Next Blue Moon is May 21, 2016

Most Blue Moons are not blue in color. This photo was created using special filters. Image via EarthSky Facebook friend Jv Noriega.

In recent years, people have been using the name Blue Moon for the second of two full moons in a single calendar month. An older definition says a Blue Moon is the third of four full moons in a single season. Someday, you might see an actual blue-colored moon. The term once in a blue moon used to mean something rare. Now that the rules for naming Blue Moons include several different possibilities, Blue Moons are pretty common! Follow the links below to learn more about Blue Moons:

Can a moon be blue in color?

Last monthly Blue Moon on August 31, 2015.

Next seasonal Blue Moon on May 21, 2016.

Which Blue Moon definition is better?

Can there be two Blue Moons in a single calendar year?

Is it possible to have only two full moons in a single season?

Desert Blue Moon from our friend Priya Kumar in Oman. August, 2012. Thank you, Priya!

Can a moon be blue in color? There’s one kind of blue moon that is still rare. It’s very rare that you would see a blue-colored moon, although unusual sky conditions – certain-sized particles of dust or smoke – can create them.

Blue-colored moons aren’t predictable. So don’t be misled by the photo above. The sorts of moons people commonly call Blue Moons aren’t usually blue.

For more about truly blue-colored moons, click here.

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The last monthly Blue Moon happened on July 31, 2015. In recent decades, many people have begun using the name Blue Moon to describe the second full moon of a calendar month. There was a full moon on July 2, 2015. There was another full moon on July 31. So the July 31 full moon was called a Blue Moon, according to this definition.

The time between one full moon and the next is close to the length of a calendar month. So the only time one month can have two full moons is when the first full moon happens in the first few days of the month. This happens every 2-3 years, so these sorts of Blue Moons come about that often.

When was the last Blue Moon, according to the monthly definition? It happened on July 31, 2015. The next one will be on January 31, 2018.

Another beautiful image by our friend Jv Noriega – the moon among fast-moving clouds. Will the next Blue Moon be blue in color like this? No. This image was made using blue filters, too. Thank you, Jv!

The idea of a Blue Moon as the second full moon in a month stemmed from the March 1946 issue of Sky and Telescope magazine, which contained an article called “Once in a Blue Moon” by James Hugh Pruett. Pruett was referring to the 1937 Maine Farmer’s Almanac, but he inadvertently simplified the definition. He wrote:

Seven times in 19 years there were — and still are — 13 full moons in a year. This gives 11 months with one full moon each and one with two. This second in a month, so I interpret it, was called Blue Moon.

Had James Hugh Pruett looked at the actual date of the 1937 Blue Moon, he would have found that it had occurred on August 21, 1937. Also, there were only 12 full moons in 1937. You need 13 full moons in one calendar year to have two full moons in one calendar month. However, that fortuitous oversight gave birth to a new and perfectly understandable definition for Blue Moon.

EarthSky’s Deborah Byrd happened upon a copy of this old 1946 issue of Sky and Telescope in the stacks of the Peridier Library at the University of Texas Astronomy Department in the late 1970s. Afterward, she began using the term Blue Moon to describe the second full moon in a calendar month on the radio. Later, this definition of Blue Moon was also popularized by a book for children by Margot McLoon-Basta and Alice Sigel, called “Kids’ World Almanac of Records and Facts,” published in New York by World Almanac Publications, in 1985. The second-full-moon-in-a-month definition was also used in the board game Trivial Pursuit.

Today, it has become part of folklore.

What most call a Blue Moon isn't blue in color. It's only Blue in name. This great moon photo from EarthSky Facebook friend Rebecca Lacey in Cambridge, Idaho.

Blue Moon as third full moon of four in a season. The Maine Farmer’s Almanac defined a Blue Moon as an extra full moon that occurred in a season. One season – winter, spring, fall, summer – typically has three full moons. If a season has four full moons, then the third full moon may be called a Blue Moon.

There was a Blue Moon by this definition happened on November 21, 2010. Another occurred on August 20-21, 2013. And the next one will occur on May 21, 2016.

Which Blue Moon definition is better? In recent years, a controversy has raged – mainly among purists – about which Blue Moon definition is better. The idea of a Blue Moon as the third of four in a season may be older than the idea of a Blue Moon as the second full moon in a month. Is it better? Is one definition right and the other wrong?

Opinions vary, but, remember, this is folklore. So we, the folk, get to decide. In the 21st century, both sorts of full moons have been called Blue.

As the folklorist Phillip Hiscock wrote in his comprehensive article Folklore of the Blue Moon:

Old folklore it is not, but real folklore it is.

Can there be two Blue Moons in a single calendar year? Yes. It last happened in 1999. There were two full moons in January and two full moons in March and no full moon in February. So both January and March had Blue Moons.

The next year of double monthly blue moons is coming up in January and March, 2018 – and then, after that, in January and March, 2037.

Very rarely, a monthly Blue Moon (second of two full moons in one calendar month) and a seasonal Blue Moon (third of four full moons in one season) can occur in the same calendar year. But for this to happen, you need 13 full moons in one calendar year AND 13 full moons in between successive December solstices. This will next happen in the year 2048, when a monthly Blue Moon falls on January 31, and a seasonal Blue Moon on August 23.

Bottom line: A blue-colored moon is rare. But folklore has defined two different kinds of Blue Moons, and moons that are Blue by name have become pretty common. A Blue Moon can be the second full moon in a month. We had that sort of Blue Moon on July 31, 2015. Or it can be the third of four full moons in a season. That’ll be the next Blue Moon, on May 21, 2016.

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Most Blue Moons are not blue in color. This photo was created using special filters. Image via EarthSky Facebook friend Jv Noriega.

In recent years, people have been using the name Blue Moon for the second of two full moons in a single calendar month. An older definition says a Blue Moon is the third of four full moons in a single season. Someday, you might see an actual blue-colored moon. The term once in a blue moon used to mean something rare. Now that the rules for naming Blue Moons include several different possibilities, Blue Moons are pretty common! Follow the links below to learn more about Blue Moons:

Can a moon be blue in color?

Last monthly Blue Moon on August 31, 2015.

Next seasonal Blue Moon on May 21, 2016.

