The Cellular Mind Training Series. Readings: OUT OF TIME JOURNAL: Page 22: To Students Of A Course In Miracles Everywhere In The World [para 1-16], SCIENTIFIC AMERICAN: Sept 2002: Page 42: Just In Time, OUT OF TIME JOURNAL: Page 22: To Students Of A Co...
Tag: Sept (page 1 of 2)
The Advent of a Great Awakening Series. Readings: TEXT: CHAPTER 13: The Function Of Time: [para 4, 6, 9, 10], TEXT: CHAPTER 13: The Two Emotions: [para 2-3], WORKBOOK: REVIEW V: Introduction: [para 4-8], OUT OF TIME JOURNAL: Page 12: The Natural Proces...
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.
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.
Excerpt from chroniclebulletin.com University of Colorado-led Mars mission has observed two unexpected phenomena in the Martian atmosphere, unveiled Wednesday at the 46th Lunar and Planetary Science Conference in Texas.NASA describes the finds by MA...
Excerpt from news.discovery.comDozens of candidate worlds reside within the "habitable zones" of their parent stars. THE GIST - NASA's Kepler telescope has found more than 1,200 extrasolar planet candidates. - Smaller worlds, like Earth,...
Kepler’s Exoplanets: A map of the locations of exoplanets, of various masses, in the Kepler field of view. 1,235 candidates are plotted (NASA/Wendy Stenzel)
news.discovery.com
Just in case you haven’t heard, our galaxy appears to be teeming with small worlds, many of which are Earth-sized candidate exoplanets and dozens appear to be orbiting their parent stars in their “habitable zones.”
Before Wednesday’s Kepler announcement, we knew of just over 500 exoplanets orbiting stars in the Milky Way. Now the space telescope has added another 1,235 candidates to the tally — what a difference 24 hours makes.
Although this is very exciting, the key thing to remember is that we are talking about exoplanet candidates, which means Kepler has detected 1,235 exoplanet signals, but more work needs to be done (i.e. more observing time) to refine their orbits, masses and, critically, to find out whether they actually exist.
But, statistically speaking, a pattern is forming. Kepler has opened our eyes to the fact our galaxy is brimming with small worlds — some candidates approaching Mars-sized dimensions!
Earth-Brand™ Life
Before Kepler, plenty of Jupiter-sized worlds could be seen, but with its precision eye for spotting the tiniest of fluctuations of star brightness (as a small exoplanet passes between Kepler and the star), the space telescope has found that smaller exoplanets outnumber the larger gas giants.Needless to say, all this talk of “Earth-sized” worlds (and the much-hyped “Earth-like” misnomer) has added fuel to the extraterrestrial life question: If there’s a preponderance of small exoplanets — some of which orbit within the “sweet-spot” of the habitable zones of their parent stars — could life as we know it (or Earth-Brand™ Life as I like to call it) also be thriving there?
Before I answer that question, let’s turn back the clock to Sept. 29, 2010, when, in the wake of the discovery of the exoplanet Gliese 581 g, Steven Vogt, professor of astronomy and astrophysics at University of California Santa Cruz, told Discovery News: “Personally, given the ubiquity and propensity of life to flourish wherever it can, I would say that the chances for life on [Gliese 581 g] are 100 percent. I have almost no doubt about it.”
Impossible? Or 100 Percent?
As it turns out, Gliese 581 g may not actually exist — an excellent example of the progress of science scrutinizing a candidate exoplanet in complex data sets as my Discovery News colleague Nicole Gugliucci discusses in “Gliese 581g and the Nature of Science” — but why was Vogt so certain that there was life on Gliese 581 g? Was he “wrong” to air this opinion?Going to the opposite end of the spectrum, Howard Smith, an astrophysicist at Harvard University, made the headlines earlier this year when he announced, rather pessimistically, that aliens will unlikely exist on the extrasolar planets we are currently detecting.
“We have found that most other planets and solar systems are wildly different from our own. They are very hostile to life as we know it,” Smith told the UK’s Telegraph.
Smith made comparisons between our own solar system with the interesting HD 10180 system, located 127 light-years away. HD 10180 was famous for a short time as being the biggest star system beyond our own, containing five exoplanets (it has since been trumped by Kepler-11, a star system containing six exoplanets as showcased in Wednesday’s Kepler announcement).
