Dark skies for 2020’s Quadrantid meteors

View larger. | In 2014, as the Quadrantids were flying, people at far northern latitudes were seeing auroras. Photo by Tommy Eliassen.

The Quadrantid meteor shower is 2020’s first major meteor shower. We’ll have moon-free skies during the predawn hours on January 4 for this year’s peak, expected late night January 3 until dawn January 4. Although the Quadrantids have been known to produce some 50-100 meteors in a dark sky, their peak is extremely narrow, time-wise. Peaks of the Perseid or Geminid meteor showers persist for a day or more, allowing all time zones around the world to enjoy a good display of Perseids or Geminids. But the Quadrantids’ peak lasts only a few hours. So you have to be on the right part of Earth – preferably with the radiant high in your sky – in order to experience the peak of the Quadrantids. What’s more, the shower favors the Northern Hemisphere because its radiant point is so far north on the sky’s dome.

So you need some luck to see the Quadrantids, and being in the Northern Hemisphere does help. Who will see the 2020 shower? Keep in mind the prediction of the Quadrantid peak represents an educated guess, not an ironclad guarantee.

That said, in 2020 the International Meteor Organization gives the peak as January 4 at 08:00 UTC. If that prediction of the peak holds true, North America has a good shot at viewing the shower at its best during the predawn hours on January 4.

Just know that meteor showers are notorious for defying the best-laid forecasts. Thus for the Quadrantids – as for any meteor shower – your best plan is simply to look for yourself.

Barry Simmons in Lake Martin, Alabama, captured this Quadrantid meteor during the 2014 shower.

Any place at mid-northern and far-northern latitudes might be in a decent position to watch the Quadrantids in 2020, especially as there is no moonlight in the predawn hours to ruin this year’s show.

All other things being equal, for any meteor shower, you are likely to see the most meteors when the radiant is high in the sky.

In the case of the Quadrantid shower, the radiant point is seen highest in the sky in the dark hours before dawn.

From mid-northern latitudes, the radiant point for the Quadrantid shower doesn’t climb over the horizon until after midnight.

Where is the Quadrantids’ radiant point?

The radiant point of the Quadrantid shower makes an approximate right angle with the Big Dipper and the bright star Arcturus. If you trace the paths of the Quadrantid meteors backward, they appear to radiate from this point on the starry sky.

Now for our usual caveat. You don’t need to find the meteor shower radiant to see the Quadrantid meteors.

You just have to be at mid-northern or far-northern latitudes, up in the wee hours of the morning and hope the peak comes at just the right time to your part of the world.

The meteors will radiate from the northern sky, but appear in all parts of the sky.

The now-defunct constellation Quadrans Muralis, for which the Quadrantids are named. Image via Atlas Coelestis.

The Quadrantids are named for a constellation that no longer exists. Most meteor showers are named for the constellations from which they appear to radiate. So it is with the Quadrantids. But the Quadrantids’ constellation no longer exists, except in memory. The name Quadrantids comes from the constellation Quadrans Muralis (Mural Quadrant), created by the French astronomer Jerome Lalande in 1795. This now-obsolete constellation was located between the constellations of Bootes the Herdsman and Draco the Dragon. Where did it go?

To understand the history of the Quadrantids’ name, we have to go back to the earliest observations of this shower. In early January 1825, Antonio Brucalassi in Italy reported that:

… the atmosphere was traversed by a multitude of the luminous bodies known by the name of falling stars.

They appeared to radiate from Quadrans Muralis. In 1839, Adolphe Quetelet of Brussels Observatory in Belgium and Edward C. Herrick in Connecticut independently made the suggestion that the Quadrantids are an annual shower.

But in 1922 the International Astronomical Union devised a list 88 modern constellations. The list was agreed upon by the International Astronomical Union at its inaugural General Assembly held in Rome in May 1922. It did not include a constellation Quadrans Muralis.

Today, this meteor shower retains the name Quadrantids, for the original and now obsolete constellation Quadrans Muralis.

The radiant point for the Quadrantids is now considered to be at the northern tip of Bootes, near the Big Dipper asterism in our sky, not far from Bootes’ brightest star Arcturus. It is very far north on the sky’s dome, which is why Southern Hemisphere observers probably won’t see many (if any) Quadrantid meteors. Most of the meteors simply won’t make it above the horizon for Southern Hemisphere skywatchers. But some might!

