Wow! Polar stratospheric clouds

Laffen Jensen wrote on New Year’s Eve: “Pearl Clouds (polar stratospheric clouds) have been observed since several days after Christmas, over large parts of Norway. The clouds have been large and covered partially large parts of the sky.”

Last week and over the weekend – as the year shifted to 2017 – we began receiving photos of vividly colored ice clouds called polar stratospheric clouds, or sometimes nacreous clouds, or mother-of-pearl clouds. Earth’s stratosphere is normally cloud-free, but these clouds do sometimes appear some 9 -16 miles (15 – 25 km) high in Earth’s atmosphere. They’re said to have more rainbow-like colors than the iridescent clouds seen around the world fairly commonly, at lower latitudes.

Ordinary clouds, like the dark one seen in the foreground of this photo, form in Earth’s troposphere, the layer of atmosphere in which nearly all our weather occurs, extending some 6 miles (10 km) above the ground. Stratospheric clouds are much higher up. Photo posted to EarthSky Facebook January 1, 2017 by Bjorn Sorhoy in Norway.

Les Cowley of the website Atmospheric Optics posted a beautiful explanation for these clouds after a February 2016 outbreak over the UK, saying:

Nacreous clouds, sometimes called mother-of-pearl clouds, are rare but once seen are never forgotten. They are mostly visible within two hours after sunset or before dawn when they blaze unbelievably bright with vivid and slowly shifting iridescent colours. They are filmy sheets slowly curling and uncurling, stretching and contracting in the semi-dark sky. Compared with dark scudding low altitude clouds that might be present, nacreous clouds stand majestically in almost the same place – an indicator of their great height.

They need the very frigid regions of the lower stratosphere some 15 – 25 km (9 -16 mile) high and well above tropospheric clouds. They are so bright after sunset and before dawn because at those heights they are still sunlit.

They are seen mostly during winter at high latitudes like Scandinavia, Iceland, Alaska and Northern Canada. Sometimes, however, they occur as far south as England.

Rob Wilson in Norway caught this polar stratospheric cloud on December 30, 2016. He wrote: “in Norwegian its is called Perlemorskyer.”

Spaceweather.com added that – although they once were thought to be “mere curiosities,” some polar stratospheric clouds (PSCs) are now known to be associated with the destruction of ozone:

Indeed, an ozone hole formed over the UK in February 2016 following an outbreak of ozone-destroying Type 1 PSCs.

Thanks to all who submitted photos or posted photos of the clouds at EarthSky Facebook!

Polar stratospheric clouds. Photo posted to EarthSky Facebook January 1, 2017 by Bjorn Sorhoy in Norway.

Polar stratospheric clouds. Photo posted to EarthSky Facebook January 1, 2017 by Bjorn Sorhoy in Norway.

Bottom line: Polar stratospheric clouds – also called nacreous clouds or mother-of-pearl clouds – have been putting on a show for those at latitudes near the Arctic Circle. Photos from the EarthSky community here.

from EarthSky http://ift.tt/2hKxkN2

Laffen Jensen wrote on New Year’s Eve: “Pearl Clouds (polar stratospheric clouds) have been observed since several days after Christmas, over large parts of Norway. The clouds have been large and covered partially large parts of the sky.”

Last week and over the weekend – as the year shifted to 2017 – we began receiving photos of vividly colored ice clouds called polar stratospheric clouds, or sometimes nacreous clouds, or mother-of-pearl clouds. Earth’s stratosphere is normally cloud-free, but these clouds do sometimes appear some 9 -16 miles (15 – 25 km) high in Earth’s atmosphere. They’re said to have more rainbow-like colors than the iridescent clouds seen around the world fairly commonly, at lower latitudes.

Ordinary clouds, like the dark one seen in the foreground of this photo, form in Earth’s troposphere, the layer of atmosphere in which nearly all our weather occurs, extending some 6 miles (10 km) above the ground. Stratospheric clouds are much higher up. Photo posted to EarthSky Facebook January 1, 2017 by Bjorn Sorhoy in Norway.

