Delta Aquariid meteors peak around now

This week presents the nominal peak of the Delta Aquariid meteor shower. That supposed peak comes during the predawn hours on or near July 28, 2019. Should you set your alarm and get up to watch the shower? Maybe. However, the Delta Aquariids are a long, rambling shower, stretching out out for weeks beyond their nominal peak. Because the peak itself isn’t very definite, the shower might be even better at the month’s end, around the time of new moon (August 1, 2019, at 03:12 UTC). With no moon at all in late July/early August 2019, this could be the best time to watch for these rather faint meteors. You may see as many as 10 to 15 meteors per hour in a dark sky.

On the other hand, if you do get up early on July 27 or 28, you can see the waning crescent moon moving through Taurus. And you might catch some Delta Aquariids as well.

As the month of July wanes, so does the moon. On July 26 to 28, the moon is moving through Taurus the Bull. Depending on where you live worldwide, the moon turns new on July 31 or August 1. Read more.

No matter where you are on Earth – and no matter whether you watch this week, or in the next few weeks – the most favorable viewing window for the Delta Aquarids begins around 1 a.m. (2 a.m. daylight saving time). Watch through the onset of morning dawn. Although this shower is visible from both the Northern and Southern Hemispheres, it tends to favor the more southerly latitudes. North of the equator, it’s better seen in the tropical and subtropical regions rather than farther north. This shower combines with the more-famous Perseid meteor shower, now also rising to its peak, but whose peak in 2019 will have to contend with the light of a bright moon.

That’s why the coming week or so – from now through early August – might present your best opportunity to watch meteors. That’s in contrast to waiting for the Perseids’ peak mornings. By the time of the Perseid meteor shower’s annual peak around August 12 or 13, 2019, the moonlight will be washing some of the meteors in its glare.

Optimize your summer meteor watching experience with EarthSky’s 2019 meteor guide

The Delta Aquarid shower is, at best, a modest shower. About five to 10 percent of these relatively faint, medium-speed meteors leave persistent trains – glowing ionized gas trails that last a second or two after the meteor has passed.

This shower recurs annually in late July, because the Earth crosses the orbital path of Comet 96P Machholz at this time of year. The stream of debris left behind by this comet smashes into the Earth’s upper atmosphere, to burn up in our sky as Delta Aquariid meteors.

Kelly Dreller in Lake Havasu City, Arizona, caught this meteor in late July 2016.

If you trace the paths of the Delta Aquariid meteors backward, they all appear to radiate from a certain point in the starry heavens – near the star Delta Aquarii (Skat). This point is called the radiant of the Delta Aquariid meteor shower. As a rule of thumb, the higher the radiant point is in your sky, the more meteors that you’re likely to see. In late July, this star climbs highest up in the sky at roughly 2:30 a.m. (3:30 a.m. daylight saving time).

Of course, you don’t have to find the radiant point of the Delta Aquariid shower to enjoy this shower. Radiating from near the star Skat, the meteors will streak every which way across the starry heavens. Just find an open view of the sky away from artificial lights, sprawl out comfortably on a reclining lawn chair, preferably between midnight and dawn, and watch.

Bottom line: Unless you live in the far northern part of the globe – where there is little or no nighttime at this time of year – the Delta Aquariid meteor shower can be seen from all around the world. The nominal peak is around July 27 or 28, in the dark hours before dawn. But the Delta Aquariids will still be going when the Perseids peak a couple of weeks from now. At that time, a bright waxing gibbous moon will interfere with the show. So start your meteor-watching now!

Read more: Black Moon supermoon on July 31

EarthSky’s 2019 meteor guide

EarthSky astronomy kits are perfect for beginners. Order yours today.

Skat: Radiant for Delta Aquarid meteors

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

This week presents the nominal peak of the Delta Aquariid meteor shower. That supposed peak comes during the predawn hours on or near July 28, 2019. Should you set your alarm and get up to watch the shower? Maybe. However, the Delta Aquariids are a long, rambling shower, stretching out out for weeks beyond their nominal peak. Because the peak itself isn’t very definite, the shower might be even better at the month’s end, around the time of new moon (August 1, 2019, at 03:12 UTC). With no moon at all in late July/early August 2019, this could be the best time to watch for these rather faint meteors. You may see as many as 10 to 15 meteors per hour in a dark sky.

On the other hand, if you do get up early on July 27 or 28, you can see the waning crescent moon moving through Taurus. And you might catch some Delta Aquariids as well.

As the month of July wanes, so does the moon. On July 26 to 28, the moon is moving through Taurus the Bull. Depending on where you live worldwide, the moon turns new on July 31 or August 1. Read more.

No matter where you are on Earth – and no matter whether you watch this week, or in the next few weeks – the most favorable viewing window for the Delta Aquarids begins around 1 a.m. (2 a.m. daylight saving time). Watch through the onset of morning dawn. Although this shower is visible from both the Northern and Southern Hemispheres, it tends to favor the more southerly latitudes. North of the equator, it’s better seen in the tropical and subtropical regions rather than farther north. This shower combines with the more-famous Perseid meteor shower, now also rising to its peak, but whose peak in 2019 will have to contend with the light of a bright moon.

That’s why the coming week or so – from now through early August – might present your best opportunity to watch meteors. That’s in contrast to waiting for the Perseids’ peak mornings. By the time of the Perseid meteor shower’s annual peak around August 12 or 13, 2019, the moonlight will be washing some of the meteors in its glare.

Optimize your summer meteor watching experience with EarthSky’s 2019 meteor guide

The Delta Aquarid shower is, at best, a modest shower. About five to 10 percent of these relatively faint, medium-speed meteors leave persistent trains – glowing ionized gas trails that last a second or two after the meteor has passed.