In 2003, Peter Jenniskens proposed that this object, 2003 EH1, is the parent body of the Quadrantid meteor shower.

Quadrantid meteors have a mysterious parent object. In 2003, astronomer Peter Jenniskens tentatively identified the parent body of the Quadrantids as the asteroid 2003 EH1. If indeed this body is the Quadrantids’ parent, then the Quadrantids, like the Geminid meteors, come from a rocky body – not an icy comet. Strange.

In turn, though, 2003 EH1 might be the same object as the comet C/1490 Y1, which was observed by Chinese, Japanese and Korean astronomers 500 years ago.

So the exact story behind the Quadrantids’ parent object remains somewhat mysterious.

Bottom line: The first major meteor shower of 2020, and every year, the Quadrantid meteor shower will probably be at its best in the hours between 2 a.m. and dawn January 4. Fortunately, in 2020, the absence of moonlight in the predawn sky means dark skies during the peak hours of this year’s annual Quadrantid meteor shower.

Best New Year’s gift ever! EarthSky moon calendar for 2019

from EarthSky https://ift.tt/35kiLUI

View larger. | In 2014, as the Quadrantids were flying, people at far northern latitudes were seeing auroras. Photo by Tommy Eliassen.

The Quadrantid meteor shower is 2020’s first major meteor shower. We’ll have moon-free skies during the predawn hours on January 4 for this year’s peak, expected late night January 3 until dawn January 4. Although the Quadrantids have been known to produce some 50-100 meteors in a dark sky, their peak is extremely narrow, time-wise. Peaks of the Perseid or Geminid meteor showers persist for a day or more, allowing all time zones around the world to enjoy a good display of Perseids or Geminids. But the Quadrantids’ peak lasts only a few hours. So you have to be on the right part of Earth – preferably with the radiant high in your sky – in order to experience the peak of the Quadrantids. What’s more, the shower favors the Northern Hemisphere because its radiant point is so far north on the sky’s dome.

So you need some luck to see the Quadrantids, and being in the Northern Hemisphere does help. Who will see the 2020 shower? Keep in mind the prediction of the Quadrantid peak represents an educated guess, not an ironclad guarantee.

That said, in 2020 the International Meteor Organization gives the peak as January 4 at 08:00 UTC. If that prediction of the peak holds true, North America has a good shot at viewing the shower at its best during the predawn hours on January 4.

Just know that meteor showers are notorious for defying the best-laid forecasts. Thus for the Quadrantids – as for any meteor shower – your best plan is simply to look for yourself.

Barry Simmons in Lake Martin, Alabama, captured this Quadrantid meteor during the 2014 shower.

Any place at mid-northern and far-northern latitudes might be in a decent position to watch the Quadrantids in 2020, especially as there is no moonlight in the predawn hours to ruin this year’s show.

All other things being equal, for any meteor shower, you are likely to see the most meteors when the radiant is high in the sky.

In the case of the Quadrantid shower, the radiant point is seen highest in the sky in the dark hours before dawn.

From mid-northern latitudes, the radiant point for the Quadrantid shower doesn’t climb over the horizon until after midnight.

Where is the Quadrantids’ radiant point?

The radiant point of the Quadrantid shower makes an approximate right angle with the Big Dipper and the bright star Arcturus. If you trace the paths of the Quadrantid meteors backward, they appear to radiate from this point on the starry sky.

Now for our usual caveat. You don’t need to find the meteor shower radiant to see the Quadrantid meteors.

You just have to be at mid-northern or far-northern latitudes, up in the wee hours of the morning and hope the peak comes at just the right time to your part of the world.

The meteors will radiate from the northern sky, but appear in all parts of the sky.

The now-defunct constellation Quadrans Muralis, for which the Quadrantids are named. Image via Atlas Coelestis.

The Quadrantids are named for a constellation that no longer exists. Most meteor showers are named for the constellations from which they appear to radiate. So it is with the Quadrantids. But the Quadrantids’ constellation no longer exists, except in memory. The name Quadrantids comes from the constellation Quadrans Muralis (Mural Quadrant), created by the French astronomer Jerome Lalande in 1795. This now-obsolete constellation was located between the constellations of Bootes the Herdsman and Draco the Dragon. Where did it go?