Which Blue Moon definition is better?

Can there be two Blue Moons in a single calendar year?

Is it possible to have only two full moons in a single season?

Desert Blue Moon from our friend Priya Kumar in Oman. August, 2012. Thank you, Priya!

Can a moon be blue in color? There’s one kind of blue moon that is still rare. It’s very rare that you would see a blue-colored moon, although unusual sky conditions – certain-sized particles of dust or smoke – can create them.

Blue-colored moons aren’t predictable. So don’t be misled by the photo above. The sorts of moons people commonly call Blue Moons aren’t usually blue.

For more about truly blue-colored moons, click here.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

The last monthly Blue Moon happened on July 31, 2015. In recent decades, many people have begun using the name Blue Moon to describe the second full moon of a calendar month. There was a full moon on July 2, 2015. There was another full moon on July 31. So the July 31 full moon was called a Blue Moon, according to this definition.

The time between one full moon and the next is close to the length of a calendar month. So the only time one month can have two full moons is when the first full moon happens in the first few days of the month. This happens every 2-3 years, so these sorts of Blue Moons come about that often.

When was the last Blue Moon, according to the monthly definition? It happened on July 31, 2015. The next one will be on January 31, 2018.

Another beautiful image by our friend Jv Noriega – the moon among fast-moving clouds. Will the next Blue Moon be blue in color like this? No. This image was made using blue filters, too. Thank you, Jv!

The idea of a Blue Moon as the second full moon in a month stemmed from the March 1946 issue of Sky and Telescope magazine, which contained an article called “Once in a Blue Moon” by James Hugh Pruett. Pruett was referring to the 1937 Maine Farmer’s Almanac, but he inadvertently simplified the definition. He wrote:

Seven times in 19 years there were — and still are — 13 full moons in a year. This gives 11 months with one full moon each and one with two. This second in a month, so I interpret it, was called Blue Moon.

Had James Hugh Pruett looked at the actual date of the 1937 Blue Moon, he would have found that it had occurred on August 21, 1937. Also, there were only 12 full moons in 1937. You need 13 full moons in one calendar year to have two full moons in one calendar month. However, that fortuitous oversight gave birth to a new and perfectly understandable definition for Blue Moon.

EarthSky’s Deborah Byrd happened upon a copy of this old 1946 issue of Sky and Telescope in the stacks of the Peridier Library at the University of Texas Astronomy Department in the late 1970s. Afterward, she began using the term Blue Moon to describe the second full moon in a calendar month on the radio. Later, this definition of Blue Moon was also popularized by a book for children by Margot McLoon-Basta and Alice Sigel, called “Kids’ World Almanac of Records and Facts,” published in New York by World Almanac Publications, in 1985. The second-full-moon-in-a-month definition was also used in the board game Trivial Pursuit.

Today, it has become part of folklore.

What most call a Blue Moon isn't blue in color. It's only Blue in name. This great moon photo from EarthSky Facebook friend Rebecca Lacey in Cambridge, Idaho.

Blue Moon as third full moon of four in a season. The Maine Farmer’s Almanac defined a Blue Moon as an extra full moon that occurred in a season. One season – winter, spring, fall, summer – typically has three full moons. If a season has four full moons, then the third full moon may be called a Blue Moon.

There was a Blue Moon by this definition happened on November 21, 2010. Another occurred on August 20-21, 2013. And the next one will occur on May 21, 2016.

Which Blue Moon definition is better? In recent years, a controversy has raged – mainly among purists – about which Blue Moon definition is better. The idea of a Blue Moon as the third of four in a season may be older than the idea of a Blue Moon as the second full moon in a month. Is it better? Is one definition right and the other wrong?

Opinions vary, but, remember, this is folklore. So we, the folk, get to decide. In the 21st century, both sorts of full moons have been called Blue.

As the folklorist Phillip Hiscock wrote in his comprehensive article Folklore of the Blue Moon:

Old folklore it is not, but real folklore it is.

Can there be two Blue Moons in a single calendar year? Yes. It last happened in 1999. There were two full moons in January and two full moons in March and no full moon in February. So both January and March had Blue Moons.

The next year of double monthly blue moons is coming up in January and March, 2018 – and then, after that, in January and March, 2037.

Very rarely, a monthly Blue Moon (second of two full moons in one calendar month) and a seasonal Blue Moon (third of four full moons in one season) can occur in the same calendar year. But for this to happen, you need 13 full moons in one calendar year AND 13 full moons in between successive December solstices. This will next happen in the year 2048, when a monthly Blue Moon falls on January 31, and a seasonal Blue Moon on August 23.

Bottom line: A blue-colored moon is rare. But folklore has defined two different kinds of Blue Moons, and moons that are Blue by name have become pretty common. A Blue Moon can be the second full moon in a month. We had that sort of Blue Moon on July 31, 2015. Or it can be the third of four full moons in a season. That’ll be the next Blue Moon, on May 21, 2016.

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Where is the Milky Way on May evenings?

Starlit band of the Milky Way. Photo by Larry Landolfi via NASA

Tonight – and throughout the month of May – if you’re in a dark location, at northern temperate latitudes – you might be searching for one of the sky’s most spectacular sights, the starlit band of the Milky Way. You won’t find it in the early part of the night. That luminous band of stars arcing across the dome of sky is nowhere to be seen as evening falls in May. Where is the the Milky Way at nightfall this month?

For starters, remember that the disk of our Milky Way galaxy is flat, like a pancake. At northern temperate latitudes, as evening falls in the month of May, the plane of the pancake-shaped galactic disk pretty much coincides with the plane of your horizon.

Because the Milky Way rims the horizon in every direction at nightfall and early evening, we can’t see this roadway of stars until late at night.

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An all-sky plot of the 25,000 brightest, whitest stars shows how these stars are concentrated along the Milky Way. This map shows our limited, inside view of the Milky Way galaxy. The large, dark patch near the middle of the picture is due to nearby dark nebulae, or clouds of gas and dust, which obscure the stars. Via altasoftheuniverse.com.

The galactic disk most closely aligns with the horizon at about 30 degrees North latitude – the latitude of St. Augustine, Florida. Appreciably north of this latitude, the galactic disk tilts a bit upward of the northern horizon. Appreciably south of 30 degrees north latitude, the galactic disk tilts a bit above the southern horizon.