Les Cowley of the website Atmospheric Optics posted a beautiful explanation for these clouds after a February 2016 outbreak over the UK, saying:

Nacreous clouds, sometimes called mother-of-pearl clouds, are rare but once seen are never forgotten. They are mostly visible within two hours after sunset or before dawn when they blaze unbelievably bright with vivid and slowly shifting iridescent colours. They are filmy sheets slowly curling and uncurling, stretching and contracting in the semi-dark sky. Compared with dark scudding low altitude clouds that might be present, nacreous clouds stand majestically in almost the same place – an indicator of their great height.

They need the very frigid regions of the lower stratosphere some 15 – 25 km (9 -16 mile) high and well above tropospheric clouds. They are so bright after sunset and before dawn because at those heights they are still sunlit.

They are seen mostly during winter at high latitudes like Scandinavia, Iceland, Alaska and Northern Canada. Sometimes, however, they occur as far south as England.

Rob Wilson in Norway caught this polar stratospheric cloud on December 30, 2016. He wrote: “in Norwegian its is called Perlemorskyer.”

Spaceweather.com added that – although they once were thought to be “mere curiosities,” some polar stratospheric clouds (PSCs) are now known to be associated with the destruction of ozone:

Indeed, an ozone hole formed over the UK in February 2016 following an outbreak of ozone-destroying Type 1 PSCs.

Thanks to all who submitted photos or posted photos of the clouds at EarthSky Facebook!

Polar stratospheric clouds. Photo posted to EarthSky Facebook January 1, 2017 by Bjorn Sorhoy in Norway.

Polar stratospheric clouds. Photo posted to EarthSky Facebook January 1, 2017 by Bjorn Sorhoy in Norway.

Bottom line: Polar stratospheric clouds – also called nacreous clouds or mother-of-pearl clouds – have been putting on a show for those at latitudes near the Arctic Circle. Photos from the EarthSky community here.

from EarthSky http://ift.tt/2hKxkN2

Study: Higher gun ownership rates up the risk of a woman being murdered (rerun) [The Pump Handle]

The Pump Handle is on a holiday break. The following, which was originally published on Jan. 29, is one of our favorite posts from 2016.

by Kim Krisberg

In the midst of another national debate over gun safety regulations, some argue that higher rates of gun ownership will protect people from dangerous strangers with deadly intentions. Physician and public health researcher Michael Siegel set out to study that argument. He ultimately found no relationship between gun ownership and stranger-related firearm homicides. But he did find that gun ownership levels translated into higher homicide risks for one group in particular — women.

“Our data refute the hypothesis that the more guns out there, the more of a deterrent there is to strangers committing firearm crimes,” Siegel, a professor in the Boston University School of Public Health, told me. “However, we found ownership rates were significantly correlated with non-stranger homicide rates. It’s the worst of both worlds because on the one hand, a higher prevalence of guns doesn’t seem to protect anyone…but it does increase the risk that non-strangers will kill each other with guns.”

To conduct the study, which was published in the journal Violence and Gender, Siegel and study co-author Emily Rothman, an associate public health professor at Boston University, examined state-specific homicide data from the Supplemental Homicide Reports of the FBI’s Uniform Crime Reports. Siegel noted that his study is the first to examine the relationship between state-level gun ownership and homicide rates in which the data is broken down by gender and by the nature of the relationship between the victim and perpetrator (i.e. stranger versus non-stranger). The study found that women living in states with higher rates of gun ownership faced a greater risk of being killed by someone they knew when compared to women in states with a lower rate of gun ownership.

But here’s the really interesting part: Among men, the difference in state-based firearm ownership rates explained about 1.5 percent of the variation in firearm-related homicide rates. For women, firearm ownership rates explained 40 percent of the variation in homicide rates with a firearm. In other words, while multiple factors must be considered in predicting the male homicide rate, just knowing a state’s gun ownership rate would allow a researcher to fairly accurately predict the female homicide rate.

“That finding was pretty striking for us,” Siegel said.

