 10.5) and at temperatures of at least 90 degrees Celsius (roughly 190 degrees Fahrenheit).

The heat was likely being generated in part by tidal forces as Saturn’s gravity kneads its icy moon. (The tidal forces are also probably what open the cracks in its surface that vent the water vapor into space.)
Somewhere inside the icy body, there was hydrothermal activity – salty warm water interacting with rocks. It’s the kind of environment that, on Earth, is very friendly to life.  

“It’s kind of obvious, the connection between hydrothermal interactions and finding life,” Hsu said. “These hydrothermal activities will provide the basic activities to sustain life: the water, the energy source and of course the nutrients that water can leach from the rocks.”

Enceladus, Hsu said, is now likely the “second-top object for astrobiology interest” – the first being Jupiter’s icy moon and fellow water-world, Europa.
This activity is in all likelihood going on right now, Hsu said – over time, these tiny grains should glom together into larger and larger particles, and because they haven’t yet, they must have been recently expelled from Enceladus, within the last few months or few years at most.

Gabriel Tobie of the University of Nantes in France, who was not involved in the research, compared the conditions that created these silica particles to a hydrothermal field in the Atlantic Ocean known as Lost City.

“Because it is relatively cold, Lost City has been posited as a potential analogue of hydrothermal systems in active icy moons. The current findings confirm this,” Tobie wrote in a commentary on the paper. “What is more, alkaline hydrothermal vents might have been the birthplace of the first living organisms on the early Earth, and so the discovery of similar environments on Enceladus opens fresh perspectives on the search for life elsewhere in the Solar System.”

However, Hsu pointed out, it’s not enough to have the right conditions for life – they have to have been around for long enough that life would have a fighting chance to emerge.

“The other factor that is also very important is the time.… For Enceladus, we don’t know how long this activity has been or how stable it is,” Hsu said. “And so that’s a big uncertainty here.”

One way to get at this question? Send another mission to Enceladus, Tobie said.

“Cassini will fly through the moon’s plume again later this year,” he wrote, “but only future missions that can undertake improved in situ investigations, and possibly even return samples to Earth, will be able to confirm Enceladus’ astrobiological potential and fully reveal the secrets of its hot springs. ”

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History Repeating? Study shows Ancient cities were bigger and denser, just like modern cities




Excerpt from  thenextdigit.com

Recently, a new research has been done, which found that the ancient cities were similar to the current modern-day cities in terms of size as well as the density of those settlements. In the research paper, the researcher explains that modern cities with large amount of populations as well as density, are similar to the characteristics of ancient cities. The research claims that the character of the inhabitants of ancient cities is similar to those of inhabitants of modern cities.

 The study was done by the researchers at Santa Fe Institute and at the University of Colorado Boulder. The main objective of the researchers is to find the functionality of the settlements and they started to find out whether current cities and ancient cities are similar in nature.

Scott Ortman, Researcher at Department of Anthropology, University of Colorado Boulder says,
“Our findings indicate the fundamental processes behind the emergence of scaling in modern cities have structured human settlement organization throughout human history, and that contemporary urban systems are best-conceived as lying on a continuum with the smaller-scale settlement systems known from historical and archaeological research.”
The researcher grouped together and analyzes the structures as well as dimensions of both cities and estimated the way of construction of monuments, housing styles, the amount of people stayed in a region and so on. They found the place or region where the density was high, the productivity was more.

Ortman also said that the results were amazing and unbelievable for them and added that the modern world is radically different from the ancient world with its capitalism, democracy, industrialization and so on. They also noticed that, once the population of a particular area grew, then the productivity of that same place rose high. Even a few patterns that are used in the ancient human societies were same as that we are following in our modern urban system.
“It was amazing and unbelievable,” Ortman said. “We’ve been raised on a steady diet, telling us that, thanks to capitalism, industrialization, and democracy, the modern world is radically different from worlds of the past. What we found here is that the fundamental drivers of robust socioeconomic patterns in modern cities precede all that.”

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Earth’s Moon May Not Be Critical to Life Afterall




Excerpt from space.com

The moon has long been viewed as a crucial component in creating an environment suitable for the evolution of complex life on Earth, but a number of scientific results in recent years have shown that perhaps our planet doesn't need the moon as much as we have thought.

In 1993, French astronomer Jacques Laskar ran a series of calculations indicating that the gravity of the moon is vital to stabilizing the tilt of our planet. Earth's obliquity, as this tilt is technically known as, has huge repercussions for climate. Laskar argued that should Earth's obliquity wander over hundreds of thousands of years, it would cause environmental chaos by creating a climate too variable for complex life to develop in relative peace.
So his argument goes, we should feel remarkably lucky to have such a large moon on our doorstep, as no other terrestrial planet in our solar system has such a moon. Mars' two satellites, Phobos and Deimos, are tiny, captured asteroids that have little known effect on the Red Planet. Consequently, Mars' tilt wobbles chaotically over timescales of millions of years, with evidence for swings in its rotational axis at least as large as 45 degrees. 


