News digest – obesity and diets, the immune system, stats galore and more

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  • In another big week for research on the immune system and cancer, the journal Nature published five separate papers on the subject. And one of those papers looking at bladder cancer caught the eye of the BBC, Mail Online and the Telegraph. We also covered the studies on our news feed.

  • New estimates revealed that almost half a million new cancer cases worldwide in adults each year are linked to excess bodyweight. We covered this, and here’s the Mail Online and the Telegraph’s take on the findings.

  • Continuing with statistics, a new study found that, although things are improving, the UK cancer survival still lags behind the best in the world – particularly for lung cancer. The Guardian has more.

  • And in even more stats news, smoking rates in Britain have more than halved in the last 40 years. Look at the data in our news report, and the Mail Online had this take.

  • US researchers discovered that the presence of particular genetic faults in the DNA of blood cells may be an indicator for the development of blood cancers later in life. TIME has more on this.

  • The BBC took a graphic look at the changing face of Australian cigarette packing.

  • This piece in the Independent, by GP Margaret McCartney, discussed the importance of end-of-life care.

  • The Mail Online covered a new trial looking to test an advanced imaging technique that could help diagnose prostate cancer.

  • This article in The Conversation debunks the hype around research on cannabis and cancer.

  • This overhyped article appeared in the Telegraph following some interesting early research looking to develop a ‘breath test’ for lung cancer. It’s still too early to say if this could be used to diagnose people earlier.


And finally


New research sparked a couple of news reports on the perceived health benefits of the 5:2 diet and claims it could prevent diseases like Alzheimer’s and cancer. But the study actually found there’s not enough evidence to reach make those conclusions. Read this NHS Choices article for a more balanced analysis.







from Cancer Research UK - Science blog http://feedproxy.google.com/~r/cancerresearchuk/SHhE/~3/x6KzXF4iAzc/
Newspapers


  • In another big week for research on the immune system and cancer, the journal Nature published five separate papers on the subject. And one of those papers looking at bladder cancer caught the eye of the BBC, Mail Online and the Telegraph. We also covered the studies on our news feed.

  • New estimates revealed that almost half a million new cancer cases worldwide in adults each year are linked to excess bodyweight. We covered this, and here’s the Mail Online and the Telegraph’s take on the findings.

  • Continuing with statistics, a new study found that, although things are improving, the UK cancer survival still lags behind the best in the world – particularly for lung cancer. The Guardian has more.

  • And in even more stats news, smoking rates in Britain have more than halved in the last 40 years. Look at the data in our news report, and the Mail Online had this take.

  • US researchers discovered that the presence of particular genetic faults in the DNA of blood cells may be an indicator for the development of blood cancers later in life. TIME has more on this.

  • The BBC took a graphic look at the changing face of Australian cigarette packing.

  • This piece in the Independent, by GP Margaret McCartney, discussed the importance of end-of-life care.

  • The Mail Online covered a new trial looking to test an advanced imaging technique that could help diagnose prostate cancer.

  • This article in The Conversation debunks the hype around research on cannabis and cancer.

  • This overhyped article appeared in the Telegraph following some interesting early research looking to develop a ‘breath test’ for lung cancer. It’s still too early to say if this could be used to diagnose people earlier.


And finally


New research sparked a couple of news reports on the perceived health benefits of the 5:2 diet and claims it could prevent diseases like Alzheimer’s and cancer. But the study actually found there’s not enough evidence to reach make those conclusions. Read this NHS Choices article for a more balanced analysis.







from Cancer Research UK - Science blog http://feedproxy.google.com/~r/cancerresearchuk/SHhE/~3/x6KzXF4iAzc/

A famous variable star in the constellation Cepheus


Tonight … come to know Delta Cephei, a famous variable star in the constellation Cepheus. With clock-like precision, this rather faint star doubles in brightness every 5.36 days. You can see the brightness change best if you contrast this star to others nearby.


The constellation Cepheus requires a dark sky to be seen, so it’ll be more obvious after moonset tonight. But if you can spot this constellation, you might be able to find the variable star. You’ll find it high in your northern sky on November and December evenings. The pattern of stars in Cepheus resembles a stick house, the kind we all drew as children. The variable star – Delta Cephei – is located near the bottom corner of the house pattern.