Even so, the Milky Way is pretty much out of sight in our Northern Hemisphere sky during the evening hours in May.

Like the sun, the stars rise in the east and set in the west. If you stay up until late night – near midnight in early May, a couple of hours earlier by June – you’ll begin to see the the stars of the Summer Triangle – Deneb, Vega, and Altair – rising above your eastern horizon.

In a dark country sky, the Milky Way’s band of stars becomes visible as well, for the Milky Way passes right through the Summer Triangle. Watch for it, if you’re up late this month.

Bottom line: The Milky Way’s softly-glowing band of luminescence hides behind the horizon at nightfall and early evening in the month of May. But if you stay up until around midnight, you’ll begin to see the starlit band of the Milky Way rising in the eastern sky.

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Starlit band of the Milky Way. Photo by Larry Landolfi via NASA

Tonight – and throughout the month of May – if you’re in a dark location, at northern temperate latitudes – you might be searching for one of the sky’s most spectacular sights, the starlit band of the Milky Way. You won’t find it in the early part of the night. That luminous band of stars arcing across the dome of sky is nowhere to be seen as evening falls in May. Where is the the Milky Way at nightfall this month?

For starters, remember that the disk of our Milky Way galaxy is flat, like a pancake. At northern temperate latitudes, as evening falls in the month of May, the plane of the pancake-shaped galactic disk pretty much coincides with the plane of your horizon.

Because the Milky Way rims the horizon in every direction at nightfall and early evening, we can’t see this roadway of stars until late at night.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!
.

An all-sky plot of the 25,000 brightest, whitest stars shows how these stars are concentrated along the Milky Way. This map shows our limited, inside view of the Milky Way galaxy. The large, dark patch near the middle of the picture is due to nearby dark nebulae, or clouds of gas and dust, which obscure the stars. Via altasoftheuniverse.com.

The galactic disk most closely aligns with the horizon at about 30 degrees North latitude – the latitude of St. Augustine, Florida. Appreciably north of this latitude, the galactic disk tilts a bit upward of the northern horizon. Appreciably south of 30 degrees north latitude, the galactic disk tilts a bit above the southern horizon.

Even so, the Milky Way is pretty much out of sight in our Northern Hemisphere sky during the evening hours in May.

Like the sun, the stars rise in the east and set in the west. If you stay up until late night – near midnight in early May, a couple of hours earlier by June – you’ll begin to see the the stars of the Summer Triangle – Deneb, Vega, and Altair – rising above your eastern horizon.

In a dark country sky, the Milky Way’s band of stars becomes visible as well, for the Milky Way passes right through the Summer Triangle. Watch for it, if you’re up late this month.

Bottom line: The Milky Way’s softly-glowing band of luminescence hides behind the horizon at nightfall and early evening in the month of May. But if you stay up until around midnight, you’ll begin to see the starlit band of the Milky Way rising in the eastern sky.

EarthSky astronomy kits are perfect for beginners. Order today from the EarthSky store

Donate: Your support means the world to us

from EarthSky http://ift.tt/1Kc4tbr

Limb regeneration in brittle stars [Life Lines]

Image of brittle star by Jerry Kirkhart from Los Osos, Calif. [CC BY 2.0 (http://ift.tt/o655VX)], via Wikimedia Commons

A new study published in Frontiers in Zoology examined the developmental process involved in regulating limb regeneration in brittle stars (Amphiura filiformis) following amputation of an arm. Limb regeneration is a multi-stage process involving initial healing and repair of the wounded site, initial growth of the limb followed by development of more complex layers of cells until ultimately the limb has been fully regenerated. Understanding this process in brittle stars may lead to better understanding of limb regeneration in other echinoderms or at least methodologies that can examine the process in other animals.

The ability for brittle stars to regenerate limbs so readily is more than likely an adaptation to avoid predation.

Source:

A Czarkwiani, C Ferrario, DV Dylus, M Sugni, P Oliveri. Skeletal regeneration in the brittle star Amphiura filiformis. Frontiers in Zoology. 13:18, 2016. DOI: 10.1186/s12983-016-0149-x

 

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Image of brittle star by Jerry Kirkhart from Los Osos, Calif. [CC BY 2.0 (http://ift.tt/o655VX)], via Wikimedia Commons

A new study published in Frontiers in Zoology examined the developmental process involved in regulating limb regeneration in brittle stars (Amphiura filiformis) following amputation of an arm. Limb regeneration is a multi-stage process involving initial healing and repair of the wounded site, initial growth of the limb followed by development of more complex layers of cells until ultimately the limb has been fully regenerated. Understanding this process in brittle stars may lead to better understanding of limb regeneration in other echinoderms or at least methodologies that can examine the process in other animals.

The ability for brittle stars to regenerate limbs so readily is more than likely an adaptation to avoid predation.

Source:

A Czarkwiani, C Ferrario, DV Dylus, M Sugni, P Oliveri. Skeletal regeneration in the brittle star Amphiura filiformis. Frontiers in Zoology. 13:18, 2016. DOI: 10.1186/s12983-016-0149-x

 

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May 2016 guide to the 5 bright planets

Jupiter pops out first thing at dusk. It’s the brightest starlike object in May and lights up the nighttime until the wee hours of the morning. Mars and Saturn ascend in the east at early-to-mid evening. Once Mars and Saturn are up, they’re out for rest of the night, near each other, getting brighter, heading toward their brightest and best in late May and early June, respectively. Mars and Saturn join up with the bright star Antares to form a bright celestial triangle: beautiful and easy to spot. Mercury transits the sun on May 9, 2016, for the first time since November 8, 2006. The brightest planet – Venus – is lost in the glare of sunrise. Follow the links below to learn more about the May planets.

Check out our latest EarthSky visible planet tee available only for a limited time!

Jupiter brightest “star” in early May

Mars, early evening until dawn, reaches opposition this month

Saturn, early evening until dawn, shines near Mars

Mercury transits sun on May 9

Venus, brightest planet, lost in the sunrise

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Astronomy events, star parties, festivals, workshops

Watch for the waxing moon to move eastward in front of the constellation Leo the Lion for several days around May 13, 14 and 15. The green line depicts the ecliptic – the sun and moon’s yearly path in front of the constellations of the Zodiac. Read more.

