Thursday, June 30, 2016
Observing the Evening Sky in Summer’s Twilight Zone [bestandroiddoubledinheadunit950.blogspot.com]
Looking down on Seattle at midnight local time on the summer solstice shows that all of western Canada and much of the United States experiences twilight all night long during the summer months.
Credit: Starry Night software.
What is twilight? Roughly speaking, it is the time between when the sun sets and when the sky becomes totally dark.
Based on how far the sun is below the horizon, scientists distinguish among three different levels of twilight: civil twilight, nautical twilight and astronomical twilight.
Civil twilight refers to the time when the sun is between the horizon and 6 degrees below the horizon. During civil twilight, objects can be clearly distinguished, but only a few of the brightest stars and planets can be seen. [Jupiter’s Moons and A Comet In June 2016 Skywatching | Video]
Nautical twilight occurs when the sun is between 6 degrees and 12 degrees below the horizon. Quite a few stars are visible, and this is when navigators make a lot of their observations.
Astronomical twilight occurs when the sun is between 12 degrees and 18 degrees below the horizon. Only at the end of astronomical twilight, when the sun is at least 18 degrees below the horizon, is the sky fully dark, and observers can see the faintest stars or deep-sky objects visible from those viewers’ locations.
This assumes freedom from other forms of light, including moonlight, and stray light from local or distant artificial light sources, or what is called light pollution.
Summer skywatching
The Earth is tilted on its axis, which means that when the Northern Hemisphere points toward the sun and experiences summer, the Southern Hemisphere points away from the sun and experiences winter. In summer, the days are longer and the nights are shorter than in winter. The sun doesn’t dip quite so far below the horizon, and as a result, the length of time during the night when the sky is totally dark is much shorter than in winter. The farther north one travels, the shorter the summertime darkness becomes.
Let’s look at one example, New York City, which is at latitude 41 degrees north, about average for the United States. In the summer, the sun rises at 5:25 a.m. and sets at 8:30 p.m. in New York. But the sky in this city (without light pollution) is only fully dark with the sun more than 18 degrees below the horizon, between 10:37 p.m. and 3:18 a.m. So, at the latitude of New York, astronomers can see a totally dark sky at midsummer for less than 5 hours.
As you move farther north, the summer twilight gets longer, and the length of total darkness shorter. In Seattle, latitude 48 degrees north, sunset is at 9:10 p.m. and sunrise at 5:11 a.m. The sky is totally dark from 12:19 a.m. until 2:03 a.m., less than 2 hours.
Moving even farther north to Edmonton, Alberta, latitude 54 degrees, sunset is at 9:07 p.m. and sunrise at 4:04 a.m. When Edmonton viewers look at the altitude of the sun during the night, they find that it never gets even close to 18 degrees below the horizon. In fact, the sun never gets further than 13 degrees below the horizon on the summer solstice night in this city. This means that for several weeks in midsummer, the sky never gets completely dark there.
Consider that some of the finest deep-sky objects are in the constellations Scorpius and Sagittarius, which reach their highest points only in June and July. Then, you can see the problem facing astronomers in northern latitudes.
In Europe, things are even worse, because the major population concentrations in that continent are much farther north than in North America. I discovered this myself when visiting Cumberland in northern England as a teenager. There, at midnight local time in midsummer, the sun is only 12 degrees below the horizon, still in nautical twilight.
The situation is not as bad in the Southern Hemisphere, as there are only a handful of cities south of 45 degrees south.
So what do northern astronomers do in the summertime? Aside from observing the sun, they do very little. I have an astronomer friend who lives in Yellowknife in Canada’s Northwest Territories, latitude 62 degrees north. In the summer, he tends to travel. I first met him at the solar eclipse in Libya in 2006.
Surprisingly, a number of dedicated deep-sky observers live in Canada’s prairie provinces, and have logged large numbers of deep-sky objects despite the challenges of observing in the summer “twilight zone.”