Black Friday to Cyber Monday! 50% off your 2015 EarthSky Lunar Calendar today!


Cepheid variable stars are a class of stars named in honor of Delta Cephei. They are known as pulsating variables. The image at right is what astronomers call a “light curve” of a variable star. Each point represents the brightness of the star at a particular time. You can see that the star’s brightness changes in a regular way over a period of days.


The brightness of a Cepheid variable star changes because the star is actually expanding and contracting in size. The radius of a Cepheid variable star changes by several million kilometers (30%) as the star expands and shrinks. There is a very precise relationship between a Cepheid variable’s luminosity, or true brightness, and pulsation period. The greater the intrinsic brightness of the star, the longer the period. For that reason, these variable stars serve as standard candles – in other words, their true brightness is known, so astronomers can see how bright they look to measure the distances to the stars – and hence to faraway galaxies.


Now look again at the chart showing the constellations Cepheus the King and Cassiopeia the Queen at the top of this page. In the actual sky, the two stars near Delta Cephei – Epsilon Cephei and Zeta Cephei – mark the low and high ends of Delta Cephei’s brightness scale. At its faintest, the variable star Delta Cephei is as dim as the fainter star, Epsilon Cephei. At its brightest, Delta Cephei matches the brightness of Zeta Cephei.


Cepheid variable stars enabled the astronomer Edwin Hubble to figure out that the Andromeda galaxy lies outside the bounds of our local galaxy, the Milky Way.


Bottom line: Delta Cephei is a famous variable star in the constellation Cepheus. With clock-like precision, this rather faint star doubles in brightness every 5.36 days.


Easily locate stars and constellations during any day and time with EarthSky’s Planisphere.






from EarthSky http://ift.tt/1rEXMHE

Tonight … come to know Delta Cephei, a famous variable star in the constellation Cepheus. With clock-like precision, this rather faint star doubles in brightness every 5.36 days. You can see the brightness change best if you contrast this star to others nearby.


The constellation Cepheus requires a dark sky to be seen, so it’ll be more obvious after moonset tonight. But if you can spot this constellation, you might be able to find the variable star. You’ll find it high in your northern sky on November and December evenings. The pattern of stars in Cepheus resembles a stick house, the kind we all drew as children. The variable star – Delta Cephei – is located near the bottom corner of the house pattern.



Black Friday to Cyber Monday! 50% off your 2015 EarthSky Lunar Calendar today!


Cepheid variable stars are a class of stars named in honor of Delta Cephei. They are known as pulsating variables. The image at right is what astronomers call a “light curve” of a variable star. Each point represents the brightness of the star at a particular time. You can see that the star’s brightness changes in a regular way over a period of days.


The brightness of a Cepheid variable star changes because the star is actually expanding and contracting in size. The radius of a Cepheid variable star changes by several million kilometers (30%) as the star expands and shrinks. There is a very precise relationship between a Cepheid variable’s luminosity, or true brightness, and pulsation period. The greater the intrinsic brightness of the star, the longer the period. For that reason, these variable stars serve as standard candles – in other words, their true brightness is known, so astronomers can see how bright they look to measure the distances to the stars – and hence to faraway galaxies.


Now look again at the chart showing the constellations Cepheus the King and Cassiopeia the Queen at the top of this page. In the actual sky, the two stars near Delta Cephei – Epsilon Cephei and Zeta Cephei – mark the low and high ends of Delta Cephei’s brightness scale. At its faintest, the variable star Delta Cephei is as dim as the fainter star, Epsilon Cephei. At its brightest, Delta Cephei matches the brightness of Zeta Cephei.


Cepheid variable stars enabled the astronomer Edwin Hubble to figure out that the Andromeda galaxy lies outside the bounds of our local galaxy, the Milky Way.


Bottom line: Delta Cephei is a famous variable star in the constellation Cepheus. With clock-like precision, this rather faint star doubles in brightness every 5.36 days.


Easily locate stars and constellations during any day and time with EarthSky’s Planisphere.






from EarthSky http://ift.tt/1rEXMHE

NASA is tracking a gargantuan iceberg, escaped from Antarctica


Earth Observatory's first look (above) at B31 following the Southern Hemisphere winter was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite on November 22, 2014.