One of HD 10180′s worlds is thought to be around 1.4 Earth-masses, making it the smallest detected exoplanet before yesterday. Alas, as Smith notes, that is where the similarities end; the “Earth-sized” world orbiting HD 10180 is too close to its star, meaning it is a roasted exoplanet where any atmosphere is blasted into space by the star’s powerful radiation and stellar winds.
Both Right and Wrong
So what can we learn about the disparity between Vogt and Smith’s opinions about the potential for life on exoplanets, regardless of how “Earth-like” they may seem?Critically, both points of view concern Earth-Brand™ Life (i.e. us and the life we know and understand). As we have no experience of any other kind of life (although the recent eruption of interest over arsenic-based life is hotly debated), it is only Earth-like life we can realistically discuss.
We could do a Stephen Hawking and say that all kinds of life is possible anywhere in the cosmos, but this is pure speculation. Science only has life on Earth to work with, so (practically speaking) it’s pointless to say a strange kind of alien lifeform could live on an exoplanet where the surface is molten rock and constantly bathed in extreme stellar radiation.
If we take Hawking’s word for it, Vogt was completely justified for being so certain about life existing on Gliese 581 g. What’s more, there’s no way we could prove he’s wrong!
But if you set the very tight limits on where we could find Earth-like life, we are suddenly left with very few exoplanet candidates that fit the bill. Also, just because an Earth-sized planet might be found in the habitable zone of its star, doesn’t mean it’s actually habitable. There are many more factors to consider. So, in this case, Smith’s pessimism is well placed.
Regardless, exoplanet science is in its infancy and the uncertainty with the “is there life?” question is a symptom of being on the “raggedy edge of science,” as Nicole would say. We simply do not know what it takes to make a world habitable for any kind of life (apart from Earth), but it is all too tempting to speculate as to whether a race of extraterrestrials, living on one of Kepler’s worlds, is pondering these same questions.
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| President Barack Obama's new $4 trillion budget plan is distributed by the Senate Budget Committee as it arrives on Capitol Hill in Washington, early Monday, Feb. 02, 2015. The fiscal blueprint for the budget year that begins Oct. 1, seeks to raise taxes on wealthier Americans and corporations and use the extra income to lift the fortunes of families who have felt squeezed during tough economic times. Republicans, who now hold the power in Congress, are accusing the president of seeking to revert to tax-and-spend policies that will harm the economy while failing to do anything about soaring spending on government benefit programs. (AP Photo/J. Scott Applewhite) |
WASHINGTON — Sure, $4 trillion sounds like a lot. But it goes fast when your budget stretches from aging highways to medical care to space travel and more.
Here's an agency-by-agency look at how President Barack Obama would spend Americans' money in the 2016 budget year beginning Oct. 1:
HEALTH AND HUMAN SERVICES
Up or down? Up 4.3 percent
What's new? Medicare could negotiate prices for cutting-edge drugs.
Highlights:
— The president's proposed health care budget asks Congress to authorize Medicare to negotiate what it pays for high-cost prescription drugs and for biologics, including advanced medications for diseases such as rheumatoid arthritis. Currently, private insurers bargain on behalf of Medicare beneficiaries. Drug makers have beaten back prior proposals to give Medicare direct pricing power. But the introduction of a $1,000-a-pill hepatitis-C drug last year may have shifted the debate.
— Tobacco taxes would nearly double, to extend health insurance for low-income children. The federal cigarette tax would rise from just under $1.01 per pack to about $1.95 per pack. Taxes on other tobacco products also would go up. That would provide financing to pay for the Children's Health Insurance Program through 2019. The federal-state program serves about 8 million children, and funding technically expires Sept. 30. The tobacco tax hike would take effect in 2016.
— Starting in 2019, the proposal increases Medicare premiums for high-income beneficiaries and adds charges for new enrollees. The charges for new enrollees include a home health copayment, changes to the Part B deductible, and a premium surcharge for seniors who've also purchased a kind of supplemental insurance whose generous benefits are seen as encouraging overuse of Medicare services.