To understand the history of the Quadrantids’ name, we have to go back to the earliest observations of this shower. In early January 1825, Antonio Brucalassi in Italy reported that:

… the atmosphere was traversed by a multitude of the luminous bodies known by the name of falling stars.

They appeared to radiate from Quadrans Muralis. In 1839, Adolphe Quetelet of Brussels Observatory in Belgium and Edward C. Herrick in Connecticut independently made the suggestion that the Quadrantids are an annual shower.

But in 1922 the International Astronomical Union devised a list 88 modern constellations. The list was agreed upon by the International Astronomical Union at its inaugural General Assembly held in Rome in May 1922. It did not include a constellation Quadrans Muralis.

Today, this meteor shower retains the name Quadrantids, for the original and now obsolete constellation Quadrans Muralis.

The radiant point for the Quadrantids is now considered to be at the northern tip of Bootes, near the Big Dipper asterism in our sky, not far from Bootes’ brightest star Arcturus. It is very far north on the sky’s dome, which is why Southern Hemisphere observers probably won’t see many (if any) Quadrantid meteors. Most of the meteors simply won’t make it above the horizon for Southern Hemisphere skywatchers. But some might!

In 2003, Peter Jenniskens proposed that this object, 2003 EH1, is the parent body of the Quadrantid meteor shower.

Quadrantid meteors have a mysterious parent object. In 2003, astronomer Peter Jenniskens tentatively identified the parent body of the Quadrantids as the asteroid 2003 EH1. If indeed this body is the Quadrantids’ parent, then the Quadrantids, like the Geminid meteors, come from a rocky body – not an icy comet. Strange.

In turn, though, 2003 EH1 might be the same object as the comet C/1490 Y1, which was observed by Chinese, Japanese and Korean astronomers 500 years ago.

So the exact story behind the Quadrantids’ parent object remains somewhat mysterious.

Bottom line: The first major meteor shower of 2020, and every year, the Quadrantid meteor shower will probably be at its best in the hours between 2 a.m. and dawn January 4. Fortunately, in 2020, the absence of moonlight in the predawn sky means dark skies during the peak hours of this year’s annual Quadrantid meteor shower.

Best New Year’s gift ever! EarthSky moon calendar for 2019

from EarthSky https://ift.tt/35kiLUI

Why the New Year begins on January 1

Goodbye 2018, and hello 2019! Singapore celebrates the New Year with spectacular fireworks. Image via Channel NewsAsia.

The date of a new year isn’t precisely fixed by any natural or seasonal marker. Instead, our celebration of New Year’s Day on January 1 is a civil event. That’s despite the fact that, for us in the Northern Hemisphere – where daylight has ebbed to its lowest point and the days are getting longer again – there’s a feeling of rebirth in the air.

Our modern celebration of New Year’s Day stems from an ancient Roman custom, the feast of the Roman god Janus: god of doorways and beginnings. The name for the month of January also comes from Janus, who was depicted as having two faces. One face of Janus looked back into the past, and the other peered forward to the future.

To celebrate the new year, the Romans made promises to Janus. From this ancient practice comes our tradition of making New Year’s Day resolutions.

Best New Year’s gift ever! EarthSky moon calendar for 2020. Almost sold out.

Janus the doorkeeper via tablesbeyondbelief.

January 1 hasn’t been New Year’s Day throughout history, though. In the past, some New Year’s celebrations took place at an equinox, a day when the sun is above Earth’s equator, and night and day are equal in length. In many cultures, the March or vernal equinox marks a time of transition and new beginnings, and so cultural celebrations of a new year were natural for that equinox. The September or autumnal equinox also had its proponents for the beginning of a new year. For example, the French Republican Calendar – implemented during the French Revolution and used for about 12 years from late 1793 to 1805 – started its year at the September equinox.

The Greeks celebrated the new year on the winter solstice, the shortest day of the year.

Today, although many do celebrate New Year’s Day on January 1, some cultures and religions do not. Jews use a lunar calendar and celebrate the New Year on Rosh Hashanah, the first day of the month of Tishri, which is the first month of the Jewish calendar. This date usually occurs in September.