A first look at Antarctic iceberg B31, following the Southern Hemisphere winter. NASA’s Aqua satellite captured this image on November 22, 2014.



Winter has lifted from Antarctica’s Pine Island Bay, so that passing satellites can once again acquire sunlit views of massive iceberg B31 as it drifts in the Amundsen Sea. NASA has been tracking this iceberg – an ice island, really – since it separated from the front of Antarctica’s Pine Island Glacier a year ago (November 2013). It’s 240 square miles (over 600 square kilometers), in contrast to about 23 square miles for New York’s Manhattan Island. When southern winter fell around May 2014, darkness came to this region of Earth and the iceberg could not be seen for six months. It was thought then it would likely be swept up in the swift currents of the Southern Ocean, but, for now, it’s still in the Amundsen Sea – moving west – free now of surrounding debris and sea ice. Scientists expect that the berg will continue moving west.


Last April, just before winter darkness fell in Antarctica, Kelly Brunt, a glaciologist at NASA’s Goddard Space Flight Center, noted:



Iceberg calving is a very normal process. However, the detachment rift, or crack, that created this iceberg was well upstream of the 30-year average calving front of Pine Island Glacier, so this a region that warrants monitoring.



Pine Island Glacier itself – the source of the massive iceberg – has been the subject of intense study in the past several decades. Scientists speak of this glacier as the weak underbelly of the West Antarctic Ice Sheet. The glacier has been thinning and draining rapidly and may be one of the largest contributors to sea level rise. Read more: As ocean warms, Antarctica’s Pine Island Glacier thaws


Large icebergs like this one pose a danger to ships. Our modern shipboard technologies – radar and warning systems – can’t always prevent accidents. For example, in 2007, the MS Explorer, an Antarctic cruise ship, sank after striking an iceberg near the South Shetland Islands. Read more at CBS News.


Read more the images of B31 from NASA Visible Earth


B31 is a huge ice island, currently floating in the Admunsen Sea. It's excepted to cross into the Southern Ocean soon. Credit: NASA images by Jeff Schmaltz, LANCE/EOSDIS Rapid Response. Caption by Michael Carlowicz.

B31 is a huge ice island, 20 miles (33 kilometers) by 12 miles (20 kilometers). Image via Jeff Schmaltz, LANCE/EOSDIS Rapid Response.



The ice island B31 - __ square miles in diameter (over 600 square kilometers) - broke away from Pine Island Glacier in November 2013.

The ice island B31 broke away from Pine Island Glacier in early November, 2013.



NASA has been using at least two satellites to track the massive floating ice chunk.

Over the course of five months of Antarctic spring and summer – in late 2013 and early 2014 – NASA used both its Terra and Aqua satellites to capture images of the massive floating ice chunk. One of the scientists involved, Grant Bigg of the University of Sheffield, said his team was busy doing research on local ocean currents to try to explain the iceberg’s motion properly. He said, “It has been surprising how there have been periods of almost no motion, interspersed with rapid flow. There were a couple of occasions early on when there might have been partial grounding or collisions with the seafloor, as B31 bounced from one side of the Bay to the other.”



In the coming months, B31 is expected to leave the Amundsen Bay and enter the waters of the Southern Ocean. Since southern winter is approaching, it'll be dark over that area, and the iceberg will be harder to track.

This image was acquired in April, 2014, during Antarctica’s autumn. Since about that time, the iceberg has been impossible to track visually. However, as of November 2014, NASA is tracking the iceberg again with the return of summer to Antarctica.



Bottom line: NASA is tracking the huge iceberg B31, which broke away from Antarctica’s Pine Island Glacier in November, 2013. Winter is now over in the southern part of the world, and acquired its first image in six months of B31 on November 22, 2014.






from EarthSky http://ift.tt/1gXYlRy

Earth Observatory's first look (above) at B31 following the Southern Hemisphere winter was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite on November 22, 2014.

A first look at Antarctic iceberg B31, following the Southern Hemisphere winter. NASA’s Aqua satellite captured this image on November 22, 2014.