Jupiter brightest “star” in early May. Jupiter lights up the sky almost immediately after sunset. From mid-northern latitudes, it shines in the southern sky at nightfall. From the Southern hemisphere, look high overhead at nightfall.

This giant planet climbs highest up for the night at roughly 8 to 9 p.m. local time (9 to 10 p.m. local Daylight Saving Time) and sets in the west before dawn.

Jupiter will remain a fine evening object for months to come.

Jupiter is almost impossible to miss. However, from southerly latitudes, it might be possible to confuse it with sparkling, blue-white Sirius, the brightest star in the night sky. At nightfall and early evening, Jupiter is either in the southern sky or high overhead, while Sirius shines to the west of Jupiter, in the western sky. From either the Northern or Southern Hemisphere, you can rely on the famous constellation Orion the Hunter to confirm that you’re looking at Sirius, and not Jupiter, because Orion’s Belt of three stars points right to this star.

But just wait. As the month of May passes, the planet Mars is brightening dramatically. By the month’s end, Mars will have attained Jupiter’s brightness, almost. It’ll be harder to mistake Mars for Jupiter, because Mars will be distinctly reddish.

The moon swings close to Jupiter on the sky’s dome for several days, centered on May 14.

If you have binoculars or a telescope, it’s fairly easy to see Jupiter’s four major moons, which look like pinpricks of light on or near the same plane. They are often called the Galilean moons to honor Galileo, who discovered these great Jovian moons in 1610. In their order from Jupiter, these moons are Io, Europa, Ganymede and Callisto.

These moons circle Jupiter around the Jovian equator. In cycles of six years, we view Jupiter’s equator edge-on. So, in 2015, we got to view a number of mutual events involving Jupiter’s moons through a high-powered telescope. Click here or here or here for more details.

Although Jupiter’s axial tilt is only 3^o out of perpendicular relative to the ecliptic (Earth’s orbital plane), Jupiter’s axis will tilt enough toward the sun and Earth so that the farthest of these four moons, Callisto, will NOT pass in front of Jupiter or behind Jupiter for a period of about three years, starting in late 2016. During this approximate 3-year period, Callisto will remain “perpetually” visible, alternately swinging “above” and “below” Jupiter.

Click here for a Jupiter moons almanac, courtesy of Sky & Telescope.

Look for the Blue Moon to pair up with Mars on the sky’s dome on May 21. The green line depicts the ecliptic – Earth’s orbital plane projected onto the dome of sky.

Mars, early evening until dawn, reaches opposition this month Mars is not as bright as Jupiter when the month begins, but this is Mars’ month, the best month in two years to watch the red planet!

Mars will brighten throughout May until its opposition on May 22.

By the time Mars reaches its crest of brightness in late May 2016, it will have quadrupled in brilliance since the beginning of April. Mars has greater swings in brilliance than any other solar system planet, except for Mercury, and is a fascinating and beautiful sight in May, 2016.

At is brightest, Mars shines some 80 times more brilliantly than at its faintest.

Why is Mars getting so bright? For most of the past two years, Earth has been fleeing ahead of Mars in orbit. Mars orbits just one step outward from us, and we move slightly faster in orbit, and – about every two years – we catch up to Mars again and pass between it and the sun. That’ll happen next in late May, 2016. Astronomers will say that Mars is in opposition to the sun around that time.

Then, believe it or not, Mars will nearly match Jupiter in brightness!

By late May, as we pass between it and the sun, Mars will be rising in the east as the sun is setting in the west. It’ll be opposite the sun, in opposition.

In early May, Mars rises at about 9 p.m. local time (10 p.m. Daylight Time) at mid-northern latitudes. By the month’s end, Mars – opposite the sun – will ascend above the horizon as the sun is setting in the west.

Looking for a sky almanac? EarthSky recommends…

And here’s the really good news. Mars is near another planet on the sky’s dome, Saturn. Look for Mars and Saturn near Antares, the brightest star in the constellation Scorpius the Scorpion. They make a noticeable triangle on the sky’s dome.

Let the moon help guide your eye to Mars (and Saturn) in the morning sky for several nights, beginning around May 20, and also on May 21 and May 22.

What’s really cool is that you can use the brilliant planet Mars as you guide “star” to the planet Saturn and the star Antares for months to come.

Saturn, early evening until dawn, shines near Mars. And both Mars and Saturn are near a fainter object – still one of the sky’s brightest stars – Antares in the constellation Scorpius.

From mid-northern latitudes, the ringed planet starts the month rising in the east around 9 to 10 p.m. local time (10 to 11 p.m. local Daylight Saving Time). As for temperate latitudes in the Southern Hemisphere, Saturn rises in the east at roughly 7 to 8 p.m. local time in early May. By the month’s end – no matter where you are on Earth – Saturn will be coming up around sunset, just a few days shy of its opposition, when Earth will pass between Saturn and the sun. That will happen on June 3.

Although Saturn shines on par with the sky’s brightest stars, its brilliance can’t match that of Mars. Look for Saturn near Mars. These two worlds form a bright celestial triangle with the star Antares in the May night sky. Mars is brighter than Saturn, which in turn is brighter than Antares.

Mars will eventually catch up with Saturn on August 24, 2016, to present a conjunction of these two worlds in the August evening sky.

Watch for the moon to swing by Saturn for several days, centered on or near May 22. Scroll up to the second sky chart above.

Saturn, the farthest world that you can easily view with the eye alone, appears golden in color. It shines with a steady light. Binoculars don’t reveal Saturn’s gorgeous rings, by the way. For that, you need a small telescope. But binoculars will enhance Saturn’s golden color.

Saturn’s rings are inclined at a little more than 26^o from edge-on in May, 2016, exhibiting their northern face. Next year, in October, 2017, the rings will open most widely, displaying a maximum inclination of 27^o.

As with so much in space (and on Earth), the appearance of Saturn’s rings from Earth is cyclical. In the year 2025, the rings will appear edge-on as seen from Earth. After that, we’ll begin to see the south side of Saturn’s rings, to increase to a maximum inclination of 27^o by May, 2032.