Most are also familiar with the Chinese New Year, celebrated for weeks in January or early February. In 2020, the Chinese Year of the Rat begins on January 25.

By the way, in addition to the longer days here in the Northern Hemisphere, there’s another astronomical occurrence around January 1 each year that’s also related to Earth’s year, as defined by our orbit around the sun. That is, Earth’s perihelion – or closest point to the sun – happens every year in early January. In 2020, perihelion comes on January 4-5.

We don’t celebrate New Year’s Day on January 1 for this reason, but it would make sense if we did. Perihelion – our closest point to the sun in our yearly orbit – takes place each year in early January. Image via NASA.

Bottom line: The reason to celebrate New Year’s Day on January 1 is historical, not astronomical. The New Year was celebrated according to astronomical events – such as equinoxes and solstices – eons ago. Our modern New Year’s celebration stems from the ancient, two-faced Roman god Janus, after whom the month of January is also named. One face of Janus looked back into the past, and the other peered forward to the future.

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Goodbye 2018, and hello 2019! Singapore celebrates the New Year with spectacular fireworks. Image via Channel NewsAsia.

The date of a new year isn’t precisely fixed by any natural or seasonal marker. Instead, our celebration of New Year’s Day on January 1 is a civil event. That’s despite the fact that, for us in the Northern Hemisphere – where daylight has ebbed to its lowest point and the days are getting longer again – there’s a feeling of rebirth in the air.

Our modern celebration of New Year’s Day stems from an ancient Roman custom, the feast of the Roman god Janus: god of doorways and beginnings. The name for the month of January also comes from Janus, who was depicted as having two faces. One face of Janus looked back into the past, and the other peered forward to the future.

To celebrate the new year, the Romans made promises to Janus. From this ancient practice comes our tradition of making New Year’s Day resolutions.

Best New Year’s gift ever! EarthSky moon calendar for 2020. Almost sold out.

Janus the doorkeeper via tablesbeyondbelief.

January 1 hasn’t been New Year’s Day throughout history, though. In the past, some New Year’s celebrations took place at an equinox, a day when the sun is above Earth’s equator, and night and day are equal in length. In many cultures, the March or vernal equinox marks a time of transition and new beginnings, and so cultural celebrations of a new year were natural for that equinox. The September or autumnal equinox also had its proponents for the beginning of a new year. For example, the French Republican Calendar – implemented during the French Revolution and used for about 12 years from late 1793 to 1805 – started its year at the September equinox.

The Greeks celebrated the new year on the winter solstice, the shortest day of the year.

Today, although many do celebrate New Year’s Day on January 1, some cultures and religions do not. Jews use a lunar calendar and celebrate the New Year on Rosh Hashanah, the first day of the month of Tishri, which is the first month of the Jewish calendar. This date usually occurs in September.

Most are also familiar with the Chinese New Year, celebrated for weeks in January or early February. In 2020, the Chinese Year of the Rat begins on January 25.

By the way, in addition to the longer days here in the Northern Hemisphere, there’s another astronomical occurrence around January 1 each year that’s also related to Earth’s year, as defined by our orbit around the sun. That is, Earth’s perihelion – or closest point to the sun – happens every year in early January. In 2020, perihelion comes on January 4-5.

We don’t celebrate New Year’s Day on January 1 for this reason, but it would make sense if we did. Perihelion – our closest point to the sun in our yearly orbit – takes place each year in early January. Image via NASA.

Bottom line: The reason to celebrate New Year’s Day on January 1 is historical, not astronomical. The New Year was celebrated according to astronomical events – such as equinoxes and solstices – eons ago. Our modern New Year’s celebration stems from the ancient, two-faced Roman god Janus, after whom the month of January is also named. One face of Janus looked back into the past, and the other peered forward to the future.

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Star Sirius rings in New Year!

This Hubble Space Telescope image shows Sirius A, the brightest star in our night sky, along with Sirius B, its faint, tiny stellar companion. Sirius B is the tiny dot at the lower left. Image via H. Bond (STScI)/ M. Barstow (University of Leicester).