Winter has lifted from Antarctica’s Pine Island Bay, so that passing satellites can once again acquire sunlit views of massive iceberg B31 as it drifts in the Amundsen Sea. NASA has been tracking this iceberg – an ice island, really – since it separated from the front of Antarctica’s Pine Island Glacier a year ago (November 2013). It’s 240 square miles (over 600 square kilometers), in contrast to about 23 square miles for New York’s Manhattan Island. When southern winter fell around May 2014, darkness came to this region of Earth and the iceberg could not be seen for six months. It was thought then it would likely be swept up in the swift currents of the Southern Ocean, but, for now, it’s still in the Amundsen Sea – moving west – free now of surrounding debris and sea ice. Scientists expect that the berg will continue moving west.


Last April, just before winter darkness fell in Antarctica, Kelly Brunt, a glaciologist at NASA’s Goddard Space Flight Center, noted:



Iceberg calving is a very normal process. However, the detachment rift, or crack, that created this iceberg was well upstream of the 30-year average calving front of Pine Island Glacier, so this a region that warrants monitoring.



Pine Island Glacier itself – the source of the massive iceberg – has been the subject of intense study in the past several decades. Scientists speak of this glacier as the weak underbelly of the West Antarctic Ice Sheet. The glacier has been thinning and draining rapidly and may be one of the largest contributors to sea level rise. Read more: As ocean warms, Antarctica’s Pine Island Glacier thaws


Large icebergs like this one pose a danger to ships. Our modern shipboard technologies – radar and warning systems – can’t always prevent accidents. For example, in 2007, the MS Explorer, an Antarctic cruise ship, sank after striking an iceberg near the South Shetland Islands. Read more at CBS News.


Read more the images of B31 from NASA Visible Earth


B31 is a huge ice island, currently floating in the Admunsen Sea. It's excepted to cross into the Southern Ocean soon. Credit: NASA images by Jeff Schmaltz, LANCE/EOSDIS Rapid Response. Caption by Michael Carlowicz.

B31 is a huge ice island, 20 miles (33 kilometers) by 12 miles (20 kilometers). Image via Jeff Schmaltz, LANCE/EOSDIS Rapid Response.



The ice island B31 - __ square miles in diameter (over 600 square kilometers) - broke away from Pine Island Glacier in November 2013.

The ice island B31 broke away from Pine Island Glacier in early November, 2013.



NASA has been using at least two satellites to track the massive floating ice chunk.

Over the course of five months of Antarctic spring and summer – in late 2013 and early 2014 – NASA used both its Terra and Aqua satellites to capture images of the massive floating ice chunk. One of the scientists involved, Grant Bigg of the University of Sheffield, said his team was busy doing research on local ocean currents to try to explain the iceberg’s motion properly. He said, “It has been surprising how there have been periods of almost no motion, interspersed with rapid flow. There were a couple of occasions early on when there might have been partial grounding or collisions with the seafloor, as B31 bounced from one side of the Bay to the other.”



In the coming months, B31 is expected to leave the Amundsen Bay and enter the waters of the Southern Ocean. Since southern winter is approaching, it'll be dark over that area, and the iceberg will be harder to track.

This image was acquired in April, 2014, during Antarctica’s autumn. Since about that time, the iceberg has been impossible to track visually. However, as of November 2014, NASA is tracking the iceberg again with the return of summer to Antarctica.



Bottom line: NASA is tracking the huge iceberg B31, which broke away from Antarctica’s Pine Island Glacier in November, 2013. Winter is now over in the southern part of the world, and acquired its first image in six months of B31 on November 22, 2014.






from EarthSky http://ift.tt/1gXYlRy

Is it true that Jupiter protects Earth?


Here’s a question we get regularly:



Is it true that Jupiter could be considered our friendliest planet because – without Jupiter – comets would be more likely to hit us?



The answer is yes … and no. Some astronomers believe that one reason Earth is habitable is that the gravity of Jupiter does help protect us from some comets. Long-period comets, in particular, enter the solar system from its outer reaches. Jupiter’s gravity is thought to sling most of these fast-moving ice balls out of the solar system before they can get close to Earth. So long-period comets are thought to strike Earth only on very long timescales of millions or tens of millions of years. Without Jupiter nearby, long-period comets would collide with our planet much more frequently.


