September’s birthstone is the sapphire

Raw blue sapphires. Image via Amy Kozak.

The sapphire, birthstone for September, is a relative of July’s birthstone, the ruby. Like ruby, it is a form of the mineral corundum, a normally drab grey mineral. Red corundum is called the ruby, while all other gem quality forms of corundum are called sapphires.

Typically, sapphires appear as blue stones, ranging from very pale blue to deep indigo, due to the presence of small amounts of titanium and iron within the crystal structure. The most valued shade of blue is the medium-deep cornflower blue. Sapphires also occur in other natural colors and tints – colorless, gray, yellow, pale pink, orange, green, violet and brown – called fancy sapphires. These different colors are caused by different kinds of impurities within the crystal. For example, yellow sapphires get their color from ferric iron, and colorless gems have no contaminants.

The Logan Sapphire Brooch, the second largest sapphire known (at 422.99 carats), is on display at the National Museum of Natural History in Washington, D.C. Image via Andrew Bossi

The biggest source of sapphires world-wide is Australia, especially New South Wales and Queensland. Found in alluvial deposits of weathered basalt, Australian sapphires typically are blue stones with a dark and inky appearance. Kashmir, in India, used to be a well-known source of the cornflower-blue stones. In the United States, a major source is the Yogo Gulch Mine in Montana that mostly yields small stones for industrial use.

The word sapphire has its roots in several ancient languages: the Arabic safir, the Latin sapphirus (meaning blue), and the Greek word sappheiros for the island of Sappherine in the Arabian Sea where sapphires were found in ancient Grecian times. Ancient Persians called sapphire the “Celestial Stone.” It was the gem of Apollo, Greek God of prophesy and was worn by worshipers visiting his shrine in Delphi to seek his help. It was used by ancient Etruscans as far back as the 7th century B.C.

The sapphire was said to represent the purity of the soul. Before and during the Middle Ages, it was worn by priests as protection from impure thoughts and temptations of the flesh. Medieval kings of Europe valued these stones for rings and brooches, believing that it protected them from harm and envy. Warriors presented their young wives with sapphire necklaces so they would remain faithful. It was believed that the stone’s color would darken if worn by an adulterer or adulteress, or by an unworthy person.

Sapphires were once believed to be protection against snakes. It was said that if poisonous reptiles and spiders were placed in a jar containing the stone, the creatures would immediately die. The French of the 13th century believed that sapphire transformed stupidity to wisdom, and irritability to good temper.

One of the most famous sapphires rests on the Imperial State Crown, worn by Queen Victoria in 1838. It resides in the British Crown Jewels in the Tower of London. This gem is called the St. Edward’s Sapphire because it once belonged to Edward the Confessor, who wore the stone on a ring during his coronation in 1042.

Find out about the birthstones for the other months of the year:
January birthstone
February birthstone
March birthstone
April birthstone
May birthstone
July birthstone
August birthstone
September birthstone
October birthstone
November birthstone
December birthstone

Bottom line: The birthstone for September is the sapphire.

from EarthSky https://ift.tt/2UnQDvH

Raw blue sapphires. Image via Amy Kozak.

The sapphire, birthstone for September, is a relative of July’s birthstone, the ruby. Like ruby, it is a form of the mineral corundum, a normally drab grey mineral. Red corundum is called the ruby, while all other gem quality forms of corundum are called sapphires.

Typically, sapphires appear as blue stones, ranging from very pale blue to deep indigo, due to the presence of small amounts of titanium and iron within the crystal structure. The most valued shade of blue is the medium-deep cornflower blue. Sapphires also occur in other natural colors and tints – colorless, gray, yellow, pale pink, orange, green, violet and brown – called fancy sapphires. These different colors are caused by different kinds of impurities within the crystal. For example, yellow sapphires get their color from ferric iron, and colorless gems have no contaminants.

The Logan Sapphire Brooch, the second largest sapphire known (at 422.99 carats), is on display at the National Museum of Natural History in Washington, D.C. Image via Andrew Bossi

The biggest source of sapphires world-wide is Australia, especially New South Wales and Queensland. Found in alluvial deposits of weathered basalt, Australian sapphires typically are blue stones with a dark and inky appearance. Kashmir, in India, used to be a well-known source of the cornflower-blue stones. In the United States, a major source is the Yogo Gulch Mine in Montana that mostly yields small stones for industrial use.

The word sapphire has its roots in several ancient languages: the Arabic safir, the Latin sapphirus (meaning blue), and the Greek word sappheiros for the island of Sappherine in the Arabian Sea where sapphires were found in ancient Grecian times. Ancient Persians called sapphire the “Celestial Stone.” It was the gem of Apollo, Greek God of prophesy and was worn by worshipers visiting his shrine in Delphi to seek his help. It was used by ancient Etruscans as far back as the 7th century B.C.

The sapphire was said to represent the purity of the soul. Before and during the Middle Ages, it was worn by priests as protection from impure thoughts and temptations of the flesh. Medieval kings of Europe valued these stones for rings and brooches, believing that it protected them from harm and envy. Warriors presented their young wives with sapphire necklaces so they would remain faithful. It was believed that the stone’s color would darken if worn by an adulterer or adulteress, or by an unworthy person.

Sapphires were once believed to be protection against snakes. It was said that if poisonous reptiles and spiders were placed in a jar containing the stone, the creatures would immediately die. The French of the 13th century believed that sapphire transformed stupidity to wisdom, and irritability to good temper.

One of the most famous sapphires rests on the Imperial State Crown, worn by Queen Victoria in 1838. It resides in the British Crown Jewels in the Tower of London. This gem is called the St. Edward’s Sapphire because it once belonged to Edward the Confessor, who wore the stone on a ring during his coronation in 1042.