This shower recurs annually in late July, because the Earth crosses the orbital path of Comet 96P Machholz at this time of year. The stream of debris left behind by this comet smashes into the Earth’s upper atmosphere, to burn up in our sky as Delta Aquariid meteors.

Kelly Dreller in Lake Havasu City, Arizona, caught this meteor in late July 2016.

If you trace the paths of the Delta Aquariid meteors backward, they all appear to radiate from a certain point in the starry heavens – near the star Delta Aquarii (Skat). This point is called the radiant of the Delta Aquariid meteor shower. As a rule of thumb, the higher the radiant point is in your sky, the more meteors that you’re likely to see. In late July, this star climbs highest up in the sky at roughly 2:30 a.m. (3:30 a.m. daylight saving time).

Of course, you don’t have to find the radiant point of the Delta Aquariid shower to enjoy this shower. Radiating from near the star Skat, the meteors will streak every which way across the starry heavens. Just find an open view of the sky away from artificial lights, sprawl out comfortably on a reclining lawn chair, preferably between midnight and dawn, and watch.

Bottom line: Unless you live in the far northern part of the globe – where there is little or no nighttime at this time of year – the Delta Aquariid meteor shower can be seen from all around the world. The nominal peak is around July 27 or 28, in the dark hours before dawn. But the Delta Aquariids will still be going when the Perseids peak a couple of weeks from now. At that time, a bright waxing gibbous moon will interfere with the show. So start your meteor-watching now!

Read more: Black Moon supermoon on July 31

EarthSky’s 2019 meteor guide

EarthSky astronomy kits are perfect for beginners. Order yours today.

Skat: Radiant for Delta Aquarid meteors

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

Why do birds sing?

A male olive-backed euphonia (Euphonia gouldi), photographed in Costa Rica. Image via Andy Morffew.

By David Steadman, University of Florida

Birds are some of the most attractive creatures on earth. Who doesn’t like to watch a blue jay, cardinal or Baltimore oriole going about its business?

But the beauty of birds isn’t just their looks – it’s also their noises. Bird songs are among nature’s most distinctive and musically satisfying sounds. Why do birds spend so much time and energy singing?

There are two main purposes, and they are connected. First, male birds sing to mark territories. A singing bird is saying, “This place is mine, and I’m willing to defend it, especially from others of my species.” He may patrol his chosen space and sing often, either from the middle or the edges of what he considers his turf.

The second purpose of singing is to attract a mate for nesting. Female birds often choose their mates based on some blend of visual and vocal cues. Even male birds with beautiful breeding-season plumage can have trouble finding mates if their songs don’t measure up.

Each bird species typically has its own unique song. That allows an individual bird to hear a song and recognize whether the singer is from its own species.

Birds are most vocal during nesting season. For example, in Florida where I live, cardinals live year-round. They usually start singing in January, just a few weeks after the days begin to get longer. After the nesting period is over, birds sing much less and their territories break down.

Birders can learn to recognize different bird species by memorizing the sonic patterns of their songs.

Many species of North American birds migrate with the seasons instead of staying in one place all year. As they fly south in the fall, they make little “chip” notes or “contact calls” that allow them to stay in touch with other birds.

In many species only male birds sing, but in others, both males and females sing. And some birds don’t sing at all. For example, vultures and storks can barely produce any sound – let alone something musical enough that we would call it a song.

Learning to identify birds by their songs is as much fun as spotting them by sight. In fact, good ears are often as important as good eyes in appreciating the birds you encounter. Take off your headphones and listen to your neighborhood birds – especially when they are active in the morning or evening. You’ll be surprised by what you hear.

David Steadman, Curator of Ornithology, Florida Museum of Natural History, University of Florida

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: Why birds sing.

from EarthSky https://ift.tt/2JPuJ0J

A male olive-backed euphonia (Euphonia gouldi), photographed in Costa Rica. Image via Andy Morffew.

By David Steadman, University of Florida

Birds are some of the most attractive creatures on earth. Who doesn’t like to watch a blue jay, cardinal or Baltimore oriole going about its business?

But the beauty of birds isn’t just their looks – it’s also their noises. Bird songs are among nature’s most distinctive and musically satisfying sounds. Why do birds spend so much time and energy singing?

There are two main purposes, and they are connected. First, male birds sing to mark territories. A singing bird is saying, “This place is mine, and I’m willing to defend it, especially from others of my species.” He may patrol his chosen space and sing often, either from the middle or the edges of what he considers his turf.

The second purpose of singing is to attract a mate for nesting. Female birds often choose their mates based on some blend of visual and vocal cues. Even male birds with beautiful breeding-season plumage can have trouble finding mates if their songs don’t measure up.

Each bird species typically has its own unique song. That allows an individual bird to hear a song and recognize whether the singer is from its own species.

Birds are most vocal during nesting season. For example, in Florida where I live, cardinals live year-round. They usually start singing in January, just a few weeks after the days begin to get longer. After the nesting period is over, birds sing much less and their territories break down.

Birders can learn to recognize different bird species by memorizing the sonic patterns of their songs.

Many species of North American birds migrate with the seasons instead of staying in one place all year. As they fly south in the fall, they make little “chip” notes or “contact calls” that allow them to stay in touch with other birds.

In many species only male birds sing, but in others, both males and females sing. And some birds don’t sing at all. For example, vultures and storks can barely produce any sound – let alone something musical enough that we would call it a song.

Learning to identify birds by their songs is as much fun as spotting them by sight. In fact, good ears are often as important as good eyes in appreciating the birds you encounter. Take off your headphones and listen to your neighborhood birds – especially when they are active in the morning or evening. You’ll be surprised by what you hear.