In addition, in recent decades, astronomers have been able to see signs of comets that have crashed into Jupiter. There was Comet Shoemaker-Levy 9 in 1994. And, in 2009, astronomers observed a dark gash in one side of the giant planet, likely caused by a comet.


A NASA Hubble Space Telescope image of Comet Shoemaker-Levy 9, taken on May 17, 1994. At this point, the comet had broken into 21 icy fragments stretched stretched across 1.1 million kilometers (710 thousand miles) of space, or 3 times the distance between Earth and moon. When this picture was taken, these fragments were on a mid-July collision course with the gas giant planet Jupiter.

A NASA Hubble Space Telescope image of Comet Shoemaker-Levy 9, taken on May 17, 1994. At this point, the comet had broken into 21 icy fragments stretched stretched across 1.1 million kilometers (710 thousand miles) of space, or 3 times the distance between Earth and moon. When this picture was taken, these fragments were on a mid-July collision course with the gas giant planet Jupiter. Image via Wikimedia Commons.



Brown spots mark the places where fragments of Comet Shoemaker-Levy 9 tore through Jupiter's atmosphere in July 1994. Image and caption via Wikimedia Commons.

Taking one for the team? Brown spots mark the places where fragments of Comet Shoemaker-Levy 9 tore through Jupiter’s atmosphere in July 1994. Image and caption via Wikimedia Commons.



In 2009, amateur astronomer Anthony Wesley noticed a dark mark on Jupiter. It turned out to be a scar from a comet impact. Read more about the 2009 impact on Jupiter here.

In 2009, amateur astronomer Anthony Wesley noticed a dark mark on Jupiter. It turned out to be a scar from an impact with some object, presumably a comet. Read more about the 2009 impact on Jupiter here.



But Jupiter creates both good and bad conditions for earthly life. Consider that its powerful gravity prevented space rocks orbiting near it from coalescing into a planet, and that’s why our solar system today has an asteroid belt, consisting of hundreds of thousands of small flying chunks of debris.


Today, Jupiter’s gravity continues to affect the asteroids – only now it nudges some asteroids toward the sun, where they have the possibility of colliding with Earth.


Another interesting story comes from several centuries ago. The late Brian G. Marsden, former director of the the International Astronomical Union’s Central Bureau for Astronomical Telegrams, related it to Dennis Overbye of the New York Times in 2009, shortly after the dark gash appeared on Jupiter. It’s rare for a comet to come within 1 astronomical unit of Earth (that is, one Earth-sun distance, 92 million miles, or about 150 million kilometers). But, in the year 1770, a Comet Lexell streaked past Earth at a distance of only a million miles. Dr. Marsden told Overbye that:



… the comet had come streaking in from the outer solar system three years earlier and passed close to Jupiter, which diverted it into a new orbit and straight toward Earth.


The comet made two passes around the sun and in 1779 again passed very close to Jupiter, which then threw it back out of the solar system.


‘It was as if Jupiter aimed at us and missed,’ said Dr. Marsden.



So is Jupiter Earth’s protector? The answer is … sometimes!


What’s the difference between comets and asteroids?






from EarthSky http://ift.tt/QDGsx4

Here’s a question we get regularly:



Is it true that Jupiter could be considered our friendliest planet because – without Jupiter – comets would be more likely to hit us?



The answer is yes … and no. Some astronomers believe that one reason Earth is habitable is that the gravity of Jupiter does help protect us from some comets. Long-period comets, in particular, enter the solar system from its outer reaches. Jupiter’s gravity is thought to sling most of these fast-moving ice balls out of the solar system before they can get close to Earth. So long-period comets are thought to strike Earth only on very long timescales of millions or tens of millions of years. Without Jupiter nearby, long-period comets would collide with our planet much more frequently.


In addition, in recent decades, astronomers have been able to see signs of comets that have crashed into Jupiter. There was Comet Shoemaker-Levy 9 in 1994. And, in 2009, astronomers observed a dark gash in one side of the giant planet, likely caused by a comet.


A NASA Hubble Space Telescope image of Comet Shoemaker-Levy 9, taken on May 17, 1994. At this point, the comet had broken into 21 icy fragments stretched stretched across 1.1 million kilometers (710 thousand miles) of space, or 3 times the distance between Earth and moon. When this picture was taken, these fragments were on a mid-July collision course with the gas giant planet Jupiter.