This article was provided to Space.com by Simulation Curriculum, the leader in space science curriculum solutions and the maker of Starry Night and SkySafari. Follow Starry Night on Twitter @StarryNightEdu. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.
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http://www.space.com/33120-skywatching-in-summer-twilight-zone.html Observing the Evening Sky in Summer's Twilight Zone
[bestandroiddoubledinheadunit950.blogspot.com]Observing the Evening Sky in Summer’s Twilight ZoneWhat Does Mars Smell Like? [bestandroiddoubledinheadunit950.blogspot.com]
Mars as viewed by NASA’s Curiosity rover. Nice vistas, but what does the Red Planet smell like?
Credit: NASA/JPL
Robot explorers have found Mars to be a world of sulfur, acids, magnesium, iron and chlorine compounds, all of which are sunbaked and wrapped in a carbon-dioxide-rich atmosphere.
But what would this complex and exotic brew smell like?
It turns out that everyone — not just Mars explorers — might be able to find out, because there may be ways to recreate whiffs of the Red Planet here on Earth. [The 7 Biggest Mysteries of Mars]
Headspace tech
One relatively recent innovation in the perfume business is “Headspace” technology.
“It gathers the molecules, and then the sample is brought back to the lab to be analyzed by spectral analysis. The results are typically synthesized to create a scent that mimics the smell of those molecules,” said Jacquelyn Ford Morie, founder and chief scientist of the California-based company All These Worlds LLC, which uses virtual reality (VR) and other technology to create “immersive experiences” for a variety of applications.
A scent collar has been invented to bring the power of smell to augment virtual-reality experiences.
Credit: All These Worlds
Morie thinks Headspace, or something like it, could be used to decode the smell of Mars.
“I think that new artisan fragrance designers would love to design a series of scents that are their own, nonsampled interpretations of what Mars might smell like,” she told Space.com.
A future mission could take a spectroscopic reading of the Martian atmosphere, then beam that information back to Earth, where Headspace hardware could reconstruct (or evoke) the Red Planet scent, Morie added.
“That’s the cool thing about the artisan scent designers,” she said. “They can add the more stinky elements to make a scent that hints at the real Mars while still being cool to smell. Many top fragrances have small bits of those otherwise smelly elements in them.”
Eau de Red Planet
Astronaut-geologist Harrison Schmitt on an Apollo 17 moonwalk in 1972. The cohesive nature of the lunar soil is borne out by the “dirty” sheen of his space suit, later tracked into the nearby lunar module. Apollo crewmembers likened the smell of lunar regolith to spent gunpowder.
Credit: NASA
Morie suspects that the predominant Mars odor is a slightly acrid, gassy smell of sulfur compounds, with a chalky, sweet overtone punching through. This scent would become a big part of Red Planet settlers’ lives.
“Imagine 30 or 40 years from now, when we have established colonies on Mars, and the colonists have become not only accepting of the scented detritus they track into their habitats, but actually consider it the smell of home,” Morie said.
Future colonists could perhaps also use finely crafted habitat scents as harmonious counterpoints to the native smells of their adopted planet, she added.
Studies have shown repeatedly that smell is intimately tied to memory; whiffs of a familiar scent can trigger nostalgia and other strong feelings about times long past.
So, if Mars colonists “need to return to Earth, they would absolutely require a vial or two of ‘Eau de Red Planet’ to remind them of their life on this distant human outpost,” Morie said.
Extraterrestrial encounters
Decoding or replicating Mars’ scent would not be the first extraterrestrial encounter of the odor kind.
During the Apollo lunar landing program, for example, some of the moonwalkers noticed that they had brought back rock and dust particles into their lunar module. The material tainted their spacesuits. Once the astronauts took off their helmets, the moon’s smell — which was likened to wet ashes in a fireplace, or spent gunpowder from a just-fired shotgun — was evident.