David Steadman, Curator of Ornithology, Florida Museum of Natural History, University of Florida

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: Why birds sing.

from EarthSky https://ift.tt/2JPuJ0J

Find M4 near the Scorpion’s Heart

Assuming you have a dark sky, look just to the right of Antares for M4.

Red Antares – the brightest star in Scorpius, often called the Heart of the Scorpion – is up in the evening now. It’s a bright red star known for twinkling rapidly. If you have binoculars, sweep for an object near Antares on the sky’s dome. This object is called Messier 4 or M4. It’s a globular cluster, one of our galaxy’s oldest inhabitants. M4 has an estimated age of 12.2 billion years, in contrast to about 4.5 billion years for our sun.

If you’ve never found a deep-sky object on your own before, M4 is a grand place to start. The M4 globular star cluster is easy to find, because it’s right next to the first-magnitude star Antares, the brightest in the constellation Scorpius the Scorpion. Your first step to locating M4 is to find Antares, the Scorpion’s heart star.

Antares and M4 are best seen in July, or the months around July, from around the globe. In early June, Antares is highest in the sky around midnight (1 a.m. daylight saving time). That means it’s high in the south for Northern Hemisphere viewers, and overhead for Southern Hemisphere viewers. The stars return to the same place in the sky some two hours earlier every month. So Antares is highest up around 10 p.m. (11 p.m. daylight saving time) in early July, and 8 p.m. (9 p.m. daylight saving time) in early August.

Red star Antares (l) and nearby star cluster M4. Image via StargazerBob@aol.com.

In short, Northern Hemisphere summer evenings – or Southern Hemisphere winter evenings – are probably your best bet for catching M4.

You might glimpse M4 on a very dark, moonless night. If you can’t see it, use binoculars to sweep for it. Antares and M4 readily fit inside the same binocular field of view, with M4 appearing a bit more than 1 degree to the west (or right) of Antares. For reference, a typical binocular field has a diameter of 5 to 6 degrees. M4 looks like a rather dim, hazy star in binoculars, and you might want a telescope to begin to resolve this cluster into stars.

A 5-minute stacked image of Antares and the surrounding region including the globular cluster Messier 4 (M4). Photo by our friend Tom Wildoner at LeisurelyScientist.com.

History and science of M4. The comet hunter Charles Messier (1730-1817) listed M4 as object #4 in his famous Messier catalog. The Messier catalog listed over 100 deep-sky objects that look like comets, but really aren’t. Charles Messier wanted to steer comet hunters away from these faint fuzzies that masquerade as comets.

Modern astronomy tells us that M4 is a globular star cluster – a globe-shape stellar city packed with perhaps a hundred thousand stars. Unlike open star clusters – such as the Pleiades and the Hyades – the Milky Way galaxy’s 200 or so globular star clusters are not part of the galactic disk.

Instead, globular clusters populate the galactic halo – the sphere-shaped region of the Milky Way circling above and below the pancake-shaped galactic disk.

At about 7,000 light-years from Earth, M4 is one of the two closest globular clusters to our sun and Earth (the other is NGC 6397). That’s among the Milky Way’s 200 or so globular clusters. Most globulars reside tens of thousands of light-years away. The farthest of globular clusters, M54, is thought to be 70,000 light-years distant.

M4 is about 75 light-years across.

Globular clusters are tightly packed with tens to hundreds of thousands of stars, whereas open clusters are loosely-bound stellar confederations with only a few hundred to a thousand stars. Globular clusters contain primitive stars that are billions of years old and almost as old as the universe itself. On the other hand, open clusters consist of young, hot stars that tend to disperse after hundreds of millions of years.

Messier 4 or M4. Image via European Southern Observatory.

M4’s position is at Right Ascension: 16h 23.6m; Declination: 26 degrees 32′ south

Bottom line: M4 or Messier 4 is a globular star cluster, one of the nearest to our solar system. It’s also one of the easiest of all globular clusters to find, in a dark sky, because it’s near the bright red star Antares in the constellation Scorpius.

from EarthSky https://ift.tt/30SdRw8

Assuming you have a dark sky, look just to the right of Antares for M4.

Red Antares – the brightest star in Scorpius, often called the Heart of the Scorpion – is up in the evening now. It’s a bright red star known for twinkling rapidly. If you have binoculars, sweep for an object near Antares on the sky’s dome. This object is called Messier 4 or M4. It’s a globular cluster, one of our galaxy’s oldest inhabitants. M4 has an estimated age of 12.2 billion years, in contrast to about 4.5 billion years for our sun.

If you’ve never found a deep-sky object on your own before, M4 is a grand place to start. The M4 globular star cluster is easy to find, because it’s right next to the first-magnitude star Antares, the brightest in the constellation Scorpius the Scorpion. Your first step to locating M4 is to find Antares, the Scorpion’s heart star.

Antares and M4 are best seen in July, or the months around July, from around the globe. In early June, Antares is highest in the sky around midnight (1 a.m. daylight saving time). That means it’s high in the south for Northern Hemisphere viewers, and overhead for Southern Hemisphere viewers. The stars return to the same place in the sky some two hours earlier every month. So Antares is highest up around 10 p.m. (11 p.m. daylight saving time) in early July, and 8 p.m. (9 p.m. daylight saving time) in early August.

Red star Antares (l) and nearby star cluster M4. Image via StargazerBob@aol.com.

In short, Northern Hemisphere summer evenings – or Southern Hemisphere winter evenings – are probably your best bet for catching M4.