A NASA Hubble Space Telescope image of Comet Shoemaker-Levy 9, taken on May 17, 1994. At this point, the comet had broken into 21 icy fragments stretched stretched across 1.1 million kilometers (710 thousand miles) of space, or 3 times the distance between Earth and moon. When this picture was taken, these fragments were on a mid-July collision course with the gas giant planet Jupiter. Image via Wikimedia Commons.



Brown spots mark the places where fragments of Comet Shoemaker-Levy 9 tore through Jupiter's atmosphere in July 1994. Image and caption via Wikimedia Commons.

Taking one for the team? Brown spots mark the places where fragments of Comet Shoemaker-Levy 9 tore through Jupiter’s atmosphere in July 1994. Image and caption via Wikimedia Commons.



In 2009, amateur astronomer Anthony Wesley noticed a dark mark on Jupiter. It turned out to be a scar from a comet impact. Read more about the 2009 impact on Jupiter here.

In 2009, amateur astronomer Anthony Wesley noticed a dark mark on Jupiter. It turned out to be a scar from an impact with some object, presumably a comet. Read more about the 2009 impact on Jupiter here.



But Jupiter creates both good and bad conditions for earthly life. Consider that its powerful gravity prevented space rocks orbiting near it from coalescing into a planet, and that’s why our solar system today has an asteroid belt, consisting of hundreds of thousands of small flying chunks of debris.


Today, Jupiter’s gravity continues to affect the asteroids – only now it nudges some asteroids toward the sun, where they have the possibility of colliding with Earth.


Another interesting story comes from several centuries ago. The late Brian G. Marsden, former director of the the International Astronomical Union’s Central Bureau for Astronomical Telegrams, related it to Dennis Overbye of the New York Times in 2009, shortly after the dark gash appeared on Jupiter. It’s rare for a comet to come within 1 astronomical unit of Earth (that is, one Earth-sun distance, 92 million miles, or about 150 million kilometers). But, in the year 1770, a Comet Lexell streaked past Earth at a distance of only a million miles. Dr. Marsden told Overbye that:



… the comet had come streaking in from the outer solar system three years earlier and passed close to Jupiter, which diverted it into a new orbit and straight toward Earth.


The comet made two passes around the sun and in 1779 again passed very close to Jupiter, which then threw it back out of the solar system.


‘It was as if Jupiter aimed at us and missed,’ said Dr. Marsden.



So is Jupiter Earth’s protector? The answer is … sometimes!


What’s the difference between comets and asteroids?






from EarthSky http://ift.tt/QDGsx4

Good morning!



.

Photo by Daniel Levy Photography. Thank you Daniel!


You can see more of Daniel’s photos here






from EarthSky http://ift.tt/1FArKxf


.

Photo by Daniel Levy Photography. Thank you Daniel!


You can see more of Daniel’s photos here






from EarthSky http://ift.tt/1FArKxf

Neptune near moon on November 28



Photo of Neptune taken by Voyager 2 spacecraft in August 1989



Tonight … don’t expect to see Neptune, even though (because!) it’s close to the waxing gibbous moon. Neptune – eighth planet out from the sun and outermost of the major planets according to the International Astronomical Union – is the only major planet in our solar system that you absolutely can’t see with the unaided eye. The even-more-distant dwarf planet Pluto isn’t visible to the unaided eye, either, of course. On November 28, 2914, Neptune shines in front of the constellation Aquarius, and near the star Sigma Aquarii (chart of Aquarius below). Neptune is also close to the ecliptic – the path the planets follow in front of the constellations of the Zodiac. Because of the moonlit glare, you probably won’t see much of Aquarius tonight. What will you see? Only the moon shining in all its splendor. You can gaze at it and imagine Neptune nearby.


Although the moon and Neptune are close together on the sky’s dome tonight, they’re nowhere close in space. The moon resides about 1.2 light-seconds from Earth, whereas Neptune looms way out there at over four light-hours away. In other words, Neptune is over 12,000 times farther away than the moon in tonight’s sky.