— There's full funding for ongoing implementation of Obama's health care law.
—The plan would end the budget sequester's 2 percent cut in Medicare payments to service providers and repeal another budget formula that otherwise will result in sharply lower payments for doctors. But what one hand gives, the other hand takes away. The budget also calls for Medicare cuts to hospitals, insurers, drug companies and other service providers.
The numbers:
Total spending: $1.1 trillion, including about $1 trillion on benefit programs including Medicare and Medicaid, already required by law.
Spending that needs Congress' annual approval: $80 billion.
NASA
Up or down? Up 2.9 percent
What's new? Not much. Just more money for planned missions.
Highlights:
—The exploration budget — which includes NASA's plans to grab either an asteroid or a chunk of an asteroid and haul it closer to Earth for exploration by astronauts — gets a slight bump in funding. But the details within the overall exploration proposal are key. The Obama plan would put more money into cutting-edge non-rocket space technology; give a 54 percent spending jump to money sent to private firms to develop ships to taxi astronauts to the International Space Station; and cut by nearly 12 percent spending to build the next government big rocket and capsule to carry astronauts. Congress in the past has cut the president's proposed spending on the private firms and technology and boosted the spending on the government big rocket and capsule.
—The president's 0.8 percent proposed increase in NASA science spending is his first proposed jump in that category in four years. It's also the first proposed jump in years in exploring other planets. It includes extra money for a 2020 unmanned Martian rover and continued funding for an eventual robotic mission to Jupiter's moon Europa. But the biggest extra science spending goes to study Earth.
— Obama's budget would cut aeronautics research 12 percent from current spending and slash NASA's educational spending by 25 percent. It also slightly trims the annual spending to build the over-budget multi-billion dollar James Webb Space Telescope, which will eventually replace the Hubble Space Telescope and is scheduled to launch in 2018.
The numbers:
Total spending: $18.5 billion
Spending that needs Congress' annual approval: $18.5 billion
TRANSPORTATION
Up or down? Up 31 percent
What's new? A plan to tackle an estimated $2 trillion in deferred maintenance for the nation's aging infrastructure by boosting highway and transit spending to $478 billion over six years.
Highlights:
— The six-year highway and transit plan would get a one-time $238 billion infusion from the general treasury. Some of the money would be offset by taxing the profits of U.S. companies that haven't been paying taxes on income made overseas. That infusion comes on top of the $35 billion a year that normally comes from gasoline and diesel taxes and other transportation fees.
— The proposal also includes tax incentives to encourage private investment in infrastructure, and an infrastructure investment bank to help finance major transportation projects.
— The new infrastructure investment would be front-loaded. The budget proposes to spend the money over six years and pay for the programs over 10 years.
— The proposal also includes a new Interagency Infrastructure Permitting Improvement Center to coordinate efforts across nearly 20 federal agencies and bureaus to speed up the permitting process. For example, the Coast Guard, Corps of Engineers and Transportation Department are trying to synchronize their reviews of projects such as bridges that cross navigation channels.
The numbers:
Total spending: $94.5 billion, including more than $80 billion already required by law, mostly for highway and transit aid to states and improvement grants to airports.
Spending that needs Congress' annual approval: $14.3 billion.
Associated Press writers Ricardo Alonso-Zaldivar, Seth Borenstein, Joan Lowy and Connie Cass contributed to this report.
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| India's first Mars orbiter Mangalyaan captured this photo of the Martian atmosphere just after arriving at Mars on Sept. 24, 2014 Indian Standard Time. The Indian Space Research Organisation released the image on Sept. 25. Credit: Indian Space Research Organisation |
scientificamerican.com
The India Space Research Organization unveils its first pictures of the red planet.
India's first Mars probe has captured its first photos, revealing an early glimpse of the surface and atmosphere of the Red Planet.
The Indian Space Research Organisation (ISRO) unveiled the first photos of Mars from its Mangalyaan spacecraft via Facebook and Twitter on Wednesday and Thursday (Sept. 24-25), just a day or so after the probe made it to the Red Planet.
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| Mars surface |
"The view is nice up here," ISRO officials tweeted about one of the images, which shows a heavily cratered portion of the Red Planet's surface.