You might glimpse M4 on a very dark, moonless night. If you can’t see it, use binoculars to sweep for it. Antares and M4 readily fit inside the same binocular field of view, with M4 appearing a bit more than 1 degree to the west (or right) of Antares. For reference, a typical binocular field has a diameter of 5 to 6 degrees. M4 looks like a rather dim, hazy star in binoculars, and you might want a telescope to begin to resolve this cluster into stars.

A 5-minute stacked image of Antares and the surrounding region including the globular cluster Messier 4 (M4). Photo by our friend Tom Wildoner at LeisurelyScientist.com.

History and science of M4. The comet hunter Charles Messier (1730-1817) listed M4 as object #4 in his famous Messier catalog. The Messier catalog listed over 100 deep-sky objects that look like comets, but really aren’t. Charles Messier wanted to steer comet hunters away from these faint fuzzies that masquerade as comets.

Modern astronomy tells us that M4 is a globular star cluster – a globe-shape stellar city packed with perhaps a hundred thousand stars. Unlike open star clusters – such as the Pleiades and the Hyades – the Milky Way galaxy’s 200 or so globular star clusters are not part of the galactic disk.

Instead, globular clusters populate the galactic halo – the sphere-shaped region of the Milky Way circling above and below the pancake-shaped galactic disk.

At about 7,000 light-years from Earth, M4 is one of the two closest globular clusters to our sun and Earth (the other is NGC 6397). That’s among the Milky Way’s 200 or so globular clusters. Most globulars reside tens of thousands of light-years away. The farthest of globular clusters, M54, is thought to be 70,000 light-years distant.

M4 is about 75 light-years across.

Globular clusters are tightly packed with tens to hundreds of thousands of stars, whereas open clusters are loosely-bound stellar confederations with only a few hundred to a thousand stars. Globular clusters contain primitive stars that are billions of years old and almost as old as the universe itself. On the other hand, open clusters consist of young, hot stars that tend to disperse after hundreds of millions of years.

Messier 4 or M4. Image via European Southern Observatory.

M4’s position is at Right Ascension: 16h 23.6m; Declination: 26 degrees 32′ south

Bottom line: M4 or Messier 4 is a globular star cluster, one of the nearest to our solar system. It’s also one of the easiest of all globular clusters to find, in a dark sky, because it’s near the bright red star Antares in the constellation Scorpius.

from EarthSky https://ift.tt/30SdRw8

What is a fogbow?

View at EarthSky Community Photos. | Alan Nicolle in New South Wales, Australia, captured this image on July 16, 2019. He wrote: “I was out geocaching in the outskirts of Broken Hill, when I turned back to see this fogbow developing. I took quite a few photos with the iPhone, and rode back to the car on my bike, but by the time I got back to the car to use my SLR, it had faded.” Thank you, Alan!

Fogbows – sometimes called white rainbows, cloudbows or ghost rainbows – are made much as rainbows are, from the same configuration of sunlight and moisture. Rainbows happen when the air is filled with raindrops, and you always see a rainbow in the direction opposite the sun. Fogbows are much the same, always opposite the sun, but fogbows are caused by the small droplets inside a fog or cloud rather than larger raindrops.

Look for fogbows in a thin fog when the sun is bright. You might see one when the sun breaks through a fog. Or watch for fogbows over the ocean.

Because the water droplets in fog are so small, fogbows have only weak colors or are colorless.

Edith Smith in Aberdeenshire, Scotland, captured this fogbow on November 1, 2018. She wrote: “The camera spotted it before I did with eye, as I was too engrossed in foggy conditions.”

Wonderful fogbow caught by Robyn Smith in New Zealand on the morning of September 19, 2017 … “opposite the foggy sunrise.”

GregDiesel Landscape Photography wrote in October 2015: “Saw my first fogbow / white rainbow. Photo taken with cell phone. Moyock, North Carolina.”

Katherine Keyes Millet captured this fogbow in July 2014 at Winter Island Park in Salem, Massachusetts.

Venus and Jupiter above a fogbow in Blacklough, Dungannon, Ireland. Mars is up there, too, but tough to see. John Fagan captured them all in October 2015.

Eileen Claffey in Brookline, Massachusetts, captured this fogbow over a field in September 2014.

Les Cowley of the great website Atmospheric Optics says:

Look away from the sun and at an angle of 35-40 degrees from your shadow which marks the direction of the antisolar point. Some fogbows have very low contrast so look for small brightenings in the misty background. Once caught, they are unmistakable.

The sun must be less than 30-40 degrees high unless you are on a hill or high up on a ship where the mist and fogbow can be viewed from above.

Fogbows are huge, almost as large as a rainbow and much, much broader.

Look here for Les Cowley’s explanation of how fogbows form.

Thomas Kast in Finland captured this fogbow in 2013. He wrote: “In this rather cold August night (+8C [46F]) there was patchy fog, especially in open fields. This lake remained clear for a long time. At one point I saw this white bow with moon in waning gibbous phase behind me.”

Jim Grant caught this fogbow over Sunset Cliffs in San Diego. He wrote: “The skies were sunny and clear, and then the fog rolled in, and with it this beautiful fogbow.”

Lynton Brown of Australia captured this fogbow over a barren field in the autumn of 2012.

Bottom line: Fogbows are made by much the same process as rainbows, but with the small water droplets inside a fog instead of larger raindrops. Because the water droplets in fog are so small, fogbows have only weak colors or are colorless.

from EarthSky https://ift.tt/2RuWZ9W

View at EarthSky Community Photos. | Alan Nicolle in New South Wales, Australia, captured this image on July 16, 2019. He wrote: “I was out geocaching in the outskirts of Broken Hill, when I turned back to see this fogbow developing. I took quite a few photos with the iPhone, and rode back to the car on my bike, but by the time I got back to the car to use my SLR, it had faded.” Thank you, Alan!