Find out about the birthstones for the other months of the year:
January birthstone
February birthstone
March birthstone
April birthstone
May birthstone
July birthstone
August birthstone
September birthstone
October birthstone
November birthstone
December birthstone

Bottom line: The birthstone for September is the sapphire.

from EarthSky https://ift.tt/2UnQDvH

Why does Mars’ methane vary across a single Martian day?

Self-portrait of the Curiosity rover on Mars. Image via NASA/JPL-Caltech/MSSS/ANU.

The mystery of Mars’ methane has been in the news again lately, starting with a study announced earlier this month saying it’s not likely caused by wind erosion of rocks. Now, another new study has refined estimates of methane gas in Mars’ atmosphere, showing how concentrations change over the course of a single Martian day.

The peer-reviewed study, led by John Moores at York University in Canada, was published in Geophysical Research Letters on August 20, 2019. According to Moores:

This new study redefines our understanding of how the concentration of methane in the atmosphere of Mars changes over time, and this helps us to solve the bigger mystery of what the source might be.

The source of Mars methane is the true mystery. Where does the methane come from? On Earth, methane gas can be associated with microbial life. The idea of living microbes on Mars has long intrigued astronomers. Various spacecraft sent to Mars have search for signs of life, but so far no sign of life has been revealed. In 2018, scientists announced that seasonal variations of Mars methane could be related to microorganisms. Or the variations in methane could be produced by geological means. It’s an interesting puzzle!

The new research involves data from the Trace Gas Orbiter (TGO) and the Curiosity rover. Curiosity, in Gale Crater, has detected bursts of methane at different times in recent years, and analysis indicates it peaks in summer and disappears in winter.

Now, the new study shows that the methane levels change over the course of a Martian day, as well. Moores noted:

This most recent work suggests that the methane concentration changes over the course of each day. We were able – for the first time – to calculate a single number for the rate of seepage of methane at Gale Crater on Mars that is equivalent to an average of 2.8 kg per Martian day.

Diagram showing the seasonal cycle of methane as detected by the Curiosity rover in Gale Crater. The new study indicates that the methane varies in concentration on a daily basis as well. Image via NASA/JPL-Caltech/Mars Exploration Program.

From the paper:

The ExoMars Trace Gas Orbiter and the Curiosity Rover have recorded different amounts of methane in the atmosphere on Mars. The Trace Gas Orbiter measured very little methane (<50 parts per trillion by volume) above 5 km in the sunlit atmosphere, while Curiosity measured substantially more (410 parts per trillion by volume) near the surface at night. In this paper we describe a framework which explains both measurements by suggesting that a small amount of methane seeps out of the ground constantly. During the day, this small amount of methane is rapidly mixed and diluted by vigorous convection, leading to low overall levels within the atmosphere. During the night, convection lessens, allowing methane to build up near the surface. At dawn, convection intensifies and the near-surface methane is mixed and diluted with much more atmosphere. Using this model and methane concentrations from both approaches, we are able – for the first time – to place a single number on the rate of seepage of methane at Gale Crater which we find equivalent to 2.8 kg per Martian day. Future spacecraft measuring methane near the surface of Mars could determine how much methane seeps out of the ground in different locations, providing insight into what processes create that methane in the subsurface.

Telescopic observations of Mars have also shown methane concentrations peaking in the summer months. Image via NASA/Trent Schindler/Wikipedia.

The findings should provide more clues as to the source of the methane, which could be either biological or non-biological, at least for the methane detected around Gale Crater. The team was able to reconcile the data between TGO and Curiosity, which had presented a puzzle. While Curiosity detected the spikes in methane levels, TGO had not. As Moores explained:

We were able to resolve these differences by showing how concentrations of methane were much lower in the atmosphere during the day and significantly higher near the planet’s surface at night, as heat transfer lessens.

TGO has focused on analyzing the upper levels of the atmosphere, which may explain why it missed the methane bursts close to the ground, or perhaps because the methane spikes are seasonal.

The seasonal and daily variations could be consistent with biology – as in microbes – as the source of the methane, but there are still other plausible geological explanations as well. According to Penny King at Australia National University (ANU):

Some microbes on Earth can survive without oxygen, deep underground, and release methane as part of their waste. The methane on Mars has other possible sources, such as water-rock reactions or decomposing materials containing methane.

Illustration depicting what processes could create and destroy methane on Mars. The methane most likely originates from below the surface and is released into the atmosphere through subsurface cracks. Image via ESA.

While what is creating the methane is still unknown, most scientists now think it originates from underground, periodically released through cracks. This again could be consistent with either biology or geology. The geological sources could include the water-rock interactions or icy methane clathrates that contain methane and release it during warmer temperatures. If it was rocks and water, that would still be an exciting finding, indicating there is still liquid water below ground and at least some residual active geological processes. That alone could provide a nice habitat for microbes, even if they didn’t produce the methane themselves.

Whatever the explanation for the methane turns out to be, it will provide a fascinating insight into current geological or biological processes on the Red Planet.

Bottom line: A new study shows how methane in Mars’ atmosphere varies in concentration on a daily basis, not just seasonal.

Source: The Methane Diurnal Variation and Microseepage Flux at Gale Crater, Mars as Constrained by the ExoMars Trace Gas Orbiter and Curiosity Observations

Via ANU

from EarthSky https://ift.tt/2ZFrBt9

Self-portrait of the Curiosity rover on Mars. Image via NASA/JPL-Caltech/MSSS/ANU.

The mystery of Mars’ methane has been in the news again lately, starting with a study announced earlier this month saying it’s not likely caused by wind erosion of rocks. Now, another new study has refined estimates of methane gas in Mars’ atmosphere, showing how concentrations change over the course of a single Martian day.

The peer-reviewed study, led by John Moores at York University in Canada, was published in Geophysical Research Letters on August 20, 2019. According to Moores:

This new study redefines our understanding of how the concentration of methane in the atmosphere of Mars changes over time, and this helps us to solve the bigger mystery of what the source might be.