Another photo depicts the curving, orange-brown limb of Mars against the blackness of space.
"A shot of Martian atmosphere. I'm getting better at it. No pressure," ISRO officials tweeted about that one.
Mangalyaan, whose name means "Mars craft" in Sanskrit, arrived at the Red Planet on Tuesday night (Sept. 23), making India's space agency just the fourth entity — after the United States, the Soviet Union and the European Space Agency — to successfully place a probe in orbit around Mars.
Mangalyaan is the centerpiece of India's $74 million Mars Orbiter Mission (MOM), which ISRO officials have described as primarily a technology demonstration. The spacecraft carries a camera and four scientific instruments that it will use to study the Martian surface and atmosphere during the course of a mission expected to last six to 10 months.
MOM reached Mars close on the heels of NASA's MAVEN (Mars Atmosphere and Volatile Evolution) probe, which was captured by the Red Planet's gravity on Sunday (Sept. 21). The $671 million MAVEN mission aims to help scientists determine what happened to Mars' atmosphere, which was once relatively thick but is now just 1 percent as dense as that of Earth.
MAVEN has also taken its first images of Mars from orbit; NASA released a few false-color views of the planet's atmosphere on Wednesday.
Mars orbit now hosts five operational spacecraft; NASA's Mars Odyssey probe and Mars Reconnaissance Orbiter, as well as Europe's Mars Express craft, share space with MAVEN and Mangalyaan. And two rovers (NASA's Opportunity and Curiosity) are actively exploriong the planet's surface.
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| This image shows water through time in the formation of the solar system, as scientists have revealed that water filling the Earth's oceans pre-date the formation of the sun |
By Brooks Hays
upi.com
"Our findings show that a significant fraction of our Solar System’s water, the most-fundamental ingredient to fostering life, is older than the Sun," said Conel Alexander.
WASHINGTON, Sept. 25 (UPI) -- If you took a dip at the beach this summer, chances are you bumped up against some truly ancient water molecules -- water older than the sun. In fact, there's probably interstellar water hanging out inside all of us -- we are 60 percent water, after all.
A new study suggests as much as a third of Earth's ocean water was likely formed prior to the birth of the sun and sourced from deep space ice.
Like all planets in our solar system, most of the Earth and much of its water was formed from the debris floating around our young sun -- a hot cloud of gas and other cosmic material known as the solar nebula. Included in this nebula were ices, but we know there are also ices floating in interstellar space -- as evidenced by meteorite samples.
What scientists haven't been sure of, however, is exactly how much of our water is made of interstellar ice, and how much was formed locally in the solar nebula. To solve that quandary, a team of scientists led by L. Ilsedore Cleeves from the University of Michigan built a model to predict the answer. The model was based on the scientists' understanding of the chemical circumstances that enable the formation of "heavy" water molecules -- a molecule with a deuterium atom instead of a hydrogen atom.
About 1 in every 3,000 water molecules has a deuterium atom. The scientists' model, part chemistry part mathematics, showed that the solar nebula wasn't capable of forming all of Earth's heavy water on its own, and thus suggested roughly a third of Earth's water is really alien water.
"Our findings show that a significant fraction of our Solar System's water, the most-fundamental ingredient to fostering life, is older than the Sun, which indicates that abundant, organic-rich interstellar ices should probably be found in all young planetary systems," said Conel Alexander, a researcher at Carnegie Science institute in Washington.
As Alexander explained, the revelation suggests the materials necessary for life are probably not as rare as scientists previously thought.
"If water in the early Solar System was primarily inherited as ice from interstellar space, then it is likely that similar ices, along with the prebiotic organic matter that they contain, are abundant in most or all protoplanetary disks around forming stars," Alexander added.
The study was published this week in the journal Science.
By Nola Taylor Redd, Space.com Contributor
A Neptune-size planet beyond the solar system has telltale traces of water vapor in its atmosphere, making it the smallest exoplanet known to have the wet stuff yet, scientists say.
Several massive Jupiter-size giants have had the components of their atmosphere examined, but until now, the atmospheres of smaller planets have proved more elusive. In this new study, scientists discovered traces of water on the alien planet HAT-P-11b, which orbits a star 124 light-years from Earth in the constellation Cygnus.