Fogbows – sometimes called white rainbows, cloudbows or ghost rainbows – are made much as rainbows are, from the same configuration of sunlight and moisture. Rainbows happen when the air is filled with raindrops, and you always see a rainbow in the direction opposite the sun. Fogbows are much the same, always opposite the sun, but fogbows are caused by the small droplets inside a fog or cloud rather than larger raindrops.

Look for fogbows in a thin fog when the sun is bright. You might see one when the sun breaks through a fog. Or watch for fogbows over the ocean.

Because the water droplets in fog are so small, fogbows have only weak colors or are colorless.

Edith Smith in Aberdeenshire, Scotland, captured this fogbow on November 1, 2018. She wrote: “The camera spotted it before I did with eye, as I was too engrossed in foggy conditions.”

Wonderful fogbow caught by Robyn Smith in New Zealand on the morning of September 19, 2017 … “opposite the foggy sunrise.”

GregDiesel Landscape Photography wrote in October 2015: “Saw my first fogbow / white rainbow. Photo taken with cell phone. Moyock, North Carolina.”

Katherine Keyes Millet captured this fogbow in July 2014 at Winter Island Park in Salem, Massachusetts.

Venus and Jupiter above a fogbow in Blacklough, Dungannon, Ireland. Mars is up there, too, but tough to see. John Fagan captured them all in October 2015.

Eileen Claffey in Brookline, Massachusetts, captured this fogbow over a field in September 2014.

Les Cowley of the great website Atmospheric Optics says:

Look away from the sun and at an angle of 35-40 degrees from your shadow which marks the direction of the antisolar point. Some fogbows have very low contrast so look for small brightenings in the misty background. Once caught, they are unmistakable.

The sun must be less than 30-40 degrees high unless you are on a hill or high up on a ship where the mist and fogbow can be viewed from above.

Fogbows are huge, almost as large as a rainbow and much, much broader.

Look here for Les Cowley’s explanation of how fogbows form.

Thomas Kast in Finland captured this fogbow in 2013. He wrote: “In this rather cold August night (+8C [46F]) there was patchy fog, especially in open fields. This lake remained clear for a long time. At one point I saw this white bow with moon in waning gibbous phase behind me.”

Jim Grant caught this fogbow over Sunset Cliffs in San Diego. He wrote: “The skies were sunny and clear, and then the fog rolled in, and with it this beautiful fogbow.”

Lynton Brown of Australia captured this fogbow over a barren field in the autumn of 2012.

Bottom line: Fogbows are made by much the same process as rainbows, but with the small water droplets inside a fog instead of larger raindrops. Because the water droplets in fog are so small, fogbows have only weak colors or are colorless.

from EarthSky https://ift.tt/2RuWZ9W

Moon and Taurus before dawn July 26 to 28

Before dawn on July 26, 27, 28, 2019, watch for the waning crescent moon to travel in front of Taurus the Bull. Assuming your sky is dark enough, the Bull is instantly recognizable; it’s one of the more prominent constellations of the zodiac. Look for this constellation’s bright reddish star Aldebaran plus its two signpost star clusters, the V-shaped Hyades and the tiny, misty, dipper-shaped Pleiades.

The moon is close to the Pleaides on the morning of July 26.

It’s closer to the Hyades on the mornings of July 27 and 28, at least as seen from North America. Your exact view will vary. How can you see your personalized view. We hear good things about the free open source planetarium software called Stellarium.

On all of these mornings, it’ll be easy to spot Aldebaran, which represents the ruddy eye of the Bull. The lit side of the moon will point directly at this star, Taurus’ one and only 1st-magnitude star on July 26 and 27. Look closely and you’ll see this star atop the famous V-shaped pattern of stars that outlines the Bull’s face.

The V-pattern is the Hyades, and it’s an actual star cluster in space, comprised of sibling stars that were born from the same cloud of dust and gas over 600 million years ago. Although Aldebaran isn’t a true member of the Hyades star cluster, this bright star accentuates the V shape of the Hyades on the sky’s dome. Aldebaran is about 65 light-years away, whereas the more far-off Hyades stars lie at about two-and-a-half times Aldebaran’s distance.

The more compact Pleiades cluster, on the other hand, is thought to be more distant (about 430 light-years versus 150 light-years) yet more youthful (100 million years versus 625 million light-years) than the Hyades. The constellation Taurus is a rarity indeed in that it showcases two easy-to-see open clusters.

The ecliptic – the sun’s yearly path through the constellations of the zodiac – passes through the constellation Taurus the Bull, to the north of the star Aldebaran and to the south of the Pleiades stars cluster. The sun shines in front of Taurus from about May 14 to June 21.

The lit side of a waning moon points in its direction of travel: east or toward sunrise. So watch the moon throughout the final week of July 2019, as the waning crescent sweeps through the constellation Taurus the Bull and then disappears into the glare of sunrise.

Depending on where you live worldwide, the upcoming new moon will be the second of two July 2019 new moons or the first of two August 2019 new moons. When there are two new moons in a month, some people call the second one a Black Moon.

Read more: Black Moon supermoon on July 31

Bottom line: On the mornings of July 26, 27 and 28, let the waning crescent moon show you the Taurus the Bull and introduce to the constellation’s two outstanding features, the Hyades and the Pleiades clusters.

from EarthSky https://ift.tt/2LF2OTx

Before dawn on July 26, 27, 28, 2019, watch for the waning crescent moon to travel in front of Taurus the Bull. Assuming your sky is dark enough, the Bull is instantly recognizable; it’s one of the more prominent constellations of the zodiac. Look for this constellation’s bright reddish star Aldebaran plus its two signpost star clusters, the V-shaped Hyades and the tiny, misty, dipper-shaped Pleiades.