Want to surprise and impress your friends on New Year’s Eve? Show them Sirius, the brightest star in the sky, sometimes called the Dog Star because it’s part of the constellation Canis Major the Greater Dog. Sirius might also be called the New Year’s star. It’ll celebrate the birth of 2020 and every new year by reaching its highest point in the sky around the stroke of midnight. That’s the case this year, and every year.

How can you find Sirius? It’s easy because this star is the brightest one we see from Earth. Its name means sparkling or scorching.

If you look for the sky’s brightest star, and are still not sure, here’s a sure-fire way to identify it. Just look for the prominent Belt stars of the constellation Orion. Orion’s Belt always points to Sirius.

EarthSky lunar calendars are cool! Great New Year’s gift. Nearly sold out. Order now!

Brightest star Sirius at dusk on December 27, 2018, via Peter Lowenstein in Mutare, Zimbabwe. Around New Year’s, the star can be found in the eastern half of the sky in the evening, highest around midnight, and in the western half of the sky between midnight and dawn.

You can always recognize Sirius, because the 3 noticeable stars in Orion’s Belt point to it.

This photo comes from EarthSky Facebook friend Susan Jensen in Odessa, Washington. See how it matches the chart above, with the 3 stars of Orion’s Belt pointing to Sirius?

So Sirius is highest in the sky at midnight every New Year’s. Astronomers call this a midnight culmination of Sirius. As the New Year rings in, Sirius is at its highest.

By midnight, by the way, we mean the middle of the night – midway between sunset and sunrise. Like the sun, the stars rise in the east and travel westward across the sky. When the sun or any star is in the eastern half of the sky, it’s climbing upward. When the sun or any star is in the western sky, it’s descending downward. Midway between rising and setting, the sun or any star reaches its highest point in the sky.

Because the stars rise and set two hours earlier with each passing month, Sirius will be highest up for the night around 10 p.m. local time on February 1.

Sirius from space. It’s the brightest star in this image, the bluish one, to the right in the photo. The 3 Belt stars of Orion – buried in the haze along Earth’s horizon – are still pointing to it.

Bottom line: Look for the star Sirius at midnight culmination – highest in the sky around midnight, or midway between sunset and sunrise – every New Year’s Eve.

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This Hubble Space Telescope image shows Sirius A, the brightest star in our night sky, along with Sirius B, its faint, tiny stellar companion. Sirius B is the tiny dot at the lower left. Image via H. Bond (STScI)/ M. Barstow (University of Leicester).

Want to surprise and impress your friends on New Year’s Eve? Show them Sirius, the brightest star in the sky, sometimes called the Dog Star because it’s part of the constellation Canis Major the Greater Dog. Sirius might also be called the New Year’s star. It’ll celebrate the birth of 2020 and every new year by reaching its highest point in the sky around the stroke of midnight. That’s the case this year, and every year.

How can you find Sirius? It’s easy because this star is the brightest one we see from Earth. Its name means sparkling or scorching.

If you look for the sky’s brightest star, and are still not sure, here’s a sure-fire way to identify it. Just look for the prominent Belt stars of the constellation Orion. Orion’s Belt always points to Sirius.

EarthSky lunar calendars are cool! Great New Year’s gift. Nearly sold out. Order now!

Brightest star Sirius at dusk on December 27, 2018, via Peter Lowenstein in Mutare, Zimbabwe. Around New Year’s, the star can be found in the eastern half of the sky in the evening, highest around midnight, and in the western half of the sky between midnight and dawn.

You can always recognize Sirius, because the 3 noticeable stars in Orion’s Belt point to it.

This photo comes from EarthSky Facebook friend Susan Jensen in Odessa, Washington. See how it matches the chart above, with the 3 stars of Orion’s Belt pointing to Sirius?

So Sirius is highest in the sky at midnight every New Year’s. Astronomers call this a midnight culmination of Sirius. As the New Year rings in, Sirius is at its highest.

By midnight, by the way, we mean the middle of the night – midway between sunset and sunrise. Like the sun, the stars rise in the east and travel westward across the sky. When the sun or any star is in the eastern half of the sky, it’s climbing upward. When the sun or any star is in the western sky, it’s descending downward. Midway between rising and setting, the sun or any star reaches its highest point in the sky.

Because the stars rise and set two hours earlier with each passing month, Sirius will be highest up for the night around 10 p.m. local time on February 1.