"Water is the most cosmically abundant molecule that we can directly observe in exoplanets, and we expect it to be prevalent in the upper atmospheres of planets at these temperatures," lead author Jonathan Fraine said in an email interview. Fraine, a graduate student at the University of Maryland, worked with a team lead by Drake Deming, also of the University of Maryland.
"Detecting it is both a confirmation of our theories and revealing for the bulk of the spectrum that we can observe," Fraine told Space.com.
This artist’s illustration depicts the alien planet HAT-P-11b, which shows signs of water in its atmosphere, as the exoplanet crosses in front of its parent star. As starlight passes through the puffed-up atmosphere surrounding the planet, shown here in orange, scientists can detect its composition.
Credit: NASA/JPL-Caltech
Credit: NASA/JPL-Caltech
Detecting alien planet atmospheres
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This image from the Hubble Space Telescope shows the star HAT-P-11 (center), which has a Neptune-size planet that is the smallest yet known to have water in its atmosphere. The planet, HAT-P-11b, is not visible in this image. The other bright object seen here is another star. Credit: NASA, ESA, J. Fraine |
As a planet passes, or transits, between Earth and its sun, it blocks light from the star. The dip in light is how many exoplanets are first found. But these transits also allow astronomers to study the atmospheres of exoplanets. By observing the spectrum of light that passes through an exoplanet’s atmosphere, scientists can determine what it is made up of.
For HAT-P-11b, a planet roughly four times the radius of Earth, that makeup is 90 percent hydrogen, with traces of water vapor. The Neptune-size planet orbits its sun every five days, at a distance that is only one-twentieth of the Earth-sun distance (which is 93 million miles, or 150 million kilometers). As a result, the temperature climbs higher on HAT P-11b than it does on gas giants in the solar system, reaching a sizzling 1,120 degrees Fahrenheit (605 degrees Celsius).
Scientists have been studying the atmospheres of Jupiter-like planets for years, but smaller planets produce a smaller signal that is more challenging to observe. For the new study, researchers examined the atmospheres of four other smaller exoplanets — two roughly the size of Neptune and two smaller super-Earths — but the results were disappointingly featureless.
"We do indeed have the technology — the resolution — to observe Neptune-size exoplanets, and even super-Earths," Fraine said.
But the chemical compositions of the other four planets were blocked by a familiar phenomenon — clouds.
"We've just been seeing a whole lot of nothing," Eliza Kempton, of Grinnell College in Iowa. Kempton models planetary atmospheres but was not involved in the research.
This artist's illustration shows what the skies may look like on different alien planets. On the left is a cloudy planet, while on the right is a planet with clear skies that may resemble the sky of exoplanet HAT-P-11b, a Neptune-size world thought to have water in its atmosphere.
Credit: NASA
Credit: NASA
Kempton added that the flat, featureless signals observed for the other planets were attributed to clouds or hazes in the upper atmosphere. The high clouds blocked light from the star, keeping it from penetrating through to the observers' side of the planet and leaving scientists unable to characterize the chemicals in the atmosphere.
"It's not crazy to think that there should be clouds in these exoplanet atmospheres, because we see clouds in all the planetary atmospheres in our solar system," Kempton said.
Although the hot, Neptune-size planet lives in a different environment from the icy giants in the solar system, it is similar to one of the four smaller planets whose atmosphere had already been studied. Those planets are known as GJ436b, GJ1214b, HD97658b and GJ3470b.
HAT-P-11b is only slightly larger and warmer than the alien planet GJ436b, making them good to compare to one another because one has clouds and one does not, Fraine said.
"I like to consider them the bigger version of the Earth-Venus twin pair," Fraine said of the planets HAT-P-11b and GJ436b.
"They are basically the same mass, radius and temperature, but small changes in the formation, or even these bulk properties, may be causing vast changes in the atmospheric composition."
The research is detailed in the Sept. 25 issue of the journal Nature, along with a commentary article by Kempton.
A planet's upper atmosphere results from what happens both above and below it. The balancing act involves irradiation from its star and from cosmic rays on the outside, as well as the chemical and dynamical systems lower in the atmosphere, Fraine explained.