The moon is close to the Pleaides on the morning of July 26.

It’s closer to the Hyades on the mornings of July 27 and 28, at least as seen from North America. Your exact view will vary. How can you see your personalized view. We hear good things about the free open source planetarium software called Stellarium.

On all of these mornings, it’ll be easy to spot Aldebaran, which represents the ruddy eye of the Bull. The lit side of the moon will point directly at this star, Taurus’ one and only 1st-magnitude star on July 26 and 27. Look closely and you’ll see this star atop the famous V-shaped pattern of stars that outlines the Bull’s face.

The V-pattern is the Hyades, and it’s an actual star cluster in space, comprised of sibling stars that were born from the same cloud of dust and gas over 600 million years ago. Although Aldebaran isn’t a true member of the Hyades star cluster, this bright star accentuates the V shape of the Hyades on the sky’s dome. Aldebaran is about 65 light-years away, whereas the more far-off Hyades stars lie at about two-and-a-half times Aldebaran’s distance.

The more compact Pleiades cluster, on the other hand, is thought to be more distant (about 430 light-years versus 150 light-years) yet more youthful (100 million years versus 625 million light-years) than the Hyades. The constellation Taurus is a rarity indeed in that it showcases two easy-to-see open clusters.

The ecliptic – the sun’s yearly path through the constellations of the zodiac – passes through the constellation Taurus the Bull, to the north of the star Aldebaran and to the south of the Pleiades stars cluster. The sun shines in front of Taurus from about May 14 to June 21.

The lit side of a waning moon points in its direction of travel: east or toward sunrise. So watch the moon throughout the final week of July 2019, as the waning crescent sweeps through the constellation Taurus the Bull and then disappears into the glare of sunrise.

Depending on where you live worldwide, the upcoming new moon will be the second of two July 2019 new moons or the first of two August 2019 new moons. When there are two new moons in a month, some people call the second one a Black Moon.

Read more: Black Moon supermoon on July 31

Bottom line: On the mornings of July 26, 27 and 28, let the waning crescent moon show you the Taurus the Bull and introduce to the constellation’s two outstanding features, the Hyades and the Pleiades clusters.

from EarthSky https://ift.tt/2LF2OTx

Breakthrough Listen’s new search for alien lasers

VERITAS will be used to help search for laser-like optical light pulses that could be beacons from an advanced alien civilization. Image via MIT/New Atlas.

The Search for Extraterrestrial Intelligence (SETI) has traditionally looked for radio signals of artificial origin, i.e. coming from an alien civilization at least as advanced as our own. We humans have been broadcasting radio waves into space for about 100 years now, since Marconi pioneered long-distance radio transmission. The reasoning has been that other civilizations might use radio, too. While that approach continues to be highly debated, there is another kind of search that is starting to be considered more seriously now as well: looking for optical signals – brief flashes of light like pulsing lasers – that could be used as beacons to communicate over interstellar distances.

On July 17, 2019, Breakthrough Initiatives – founded in 2015 by entrepreneur Yuri Milner – announced a new partnership with the VERITAS Collaboration to focus on this strategy. VERITAS (the Very Energetic Radiation Imaging Telescope Array System) will search for such pulsed optical beacons, as well as radio signals, with its array of four 12-meter telescopes at the Whipple Observatory in Amado, Arizona.

Breakthrough Listen, part of Breakthrough Initiatives, has already been conducting searches using its still-ongoing radio frequency survey and spectroscopic optical laser survey. But VERITAS can take the search to a new level. It was built to detect cosmic gamma rays and is the most powerful telescope array in the world for studying high energy astrophysics. As it turns out, it can also be used to look for “pulsed optical beacons” – laser-like pulses of light – that are very short in duration, only a few nanoseconds (one nanosecond is a billionth of a second).

Closer view of one of the 4 telescopes in the VERITAS array. Image via CfA/SciTechDaily.

An advantage of this method is that any artificial pulses could outshine stars that happen to lie in the same direction. The use of all four telescopes would also help to eliminate false positives from any detections made. VERITAS will provide a unique way of expanding the search for alien intelligence beyond previous methods, as noted by Yuri Milner:

When it comes to intelligent life beyond Earth, we don’t know where it exists or how it communicates. So our philosophy is to look in as many places, and in as many ways, as we can. VERITAS expands our range of observation even further.

Andrew Siemion at the Berkeley SETI Research Center added:

Breakthrough Listen is already the most powerful, comprehensive, and intensive search yet undertaken for signs of intelligent life beyond Earth. Now, with the addition of VERITAS, we’re sensitive to an important new class of signals: fast optical pulses. Optical communication has already been used by NASA to transmit high definition images to Earth from the moon, so there’s reason to believe that an advanced civilization might use a scaled-up version of this technology for interstellar communication.

VERITAS will be able to detect very faint light signals, if any exist, according to Jamie Holder at the University of Delaware:

Using the huge mirror area of the four VERITAS telescopes will allow us to search for these extremely faint optical flashes in the night sky, which could correspond to signals from an extraterrestrial civilization.

Aerial view of the VERITAS telescope array and the Fred Lawrence Whipple Observatory basecamp in Amado, Arizona. Image via VERITAS.

Just how sensitive is VERITAS? The most powerful lasers on Earth can transmit a pulse of 500 terawatts lasting only a few nanoseconds. If one were placed at the distance of Tabby’s Star – that weird dimming star about 1,470 light-years away – then VERITAS could detect it. However, most of the stars that VERITAS will observe are 10-100 times closer than that, so feasibly a pulse of light 100-10,000 times fainter than that earthly laser could be found.