The source of Mars methane is the true mystery. Where does the methane come from? On Earth, methane gas can be associated with microbial life. The idea of living microbes on Mars has long intrigued astronomers. Various spacecraft sent to Mars have search for signs of life, but so far no sign of life has been revealed. In 2018, scientists announced that seasonal variations of Mars methane could be related to microorganisms. Or the variations in methane could be produced by geological means. It’s an interesting puzzle!

The new research involves data from the Trace Gas Orbiter (TGO) and the Curiosity rover. Curiosity, in Gale Crater, has detected bursts of methane at different times in recent years, and analysis indicates it peaks in summer and disappears in winter.

Now, the new study shows that the methane levels change over the course of a Martian day, as well. Moores noted:

This most recent work suggests that the methane concentration changes over the course of each day. We were able – for the first time – to calculate a single number for the rate of seepage of methane at Gale Crater on Mars that is equivalent to an average of 2.8 kg per Martian day.

Diagram showing the seasonal cycle of methane as detected by the Curiosity rover in Gale Crater. The new study indicates that the methane varies in concentration on a daily basis as well. Image via NASA/JPL-Caltech/Mars Exploration Program.

From the paper:

The ExoMars Trace Gas Orbiter and the Curiosity Rover have recorded different amounts of methane in the atmosphere on Mars. The Trace Gas Orbiter measured very little methane (<50 parts per trillion by volume) above 5 km in the sunlit atmosphere, while Curiosity measured substantially more (410 parts per trillion by volume) near the surface at night. In this paper we describe a framework which explains both measurements by suggesting that a small amount of methane seeps out of the ground constantly. During the day, this small amount of methane is rapidly mixed and diluted by vigorous convection, leading to low overall levels within the atmosphere. During the night, convection lessens, allowing methane to build up near the surface. At dawn, convection intensifies and the near-surface methane is mixed and diluted with much more atmosphere. Using this model and methane concentrations from both approaches, we are able – for the first time – to place a single number on the rate of seepage of methane at Gale Crater which we find equivalent to 2.8 kg per Martian day. Future spacecraft measuring methane near the surface of Mars could determine how much methane seeps out of the ground in different locations, providing insight into what processes create that methane in the subsurface.

Telescopic observations of Mars have also shown methane concentrations peaking in the summer months. Image via NASA/Trent Schindler/Wikipedia.

The findings should provide more clues as to the source of the methane, which could be either biological or non-biological, at least for the methane detected around Gale Crater. The team was able to reconcile the data between TGO and Curiosity, which had presented a puzzle. While Curiosity detected the spikes in methane levels, TGO had not. As Moores explained:

We were able to resolve these differences by showing how concentrations of methane were much lower in the atmosphere during the day and significantly higher near the planet’s surface at night, as heat transfer lessens.

TGO has focused on analyzing the upper levels of the atmosphere, which may explain why it missed the methane bursts close to the ground, or perhaps because the methane spikes are seasonal.

The seasonal and daily variations could be consistent with biology – as in microbes – as the source of the methane, but there are still other plausible geological explanations as well. According to Penny King at Australia National University (ANU):

Some microbes on Earth can survive without oxygen, deep underground, and release methane as part of their waste. The methane on Mars has other possible sources, such as water-rock reactions or decomposing materials containing methane.

Illustration depicting what processes could create and destroy methane on Mars. The methane most likely originates from below the surface and is released into the atmosphere through subsurface cracks. Image via ESA.

While what is creating the methane is still unknown, most scientists now think it originates from underground, periodically released through cracks. This again could be consistent with either biology or geology. The geological sources could include the water-rock interactions or icy methane clathrates that contain methane and release it during warmer temperatures. If it was rocks and water, that would still be an exciting finding, indicating there is still liquid water below ground and at least some residual active geological processes. That alone could provide a nice habitat for microbes, even if they didn’t produce the methane themselves.

Whatever the explanation for the methane turns out to be, it will provide a fascinating insight into current geological or biological processes on the Red Planet.

Bottom line: A new study shows how methane in Mars’ atmosphere varies in concentration on a daily basis, not just seasonal.

Source: The Methane Diurnal Variation and Microseepage Flux at Gale Crater, Mars as Constrained by the ExoMars Trace Gas Orbiter and Curiosity Observations

Via ANU

from EarthSky https://ift.tt/2ZFrBt9

A dynamic dying star, caught by Hubble

You’ve heard of planetary nebulae? They have nothing to do with planets. They’re shells of gas, sloughed off by dying stars. This image – taken with the Hubble Space Telescope – shows a 2-lobed planetary nebula known as NGC 2371/2. The lobes are the cloudy regions in the lower left and upper right, released by the bright star at the center of the frame. The star, now dying, will eventually cool and dim to become a white dwarf. Image via ESA/Hubble & NASA, R. Wade et al.

Here’s how NASA described this Hubble Space Telescope photo:

The subject of this image confused astronomers when it was first studied – rather than being classified as a single object, it was instead recorded as two objects, owing to its symmetrical lobed structure (known as NGC 2371 and NGC 2372, though sometimes referred to together as NGC 2371/2).

These two lobes are visible to the lower left and upper right of the frame, and together form something known as a planetary nebula. Despite the name, such nebulas have nothing to do with planets; NGC 2371/2 formed when a sun-like star reached the end of its life and blasted off its outer layers, shedding the constituent material and pushing it out into space to leave just a superheated stellar remnant behind. This remnant is visible as the bright star at the center of the frame, sitting neatly between the two lobes.

The structure of this region is complex. It is filled with dense knots of gas, fast-moving jets that appear to be changing direction over time, and expanding clouds of material streaming outwards on diametrically opposite sides of the remnant star. Patches of this scene glow brightly as the remnant star emits energetic radiation that excites the gas within these regions, causing it to light up. This scene will continue to change over the next few thousand years. Eventually the knotty lobes will dissipate completely, and the remnant star will cool and dim to form a white dwarf.