Click here for recommended almanacs. They can help you know when the planets rise, transit and set in your sky

Transit of Mercury on May 9, 2016 from LarryKoehn on Vimeo. Visit Larry’s great website shadowandsubstance.com

Mercury transits the sun on May 9, 2016. Mercury transitions from the evening to morning sky on May 9, 2016. Usually, you can’t see Mercury at this juncture because it swings to the north or south of the solar disk, so is lost in the sun’s glare.

This time around, however, the planet Mercury in its orbit will swing directly in between the Earth and sun on May 9, 2016. Mercury will appear as a small black dot in front of the sun. Warning: A telescope and a proper solar filter is absolutely essential to safely watch this transit, so you might want to seek out an astronomical organization hosting a public presentation of this event.

For the Southern Hemisphere, Mercury might become bright enough to view in the morning sky by late May. However, it’s really the first couple of weeks in June that will feature a good time for catching Mercury before sunrise in the Southern Hemisphere and the northern tropics. It’ll be more of a challenge to spot Mercury as a morning “star” from mid-northern latitudes. Mercury will reach its greatest western (morning) elongation on June 5, 2016.

Photo of the transit of Venus on June 6, 2012, via NASA Goddard Space Flight Center,

Venus, brightest planet, lost in the sunrise. From all over the world, Venus sinks closer to the glare of sunrise all month long. From the Southern Hemisphere, you might be able to glimpse Venus before sunrise in the early part of May. From northerly latitudes, Venus will be extremely hard to catch this month. Venus will pass directly behind the sun on June 6, 2016, as it transitions from the morning to the evening sky.

Exactly four years previous to Venus passing directly behind the sun on June 6, 2016, Venus swung directly in front of the sun on June 6, 2012, to present the last transit of Venus until December 11, 2117. See the photo above.

What do we mean by bright planet? By bright planet, we mean any solar system planet that is easily visible without an optical aid and that has been watched by our ancestors since time immemorial. In their outward order from the sun, the five bright planets are Mercury, Venus, Mars, Jupiter and Saturn. These planets actually do appear bright in our sky. They are typically as bright as – or brighter than – the brightest stars. Plus, these relatively nearby worlds tend to shine with a steadier light than the distant, twinkling stars. You can spot them, and come to know them as faithful friends, if you try.

Bottom line: In May, 2016, Jupiter is the brightest starlike object up when the sun goes down. Earth swings between Mars and the sun on May 22, giving us our best view of the planet in about two years! Saturn and the bright star Antares make a triangle with Mars on the sky’s dome. Mercury, the innermost planet, tranists the sun on May 9. Venus is behind the sun.

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From late January, and through mid-February, 5 bright planets were visible at once in the predawn sky. This image is from February 8, 2016. It’s by Eliot Herman in Tucson, Arizona. View on Flickr.

Awesome month for planets before dawn: October, 2015! Photo taken October 2, 2015 by Mohamed Laaifat Photographies in Normandy, France.

Eastern sky before dawn now. Photo taken September 18, 2015 and submitted to EarthSky by Greg Hogan in Kathleen, Georgia. Thanks, Greg!

View larger. Evening dusk on August 5: Venus at left. Mercury is climbing higher, toward Regulus (at top) and Jupiter (beneath Regulus).

By the evening of July 12, Venus and Jupiter were farther apart and lower in the western sky after sunset. Photo by Robert Kelly. Thanks, Robert!

Photo taken June 13, 2015 by John Nelson at Puget Sound, Washington. Thanks, John!

View larger. | Photo taken in early June, 2015 by Göran Strand in Sweden. He wrote: “One of the last nights during the spring when the stars were still visible … ” Follow Fotograf Göran Strand on Facebook, or @astrofotografen on Instagram. Or visit his website.

Lunar eclipse on the night of October 8, 2014. The object to the left is the planet Uranus! This beautiful photo is by Janey Wing Kenyon of Story, Wyoming.

Debra Fryar in Calobreves, Texas captured this photo of the moon and Jupiter on May 31, 2014. Jupiter was close to the twilight then.

With only a modest backyard telescope, you can easily see Jupiter’s four largest moons. Here they are through a 10″ (25 cm) Meade LX200 telescope. Image credit: Jan Sandberg

Jupiter was rivaling the streetlights, when Mohamed Laaifat Photographies captured this photo in Normandy, France. Visit his page on Facebook.

Venus by Danny Crocker-Jensen

These are called star trails. It’s a long-exposure photo, which shows you how Earth is turning under the stars. The brightest object here is Jupiter, which is the second-brightest planet, after Venus. This awesome photo by EarthSky Facebook friend Mohamed Laaifat in Normandy, France. Thank you, Mohamed.

Skywatcher, by Predrag Agatonovic.

Easily locate stars and constellations with EarthSky’s planisphere.

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Jupiter pops out first thing at dusk. It’s the brightest starlike object in May and lights up the nighttime until the wee hours of the morning. Mars and Saturn ascend in the east at early-to-mid evening. Once Mars and Saturn are up, they’re out for rest of the night, near each other, getting brighter, heading toward their brightest and best in late May and early June, respectively. Mars and Saturn join up with the bright star Antares to form a bright celestial triangle: beautiful and easy to spot. Mercury transits the sun on May 9, 2016, for the first time since November 8, 2006. The brightest planet – Venus – is lost in the glare of sunrise. Follow the links below to learn more about the May planets.

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Jupiter brightest “star” in early May

Mars, early evening until dawn, reaches opposition this month

Saturn, early evening until dawn, shines near Mars

Mercury transits sun on May 9

Venus, brightest planet, lost in the sunrise

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Astronomy events, star parties, festivals, workshops

Watch for the waxing moon to move eastward in front of the constellation Leo the Lion for several days around May 13, 14 and 15. The green line depicts the ecliptic – the sun and moon’s yearly path in front of the constellations of the Zodiac. Read more.

Jupiter brightest “star” in early May. Jupiter lights up the sky almost immediately after sunset. From mid-northern latitudes, it shines in the southern sky at nightfall. From the Southern hemisphere, look high overhead at nightfall.

This giant planet climbs highest up for the night at roughly 8 to 9 p.m. local time (9 to 10 p.m. local Daylight Saving Time) and sets in the west before dawn.