"If we know the input from above — the host star — and the upper atmosphere from our observations, then the missing piece of the puzzle is the interior composition," he said.
Although the interior of a planet is complex, Fraine called the newly characterized atmosphere "a great step forward in solving the puzzle."
The composition of the small planet's atmosphere also supports the core accretion model of planetary formation, where smaller particles combine to create larger and larger particles, eventually reaching planet-size proportions.
"Core accretion predicts that planets are built from the inside out," Fraine said.
"Measuring that HAT P-11b likely has a relatively hydrogen-poor atmosphere implies that it was formed from rocky material that later acquired a thick atmosphere above it, which is what the core-accretion model predicts."
Had the planet formed along the lines of the competing gravitational instability model, its composition and that of its atmosphere should bear a stronger similarity to its star than what was measured by scientists.
Because of its crucial role in the balancing act, the water vapor detected in the exoplanet's atmosphere played an important part in modeling its formation and evolution.
"In the long run, if we can detect water, methane, carbon monoxide, carbon dioxide, etc., in dozens to hundreds of exoplanet atmospheres of various bulk properties, then we will be able to paint a much clearer picture of how planets form, and, likewise, how Earth formed," Fraine said.
"This was just one of the beginning brush strokes to painting the full picture of how planets, as well as ourselves, were formed."
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The start of fall in the Northern Hemisphere begins Sept. 22, 2014. |
By Joe Rao, Space.com Skywatching Columnist
Sick of long, hot summer days? Well, you're in luck. Astronomically speaking, autumn is about to begin in the north.
On Monday (Sept. 22), at 10:29 p.m. EDT (0229 Sept. 23 GMT) autumn begins astronomically in the Northern Hemisphere. This also marks the start of spring in the southern half of the globe.
This date is called an equinox, from the Latin for "equal night," alluding to the fact that day and night are then of equal length worldwide. But that is not necessarily correct. [Earth's Equinoxes & Solstices Explained (Infographic)]
Not so equal
Referring to the equinox as being a time of equal day and night is a convenient oversimplification. For one thing, it treats night as simply the time the sun is beneath the horizon, and completely ignores twilight. If the sun were nothing more than a point of light in the sky, and if the Earth lacked an atmosphere, then at the time of an equinox, the sun would indeed spend one half of its path above the horizon and one half below.But in reality, atmospheric refraction raises the sun's disc by more than its own apparent diameter while it is rising or setting. Thus, when the sun looks like a reddish-orange ball just sitting on the horizon, it's really an optical illusion. It is actually completely below the horizon.
In addition to refraction hastening sunrise and delaying sunset, there is another factor that makes daylight longer than night at an equinox: Sunrise and sunset are defined as the times when the first or last speck of the sun's upper or lower limbs — not the center of the disc — are visible above the horizon.
And this is why if you check your newspaper's almanac or weather page on Monday and look up the times of local sunrise and sunset, you'll notice that the duration of daylight, or the amount of time from sunrise to sunset, still lasts a bit more than 12 hours.
In New York City, for instance, sunrise is at 6:43 a.m., and sunset comes at 6:54 p.m. So the amount of daylight is not 12 hours, but rather 12 hours and 11 minutes. Not until Sept. 26 are the days and nights truly equal. (On Sept. 26, sunrise is at 6:47 a.m., and sunset is 12 hours later).
At the North Pole, the sun currently is tracing out a 360-degree circle around the entire sky, appearing to skim just above the edge of the horizon. At the moment of this year's autumnal equinox, it should theoretically disappear completely from view, and yet its disc will still be hovering just above the horizon. Not until 52 hours and 10 minutes later will the last speck of the sun's upper limb finally drop completely out of sight.
This strong refraction effect also causes the sun's disc to appear oval when it is near the horizon. The amount of refraction increases so rapidly as the sun approaches the horizon that its lower limb is lifted more than the upper one, distorting the sun's disc noticeably.
Not as dark as it seems
Certain astronomical myths die hard. One of these is that the entire Arctic region experiences six months of daylight and six months of darkness. Often, "night" is simply defined by the moment when the sun is beneath the horizon, as if twilight didn't exist. This fallacy is repeated in innumerable geography textbooks, as well as travel articles and guides.But twilight illuminates the sky to some extent whenever the sun's upper rim is less than 18 degrees below the horizon. This marks the limit of astronomical twilight, when the sky is indeed totally dark from horizon to horizon.