Simply put, more guns in a state means more women are killed. Siegel and Rothman write:

The magnitude of the association between firearm ownership and femicide committed by firearm was substantial. For each 10 percentage point increase in firearm ownership, our model predicts that the female firearm-related homicide rate increases by 10.2 percent. Thus, if the proportion of firearm ownership in Wyoming were 40 percent (the mean for all states) instead of 73 percent, our model predicts that its homicide rate would be approximately 33.8 percent lower (2.2 per 100,000 instead of 3.3 per 100,000).

In studying data that spanned from 1981 to 2013, researchers found that firearms were used in about 62 percent of homicides. More than 78 percent of all homicides involved an offender who was an intimate partner, family member or other acquaintance. In all, a non-stranger perpetrated more than three-quarters of the firearm-related homicides studied. But while men were more likely to be killed with a firearm, women were more likely to be killed with a gun by someone they knew.

The study found no evidence that greater availability of guns protects women from being killed. On the contrary, the study suggests that greater availability of guns translates into a higher risk that a woman will be killed by someone she knows.

“The data is just not consistent with the argument that having a high prevalence of firearms is protective against stranger homicide,” Siegel told me. “But for women, the level of gun ownership in a state is one of the primary factors in predicting her risk of being killed by a firearm.”

One of the obvious policy implications of Siegel and Rothman’s study is underscoring the importance of rules that restrict gun ownership among domestic violence offenders or those who’ve violated restraining orders. However, Siegel said the study also speaks to the critical importance of studying gun violence from a public health perspective — something the Centers for Disease Control and Prevention has been prohibited from doing for years. In 2013, President Obama signed an executive order allowing CDC to resume gun violence research and has recommended new funding for such research, though such funding proposals haven’t made it through Congress.

“This is a national problem — a societal problem — and everyone needs to be involved in tackling it,” Siegel said. “It really will take national resolve.”

To request a full copy of the new study, visit Violence and Gender.

Kim Krisberg is a freelance public health writer living in Austin, Texas, and has been writing about public health for nearly 15 years.

from ScienceBlogs http://ift.tt/2iBfLir

The Pump Handle is on a holiday break. The following, which was originally published on Jan. 29, is one of our favorite posts from 2016.

by Kim Krisberg

In the midst of another national debate over gun safety regulations, some argue that higher rates of gun ownership will protect people from dangerous strangers with deadly intentions. Physician and public health researcher Michael Siegel set out to study that argument. He ultimately found no relationship between gun ownership and stranger-related firearm homicides. But he did find that gun ownership levels translated into higher homicide risks for one group in particular — women.

“Our data refute the hypothesis that the more guns out there, the more of a deterrent there is to strangers committing firearm crimes,” Siegel, a professor in the Boston University School of Public Health, told me. “However, we found ownership rates were significantly correlated with non-stranger homicide rates. It’s the worst of both worlds because on the one hand, a higher prevalence of guns doesn’t seem to protect anyone…but it does increase the risk that non-strangers will kill each other with guns.”

To conduct the study, which was published in the journal Violence and Gender, Siegel and study co-author Emily Rothman, an associate public health professor at Boston University, examined state-specific homicide data from the Supplemental Homicide Reports of the FBI’s Uniform Crime Reports. Siegel noted that his study is the first to examine the relationship between state-level gun ownership and homicide rates in which the data is broken down by gender and by the nature of the relationship between the victim and perpetrator (i.e. stranger versus non-stranger). The study found that women living in states with higher rates of gun ownership faced a greater risk of being killed by someone they knew when compared to women in states with a lower rate of gun ownership.

But here’s the really interesting part: Among men, the difference in state-based firearm ownership rates explained about 1.5 percent of the variation in firearm-related homicide rates. For women, firearm ownership rates explained 40 percent of the variation in homicide rates with a firearm. In other words, while multiple factors must be considered in predicting the male homicide rate, just knowing a state’s gun ownership rate would allow a researcher to fairly accurately predict the female homicide rate.

“That finding was pretty striking for us,” Siegel said.