Jupiter will remain a fine evening object for months to come.

Jupiter is almost impossible to miss. However, from southerly latitudes, it might be possible to confuse it with sparkling, blue-white Sirius, the brightest star in the night sky. At nightfall and early evening, Jupiter is either in the southern sky or high overhead, while Sirius shines to the west of Jupiter, in the western sky. From either the Northern or Southern Hemisphere, you can rely on the famous constellation Orion the Hunter to confirm that you’re looking at Sirius, and not Jupiter, because Orion’s Belt of three stars points right to this star.

But just wait. As the month of May passes, the planet Mars is brightening dramatically. By the month’s end, Mars will have attained Jupiter’s brightness, almost. It’ll be harder to mistake Mars for Jupiter, because Mars will be distinctly reddish.

The moon swings close to Jupiter on the sky’s dome for several days, centered on May 14.

If you have binoculars or a telescope, it’s fairly easy to see Jupiter’s four major moons, which look like pinpricks of light on or near the same plane. They are often called the Galilean moons to honor Galileo, who discovered these great Jovian moons in 1610. In their order from Jupiter, these moons are Io, Europa, Ganymede and Callisto.

These moons circle Jupiter around the Jovian equator. In cycles of six years, we view Jupiter’s equator edge-on. So, in 2015, we got to view a number of mutual events involving Jupiter’s moons through a high-powered telescope. Click here or here or here for more details.

Although Jupiter’s axial tilt is only 3^o out of perpendicular relative to the ecliptic (Earth’s orbital plane), Jupiter’s axis will tilt enough toward the sun and Earth so that the farthest of these four moons, Callisto, will NOT pass in front of Jupiter or behind Jupiter for a period of about three years, starting in late 2016. During this approximate 3-year period, Callisto will remain “perpetually” visible, alternately swinging “above” and “below” Jupiter.

Click here for a Jupiter moons almanac, courtesy of Sky & Telescope.

Look for the Blue Moon to pair up with Mars on the sky’s dome on May 21. The green line depicts the ecliptic – Earth’s orbital plane projected onto the dome of sky.

Mars, early evening until dawn, reaches opposition this month Mars is not as bright as Jupiter when the month begins, but this is Mars’ month, the best month in two years to watch the red planet!

Mars will brighten throughout May until its opposition on May 22.

By the time Mars reaches its crest of brightness in late May 2016, it will have quadrupled in brilliance since the beginning of April. Mars has greater swings in brilliance than any other solar system planet, except for Mercury, and is a fascinating and beautiful sight in May, 2016.

At is brightest, Mars shines some 80 times more brilliantly than at its faintest.

Why is Mars getting so bright? For most of the past two years, Earth has been fleeing ahead of Mars in orbit. Mars orbits just one step outward from us, and we move slightly faster in orbit, and – about every two years – we catch up to Mars again and pass between it and the sun. That’ll happen next in late May, 2016. Astronomers will say that Mars is in opposition to the sun around that time.

Then, believe it or not, Mars will nearly match Jupiter in brightness!

By late May, as we pass between it and the sun, Mars will be rising in the east as the sun is setting in the west. It’ll be opposite the sun, in opposition.

In early May, Mars rises at about 9 p.m. local time (10 p.m. Daylight Time) at mid-northern latitudes. By the month’s end, Mars – opposite the sun – will ascend above the horizon as the sun is setting in the west.

Looking for a sky almanac? EarthSky recommends…

And here’s the really good news. Mars is near another planet on the sky’s dome, Saturn. Look for Mars and Saturn near Antares, the brightest star in the constellation Scorpius the Scorpion. They make a noticeable triangle on the sky’s dome.

Let the moon help guide your eye to Mars (and Saturn) in the morning sky for several nights, beginning around May 20, and also on May 21 and May 22.

What’s really cool is that you can use the brilliant planet Mars as you guide “star” to the planet Saturn and the star Antares for months to come.

Saturn, early evening until dawn, shines near Mars. And both Mars and Saturn are near a fainter object – still one of the sky’s brightest stars – Antares in the constellation Scorpius.

From mid-northern latitudes, the ringed planet starts the month rising in the east around 9 to 10 p.m. local time (10 to 11 p.m. local Daylight Saving Time). As for temperate latitudes in the Southern Hemisphere, Saturn rises in the east at roughly 7 to 8 p.m. local time in early May. By the month’s end – no matter where you are on Earth – Saturn will be coming up around sunset, just a few days shy of its opposition, when Earth will pass between Saturn and the sun. That will happen on June 3.

Although Saturn shines on par with the sky’s brightest stars, its brilliance can’t match that of Mars. Look for Saturn near Mars. These two worlds form a bright celestial triangle with the star Antares in the May night sky. Mars is brighter than Saturn, which in turn is brighter than Antares.

Mars will eventually catch up with Saturn on August 24, 2016, to present a conjunction of these two worlds in the August evening sky.

Watch for the moon to swing by Saturn for several days, centered on or near May 22. Scroll up to the second sky chart above.

Saturn, the farthest world that you can easily view with the eye alone, appears golden in color. It shines with a steady light. Binoculars don’t reveal Saturn’s gorgeous rings, by the way. For that, you need a small telescope. But binoculars will enhance Saturn’s golden color.

Saturn’s rings are inclined at a little more than 26^o from edge-on in May, 2016, exhibiting their northern face. Next year, in October, 2017, the rings will open most widely, displaying a maximum inclination of 27^o.

As with so much in space (and on Earth), the appearance of Saturn’s rings from Earth is cyclical. In the year 2025, the rings will appear edge-on as seen from Earth. After that, we’ll begin to see the south side of Saturn’s rings, to increase to a maximum inclination of 27^o by May, 2032.

Click here for recommended almanacs. They can help you know when the planets rise, transit and set in your sky

Transit of Mercury on May 9, 2016 from LarryKoehn on Vimeo. Visit Larry’s great website shadowandsubstance.com

Mercury transits the sun on May 9, 2016. Mercury transitions from the evening to morning sky on May 9, 2016. Usually, you can’t see Mercury at this juncture because it swings to the north or south of the solar disk, so is lost in the sun’s glare.