Then, in 1998, scientists with New York-based International Flavors & Fragrances Inc. (IFF) sent a miniature rose plant aboard the space shuttle Discovery on its STS-95 mission, to study the effect of microgravity on scent.
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Mars Myths & Misconceptions: Quiz
No planet is more steeped in myth and misconception than Mars. This quiz will reveal how much you really know about some of the goofiest claims about the red planet.
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Using proprietary technologies, the team, led by Braja Mookherjee, tracked radical shifts in the living flower’s scent over the course of the shuttle flight.
“Ultimately, they discovered and created new-to-world profiles that have since gone on to enormous commercial success,” IFF representatives wrote in a blog post late last year.
In addition, artisan Carrie Paterson has investigated making scents of life on Earth that can be embedded as olfactory information into multichannel interstellar messages. Then, there’s the work of designer Saskia Wilson-Brown, who’s interested in finding out what UFOs might smell like.
Leonard David is author of “Mars: Our Future on the Red Planet,” to be published by National Geographic this October. The book is a companion to the National Geographic Channel six-part series coming in November. A longtime writer for Space.com, David has been reporting on the space industry for more than five decades. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.
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http://www.space.com/33115-what-does-mars-smell-like.html What Does Mars Smell Like?
[bestandroiddoubledinheadunit950.blogspot.com]What Does Mars Smell Like?Is This 12-Year-Old Girl ‘The Next Taylor Swift?’ Simon Cowell Says So [bestandroiddoubledinheadunit950.blogspot.com]
She might only be 12, but Grace VanderWaal’s powerhouse vocals and ukulele skills have already caught the attention of some of music’s toughest critics, including one Mr. Simon Cowell.
The precocious singer appeared on America’s Got Talent on Tuesday night, where her flawless performance of an original song, “I Don’t Know My Name,” earned Grace an endorsement from Howie Mandel‘s golden buzzer, with judge going so far as to call her “a living, beautiful, walking miracle.”
However, the biggest compliment of the night came from the infamously hard-to-impress Cowell, who told the aspiring chanteuse that she reminded him of one of America’s biggest pop stars.
“Grace, you know what I predict for you? I think you are the next Taylor Swift,” Cowell said.
Watch her full performance below.
Entertainment – TIME
She might only be 12, but Grace VanderWaal’s powerhouse vocals and ukulele skills have already caught the attention of some of music’s toughest critics, including one Mr. Simon Cowell.
The precocious singer appeared on America’s Got Talent on Tuesday night, where her flawless performance of an original song, “I Don’t Know My Name,” earned Grace an endorsement from Howie Mandel‘s golden buzzer, with judge going so far as to call her “a living, beautiful, walking miracle.”
However, the biggest compliment of the night came from the infamously hard-to-impress Cowell, who told the aspiring chanteuse that she reminded him of one of America’s biggest pop stars.
“Grace, you know what I predict for you? I think you are the next Taylor Swift,” Cowell said.
Watch her full performance below.
Entertainment – TIME
She might only be 12, but Grace VanderWaal’s powerhouse vocals and ukulele skills have already caught the attention of some of music’s toughest critics, including one Mr. Simon Cowell.
The precocious singer appeared on America’s Got Talent on Tuesday night, where her flawless performance of an original song, “I Don’t Know My Name,” earned Grace an endorsement from Howie Mandel‘s golden buzzer, with judge going so far as to call her “a living, beautiful, walking miracle.”
However, the biggest compliment of the night came from the infamously hard-to-impress Cowell, who told the aspiring chanteuse that she reminded him of one of America’s biggest pop stars.
“Grace, you know what I predict for you? I think you are the next Taylor Swift,” Cowell said.
Watch her full performance below.
Entertainment – TIME
She might only be 12, but Grace VanderWaal’s powerhouse vocals and ukulele skills have already caught the attention of some of music’s toughest critics, including one Mr. Simon Cowell.