The stroke of good fortune that led to Earth possessing an unlikely moon, specifically the collision 4.5 billion years ago between Earth and a Mars-sized proto-planet that produced the debris from which our Moon formed, has become one of the central tenets of the 'Rare Earth' hypothesis. Famously promoted by Peter Ward and Don Brownlee, it argues that planets where everything is just right for complex life are exceedingly rare.

New findings, however, are tearing up the old rule book. In 2011, a trio of scientists — Jack Lissauer of NASA Ames Research Center, Jason Barnes of the University of Idaho and John Chambers of the Carnegie Institution for Science — published results from new simulations describing what Earth's obliquity would be like without the moon. What they found was surprising.

"We were looking into how obliquity might vary for all sorts of planetary systems," says Lissauer. "To test our code we began with integrations following the obliquity of Mars and found similar results to other people. But when we did the obliquity of Earth we found the variations were much smaller than expected — nowhere near as extreme as previous calculations suggested they would be."
Lissauer's team found that without the moon, Earth's rotational axis would only wobble by 10 degrees more than its present day angle of 23.5 degrees. The reason for such vastly different results to those attained by Jacques Laskar is pure computing power. Today's computers are much faster and capable of more accurate modeling with far more data than computers of the 1990s.

Lissauer and his colleagues also found that if Earth were spinning fast, with one day lasting less than 10 hours, or rotating retrograde (i.e. backwards so that the sun rose in the West and set in the East), then Earth stabilized itself thanks to the gravitational resonances with other planets, most notably giant Jupiter. There would be no need for a large moon. 

Earth's rotation has not always been as leisurely as the current 24 hour spin-rate. Following the impact that formed the moon, Earth was spinning once every four or five hours, but it has since gradually slowed by the moon's presence. As for the length of Earth's day prior to the moon-forming impact, nobody really knows, but some models of the impact developed by Robin Canup of the Southwest Research Institute, in Boulder, Colorado, suggest that Earth could have been rotating fast, or even retrograde, prior to the collision.

Tilted Orbits
Planets with inclined orbits could find that their increased obliquity is beneficial to their long-term climate – as long as they do not have a large moon.


"Collisions in the epoch during which Earth was formed determined its initial rotation," says Lissauer. "For rocky planets, some of the models say most of them will be prograde, but others say comparable numbers of planets will be prograde and retrograde. Certainly, retrograde worlds are not expected to be rare."

The upshot of Lissauer's findings is that the presence of a moon is not the be all and end all as once thought, and a terrestrial planet can exist without a large moon and still retain its habitability. Indeed, it is possible to imagine some circumstances where having a large moon would actually be pretty bad for life.

Rory Barnes, of the University of Washington, has also tackled the problem of obliquity, but from a different perspective. Planets on the edge of habitable zones exist in a precarious position, far enough away from their star that, without a thick, insulating atmosphere, they freeze over, just like Mars. Barnes and his colleagues including John Armstrong of Weber State University, realized that torques from other nearby worlds could cause a planet's inclination to the ecliptic plane to vary. This in turn would result in a change of obliquity; the greater the inclination, the greater the obliquity to the Sun. Barnes and Armstrong saw that this could be a good thing for planets on the edges of habitable zones, allowing heat to be distributed evenly over geological timescales and preventing "Snowball Earth" scenarios. They called these worlds "tilt-a-worlds," but the presence of a large moon would counteract this beneficial obliquity change.

"I think one of the most important points from our tilt-a-world paper is that at the outer edge of the habitable zone, having a large moon is bad, there's no other way to look at it," says Barnes. "If you have a large moon that stabilizes the obliquity then you have a tendency to completely freeze over."

Barnes is impressed with the work of Lissauer's team.
"I think it is a well done study," he says. "It suggests that Earth does not need the moon to have a relatively stable climate. I don't think there would be any dire consequences to not having a moon."

Mars' Changing Tilt
The effects of changing obliquity on Mars’ climate. Mars’ current 25-degree tilt is seen at top left. At top right is a Mars that has a high obliquity, leading to ice gather at its equator while the poles point sunwards. At bottom is Mars with low obliquity, which sees its polar caps grow in size.


Of course, the moon does have a hand in other factors important to life besides planetary obliquity. Tidal pools may have been the point of origin of life on Earth. Although the moon produces the largest tides, the sun also influences tides, so the lack of a large moon is not necessarily a stumbling block. Some animals have also evolved a life cycle based on the cycle of the moon, but that's more happenstance than an essential component for life.