This time around, however, the planet Mercury in its orbit will swing directly in between the Earth and sun on May 9, 2016. Mercury will appear as a small black dot in front of the sun. Warning: A telescope and a proper solar filter is absolutely essential to safely watch this transit, so you might want to seek out an astronomical organization hosting a public presentation of this event.

For the Southern Hemisphere, Mercury might become bright enough to view in the morning sky by late May. However, it’s really the first couple of weeks in June that will feature a good time for catching Mercury before sunrise in the Southern Hemisphere and the northern tropics. It’ll be more of a challenge to spot Mercury as a morning “star” from mid-northern latitudes. Mercury will reach its greatest western (morning) elongation on June 5, 2016.

Photo of the transit of Venus on June 6, 2012, via NASA Goddard Space Flight Center,

Venus, brightest planet, lost in the sunrise. From all over the world, Venus sinks closer to the glare of sunrise all month long. From the Southern Hemisphere, you might be able to glimpse Venus before sunrise in the early part of May. From northerly latitudes, Venus will be extremely hard to catch this month. Venus will pass directly behind the sun on June 6, 2016, as it transitions from the morning to the evening sky.

Exactly four years previous to Venus passing directly behind the sun on June 6, 2016, Venus swung directly in front of the sun on June 6, 2012, to present the last transit of Venus until December 11, 2117. See the photo above.

What do we mean by bright planet? By bright planet, we mean any solar system planet that is easily visible without an optical aid and that has been watched by our ancestors since time immemorial. In their outward order from the sun, the five bright planets are Mercury, Venus, Mars, Jupiter and Saturn. These planets actually do appear bright in our sky. They are typically as bright as – or brighter than – the brightest stars. Plus, these relatively nearby worlds tend to shine with a steadier light than the distant, twinkling stars. You can spot them, and come to know them as faithful friends, if you try.

Bottom line: In May, 2016, Jupiter is the brightest starlike object up when the sun goes down. Earth swings between Mars and the sun on May 22, giving us our best view of the planet in about two years! Saturn and the bright star Antares make a triangle with Mars on the sky’s dome. Mercury, the innermost planet, tranists the sun on May 9. Venus is behind the sun.

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From late January, and through mid-February, 5 bright planets were visible at once in the predawn sky. This image is from February 8, 2016. It’s by Eliot Herman in Tucson, Arizona. View on Flickr.

Awesome month for planets before dawn: October, 2015! Photo taken October 2, 2015 by Mohamed Laaifat Photographies in Normandy, France.

Eastern sky before dawn now. Photo taken September 18, 2015 and submitted to EarthSky by Greg Hogan in Kathleen, Georgia. Thanks, Greg!

View larger. Evening dusk on August 5: Venus at left. Mercury is climbing higher, toward Regulus (at top) and Jupiter (beneath Regulus).

By the evening of July 12, Venus and Jupiter were farther apart and lower in the western sky after sunset. Photo by Robert Kelly. Thanks, Robert!

Photo taken June 13, 2015 by John Nelson at Puget Sound, Washington. Thanks, John!

View larger. | Photo taken in early June, 2015 by Göran Strand in Sweden. He wrote: “One of the last nights during the spring when the stars were still visible … ” Follow Fotograf Göran Strand on Facebook, or @astrofotografen on Instagram. Or visit his website.

Lunar eclipse on the night of October 8, 2014. The object to the left is the planet Uranus! This beautiful photo is by Janey Wing Kenyon of Story, Wyoming.

Debra Fryar in Calobreves, Texas captured this photo of the moon and Jupiter on May 31, 2014. Jupiter was close to the twilight then.

With only a modest backyard telescope, you can easily see Jupiter’s four largest moons. Here they are through a 10″ (25 cm) Meade LX200 telescope. Image credit: Jan Sandberg

Jupiter was rivaling the streetlights, when Mohamed Laaifat Photographies captured this photo in Normandy, France. Visit his page on Facebook.

Venus by Danny Crocker-Jensen

These are called star trails. It’s a long-exposure photo, which shows you how Earth is turning under the stars. The brightest object here is Jupiter, which is the second-brightest planet, after Venus. This awesome photo by EarthSky Facebook friend Mohamed Laaifat in Normandy, France. Thank you, Mohamed.

Skywatcher, by Predrag Agatonovic.

Easily locate stars and constellations with EarthSky’s planisphere.

Don’t miss anything. Subscribe to EarthSky News by email

from EarthSky http://ift.tt/IJfHCr

Worker Memorial Day 2016: Names, Faces, Places, Data [The Pump Handle]

If only The Pump Handle had a crew of correspondents to report from the many Worker Memorial Day events held this past week. If you attended a Worker Memorial Day event, I’m calling on you to share some highlights from it in the comment section below.

I spent time in Houston, TX where Mayor Sylvester Turner and the City Council issued a proclamation to remember workers who were killed, injured, or made ill because of their jobs. Our event featured remarks by Mr. Joseph Reyna, whose son Steven Reyna died in November 2015 while working for Atlantic Coffee Solutions, four workers from La Espiga De Oro, and a representative of the Seafarers International Union in memory of the 33-person crew of the El Faro who perished at sea in November 2015.

Among my favorite part of Worker Memorial Day are the excellent reports prepared by local and national organizations, including MassCOSH (here), South Florida COSH (here), and National COSH (here.)  MassCOSH’s report impressed me with profiles on the occupational health and safety problems faced today by US workers, from climate-change effects, to guns and trouble with “worksite wellness” programs. The South Florida COSH report makes a special point to provide state-specific data on the hazards and industries in which Florida workers are harmed. National COSH’s report was enhanced by 10 attention-grabbing infographics. A Worker Memorial Day report for the Houston, TX area, which I co-authored, is available in both English (here) and Spanish (here). It features the names and circumstances of 63 Houston-area workers who were killed on-the-job in 2015, including photos for 33 of them.