VERITAS being able to search for alien light signals is a great bonus, since that is not what it was designed for. As David Williams at the University of California, Santa Cruz said:

It is impressive how well-suited the VERITAS telescopes are for this project, since they were built only with the purpose of studying very-high-energy gamma rays in mind.

In California, the SETI Institute is also using Lick Observatory‘s 40-inch Nickel Telescope on Mount Hamilton with a new pulse-detection system, to look for similar laser beacons from civilizations many light-years distant. Optical SETI has its advantages over radio SETI, such as no radio signal interference, according to Frank Drake, director of the Carl Sagan Center for Research:

One great advantage of optical SETI is that there’s no terrestrial interference. It’s an exciting new field.

This Lick experiment is unique as it uses three light detectors (photomultipliers) to search for bright pulses that arrive in a short period of time (less than a billionth of a second). Light from the star itself can also trigger the detectors as well, but seldom will all three photomultipliers be hit by photons within a billionth of a second time frame. This means few false alarms are expected, only about one per year.

Other SETI searches, such as with Lick Observatory’s 40-inch Nickel Telescope, are also looking for laser pulses from advanced civilizations. Image via SETI/LaserFocusWorld.

New and novel ways of looking for evidence of extraterrestrial intelligence are welcome, since the previous, traditional SETI method of just searching for radio signals is considered by many to be antiquated. Would a civilization thousands or millions of years more advanced then us still be using radio waves to communicate? SETI and other searches should be as broad as possible, and consider alternate possibilities for the best chance of success. With billions of stars in our galaxy alone, the hunt for such signals is like looking for a needle in a haystack. VERITAS is just one such alternate method, but it is a good start.

Breakthrough Listen is a comprehensive initiative to search for evidence of intelligent, technological life from nearby stars to the universe at large. The objective is to examine one million nearby stars, all the stars in the galactic plane and 100 nearby galaxies, for both radio and optical signals. Not a small undertaking, but if there is to be any chance of finding an alien light show, then we must look.

This is how far human radio broadcasts have reached into the galaxy – not the black square – but the little blue dot at the center of that zoomed-in square. The ever-expanding bubble announcing humanity’s presence to anyone listening in the Milky Way is now only about 200 light-years wide, in contrast to our 100,000-light-year galaxy. Graphic created by Adam Grossman. Read more from Emily Lakdawalla at the Planetary Society.

Bottom line: Using VERITAS, the search for intelligent alien life will broaden in its scope, looking not only for radio signals but also laser-like optical flashes of light that an advanced civilization might use as communication beacons.

Via Breakthrough Initiatives

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

VERITAS will be used to help search for laser-like optical light pulses that could be beacons from an advanced alien civilization. Image via MIT/New Atlas.

The Search for Extraterrestrial Intelligence (SETI) has traditionally looked for radio signals of artificial origin, i.e. coming from an alien civilization at least as advanced as our own. We humans have been broadcasting radio waves into space for about 100 years now, since Marconi pioneered long-distance radio transmission. The reasoning has been that other civilizations might use radio, too. While that approach continues to be highly debated, there is another kind of search that is starting to be considered more seriously now as well: looking for optical signals – brief flashes of light like pulsing lasers – that could be used as beacons to communicate over interstellar distances.

On July 17, 2019, Breakthrough Initiatives – founded in 2015 by entrepreneur Yuri Milner – announced a new partnership with the VERITAS Collaboration to focus on this strategy. VERITAS (the Very Energetic Radiation Imaging Telescope Array System) will search for such pulsed optical beacons, as well as radio signals, with its array of four 12-meter telescopes at the Whipple Observatory in Amado, Arizona.

Breakthrough Listen, part of Breakthrough Initiatives, has already been conducting searches using its still-ongoing radio frequency survey and spectroscopic optical laser survey. But VERITAS can take the search to a new level. It was built to detect cosmic gamma rays and is the most powerful telescope array in the world for studying high energy astrophysics. As it turns out, it can also be used to look for “pulsed optical beacons” – laser-like pulses of light – that are very short in duration, only a few nanoseconds (one nanosecond is a billionth of a second).

Closer view of one of the 4 telescopes in the VERITAS array. Image via CfA/SciTechDaily.

An advantage of this method is that any artificial pulses could outshine stars that happen to lie in the same direction. The use of all four telescopes would also help to eliminate false positives from any detections made. VERITAS will provide a unique way of expanding the search for alien intelligence beyond previous methods, as noted by Yuri Milner:

When it comes to intelligent life beyond Earth, we don’t know where it exists or how it communicates. So our philosophy is to look in as many places, and in as many ways, as we can. VERITAS expands our range of observation even further.

Andrew Siemion at the Berkeley SETI Research Center added:

Breakthrough Listen is already the most powerful, comprehensive, and intensive search yet undertaken for signs of intelligent life beyond Earth. Now, with the addition of VERITAS, we’re sensitive to an important new class of signals: fast optical pulses. Optical communication has already been used by NASA to transmit high definition images to Earth from the moon, so there’s reason to believe that an advanced civilization might use a scaled-up version of this technology for interstellar communication.

VERITAS will be able to detect very faint light signals, if any exist, according to Jamie Holder at the University of Delaware:

Using the huge mirror area of the four VERITAS telescopes will allow us to search for these extremely faint optical flashes in the night sky, which could correspond to signals from an extraterrestrial civilization.

Aerial view of the VERITAS telescope array and the Fred Lawrence Whipple Observatory basecamp in Amado, Arizona. Image via VERITAS.