Simply put, more guns in a state means more women are killed. Siegel and Rothman write:

The magnitude of the association between firearm ownership and femicide committed by firearm was substantial. For each 10 percentage point increase in firearm ownership, our model predicts that the female firearm-related homicide rate increases by 10.2 percent. Thus, if the proportion of firearm ownership in Wyoming were 40 percent (the mean for all states) instead of 73 percent, our model predicts that its homicide rate would be approximately 33.8 percent lower (2.2 per 100,000 instead of 3.3 per 100,000).

In studying data that spanned from 1981 to 2013, researchers found that firearms were used in about 62 percent of homicides. More than 78 percent of all homicides involved an offender who was an intimate partner, family member or other acquaintance. In all, a non-stranger perpetrated more than three-quarters of the firearm-related homicides studied. But while men were more likely to be killed with a firearm, women were more likely to be killed with a gun by someone they knew.

The study found no evidence that greater availability of guns protects women from being killed. On the contrary, the study suggests that greater availability of guns translates into a higher risk that a woman will be killed by someone she knows.

“The data is just not consistent with the argument that having a high prevalence of firearms is protective against stranger homicide,” Siegel told me. “But for women, the level of gun ownership in a state is one of the primary factors in predicting her risk of being killed by a firearm.”

One of the obvious policy implications of Siegel and Rothman’s study is underscoring the importance of rules that restrict gun ownership among domestic violence offenders or those who’ve violated restraining orders. However, Siegel said the study also speaks to the critical importance of studying gun violence from a public health perspective — something the Centers for Disease Control and Prevention has been prohibited from doing for years. In 2013, President Obama signed an executive order allowing CDC to resume gun violence research and has recommended new funding for such research, though such funding proposals haven’t made it through Congress.

“This is a national problem — a societal problem — and everyone needs to be involved in tackling it,” Siegel said. “It really will take national resolve.”

To request a full copy of the new study, visit Violence and Gender.

Kim Krisberg is a freelance public health writer living in Austin, Texas, and has been writing about public health for nearly 15 years.

from ScienceBlogs http://ift.tt/2iBfLir

Galaxy clusters prove dark matter’s existence (Synopsis) [Starts With A Bang]

“You may hate gravity, but gravity doesn’t care.” –Clayton Christensen

If all we had were galactic rotation curves — like those measured by Vera Rubin — we would know that something was wrong with our picture of the Universe, but we wouldn’t know how. Two equally good explanations, that there was either a flaw in the law of gravity or there was the existence of some unseen mass, could account for what we saw. But observations of galaxy clusters point to dark matter in a dramatic fashion.

The Coma cluster of galaxies, whose galaxies move far too quickly to be accounted for by gravitation given the mass observed alone. Image credit: KuriousG of Wikimedia Commons, under a c.c.a.-s.a.-4.0 license.

Both dark matter and the modifications one can make to gravity to explain galactic rotation make specific predictions for other phenomena. The motions of individual galaxies within a cluster, the bending of background light by strong lensing, the distortion of galaxy shape from weak lensing and the separation of effective mass from normal matter are four independent ways clusters can discriminate. On all four counts, they point to dark matter, not modified gravity.

The overlay in the lower left hand corner represents the distortion of background images due to gravitational lensing expected from the dark matter “haloes” of the foreground galaxies, indicated by red ellipses. The blue polarization “sticks” indicate the distortion. Image credit: Mike Hudson, of shear and weak lensing in the Hubble Deep field. His research page is at http://ift.tt/2iv9oe4.

Come get the full story in pictures, video and no more than 200 words on today’s Mostly Mute Monday!

from ScienceBlogs http://ift.tt/2iHDL0v

“You may hate gravity, but gravity doesn’t care.” –Clayton Christensen

If all we had were galactic rotation curves — like those measured by Vera Rubin — we would know that something was wrong with our picture of the Universe, but we wouldn’t know how. Two equally good explanations, that there was either a flaw in the law of gravity or there was the existence of some unseen mass, could account for what we saw. But observations of galaxy clusters point to dark matter in a dramatic fashion.

The Coma cluster of galaxies, whose galaxies move far too quickly to be accounted for by gravitation given the mass observed alone. Image credit: KuriousG of Wikimedia Commons, under a c.c.a.-s.a.-4.0 license.