"Those are just minor things," says Lissauer.

Without the absolute need for a moon, astrobiologists seeking life and habitable worlds elsewhere face new opportunities. Maybe Earth, with its giant moon, is actually the oddball amongst habitable planets. Rory Barnes certainly doesn't think we need it.
"It will be a step forward to see the myth that a habitable planet needs a large moon dispelled," he says, to which Lissauer agrees.
Earth without its moon might therefore remain habitable, but we should still cherish its friendly presence. After all, would Beethoven have written the Moonlight Sonata without it?

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Hubble Juiced! ~ CU-Boulder to Design Space Telescope 1000 Times Sharper than Hubble



CU-Boulder to Design Space Telescope 1000 Times Sharper than Hubble
The Hubble Space Telescope


Excerpt from utahpeoplespost.com


Researchers from the Department of Astrophysical and Planetary Sciences at the University of Colorado Boulder are currently working on an improved version of space telescope that could provide space images nearly 1,000 times sharper than those provided by long-running Hubble.

The new space telescope, dubbed the Aragoscope, is named after a French astronomer called Francois Arago. The new telescope is exclusively designed by the CU- Boulder scientists and involves a brand new technology developed by the university. According to its designers, the space optical instrument would be lighter, slimmer, and sharper than Hubble.

Additionally, the Aragoscope will involve several independent pieces that can be later assembled in space. So, the launching costs of these smaller building blocks will be significantly reduced.
Traditionally, space telescopes have essentially been monolithic pieces of glass like the Hubble Space Telescope. But the heavier the space telescope, the more expensive the cost of the launch,”
said Anthony Harness, one of the researchers involved in the project and doctoral student at the CU-Boulder.

However, the new instrument will not replace Hubble, which is scheduled to be shut down in 5 years time. Last year, Hubble had its fifth and final maintenance service, and it was still in a pretty good shape although one of its six gyroscopes couldn’t be stabilized. Despite Hubble has been operating since 1990, NASA engineers hope that it will make it to its 30th anniversary.

If Hubble remains operational, NASA plans to use it along with its successor, the James Webb Space Telescope, which is scheduled to be launched in October 2018. Astronomers hope that the two space telescopes, which use two different imaging methods, would help them better understand the origins and early evolution of the universe.

But the UC-Boulder team claim that their new space telescope would surpass Hubble with its enhanced capacity of spotting distant Earth-like planets in the depths of a remote universe...

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Sleepy space probe New Horizons awakens for close-up with Pluto

Excerpt from (CNN) -- Three billion miles away from Earth, in an unchartered slice of our solar system, a small space probe is shaking off its deep sleep and getting ready to become the first spacecraft to visit Pluto and its moons.It's the "beginni...

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Invisible shield in space protects Earth from ‘killer electrons’


A cloud of cold, charged gas around Earth, called the plasmasphere and seen here in purple, interacts with the particles in Earth's radiation belts — shown in grey— to create an impenetrable barrier that blocks the fastest electrons from moving in closer to our planet. Image by NASA/Goddard
A cloud of cold, charged gas around Earth, called the plasmasphere and seen here in purple, interacts with the particles in Earth’s radiation belts — shown in grey— to create an impenetrable barrier that blocks the fastest electrons from moving in closer to our planet. These findings were published in Nature magazine on Nov. 26, 2014. Image by NASA/Goddard



Excerpt from pbs.org

A team led by professors and scientists from the University of Colorado at Boulder have discovered an invisible shield in space that blocks Earth from so-called “killer electrons,” according to findings published in Nature on Thursday.

“Somewhat like the shields created by force fields on Star Trek that were used to repel alien weapons, we are seeing an invisible shield blocking these electrons,” said Professor Daniel N. Baker, the lead author of the study in a press release.

“It’s an extremely puzzling phenomenon.”

According to NASA, “killer electrons” are the devilish doppelgangers of Earth’s subatomic allies.

While the flow of electrons is used as electricity to power everything from cell phones to light bulbs, when electrons reach high speeds like that of more than 100,000 miles per second in space, they can become dangerous and have been known to destroy satellites and even injure astronauts.

The shield, said to be located some 7,200 miles from Earth and impenetrable, lies within the Van Allen radiation belts, two rings around Earth containing potent electrons and protons trapped by the Earth’s magnetic field.

In 2008, NASA’s STEREO spacecraft, discovered that electrons turn into speedy, destructive “killer electrons” in part when picked up in the Belts by powerful radio waves known as whistlers.

Luckily though: “It’s almost like theses electrons are running into a glass wall in space,” said Baker of the shield, which was discovered using data collected by NASA’s Van Allen probes.

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