Just how sensitive is VERITAS? The most powerful lasers on Earth can transmit a pulse of 500 terawatts lasting only a few nanoseconds. If one were placed at the distance of Tabby’s Star – that weird dimming star about 1,470 light-years away – then VERITAS could detect it. However, most of the stars that VERITAS will observe are 10-100 times closer than that, so feasibly a pulse of light 100-10,000 times fainter than that earthly laser could be found.

VERITAS being able to search for alien light signals is a great bonus, since that is not what it was designed for. As David Williams at the University of California, Santa Cruz said:

It is impressive how well-suited the VERITAS telescopes are for this project, since they were built only with the purpose of studying very-high-energy gamma rays in mind.

In California, the SETI Institute is also using Lick Observatory‘s 40-inch Nickel Telescope on Mount Hamilton with a new pulse-detection system, to look for similar laser beacons from civilizations many light-years distant. Optical SETI has its advantages over radio SETI, such as no radio signal interference, according to Frank Drake, director of the Carl Sagan Center for Research:

One great advantage of optical SETI is that there’s no terrestrial interference. It’s an exciting new field.

This Lick experiment is unique as it uses three light detectors (photomultipliers) to search for bright pulses that arrive in a short period of time (less than a billionth of a second). Light from the star itself can also trigger the detectors as well, but seldom will all three photomultipliers be hit by photons within a billionth of a second time frame. This means few false alarms are expected, only about one per year.

Other SETI searches, such as with Lick Observatory’s 40-inch Nickel Telescope, are also looking for laser pulses from advanced civilizations. Image via SETI/LaserFocusWorld.

New and novel ways of looking for evidence of extraterrestrial intelligence are welcome, since the previous, traditional SETI method of just searching for radio signals is considered by many to be antiquated. Would a civilization thousands or millions of years more advanced then us still be using radio waves to communicate? SETI and other searches should be as broad as possible, and consider alternate possibilities for the best chance of success. With billions of stars in our galaxy alone, the hunt for such signals is like looking for a needle in a haystack. VERITAS is just one such alternate method, but it is a good start.

Breakthrough Listen is a comprehensive initiative to search for evidence of intelligent, technological life from nearby stars to the universe at large. The objective is to examine one million nearby stars, all the stars in the galactic plane and 100 nearby galaxies, for both radio and optical signals. Not a small undertaking, but if there is to be any chance of finding an alien light show, then we must look.

This is how far human radio broadcasts have reached into the galaxy – not the black square – but the little blue dot at the center of that zoomed-in square. The ever-expanding bubble announcing humanity’s presence to anyone listening in the Milky Way is now only about 200 light-years wide, in contrast to our 100,000-light-year galaxy. Graphic created by Adam Grossman. Read more from Emily Lakdawalla at the Planetary Society.

Bottom line: Using VERITAS, the search for intelligent alien life will broaden in its scope, looking not only for radio signals but also laser-like optical flashes of light that an advanced civilization might use as communication beacons.

Via Breakthrough Initiatives

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

June 2019 hottest on record for globe

View larger. | An annotated map of the world showing notable climate events that occurred around the world in June 2019. Find out more. Image via NOAA.

According to a NOAA report published on July 18, scorching temperatures made June 2019 the hottest June for the globe in the agency’s 140-year global temperature dataset. The year-to-date temperature for 2019 was the second warmest January–June on record. And for the second month in a row, warmth brought Antarctic sea-ice coverage to a new low.

The average global temperature in June was 1.71 degrees Fahrenheit (.95 degrees Celsius) above the 20th-century average of 59.9 degrees F (15.5 degrees C), making it the hottest June in the 140-year record, according to scientists at NOAA’s National Centers for Environmental Information.

View larger. | Image via NOAA.

Nine of the 10 warmest Junes have occurred since 2010. June 1998 is the only year from the previous century that’s among the 10 warmest Junes on record (the eighth warmest June on record).

June 2019 also marks the 43rd consecutive June and the 414th consecutive month with temperatures, at least nominally, above the 20th century average.

Read the complete NOAA report.

Image via NOAA.

Average Antarctic sea-ice coverage was 8.5 percent below the 1981-2010 average – the smallest on record for June. Average Arctic sea ice coverage was 10.5 percent below average – the second-smallest on record for June.

Bottom line: According to NOAA, June 2019 was the planet’s hottest June in the climate record, which dates back to 1880.

Via NOAA

from EarthSky https://ift.tt/2LCA9hR

View larger. | An annotated map of the world showing notable climate events that occurred around the world in June 2019. Find out more. Image via NOAA.

According to a NOAA report published on July 18, scorching temperatures made June 2019 the hottest June for the globe in the agency’s 140-year global temperature dataset. The year-to-date temperature for 2019 was the second warmest January–June on record. And for the second month in a row, warmth brought Antarctic sea-ice coverage to a new low.

The average global temperature in June was 1.71 degrees Fahrenheit (.95 degrees Celsius) above the 20th-century average of 59.9 degrees F (15.5 degrees C), making it the hottest June in the 140-year record, according to scientists at NOAA’s National Centers for Environmental Information.

View larger. | Image via NOAA.

Nine of the 10 warmest Junes have occurred since 2010. June 1998 is the only year from the previous century that’s among the 10 warmest Junes on record (the eighth warmest June on record).

June 2019 also marks the 43rd consecutive June and the 414th consecutive month with temperatures, at least nominally, above the 20th century average.

Read the complete NOAA report.

Image via NOAA.

Average Antarctic sea-ice coverage was 8.5 percent below the 1981-2010 average – the smallest on record for June. Average Arctic sea ice coverage was 10.5 percent below average – the second-smallest on record for June.

Bottom line: According to NOAA, June 2019 was the planet’s hottest June in the climate record, which dates back to 1880.

Via NOAA

from EarthSky https://ift.tt/2LCA9hR