Both dark matter and the modifications one can make to gravity to explain galactic rotation make specific predictions for other phenomena. The motions of individual galaxies within a cluster, the bending of background light by strong lensing, the distortion of galaxy shape from weak lensing and the separation of effective mass from normal matter are four independent ways clusters can discriminate. On all four counts, they point to dark matter, not modified gravity.

The overlay in the lower left hand corner represents the distortion of background images due to gravitational lensing expected from the dark matter “haloes” of the foreground galaxies, indicated by red ellipses. The blue polarization “sticks” indicate the distortion. Image credit: Mike Hudson, of shear and weak lensing in the Hubble Deep field. His research page is at http://ift.tt/2iv9oe4.

Come get the full story in pictures, video and no more than 200 words on today’s Mostly Mute Monday!

from ScienceBlogs http://ift.tt/2iHDL0v

Best Reads Of 2016 [Aardvarchaeology]

The Detective: Jonathan L. Howard’s second book about Johannes Cabal, the necromancer.

Here are my best reads in English during 2016. My total was 42 books and 13 of them were e-books. Find me at Goodreads!

Dear Reader, what were your best reads of the year?

• The Detective. (Johannes Cabal #2.) Jonathan L. Howard 2010. Sardonically funny Ruritanian detective story.
• Bully for Brontosaurus. Stephen Jay Gould 1991. Essays on natural history.
• Ready Player One. Ernest Cline 2011. Wonderful adventure story for anyone who played video games in the 1980s.
• Murder at the Vicarage. Agatha Christie 1930. Parts of it very funny.
• The Hobbit. J.R.R. Tolkien 1937. There and back again!
• Personal Narrative of a Pilgrimage to Al Madinah and Meccah, Vol 1. Richard Francis Burton 1857. Victorian genius dresses up as a Muslim and enters a forbidden holy city.
• Thud! Terry Pratchett 2005. Inter-ethnic tensions in Ankh-Morpork.
• A Canticle for Leibowitz. Walter M. Miller Jr. 1959. What happens after WW3?
• Swallows and Amazons. Arthur Ransome 1930. Sibling quartet have summer adventures in the Lake District.
• Collected Stories. Lewis Shiner 2009.
• The Cruciform Brooch and Anglo-Saxon England. Toby F. Martin 2015.
• Errantry: Strange Stories. Elizabeth Hand 2012.
• 6 Stories. Kathe Koja.
• The Green Leopard Plague and Other Stories. Walter Jon Williams 2010.
• Borders of Infinity. Lois McMaster Bujold 1989. Miles Vorkosigan stories.
• Wild Things (Short stories.). C.C. Finlay 2005.
• Women Up to No Good: A Collection of Short Stories. Pat Murphy 2013.
• Moving Pictures. Terry Pratchett 1990. Hollywood on Discworld.

Here’s my list for 2015.

from ScienceBlogs http://ift.tt/2iZtLmA

The Detective: Jonathan L. Howard’s second book about Johannes Cabal, the necromancer.

Here are my best reads in English during 2016. My total was 42 books and 13 of them were e-books. Find me at Goodreads!

Dear Reader, what were your best reads of the year?

• The Detective. (Johannes Cabal #2.) Jonathan L. Howard 2010. Sardonically funny Ruritanian detective story.
• Bully for Brontosaurus. Stephen Jay Gould 1991. Essays on natural history.
• Ready Player One. Ernest Cline 2011. Wonderful adventure story for anyone who played video games in the 1980s.
• Murder at the Vicarage. Agatha Christie 1930. Parts of it very funny.
• The Hobbit. J.R.R. Tolkien 1937. There and back again!
• Personal Narrative of a Pilgrimage to Al Madinah and Meccah, Vol 1. Richard Francis Burton 1857. Victorian genius dresses up as a Muslim and enters a forbidden holy city.
• Thud! Terry Pratchett 2005. Inter-ethnic tensions in Ankh-Morpork.
• A Canticle for Leibowitz. Walter M. Miller Jr. 1959. What happens after WW3?
• Swallows and Amazons. Arthur Ransome 1930. Sibling quartet have summer adventures in the Lake District.
• Collected Stories. Lewis Shiner 2009.
• The Cruciform Brooch and Anglo-Saxon England. Toby F. Martin 2015.
• Errantry: Strange Stories. Elizabeth Hand 2012.
• 6 Stories. Kathe Koja.
• The Green Leopard Plague and Other Stories. Walter Jon Williams 2010.
• Borders of Infinity. Lois McMaster Bujold 1989. Miles Vorkosigan stories.
• Wild Things (Short stories.). C.C. Finlay 2005.
• Women Up to No Good: A Collection of Short Stories. Pat Murphy 2013.
• Moving Pictures. Terry Pratchett 1990. Hollywood on Discworld.