The precocious singer appeared on America’s Got Talent on Tuesday night, where her flawless performance of an original song, “I Don’t Know My Name,” earned Grace an endorsement from Howie Mandel‘s golden buzzer, with judge going so far as to call her “a living, beautiful, walking miracle.”
However, the biggest compliment of the night came from the infamously hard-to-impress Cowell, who told the aspiring chanteuse that she reminded him of one of America’s biggest pop stars.
“Grace, you know what I predict for you? I think you are the next Taylor Swift,” Cowell said.
Watch her full performance below.
Entertainment – TIME
Wednesday, June 29, 2016
Falling for the Sun: Heart-Shaped Sunspot Thrills Astrophotographer [bestandroiddoubledinheadunit950.blogspot.com]
Astrophotographer John Chumack. captured the heart-shaped sunspot from his backyard Observatory in Dayton, Ohio on April 12, 2016.
Credit: John Chumack | www.galacticimages.com
You can’t help falling in love with the recent sunspot AR2529 and that’s exactly what happened to astrophotographer John Chumack.
Chumack captured the heart-shaped sunspot from his backyard Observatory in Dayton, Ohio on April 12.
“I caught sunspot AR2529 flaring at lunch time in this close-up view,” he wrote in an email to Space.com. “[It] looks like a dachshund dog face with folded over ears or a heart.”
The sunspot was large enough to hold two Earthsas it crossed the face of the sun in April, making it a great target for amateur astronomers to safely observe.
Warning: NEVER look directly at or photograph the sun unless you have the proper protective equipment. Serious and permanent eye damage can result.
Sunspots are dark patches on the surface of the sun that are a bit cooler than surrounding areas. As the term “active region” suggests, sunspots serve as launchpads for solar flares and coronal mass ejections (CMEs) — huge eruptions that send clouds of solar plasma racing into space at millions of miles per hour.
To see more amazing night sky photos submitted by readers, visit our astrophotography archive.
Editor’s note: If you have an amazing night sky photo you’d like to share with Space.com and our news partners for a possible story or image gallery, send images and comments in to spacephotos@space.com.
Follow us on Twitter @Spacedotcom. We’re also on Facebook and Google+. Original story on Space.com.
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http://www.space.com/32676-heart-sunspot-astrophotographer-john-chumack-photo.html Falling for the Sun: Heart-Shaped Sunspot Thrills Astrophotographer
[bestandroiddoubledinheadunit950.blogspot.com]Falling for the Sun: Heart-Shaped Sunspot Thrills AstrophotographerWormholes Might Burrow Through Black Hole Cores [bestandroiddoubledinheadunit950.blogspot.com]
Credit: Kristof Wesely, Wikimedia Commons
Black holes and wormholes are the ultimate fodder for science fiction. Need to travel through time? No problem! Build a wormhole. Want to see a different universe? Dive into a black hole!
Though these imaginings are often far-fetched and, let’s face it, likely impossible, most are based on real theoretical physics ideas and, in new research focused on the nature of space-time inside a black hole, theorists have come up with a possible means of zipping around time and space… though it certainly wouldn’t be comfortable.
RELATED: Hawking Tries to Find Black Hole’s Emergency Exit
A black hole is as gravitationally extreme as it can get. Throw together enough matter in the same place and its mutual gravity will crush everything down to a single point until space-time itself collapses in on itself. Everything we know and love occupies space-time, so as it becomes warped around a black hole nothing, not even light, can escape its gravitational clutches. The point of no escape (where the gradient of space-time is so steep it traps light) is known as the event horizon.
For the most part, we have no experience of what goes on beyond the event horizon, it is off-limits to external observers. But theory says that for the black hole to exist, there needs to be a singularity in the center. A singularity is basically where math (and, by extension, nature) breaks down; it’s where the cosmic calculator divided by zero and got infinity. This cosmic computing mistake is hidden in the depths of the event horizon — if we can’t experience it, does it really matter what it is?