Bottom line: Two-lobed planetary nebula NGC 2371/2, as seen by the Hubble Space Telescope.

Via NASA

from EarthSky https://ift.tt/32a8EAy

You’ve heard of planetary nebulae? They have nothing to do with planets. They’re shells of gas, sloughed off by dying stars. This image – taken with the Hubble Space Telescope – shows a 2-lobed planetary nebula known as NGC 2371/2. The lobes are the cloudy regions in the lower left and upper right, released by the bright star at the center of the frame. The star, now dying, will eventually cool and dim to become a white dwarf. Image via ESA/Hubble & NASA, R. Wade et al.

Here’s how NASA described this Hubble Space Telescope photo:

The subject of this image confused astronomers when it was first studied – rather than being classified as a single object, it was instead recorded as two objects, owing to its symmetrical lobed structure (known as NGC 2371 and NGC 2372, though sometimes referred to together as NGC 2371/2).

These two lobes are visible to the lower left and upper right of the frame, and together form something known as a planetary nebula. Despite the name, such nebulas have nothing to do with planets; NGC 2371/2 formed when a sun-like star reached the end of its life and blasted off its outer layers, shedding the constituent material and pushing it out into space to leave just a superheated stellar remnant behind. This remnant is visible as the bright star at the center of the frame, sitting neatly between the two lobes.

The structure of this region is complex. It is filled with dense knots of gas, fast-moving jets that appear to be changing direction over time, and expanding clouds of material streaming outwards on diametrically opposite sides of the remnant star. Patches of this scene glow brightly as the remnant star emits energetic radiation that excites the gas within these regions, causing it to light up. This scene will continue to change over the next few thousand years. Eventually the knotty lobes will dissipate completely, and the remnant star will cool and dim to form a white dwarf.

Bottom line: Two-lobed planetary nebula NGC 2371/2, as seen by the Hubble Space Telescope.

Via NASA

from EarthSky https://ift.tt/32a8EAy

Watch for a young moon after sunset

The hunt for a young moon – a thin crescent moon visible in the west after sunset – has become a favorite activity for many of EarthSky’s moon-watching fans. Although the new moon came to pass on August 30, 2019, we’re expecting a number of people around the world to catch the whisker-thin waxing crescent after sunset August 31. If you miss the exceedingly slender young moon at dusk on August 31, give it another try on September 1, 2 or 3. Look west, shortly after sunset.

It’s best to have an unobstructed horizon in the direction of sunset for any young moon quest. If possible, find a hill or balcony to stand on, enabling you to peek above that pesky line of trees on your horizon. Binoculars come in handy, too, especially around August 31 and September 1, because it’s possible for the bright evening twilight to bleach out the tiny, ghostly lunar crescent from naked eye visibility.

For most of the world, the moon will be over one day old (more than 24 hours past new moon) as the sun sets on August 31. The worldwide map below shows you the line of sunset running through eastern Asia when it’s exactly one day (24 hours) past new moon on August 31, at 10:37 Universal Time (UTC). At this juncture, the moon is about 14 degrees (28 moon-diameters) east of the setting sun.

It’s usually quite difficult to see a young moon that’s less than 24 hours old. For Japan and Australia on August 31, the young moon will set roughly 50 minutes after the sun, so it may be hard to spot this skinny moon with the eye alone.

Visit Sunrise Sunset Calendars to find out when the moon sets in your sky, remembering to check the moonrise and moonset box.

The worldwide map shows the line of sunset (running across Asia) one day after new moon (August 31 at 10:37 UTC). By the time the line of sunset crosses Africa and Europe, the moon will be about 7 moon-diameters farther east of the setting sun that it was at sunset in eastern Asia. When the line of sunset reaches North America, the moon will be about 18 moon-diameters farther east of the sun than it was in eastern Asia. Image via EarthView.

By the time the line of sunset reaches Africa and the Middle East on August 31, the moon will be 1 1/4 days old (on August 31 at 16:37 UTC). The moon will also be about 7 moon-diameters farther from the setting sun than six hours previously (when it was one day old on August 31 at 10:37 UTC). That means a wider crescent (2.4 percent illuminated versus 1.5 percent illuminated), which, in addition, stays out longer after sunset.

By the time the line of sunset reaches North America on August 31 (local time), the young moon will be about one day and 15 hours old (on September 1 at 01:37 UTC). So, in North America, the young waxing crescent will be about 4 percent illuminated at sunset August 31, and the moon will be some 18 moon-diameters farther away from the setting sun than 15 hours previously (when the moon was one day old on August 31 at 10:37 UTC). Yes, the Americas have the big advantage for catching the young moon after sunset August 31.

A very young moon and Jupiter on September 2, 2016, captured by Greg Hogan in Kathleen, Georgia.

However, the world as a whole enjoys an advantage for this particular young moon hunt. The closest new moon of the year fell on August 30, 2019. With the new moon coming so close to Earth, the moon is now orbiting Earth at a maximum speed. Hence, the young moon is moving away from the setting sun on the sky’s dome at a faster clip than it usually does.

Read about the year’s closest new supermoon on August 30

Normally, the Southern Hemisphere has the advantage over the Northern Hemisphere for catching a young moon in late August or September. It is now winter in the Southern Hemisphere, and, as a general rule, late winter is favorable for a young moon hunt. In late winter, the ecliptic – the moon’s monthly pathway – hits the sunset horizon at a steep angle. Because the young moon is generally higher up at sunset in late winter, it tends to stay out longer after sundown than at other times of the year.

It is now late summer in the Northern Hemisphere, and, generally, late summer is not so favorable for catching a young moon. The ecliptic hits the sunset horizon at a shallow angle in late summer, tending to bury the young moon in the glare of evening twilight.