Once the moon leaves the evening sky, starting the second week in December, Aquarius will easy to spot in a dark country sky. Then, if you’re armed with a telescope or powerful binoculars and a good sky chart, you might be able to glimpse Neptune.


Happy Black Friday! EarthSky lunar calendars 50% off Friday to Monday.


View larger We have labeled Sigma Aquarii (abbreviated Sigma) on the above sky chart. It's a 5th-magnitude star, which is dimly visible to the unaided eye in a dark sky.

View larger | Star chart of constellation Aquarius. We’ve labeled the star Sigma Aquarii (abbreviated Sigma). It’s a 5th-magnitude star, meaning it’s only dimly visible to the unaided eye in a dark sky.



For a stellar reference, learn how to star-hop to Sigma Aquarii, your guide star to Neptune. Neptune demands high-quality binoculars or a telescope, patience and a detailed star chart. Look for Neptune and the star Sigma Aquarii to take stage within the same binocular field.


Bottom line: On this November night – November 28, 2014 – use your mind’s eye to envision the solar system’s most distant major planet – Neptune – by tonight’s waxing gibbous moon.


Do you love stargazing? Order your EarthSky Planisphere today!






from EarthSky http://ift.tt/1vTY66K


Photo of Neptune taken by Voyager 2 spacecraft in August 1989



Tonight … don’t expect to see Neptune, even though (because!) it’s close to the waxing gibbous moon. Neptune – eighth planet out from the sun and outermost of the major planets according to the International Astronomical Union – is the only major planet in our solar system that you absolutely can’t see with the unaided eye. The even-more-distant dwarf planet Pluto isn’t visible to the unaided eye, either, of course. On November 28, 2914, Neptune shines in front of the constellation Aquarius, and near the star Sigma Aquarii (chart of Aquarius below). Neptune is also close to the ecliptic – the path the planets follow in front of the constellations of the Zodiac. Because of the moonlit glare, you probably won’t see much of Aquarius tonight. What will you see? Only the moon shining in all its splendor. You can gaze at it and imagine Neptune nearby.


Although the moon and Neptune are close together on the sky’s dome tonight, they’re nowhere close in space. The moon resides about 1.2 light-seconds from Earth, whereas Neptune looms way out there at over four light-hours away. In other words, Neptune is over 12,000 times farther away than the moon in tonight’s sky.


Once the moon leaves the evening sky, starting the second week in December, Aquarius will easy to spot in a dark country sky. Then, if you’re armed with a telescope or powerful binoculars and a good sky chart, you might be able to glimpse Neptune.


Happy Black Friday! EarthSky lunar calendars 50% off Friday to Monday.


View larger We have labeled Sigma Aquarii (abbreviated Sigma) on the above sky chart. It's a 5th-magnitude star, which is dimly visible to the unaided eye in a dark sky.

View larger | Star chart of constellation Aquarius. We’ve labeled the star Sigma Aquarii (abbreviated Sigma). It’s a 5th-magnitude star, meaning it’s only dimly visible to the unaided eye in a dark sky.



For a stellar reference, learn how to star-hop to Sigma Aquarii, your guide star to Neptune. Neptune demands high-quality binoculars or a telescope, patience and a detailed star chart. Look for Neptune and the star Sigma Aquarii to take stage within the same binocular field.


Bottom line: On this November night – November 28, 2014 – use your mind’s eye to envision the solar system’s most distant major planet – Neptune – by tonight’s waxing gibbous moon.


Do you love stargazing? Order your EarthSky Planisphere today!






from EarthSky http://ift.tt/1vTY66K

Does eating turkey really make you sleepy?


Ah, Thanksgiving Day. You pile your plates with turkey, dressing, two kinds of potatoes, cranberries – all the traditional foods – and dig in. Second helpings? Of course! An hour later, after plenty of food and conversation, you push back and notice you’ve become very, very sleepy. You think, “I’m sleepy because turkey is high in tryptophan.”


Photo credit: Lotus Carroll/Flickr

Photo credit: Lotus Carroll/Flickr



True? Or myth?



The answer is – don’t blame it on the turkey. While it’s a commonly held myth that turkey is especially high in tryptophan – and causes that drowsiness (“turkey coma”) you feel after a big Thanksgiving meal – the reality is that the amount of tryptophan in turkey is comparable to that found in chicken, beef, and other meats. In fact, turkey doesn’t result in higher levels of tryptophan in your blood than other common foods.