WATCH VIDEO: The Race To See The Black Hole At The Center Of Our Galaxy
According to a team of physicists led by Diego Rubiera-Garcia of the University of Lisbon, Portugal, actually the weird physics of a black hole’s singularity could turn our “classical” idea about black holes on its head. What if general relativity breaks down and the singularity isn’t a singularity at all? What if we replace the singularity with a wormhole? Suddenly, instead of being the ultimate trash compactors of the universe, black holes become the ultimate sci-fi dream: they could be space-time transportation hubs.
But, as is the case with most black hole stories, there’s a catch.
RELATED: The Race to See Our Supermassive Black Hole
In previous calculations, Rubiera-Garcia’s team created a theoretical model of a black hole without a singularity. To their surprise, in the singularity’s place, a finite-sized and spherical wormhole structure appeared. This is very important; it seems that instead of spitting out a confounding singularity, the math naturally creates a wormhole.
Before we can understand why this is important, we first have to consider why singularities are a thorn in the side of theorists and sci-fi writers alike. It is predicted that as an object (or unfortunate astronaut) falls into a black hole, tidal forces will be so extreme that “spaghettification” becomes a thing. The tidal forces at the astronaut’s toes would be much larger than what they’d feel at their head. They’d experience crushing forces from the sides, but extreme stretching between their toes and head. The best way to imagine it is to think about making spaghetti, only with the human body instead of pasta.
Should our stretched astronaut reach the singularity, they’d be infinitely long and infinitely thin — a situation that doesn’t make much sense.
But swap an infinitely tiny singularity with a finite-sized wormhole and things get a lot more interesting. Wormholes are a mathematical consequence of Einstein’s general relativity, but we have yet to find any evidence they actually exist. If they do exist, they would be made of a tube of spacetime, opening a passageway to another location or time (as space and time are intimately linked) in the universe. As the “neck” of the wormhole’s opening is finite, there’s none of this mathematical singularity nonsense messing with our astronaut. Sure, he or she would still be spaghettified, but they’d be more of a linguine than a spaghetti. So, hypothetically, their extremely tidally deformed body could pass through the neck of the wormhole.
RELATED: Has Stephen Hawking Just Solved a Huge Black-Hole Mystery?
“Each particle of the observer follows a geodesic line determined by the gravitational field,” said Rubiera-Garcia in a statement. “Each geodesic feels a slightly different gravitational force, but the interactions among the constituents of the body could nonetheless sustain the body.”
In the paper published in the journal Classical and Quantum Gravity, the researchers do point out that this wormhole isn’t a “traditionally traversable” wormhole, so it’s not the kind of wormhole that you could fit a stonking great spaceship through and expect it to resemble a spaceship on the other side. It would be microscopic and not traversable by macroscopic objects, but it would be a wormhole nonetheless.
Needless to say, this work is steeped in theoretical number-crunching and it’s hard to see how we could prove there’s a wormhole sitting in the centers of black holes except, perhaps, to do a Matthew McConaughey and find out for ourselves.
Source: Univ. of Lisbon
Originally published on Discovery News.
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http://www.space.com/33114-wormholes-might-burrow-through-black-hole-cores.html Wormholes Might Burrow Through Black Hole Cores
[bestandroiddoubledinheadunit950.blogspot.com]Wormholes Might Burrow Through Black Hole CoresSir Patrick Stewart Narrates ‘Journey To Space’ – ISS History Clip [bestandroiddoubledinheadunit950.blogspot.com]
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http://www.space.com/33117-sir-patrick-stewart-narrates-journey-to-space-iss-history-clip.html Sir Patrick Stewart Narrates 'Journey To Space' – ISS History Clip
[bestandroiddoubledinheadunit950.blogspot.com]Sir Patrick Stewart Narrates ‘Journey To Space’ – ISS History Clip