Fortunately for us northerners, this particular young moon swings a maximum of five degrees (10 moon-diameters) north of the ecliptic. That pretty much cancels out the Northern Hemisphere’s disadvantage and the Southern Hemisphere’s advantage, giving the Northern Hemisphere a better-than-usual opportunity for catching a late-summer young moon.

By the way, that bright star close to the young moon is Spica, the constellation Virgo’s one and only 1st-magnitude star. This star will probably be much easier to spot with the eye alone from the Southern Hemisphere. Visit Heavens-Above to know which constellation of the zodiac is presently behind the moon.

Wherever you may reside worldwide, try catching the young moon after sunset in late August or early September. For a special treat, check out the earthshine softly illuminating the dark side of the moon with either the unaided eye or binoculars. Day by day, watch the illumined portion of the lunar crescent to grow, and for the moon to stay out longer after sundown.

Bottom line: Look for the young moon on August 31, 2019, through the first days of September.

from EarthSky https://ift.tt/2ZFmYDs

The hunt for a young moon – a thin crescent moon visible in the west after sunset – has become a favorite activity for many of EarthSky’s moon-watching fans. Although the new moon came to pass on August 30, 2019, we’re expecting a number of people around the world to catch the whisker-thin waxing crescent after sunset August 31. If you miss the exceedingly slender young moon at dusk on August 31, give it another try on September 1, 2 or 3. Look west, shortly after sunset.

It’s best to have an unobstructed horizon in the direction of sunset for any young moon quest. If possible, find a hill or balcony to stand on, enabling you to peek above that pesky line of trees on your horizon. Binoculars come in handy, too, especially around August 31 and September 1, because it’s possible for the bright evening twilight to bleach out the tiny, ghostly lunar crescent from naked eye visibility.

For most of the world, the moon will be over one day old (more than 24 hours past new moon) as the sun sets on August 31. The worldwide map below shows you the line of sunset running through eastern Asia when it’s exactly one day (24 hours) past new moon on August 31, at 10:37 Universal Time (UTC). At this juncture, the moon is about 14 degrees (28 moon-diameters) east of the setting sun.

It’s usually quite difficult to see a young moon that’s less than 24 hours old. For Japan and Australia on August 31, the young moon will set roughly 50 minutes after the sun, so it may be hard to spot this skinny moon with the eye alone.

Visit Sunrise Sunset Calendars to find out when the moon sets in your sky, remembering to check the moonrise and moonset box.

The worldwide map shows the line of sunset (running across Asia) one day after new moon (August 31 at 10:37 UTC). By the time the line of sunset crosses Africa and Europe, the moon will be about 7 moon-diameters farther east of the setting sun that it was at sunset in eastern Asia. When the line of sunset reaches North America, the moon will be about 18 moon-diameters farther east of the sun than it was in eastern Asia. Image via EarthView.

By the time the line of sunset reaches Africa and the Middle East on August 31, the moon will be 1 1/4 days old (on August 31 at 16:37 UTC). The moon will also be about 7 moon-diameters farther from the setting sun than six hours previously (when it was one day old on August 31 at 10:37 UTC). That means a wider crescent (2.4 percent illuminated versus 1.5 percent illuminated), which, in addition, stays out longer after sunset.

By the time the line of sunset reaches North America on August 31 (local time), the young moon will be about one day and 15 hours old (on September 1 at 01:37 UTC). So, in North America, the young waxing crescent will be about 4 percent illuminated at sunset August 31, and the moon will be some 18 moon-diameters farther away from the setting sun than 15 hours previously (when the moon was one day old on August 31 at 10:37 UTC). Yes, the Americas have the big advantage for catching the young moon after sunset August 31.

A very young moon and Jupiter on September 2, 2016, captured by Greg Hogan in Kathleen, Georgia.

However, the world as a whole enjoys an advantage for this particular young moon hunt. The closest new moon of the year fell on August 30, 2019. With the new moon coming so close to Earth, the moon is now orbiting Earth at a maximum speed. Hence, the young moon is moving away from the setting sun on the sky’s dome at a faster clip than it usually does.

Read about the year’s closest new supermoon on August 30

Normally, the Southern Hemisphere has the advantage over the Northern Hemisphere for catching a young moon in late August or September. It is now winter in the Southern Hemisphere, and, as a general rule, late winter is favorable for a young moon hunt. In late winter, the ecliptic – the moon’s monthly pathway – hits the sunset horizon at a steep angle. Because the young moon is generally higher up at sunset in late winter, it tends to stay out longer after sundown than at other times of the year.

It is now late summer in the Northern Hemisphere, and, generally, late summer is not so favorable for catching a young moon. The ecliptic hits the sunset horizon at a shallow angle in late summer, tending to bury the young moon in the glare of evening twilight.

Fortunately for us northerners, this particular young moon swings a maximum of five degrees (10 moon-diameters) north of the ecliptic. That pretty much cancels out the Northern Hemisphere’s disadvantage and the Southern Hemisphere’s advantage, giving the Northern Hemisphere a better-than-usual opportunity for catching a late-summer young moon.

By the way, that bright star close to the young moon is Spica, the constellation Virgo’s one and only 1st-magnitude star. This star will probably be much easier to spot with the eye alone from the Southern Hemisphere. Visit Heavens-Above to know which constellation of the zodiac is presently behind the moon.

Wherever you may reside worldwide, try catching the young moon after sunset in late August or early September. For a special treat, check out the earthshine softly illuminating the dark side of the moon with either the unaided eye or binoculars. Day by day, watch the illumined portion of the lunar crescent to grow, and for the moon to stay out longer after sundown.

Bottom line: Look for the young moon on August 31, 2019, through the first days of September.

from EarthSky https://ift.tt/2ZFmYDs

News digest – HRT and breast cancer risk, a billion fewer cigarettes and misunderstanding around HPV

Hormone replacement therapy (HRT) linked to longer breast cancer risk

The Guardian covered new research looking at the link between HRT, which is used to relieve menopause symptoms, and the risk of breast cancer. The fact that HRT raises the risk of breast cancer is not new, but this study found the risk may persist for longer after stopping HRT than was previously thought. The increased risk was associated with almost all types of HRT and experts said it’s important for women to know the risks of HRT when deciding if taking it is right for them.