Here’s my list for 2015.

from ScienceBlogs http://ift.tt/2iZtLmA

See it! Last night’s moon and Venus

As seen from the Northern Hemisphere, the moon, Venus and Mars arced up and to the left of the sunset Sunday evening. Photo by Gowrishankar Lakshminarayanan Parsippany, New Jersey. Thank you, Gowri!

As seen from the Southern Hemisphere, they arced up and to the right of the sunset. Photo by Michael Coonan in Wodonga, Australia. Thank you, Michael.

You could see them as soon as it got dark outside. Photo by Patricia J Agustin M at Lydgate State Park in Hawaii. Thanks, Patricia!

If you had enough optical aid, you could see Neptune, too. Photo by Stuart Kenn in Beeton, Ontario, Canada. Thank you, Stuart.

Karl Diefenderfer in Quakertown, Pennsylvania wrote: “Earthshining moon and Venus in a sea of stars. What a great way to begin a new year of watching the heavens.” Agree! Thank you, Karl.

As Earth spun on its axis, they followed the sun below the western horizon. By early evening, they were gone. Animation by Helio C. Vital in Rio de Janeiro, Brazil. Thanks, Helio.

Venus and the moon are Earth’s two brightest nighttime objects. See them shining in the water? Photo by Tony Leeat the upper Niagara River, looking west to Grand Island. Thank you, Tony!

A few thin clouds enhanced the view for our friend Lunar 101-MoonBook. Thank you for all you do!

Azya Matsumoto in Malaysia – just west of the International Date Line – caught the youngest moon of the pics we saw … farthest from Venus. Because the moon is always moving in orbit around Earth, it edged closer to Venus throughout the day on January 1, 2017. Thank you, Azya!

If you look westward after sunset, you’ll easily see a very bright starlike object. That’s the planet Venus. The moon is sweeping past Venus on the first few evenings of 2017.

The moon will sweep by Venus and Mars again before January, 2017 ends. Read more.

Bottom line: Photos of the moon, Venus and Mars (and Neptune) in early January, 2017.

from EarthSky http://ift.tt/2iH2jq9

As seen from the Northern Hemisphere, the moon, Venus and Mars arced up and to the left of the sunset Sunday evening. Photo by Gowrishankar Lakshminarayanan Parsippany, New Jersey. Thank you, Gowri!

As seen from the Southern Hemisphere, they arced up and to the right of the sunset. Photo by Michael Coonan in Wodonga, Australia. Thank you, Michael.

You could see them as soon as it got dark outside. Photo by Patricia J Agustin M at Lydgate State Park in Hawaii. Thanks, Patricia!

If you had enough optical aid, you could see Neptune, too. Photo by Stuart Kenn in Beeton, Ontario, Canada. Thank you, Stuart.

Karl Diefenderfer in Quakertown, Pennsylvania wrote: “Earthshining moon and Venus in a sea of stars. What a great way to begin a new year of watching the heavens.” Agree! Thank you, Karl.

As Earth spun on its axis, they followed the sun below the western horizon. By early evening, they were gone. Animation by Helio C. Vital in Rio de Janeiro, Brazil. Thanks, Helio.

Venus and the moon are Earth’s two brightest nighttime objects. See them shining in the water? Photo by Tony Leeat the upper Niagara River, looking west to Grand Island. Thank you, Tony!

A few thin clouds enhanced the view for our friend Lunar 101-MoonBook. Thank you for all you do!