So why do you get so sleepy after a big turkey dinner? Post-meal drowsiness on Thanksgiving might have more to do with what else is on your plate – in particular, carbohydrates. A heavy meal rich in carbohydrates increases the production of sleep-promoting melatonin in the brain.


Melatonin is a hormone – produced in the pineal gland – that plays a role in regulating biological rhythms, including sleep. Melatonin is sold as a sleep aid. People often use it to combat jet lag when flying between time zones. Hence, “feast-induced drowsiness” — which many people across the U.S. will feel this afternoon – might be the result of a rich meal high in carbohydrates – not because of the tryptophan in turkey.



And there are other factors in post-Thanksgiving meal drowsiness including, possibly, the amount of fat in the meal (slows down the digestion), alcohol consumption, overeating and just plain tiredness from all the conversation with relatives and friends, plus the work of preparing the meal itself.


By the way, certain foods, such as soybeans, sesame and sunflower seeds, and certain cheeses, are high in tryptophan. Although it is possible these might induce sleepiness if consumed in sufficient quantities, this is not well-studied.


So enjoy your Thanksgiving meal today, and aim for a nap afterwards. Why not? Happy Thanksgiving!


Bottom line: Turkey does contain tryptophan but no more so than chicken, beef, and other meats. The drowsiness you feel after a rich Thanksgiving meal might result from the inclusion of large amounts of carbohydrates (the dressing, rolls, mashed potatoes), which increases the production of sleep-inducing melatonin in the brain. Plus the fats in the meal, alcohol, overeating and just plain tiredness all can have an effect.






from EarthSky http://ift.tt/1ykR5dT

Ah, Thanksgiving Day. You pile your plates with turkey, dressing, two kinds of potatoes, cranberries – all the traditional foods – and dig in. Second helpings? Of course! An hour later, after plenty of food and conversation, you push back and notice you’ve become very, very sleepy. You think, “I’m sleepy because turkey is high in tryptophan.”


Photo credit: Lotus Carroll/Flickr

Photo credit: Lotus Carroll/Flickr



True? Or myth?



The answer is – don’t blame it on the turkey. While it’s a commonly held myth that turkey is especially high in tryptophan – and causes that drowsiness (“turkey coma”) you feel after a big Thanksgiving meal – the reality is that the amount of tryptophan in turkey is comparable to that found in chicken, beef, and other meats. In fact, turkey doesn’t result in higher levels of tryptophan in your blood than other common foods.


So why do you get so sleepy after a big turkey dinner? Post-meal drowsiness on Thanksgiving might have more to do with what else is on your plate – in particular, carbohydrates. A heavy meal rich in carbohydrates increases the production of sleep-promoting melatonin in the brain.


Melatonin is a hormone – produced in the pineal gland – that plays a role in regulating biological rhythms, including sleep. Melatonin is sold as a sleep aid. People often use it to combat jet lag when flying between time zones. Hence, “feast-induced drowsiness” — which many people across the U.S. will feel this afternoon – might be the result of a rich meal high in carbohydrates – not because of the tryptophan in turkey.



And there are other factors in post-Thanksgiving meal drowsiness including, possibly, the amount of fat in the meal (slows down the digestion), alcohol consumption, overeating and just plain tiredness from all the conversation with relatives and friends, plus the work of preparing the meal itself.


By the way, certain foods, such as soybeans, sesame and sunflower seeds, and certain cheeses, are high in tryptophan. Although it is possible these might induce sleepiness if consumed in sufficient quantities, this is not well-studied.


So enjoy your Thanksgiving meal today, and aim for a nap afterwards. Why not? Happy Thanksgiving!


Bottom line: Turkey does contain tryptophan but no more so than chicken, beef, and other meats. The drowsiness you feel after a rich Thanksgiving meal might result from the inclusion of large amounts of carbohydrates (the dressing, rolls, mashed potatoes), which increases the production of sleep-inducing melatonin in the brain. Plus the fats in the meal, alcohol, overeating and just plain tiredness all can have an effect.






from EarthSky http://ift.tt/1ykR5dT