More than a billion fewer cigarettes smoked each year in England

The number of cigarettes smoked each month in England fell by nearly a quarter between 2011 and 2018. That equates to around 118 million fewer cigarettes being smoked every month. This incredibly positive news was reported by the BBC, The Guardian, Mail Online as well as other news outlets. For the full story, check out our press release.

Survey reveals more public misunderstanding about HPV, the leading cause of cervical cancer

A new YouGov survey of 1,500 women found that almost half mistakenly believe they’re not at risk of getting the human papillomavirus (HPV) if they’re in a long-term relationship. But HPV, the leading cause of cervical cancer, can be dormant for many years. Most of the time HPV won’t cause any problems and will get better on its own, but being in a relationship doesn’t remove the risk of getting infected. The findings follow survey results from earlier this year showing that myths and stigma surrounding HPV could put some people off cervical cancer screening. Experts say the misinformation and stigma around HPV needs to be tackled, as ITV News reports.

Lack of NHS funding a fear for bosses

According the The Guardian, 82% of chief executives and chief finance officers in the NHS think that the lack of NHS capital funding is putting patients in danger. Hospitals have reported being unable to fix leaky roofs, broken boilers and faulty scanners. And there’s a broader concern about the lack of scanners and diagnostic equipment. The NHS 10-year plan committed to delivering new scanners to help diagnose patients earlier, but the Government needs to invest more if they’re to achieve this.

Advertising industry hits back at plans to ban junk food adverts before 9pm

With a new Prime Minister in office, the advertising industry is lobbying to against proposals to ban junk food adverts before 9pm, reports iNews. The proposal was put forward under former Prime Minister Theresa May, as part of plans to help reduce levels of childhood obesity. We’ve blogged before about why regulating junk food marketing is so important, as well as speaking to a former junk food ad exec about tactics the ad industry use when marketing to children.

Researchers encourage government to print ‘smoking kills’ on every cigarette

Researchers in Scotland found that printing ‘smoking kills’ on every cigarette puts some people off, The Times (£) and Huffington Post reports. The tactic was particularly effective amongst young people, non-smokers and those who had just started smoking.

iKnife being used to test for endometrial cancer

The iKnife is a piece of surgical equipment designed to sniff out cancer. We’ve blogged about the innovative instrument before, which is currently being tested in ovarian and breast cancer. Now, the Evening Standard reports that a team at Imperial College London is testing the iKnife to see if it can accurately detect womb cancers too.

And finally…

An NHS survey of students aged 11-15 revealed that 16 in 100 said they had smoked at least once in the last year, down from 19 in 100 in 2016. It’s the lowest level ever recorded in this survey, which is done every two years. The Evening Standard has this one.

Ethan

from Cancer Research UK – Science blog https://ift.tt/32iOYKW

Hormone replacement therapy (HRT) linked to longer breast cancer risk

The Guardian covered new research looking at the link between HRT, which is used to relieve menopause symptoms, and the risk of breast cancer. The fact that HRT raises the risk of breast cancer is not new, but this study found the risk may persist for longer after stopping HRT than was previously thought. The increased risk was associated with almost all types of HRT and experts said it’s important for women to know the risks of HRT when deciding if taking it is right for them.

More than a billion fewer cigarettes smoked each year in England

The number of cigarettes smoked each month in England fell by nearly a quarter between 2011 and 2018. That equates to around 118 million fewer cigarettes being smoked every month. This incredibly positive news was reported by the BBC, The Guardian, Mail Online as well as other news outlets. For the full story, check out our press release.

Survey reveals more public misunderstanding about HPV, the leading cause of cervical cancer

A new YouGov survey of 1,500 women found that almost half mistakenly believe they’re not at risk of getting the human papillomavirus (HPV) if they’re in a long-term relationship. But HPV, the leading cause of cervical cancer, can be dormant for many years. Most of the time HPV won’t cause any problems and will get better on its own, but being in a relationship doesn’t remove the risk of getting infected. The findings follow survey results from earlier this year showing that myths and stigma surrounding HPV could put some people off cervical cancer screening. Experts say the misinformation and stigma around HPV needs to be tackled, as ITV News reports.

Lack of NHS funding a fear for bosses

According the The Guardian, 82% of chief executives and chief finance officers in the NHS think that the lack of NHS capital funding is putting patients in danger. Hospitals have reported being unable to fix leaky roofs, broken boilers and faulty scanners. And there’s a broader concern about the lack of scanners and diagnostic equipment. The NHS 10-year plan committed to delivering new scanners to help diagnose patients earlier, but the Government needs to invest more if they’re to achieve this.

Advertising industry hits back at plans to ban junk food adverts before 9pm

With a new Prime Minister in office, the advertising industry is lobbying to against proposals to ban junk food adverts before 9pm, reports iNews. The proposal was put forward under former Prime Minister Theresa May, as part of plans to help reduce levels of childhood obesity. We’ve blogged before about why regulating junk food marketing is so important, as well as speaking to a former junk food ad exec about tactics the ad industry use when marketing to children.

Researchers encourage government to print ‘smoking kills’ on every cigarette

Researchers in Scotland found that printing ‘smoking kills’ on every cigarette puts some people off, The Times (£) and Huffington Post reports. The tactic was particularly effective amongst young people, non-smokers and those who had just started smoking.

iKnife being used to test for endometrial cancer

The iKnife is a piece of surgical equipment designed to sniff out cancer. We’ve blogged about the innovative instrument before, which is currently being tested in ovarian and breast cancer. Now, the Evening Standard reports that a team at Imperial College London is testing the iKnife to see if it can accurately detect womb cancers too.