There are two other types of twilight. Civil (bright) twilight exists when the sun is less than 6 degrees beneath the horizon. It is loosely defined as when most outdoor daytime activities can be continued. Some daily newspapers provide a time when you should turn on your car's headlights. That time usually corresponds to the end of civil twilight.
So, even at the North Pole, while the sun disappears from view for six months beginning Sept. 25, to state that "total darkness" immediately sets in is hardly the case. In fact, civil twilight does not end there until Oct. 8.
When the sun drops down to 12 degrees below the horizon, it marks the end of nautical twilight, when a sea horizon becomes difficult to discern. In fact, at the end of nautical twilight, most people will regard night as having begun. At the North Pole, nautical twilight does not end until Oct. 25. Finally, astronomical twilight — when the sky indeed becomes completely dark — ends Nov. 13. It then remains perpetually dark until Jan. 29, when the twilight cycles begin anew. So, at the North Pole, the duration of 24-hour darkness lasts almost 11 weeks, not six months.
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| Satellite images show how much destruction has happened in Syria between December 2011 and July 2014. The Ministry of Justice building (red arrow) is damaged, as is the Khusriwiye Mosque (green arrow). |
Excerpt from news.yahoo.com
By Laura Geggel, Staff Writer
Three years of heavy fighting have taken a toll on Syria's archaeological treasures. Five of the country's six World Heritage sites "exhibit significant damage," and some buildings are now "reduced to rubble," according to high-resolution satellite images examined by the nonprofit and nonpartisan American Association for the Advancement of Science (AAAS).
"Only one of Syria's six World Heritage sites — the ancient city of Damascus — appears to remain undamaged in satellite imagery since the onset of civil war in 2011," Susan Wolfinbarger, director of the Geospatial Technologies and Human Rights Project at AAAS, said in a statement.
The analysis showed widespread damage in Aleppo, one of the oldest continuously occupied cities in the world, which dates back to the second millennium B.C.
A before-and-after analysis from 2011 to 2014 indicates new damage to historic mosques, Koranic schools called madrasas, the Great Mosque of Aleppo, the Souq al-Madina, the Grand Serail of Aleppo, the Hammam Yalbougha an-Nasry, the Khusruwiye Mosque, the Carlton Citadel Hotel, the Khan Qurt Bey caravanserai and other historic buildings south and north of the citadel.
The Great Mosque has extensive damage. Satellite imagery showed destruction of the roof and a destroyed minaret, or tall spire, as well as two craters on the mosque's eastern wall. Researchers saw the heaviest damage south of the citadel, but the area to the north, which has buildings from the late Mamluk to Ottoman periods (13th to 19th centuries) also showed signs of destruction.
The other World Heritage sites have damage ranging from mortar impacts near an ancient Roman theater in Bosra to newly constructed military compounds on an archaeological site. New roads and mounds of earth are scattered through the Northern Roman Necropolis in Palmyra.
The AAAS released the analysis yesterday (Sept. 18), a day before the Smithsonian Institution's meeting to honor the 1954 Hague Convention for the Protection of Cultural Property. Researchers plan to discuss the damage and intervention efforts in Syria at the meeting.
"There is hope, and it lies with our Syrian colleagues because they are the stewards and caretakers of these sites, and they see the value in preserving and protecting them for future generations," said Corine Wegener, cultural heritage preservation officer for the Smithsonian Institution. "What they need from their international colleagues is some help to do that — training, materials and other support in the international arena for the notion that it is possible to mitigate and prevent damage to cultural heritage, even in the midst of conflicts."
In “She Used to Be In A Wheelchair – The TED Talk That Comes With a Warning” I showcase Dr. Terry Wahls who successfully reversed her debilitating multiple sclerosis with the application of nutrients and meditation. She talks about the importance “minding your mitochondria” and how lifestyle, diet and environment can switch genes on or off. Similarly, there are people reversing ALS or Lou Gehrig’s disease using similar methods.What’s [...]
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