I credit the AFL-CIO’s Peg Seminario for starting the tradition of Worker Memorial Day reports. Their annual Death on the Job (DOTJ) report marks its 25th anniversary this year. It is the go-to compendium for national and state-level OHS data. Complementing the AFL-CIO’s report are eye-catching infographics like this one:

Some of the biggest Worker Memorial Day events take place outside the U.S.  Hazards magazine and the International Trade Union Confederation provides information about many of them. For example, here’s a photo from a rally in Istanbul:

I’m calling on readers of The Pump Handle to share some highlights in the comment section below from the Worker Memorial Day event(s) you attended this past week.

from ScienceBlogs http://ift.tt/1rIykCq

If only The Pump Handle had a crew of correspondents to report from the many Worker Memorial Day events held this past week. If you attended a Worker Memorial Day event, I’m calling on you to share some highlights from it in the comment section below.

I spent time in Houston, TX where Mayor Sylvester Turner and the City Council issued a proclamation to remember workers who were killed, injured, or made ill because of their jobs. Our event featured remarks by Mr. Joseph Reyna, whose son Steven Reyna died in November 2015 while working for Atlantic Coffee Solutions, four workers from La Espiga De Oro, and a representative of the Seafarers International Union in memory of the 33-person crew of the El Faro who perished at sea in November 2015.

Among my favorite part of Worker Memorial Day are the excellent reports prepared by local and national organizations, including MassCOSH (here), South Florida COSH (here), and National COSH (here.)  MassCOSH’s report impressed me with profiles on the occupational health and safety problems faced today by US workers, from climate-change effects, to guns and trouble with “worksite wellness” programs. The South Florida COSH report makes a special point to provide state-specific data on the hazards and industries in which Florida workers are harmed. National COSH’s report was enhanced by 10 attention-grabbing infographics. A Worker Memorial Day report for the Houston, TX area, which I co-authored, is available in both English (here) and Spanish (here). It features the names and circumstances of 63 Houston-area workers who were killed on-the-job in 2015, including photos for 33 of them.

I credit the AFL-CIO’s Peg Seminario for starting the tradition of Worker Memorial Day reports. Their annual Death on the Job (DOTJ) report marks its 25th anniversary this year. It is the go-to compendium for national and state-level OHS data. Complementing the AFL-CIO’s report are eye-catching infographics like this one:

Some of the biggest Worker Memorial Day events take place outside the U.S.  Hazards magazine and the International Trade Union Confederation provides information about many of them. For example, here’s a photo from a rally in Istanbul:

I’m calling on readers of The Pump Handle to share some highlights in the comment section below from the Worker Memorial Day event(s) you attended this past week.

from ScienceBlogs http://ift.tt/1rIykCq

Happy birthday to the GWPF “inquiry” [Stoat]

Moyhu wins the prize for actually bothering to track the GWPF and its waste-of-time “inquiry”. That’s about all there is to say, really. I could take the piss out of them a bit more I suppose but it hardly seems worth the effort. Terence Kealey (chairman) ends up looking like an idiot, which in GW terms he probably is; rapidly heading Emeritus I’d guess.

I must remember to add it to WATN in 2016; speaking of which, has anyone seen any life out of AW’s poor stillborn paper?

NS must be an elephant: he can also remember the OAS.

from ScienceBlogs http://ift.tt/1TlUIHB

Moyhu wins the prize for actually bothering to track the GWPF and its waste-of-time “inquiry”. That’s about all there is to say, really. I could take the piss out of them a bit more I suppose but it hardly seems worth the effort. Terence Kealey (chairman) ends up looking like an idiot, which in GW terms he probably is; rapidly heading Emeritus I’d guess.

I must remember to add it to WATN in 2016; speaking of which, has anyone seen any life out of AW’s poor stillborn paper?

NS must be an elephant: he can also remember the OAS.

from ScienceBlogs http://ift.tt/1TlUIHB

Ask Ethan: Can We Use Quantum Entanglement To Communicate Faster-Than-Light? (Synopsis) [Starts With A Bang]

“Trying to understand the way nature works involves a most terrible test of human reasoning ability. It involves subtle trickery, beautiful tightropes of logic on which one has to walk in order not to make a mistake in predicting what will happen.” -Richard Feynman

If you were to send a space probe to a distant star system, gather information about it and send it back to Earth, you’d have to wait years for the information to arrive. But if you have an entangled quantum system — say, two photons, one with spin +1 and one with spin -1 — you could know the spin of the distant one instantly by measuring the spin of the one in your possession.

The quantum mechanical Bell test for half-integer spin particles. Image credit: Wikimedia Commons user Maksim, under a c.c.a.-s.a.-3.0 license.

Are there prospects, then, for entangling quantum particles, placing one aboard a spacecraft and sending it to a distant star, making a measurement at that distant location and then making a measurement here to know what you saw over there? It’s an incredible idea to exploit quantum weirdness. While the laws of physics allow you to indeed know the properties of the other member of the pair by making a measurement here, they conspire to prevent you from transmitting information faster-than-light.

Artist’s impression of a sunset from the world Gliese 667 Cc, in a trinary star system. Image credit: ESO/L. Calçada.

Go get the full story on this week’s Ask Ethan!

from ScienceBlogs http://ift.tt/1VZlH1C

“Trying to understand the way nature works involves a most terrible test of human reasoning ability. It involves subtle trickery, beautiful tightropes of logic on which one has to walk in order not to make a mistake in predicting what will happen.” -Richard Feynman

If you were to send a space probe to a distant star system, gather information about it and send it back to Earth, you’d have to wait years for the information to arrive. But if you have an entangled quantum system — say, two photons, one with spin +1 and one with spin -1 — you could know the spin of the distant one instantly by measuring the spin of the one in your possession.

The quantum mechanical Bell test for half-integer spin particles. Image credit: Wikimedia Commons user Maksim, under a c.c.a.-s.a.-3.0 license.

Are there prospects, then, for entangling quantum particles, placing one aboard a spacecraft and sending it to a distant star, making a measurement at that distant location and then making a measurement here to know what you saw over there? It’s an incredible idea to exploit quantum weirdness. While the laws of physics allow you to indeed know the properties of the other member of the pair by making a measurement here, they conspire to prevent you from transmitting information faster-than-light.

Artist’s impression of a sunset from the world Gliese 667 Cc, in a trinary star system. Image credit: ESO/L. Calçada.

Go get the full story on this week’s Ask Ethan!

from ScienceBlogs http://ift.tt/1VZlH1C