Azya Matsumoto in Malaysia – just west of the International Date Line – caught the youngest moon of the pics we saw … farthest from Venus. Because the moon is always moving in orbit around Earth, it edged closer to Venus throughout the day on January 1, 2017. Thank you, Azya!

If you look westward after sunset, you’ll easily see a very bright starlike object. That’s the planet Venus. The moon is sweeping past Venus on the first few evenings of 2017.

The moon will sweep by Venus and Mars again before January, 2017 ends. Read more.

Bottom line: Photos of the moon, Venus and Mars (and Neptune) in early January, 2017.

from EarthSky http://ift.tt/2iH2jq9

Today in science: 1st spacecraft to moon

Luna 1 was a milestone for exploration of the solar system, but American historians suspect the spacecraft failed one major objective: to hit the moon. Image credit: NASA

January 2, 1959. The Luna 1 spacecraft broke free of Earth’s gravity on this date, to head towards the moon. Many believe this craft – launched by the Soviet Union – was supposed to hit the moon. If it had, it would have been a large coup for the Soviets during the early days of the Space Race with the United States. It didn’t strike the moon, but it did fly successfully past Earth’s neighbor on January 4, 1959.

It zoomed past the moon at a distance of 3,725 miles (5,995 km) after a flight of 34 hours. Eventually, Luna 1 became the first spacecraft from Earth to go into orbit around our sun.

A cool feature of Luna 1 was its release on January 3, 1959 of a large, glowing, orange trail of gas. The gas was visible over the Indian Ocean with the brightness of a 6th-magnitude; that’s the faintest star you can see with the eye alone. The gas turned out to be made of sodium vapor. It let astronomers track the spacecraft. It also served as an experiment on the behavior of gas in outer space.

On its journey moonward, the 795-pound (360-kilogram) spacecraft also picked up new data on Earth’s mysterious Van Allen radiation belts – a zone of charged particles, held in place by Earth’s magnetic field – which had been discovered only a year before.

Bottom line: On January 2, 1959, the Luna 1 spacecraft broke free of Earth’s gravity on this date, heading towards the moon.

from EarthSky http://ift.tt/1vPIE6t

Luna 1 was a milestone for exploration of the solar system, but American historians suspect the spacecraft failed one major objective: to hit the moon. Image credit: NASA

January 2, 1959. The Luna 1 spacecraft broke free of Earth’s gravity on this date, to head towards the moon. Many believe this craft – launched by the Soviet Union – was supposed to hit the moon. If it had, it would have been a large coup for the Soviets during the early days of the Space Race with the United States. It didn’t strike the moon, but it did fly successfully past Earth’s neighbor on January 4, 1959.

It zoomed past the moon at a distance of 3,725 miles (5,995 km) after a flight of 34 hours. Eventually, Luna 1 became the first spacecraft from Earth to go into orbit around our sun.

A cool feature of Luna 1 was its release on January 3, 1959 of a large, glowing, orange trail of gas. The gas was visible over the Indian Ocean with the brightness of a 6th-magnitude; that’s the faintest star you can see with the eye alone. The gas turned out to be made of sodium vapor. It let astronomers track the spacecraft. It also served as an experiment on the behavior of gas in outer space.

On its journey moonward, the 795-pound (360-kilogram) spacecraft also picked up new data on Earth’s mysterious Van Allen radiation belts – a zone of charged particles, held in place by Earth’s magnetic field – which had been discovered only a year before.

Bottom line: On January 2, 1959, the Luna 1 spacecraft broke free of Earth’s gravity on this date, heading towards the moon.

from EarthSky http://ift.tt/1vPIE6t

January’s birthstone is the garnet

Photo via cobalt123

The birthstone for January is the garnet.

The name “garnet” is derived from the Latin “granatum” meaning “pomegranate” because the crystals resemble the fruit’s red color and seed-like form. Most people think of the garnet as a red gemstone, but in fact, it exists in all kinds of colors – such as black – as well as many shades of red and green. It can even be colorless. The garnet’s variety of colors comes from metals such as manganese, iron, calcium, and aluminum. Some varieties even contain mineral fibers that produce the illusion of a four- or six-rayed star within the stone. Green garnets are most highly prized but are very rare. Emerald green and colorless stones are highly valued, followed by pure red garnets.