Sirius from space. It’s the brightest star in this image, the bluish one, to the right in the photo. The 3 Belt stars of Orion – buried in the haze along Earth’s horizon – are still pointing to it.

Bottom line: Look for the star Sirius at midnight culmination – highest in the sky around midnight, or midway between sunset and sunrise – every New Year’s Eve.

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Moon phase a clue to the sun’s position

Above: Draw a straight line from one horn of a crescent moon to the other. Then from the middle of that line, between the horns, draw another straight line perpendicular to the first. The illuminated part of the crescent points to the sun. You can extend the line down to the point on the horizon roughly where the sun went down.

In late December 2019 – if you look in a clear western sky after sunset – you’ll easily spot the very bright planet Venus, along with a waxing crescent moon. There might be earthshine illuminating the moon’s darkened portion. You know, of course, that the moon changes its phase. But did you know you can tell where the sun is – even when the sun is below the horizon – just by observing the moon phase? It’s especially easy with a crescent moon up to first quarter phase.

And, once you learn to use the moon in this way, you’ll gain a lot understanding about what causes the moon to change its phase in the first place. Plus just thinking about it, each time you see a crescent moon, will add to your perception of yourself as a person standing on a world in space.

So here’s what you do. When you see a crescent moon, notice that it has two ends or “horns.”

Imagine that you draw a straight line from one horn to the other. Then from the middle of that line, between the horns, imagine another straight line perpendicular to the first (that is, at a “right” angle). Imagine that line drawn down through the illuminated part of the crescent. That line points to the sun. You can extend the line down to the point on the horizon roughly where the sun went down.

Draw a straight line from one horn to the other. Then from the middle of that line, between the horns, imagine another straight line perpendicular to the first (that is, at a “right” angle). The illuminated part of the crescent points to the sun. You can extend the line down to the point on the horizon roughly where the sun went down.

By the time the moon waxes to the first quarter phase, of course, the first line above is just the “flat” edge of the moon. After that phase, it becomes a bit harder to use the moon to find the sun’s position, when the sun is below the horizon, but experienced stargazers can and do still do it.

Why does this work? Well, it’s the sun that causes the moon’s phases. The moon is a globe in space, just as Earth is a globe. And like the Earth, the moon has a day side and a night side. The varying moon phases we see are just varying fractions of the moon’s day side. Want more about this? Try our article 4 keys to understanding moon phases.

About the moon on New Year’s Eve 2019 … it’s near the dazzlingly bright planet Venus and exceedingly faint planet Neptune.

On the evening of December 31, 2019, you’ll find the moon in about this position with respect to the very bright planet Venus. The planet Neptune is near the moon in our sky on this date, but Neptune cannot be seen with the eye alone.

You’ll notice Venus right away, but you won’t see Neptune with the unaided eye. You’ll need at least binoculars to see this distant planet. Click here for a detailed sky chart showing Neptune’s location in 2019 and 2020.

Bottom line: The moon phase can point you to the sun’s location in the sky, even when the sun is below the horizon.

Read more: EarthSky’s guide to the bright planets

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

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Above: Draw a straight line from one horn of a crescent moon to the other. Then from the middle of that line, between the horns, draw another straight line perpendicular to the first. The illuminated part of the crescent points to the sun. You can extend the line down to the point on the horizon roughly where the sun went down.

In late December 2019 – if you look in a clear western sky after sunset – you’ll easily spot the very bright planet Venus, along with a waxing crescent moon. There might be earthshine illuminating the moon’s darkened portion. You know, of course, that the moon changes its phase. But did you know you can tell where the sun is – even when the sun is below the horizon – just by observing the moon phase? It’s especially easy with a crescent moon up to first quarter phase.

And, once you learn to use the moon in this way, you’ll gain a lot understanding about what causes the moon to change its phase in the first place. Plus just thinking about it, each time you see a crescent moon, will add to your perception of yourself as a person standing on a world in space.

So here’s what you do. When you see a crescent moon, notice that it has two ends or “horns.”

Imagine that you draw a straight line from one horn to the other. Then from the middle of that line, between the horns, imagine another straight line perpendicular to the first (that is, at a “right” angle). Imagine that line drawn down through the illuminated part of the crescent. That line points to the sun. You can extend the line down to the point on the horizon roughly where the sun went down.