And finally…

An NHS survey of students aged 11-15 revealed that 16 in 100 said they had smoked at least once in the last year, down from 19 in 100 in 2016. It’s the lowest level ever recorded in this survey, which is done every two years. The Evening Standard has this one.

Ethan

from Cancer Research UK – Science blog https://ift.tt/32iOYKW

A lecture program about climate change for people with learning disabilities

Earlier this year I was asked if I could support a lecture program about climate change for people with learning disabilities. The program was organised by Christa Rommel who works at the Remstal Werkstätten which are part of the Diakonie Stetten in southern Germany. They regularly offer such lecture programs for the people working there in order to have them learn about and get involved with general societal topics. One of the biggest challenges of such programs is that the information has to be presented in easy to understand language. This write-up is a short summary of the program with the emphasis on the part I was actively involved with. A report about the full program was put together by Christa Rommel and you can download it (in German) here.

The program was divided into three parts, happening within one week in February 2019:

• Day 1 featured an inhouse lecture about the basics of human-caused climate change held by Jürgen Lutz
• On day 2 I met the group in the Wilhelma, the zoological and botanical garden in Stuttgart for a climate-themed tour which also included information presented by Benedikt Mathes, one of the participants
• Day 3 was used to summarise what the group learned during the program and how they already try to lessen their own carbon footprint

Here are some impressions from the Wilhelma-tour with translations of easy to understand wording used in the report.

During the tour on a sunny February morning I for example explained the following:

• How the greenhouse effect works - using some of our graphics
• Why global warming impacts many animal and plant species. With the South African penguins we have at the Wilhelma as an example where it's not yet clear if the impacts will overall be negative or positive. They depend on ocean currents and how changes in them will affect the penguin's main food source: fish
• That some species like insects may profit by moving into other areas, and that some of them sting and can spread diseases

Benedikt Mathes, one of the participants, supported the tour with sharing some information he had prepared based on material from the exhibition "Donnerwetter! Klima schreibt Geschichte" in the Municipal Museum in Heilbronn.

We ended the tour with the story about how marine mammals help climate scientists to gather data. Something, the participants found as fascinating as I did!

Weddell Seal West Antarctic Peninsula (photo: Dan Costa - NMFS 87-1851-03)

In case you'd like to see/read the write-up prepared by Christa Rommel and some of the participants, you can download the PDF here - it's however in German and - because it will get shared within the institution - it is written in easy to understand language (and doesn't go into too much detail).

This for sure was an interesting and challenging project for me to be involved with!

from Skeptical Science https://ift.tt/30OGWsG

Earlier this year I was asked if I could support a lecture program about climate change for people with learning disabilities. The program was organised by Christa Rommel who works at the Remstal Werkstätten which are part of the Diakonie Stetten in southern Germany. They regularly offer such lecture programs for the people working there in order to have them learn about and get involved with general societal topics. One of the biggest challenges of such programs is that the information has to be presented in easy to understand language. This write-up is a short summary of the program with the emphasis on the part I was actively involved with. A report about the full program was put together by Christa Rommel and you can download it (in German) here.

The program was divided into three parts, happening within one week in February 2019:

• Day 1 featured an inhouse lecture about the basics of human-caused climate change held by Jürgen Lutz
• On day 2 I met the group in the Wilhelma, the zoological and botanical garden in Stuttgart for a climate-themed tour which also included information presented by Benedikt Mathes, one of the participants
• Day 3 was used to summarise what the group learned during the program and how they already try to lessen their own carbon footprint

Here are some impressions from the Wilhelma-tour with translations of easy to understand wording used in the report.

During the tour on a sunny February morning I for example explained the following:

• How the greenhouse effect works - using some of our graphics
• Why global warming impacts many animal and plant species. With the South African penguins we have at the Wilhelma as an example where it's not yet clear if the impacts will overall be negative or positive. They depend on ocean currents and how changes in them will affect the penguin's main food source: fish
• That some species like insects may profit by moving into other areas, and that some of them sting and can spread diseases

Benedikt Mathes, one of the participants, supported the tour with sharing some information he had prepared based on material from the exhibition "Donnerwetter! Klima schreibt Geschichte" in the Municipal Museum in Heilbronn.

We ended the tour with the story about how marine mammals help climate scientists to gather data. Something, the participants found as fascinating as I did!

Weddell Seal West Antarctic Peninsula (photo: Dan Costa - NMFS 87-1851-03)

In case you'd like to see/read the write-up prepared by Christa Rommel and some of the participants, you can download the PDF here - it's however in German and - because it will get shared within the institution - it is written in easy to understand language (and doesn't go into too much detail).

This for sure was an interesting and challenging project for me to be involved with!

from Skeptical Science https://ift.tt/30OGWsG

Year’s closest new supermoon August 30

Above: Simulation of a full Earth as viewed from the August 30 new moon. A new moon is between the sun and Earth. When the moon is new for us on Earth, Earth is full as seen from the moon. Image via Fourmilab.

Today – August 30, 2019 – presents the closest new moon supermoon of the year. In other words, it’s the year’s closest coincidence of new moon to lunar perigee, the moon’s nearest point to Earth in its monthly orbit:

New moon: August 30, 2019, at 10:37 UTC; (translate UTC to your time)
Perigee: August 30, 2019, 30 at 15:57 UTC

We’re smack-dab in the middle of a “season” of three straight new moon supermoons. The three new moons falling on August 1 and 30, plus September 28, 2019, all count as supermoons because of their relative nearness to Earth. The new moon on August 30, 2019, features the closest of the bunch:

New moon distance (August 1, 2019): 224,074 miles or 360,612 km
New moon distance (August 30, 2019): 221,971 miles or 357,227 km
New moon distance (September 28, 2019): 222,596 miles or 358,233 km

Although you can’t see a new moon supermoon, its impact can be seen along the ocean coastlines. The tidal influence of the extra-close new moon and the sun team up to usher in extra large spring tides, whereby the range between high and low tide is especially profound. Spring tides are not named for the season, but in the sense of jump, burst forth, or rise. Spring tides typically occur at the vicinity of new and full moons.