Image via USGS

Garnets are commonly found as small pebbles in streams, where the igneous and metamorphic rocks that contain them have weathered away. They’re found in many places around the world, including North and South America, Australia, India, Asia and Spain.

Ancient warriors believed that garnets brought victory. The Crusaders used them as protection against wounds and accidents during their journeys. In contrast, Asiatic warriors believed that glowing garnets, used as bullets, inflicted more severe wounds. In 1892, during hostilities on the Kashmir frontier, the Hanza tribesmen fired on British soldiers with garnet bullets, believing them to be more effective than lead bullets.

In the former Czechoslovakia, evidence of garnet jewelry dating to the Bronze age was found in ancient graves. Garnet jewelry has also been discovered dating back to 3100 B.C. in Egypt, 2300 B.C. in Sumeria, and 2000-1000 B.C. in Sweden. Garnets were treasured in 3rd and 4th century Greece, and continued in popularity during Roman times. Across the Atlantic, Pre-Columbian Aztec and Native Americans also used garnets in their ornaments.

As with many precious stones, garnets were once believed to hold medicinal powers. In Medieval times, it protected its wearer against poisons, wounds and bad dreams, and cured depression. Red garnets relieved fever, hemorrhages and inflammatory diseases.

January’s birthstone, the garnet, symbolizes a light heart, loyalty and enduring affections. Find out about the birthstones for the other months of the year.

January birthstone
February birthstone
March birthstone
April birthstone
May birthstone
June birthstone
July birthstone
August birthstone
September birthstone
October birthstone
November birthstone
December birthstone

Bottom line: If you were born in January, your birthstone is the garnet

from EarthSky http://ift.tt/SdpVoH

Photo via cobalt123

The birthstone for January is the garnet.

The name “garnet” is derived from the Latin “granatum” meaning “pomegranate” because the crystals resemble the fruit’s red color and seed-like form. Most people think of the garnet as a red gemstone, but in fact, it exists in all kinds of colors – such as black – as well as many shades of red and green. It can even be colorless. The garnet’s variety of colors comes from metals such as manganese, iron, calcium, and aluminum. Some varieties even contain mineral fibers that produce the illusion of a four- or six-rayed star within the stone. Green garnets are most highly prized but are very rare. Emerald green and colorless stones are highly valued, followed by pure red garnets.

Image via USGS

Garnets are commonly found as small pebbles in streams, where the igneous and metamorphic rocks that contain them have weathered away. They’re found in many places around the world, including North and South America, Australia, India, Asia and Spain.

Ancient warriors believed that garnets brought victory. The Crusaders used them as protection against wounds and accidents during their journeys. In contrast, Asiatic warriors believed that glowing garnets, used as bullets, inflicted more severe wounds. In 1892, during hostilities on the Kashmir frontier, the Hanza tribesmen fired on British soldiers with garnet bullets, believing them to be more effective than lead bullets.

In the former Czechoslovakia, evidence of garnet jewelry dating to the Bronze age was found in ancient graves. Garnet jewelry has also been discovered dating back to 3100 B.C. in Egypt, 2300 B.C. in Sumeria, and 2000-1000 B.C. in Sweden. Garnets were treasured in 3rd and 4th century Greece, and continued in popularity during Roman times. Across the Atlantic, Pre-Columbian Aztec and Native Americans also used garnets in their ornaments.

As with many precious stones, garnets were once believed to hold medicinal powers. In Medieval times, it protected its wearer against poisons, wounds and bad dreams, and cured depression. Red garnets relieved fever, hemorrhages and inflammatory diseases.

January’s birthstone, the garnet, symbolizes a light heart, loyalty and enduring affections. Find out about the birthstones for the other months of the year.

January birthstone
February birthstone
March birthstone
April birthstone
May birthstone
June birthstone
July birthstone
August birthstone
September birthstone
October birthstone
November birthstone
December birthstone

Bottom line: If you were born in January, your birthstone is the garnet

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