Read more: What’s a new moon?

Read more: Tides, and the pull of the moon and sun

Around each new moon and full moon – when the sun, Earth, and moon are located more or less on a line in space – the range between high and low tides is greatest. These are the spring tides. Image via physicalgeography.net. Read more: Tides, and the pull of the moon and sun.

The year’s farthest and smallest full moon (micro-moon) will occur on September 14, 2019, which is one fortnight (approximately two weeks) after the new moon supermoon of August 30. Moreover, this micro-moon comes one fortnight before the new moon supermoon of September 28, 2019. The year’s farthest full moon on September 14 will be some 30,000 miles (49,000 km) farther away from Earth than the year’s closest new moon on August 30, 2019.

New supermoons tend to recur in cycles of 14 lunar months (14 returns to new moon), representing a period of about one year one month and 18 days. Next year, in 2020, the year’s closest new moon will fall on October 16, 2020, marking the midpoint in 2020’s “season” of three new moon supermoons:

New moon distance (September 17, 2020): 223,828 miles or 360,216 km
New moon distance (October 16, 2020): 221,797 miles or 356,948 km
New moon distance (November 15, 2020): 222,666 miles or 358,347 km

Source: The Moon Tonight

In 2020, the year’s farthest and smallest full moon (micro-moon) will occur on October 31, 2020. As in 2019, the 2020 full moon micro-moon will come one fortnight after the year’s closest new moon.

Read more: Black Moon supermoon on July 31

These aren’t new moons. They’re full moons, but they’ll still show you the size comparison of close and far moons. This comparison shows the December 3, 2017, full moon at perigee (closest to Earth for the month) and 2017’s farthest full moon in June at apogee (farthest from Earth for the month). It’s via Muzamir Mazlan at Telok Kemang Observatory, Port Dickson, Malaysia. Although you can’t see the moon at new phase, the new moon on February 4, 2019, closely aligns with apogee; whereas the new moons of August 30 and September 28, 2019, closely align with perigee.

Bottom line: Today – August 30, 2019 – presents the closest new moon of the year, which occurs one fortnight before the year’s farthest and smallest full moon on September 14, 2019.

from EarthSky https://ift.tt/34coNHv

Above: Simulation of a full Earth as viewed from the August 30 new moon. A new moon is between the sun and Earth. When the moon is new for us on Earth, Earth is full as seen from the moon. Image via Fourmilab.

Today – August 30, 2019 – presents the closest new moon supermoon of the year. In other words, it’s the year’s closest coincidence of new moon to lunar perigee, the moon’s nearest point to Earth in its monthly orbit:

New moon: August 30, 2019, at 10:37 UTC; (translate UTC to your time)
Perigee: August 30, 2019, 30 at 15:57 UTC

We’re smack-dab in the middle of a “season” of three straight new moon supermoons. The three new moons falling on August 1 and 30, plus September 28, 2019, all count as supermoons because of their relative nearness to Earth. The new moon on August 30, 2019, features the closest of the bunch:

New moon distance (August 1, 2019): 224,074 miles or 360,612 km
New moon distance (August 30, 2019): 221,971 miles or 357,227 km
New moon distance (September 28, 2019): 222,596 miles or 358,233 km

Although you can’t see a new moon supermoon, its impact can be seen along the ocean coastlines. The tidal influence of the extra-close new moon and the sun team up to usher in extra large spring tides, whereby the range between high and low tide is especially profound. Spring tides are not named for the season, but in the sense of jump, burst forth, or rise. Spring tides typically occur at the vicinity of new and full moons.

Read more: What’s a new moon?

Read more: Tides, and the pull of the moon and sun

Around each new moon and full moon – when the sun, Earth, and moon are located more or less on a line in space – the range between high and low tides is greatest. These are the spring tides. Image via physicalgeography.net. Read more: Tides, and the pull of the moon and sun.

The year’s farthest and smallest full moon (micro-moon) will occur on September 14, 2019, which is one fortnight (approximately two weeks) after the new moon supermoon of August 30. Moreover, this micro-moon comes one fortnight before the new moon supermoon of September 28, 2019. The year’s farthest full moon on September 14 will be some 30,000 miles (49,000 km) farther away from Earth than the year’s closest new moon on August 30, 2019.

New supermoons tend to recur in cycles of 14 lunar months (14 returns to new moon), representing a period of about one year one month and 18 days. Next year, in 2020, the year’s closest new moon will fall on October 16, 2020, marking the midpoint in 2020’s “season” of three new moon supermoons:

New moon distance (September 17, 2020): 223,828 miles or 360,216 km
New moon distance (October 16, 2020): 221,797 miles or 356,948 km
New moon distance (November 15, 2020): 222,666 miles or 358,347 km

Source: The Moon Tonight

In 2020, the year’s farthest and smallest full moon (micro-moon) will occur on October 31, 2020. As in 2019, the 2020 full moon micro-moon will come one fortnight after the year’s closest new moon.

Read more: Black Moon supermoon on July 31

These aren’t new moons. They’re full moons, but they’ll still show you the size comparison of close and far moons. This comparison shows the December 3, 2017, full moon at perigee (closest to Earth for the month) and 2017’s farthest full moon in June at apogee (farthest from Earth for the month). It’s via Muzamir Mazlan at Telok Kemang Observatory, Port Dickson, Malaysia. Although you can’t see the moon at new phase, the new moon on February 4, 2019, closely aligns with apogee; whereas the new moons of August 30 and September 28, 2019, closely align with perigee.

Bottom line: Today – August 30, 2019 – presents the closest new moon of the year, which occurs one fortnight before the year’s farthest and smallest full moon on September 14, 2019.

from EarthSky https://ift.tt/34coNHv