Draw a straight line from one horn to the other. Then from the middle of that line, between the horns, imagine another straight line perpendicular to the first (that is, at a “right” angle). The illuminated part of the crescent points to the sun. You can extend the line down to the point on the horizon roughly where the sun went down.

By the time the moon waxes to the first quarter phase, of course, the first line above is just the “flat” edge of the moon. After that phase, it becomes a bit harder to use the moon to find the sun’s position, when the sun is below the horizon, but experienced stargazers can and do still do it.

Why does this work? Well, it’s the sun that causes the moon’s phases. The moon is a globe in space, just as Earth is a globe. And like the Earth, the moon has a day side and a night side. The varying moon phases we see are just varying fractions of the moon’s day side. Want more about this? Try our article 4 keys to understanding moon phases.

About the moon on New Year’s Eve 2019 … it’s near the dazzlingly bright planet Venus and exceedingly faint planet Neptune.

On the evening of December 31, 2019, you’ll find the moon in about this position with respect to the very bright planet Venus. The planet Neptune is near the moon in our sky on this date, but Neptune cannot be seen with the eye alone.

You’ll notice Venus right away, but you won’t see Neptune with the unaided eye. You’ll need at least binoculars to see this distant planet. Click here for a detailed sky chart showing Neptune’s location in 2019 and 2020.

Bottom line: The moon phase can point you to the sun’s location in the sky, even when the sun is below the horizon.

Read more: EarthSky’s guide to the bright planets

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

from EarthSky https://ift.tt/2ZD92HQ

Can you see stars’ different colors?

Tonight … notice that the stars are like wildflowers, in that each star radiates with a different color of the rainbow. Have you ever noticed their various hues? Let’s explore some of the stars that you’ll see in the meadow of night tonight.

In the northeastern sky at evening shines a bright star called Capella, the Little She Goat, in the constellation Auriga. Like brighter Sirius, which rises around 8 to 9 p.m. in the southeast, Capella often flickers madly when low in the sky. This effect has nothing to do with the stars themselves but rather is caused by Earth’s turbulent atmosphere.

The effect is particularly prominent with the stars Capella and Sirius because they are so bright.

Can you spot Capella? If so, notice that it’s a golden star. A star’s spectral type indicates its color. Capella is a G star, and, in that classification, it’s like our sun. Both our sun and Capella shine with a golden light.

Sirius, by the way – the sky’s brightest star, after the sun – is almost always described as a white star.

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The constellation Auriga in the northeast sky at nightfall in December. The brightest star in this constellation is golden Capella. The bright red star just above the horizon is Aldebaran in the constellation Taurus. Image via AlltheSky.com

The stars’ true colors are apparent when they climb higher in the sky and above the turbulence of Earth’s atmosphere. If you have good eyesight and a dark, clear sky, you should be able to detect hints of color with the brighter stars. If you have difficulty discerning star colors with the unaided eye, try looking at these stars with binoculars.

Also contrast golden Capella with the reddish star Aldebaran and the stars of the misty Pleiades cluster higher up.

The light of a star reveals many things, but most directly the stars’ surface temperatures. The yellowish color of Capella indicates a mid-range surface temperature, much like our sun. The red of Aldebaran is typical of the lower surface temperature of an older star, whereas the blue of the Pleiades reveals their high surface temperature and young age.

The blue-white star Elnath, by the way, is officially part of Taurus, but it typically is considered part of Auriga as well.

There is a whole spectrum of stellar color sparkling in the sky tonight, from cool red stars to hot blue-white ones, and middle range yellow stars!

The H-R diagram, showing the colors of stars. Image via Wikipedia

Bottom line: Winter is the perfect season for noticing the colors of the stars. Never noticed them? Our sky chart can help guide your eye.

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Tonight … notice that the stars are like wildflowers, in that each star radiates with a different color of the rainbow. Have you ever noticed their various hues? Let’s explore some of the stars that you’ll see in the meadow of night tonight.

In the northeastern sky at evening shines a bright star called Capella, the Little She Goat, in the constellation Auriga. Like brighter Sirius, which rises around 8 to 9 p.m. in the southeast, Capella often flickers madly when low in the sky. This effect has nothing to do with the stars themselves but rather is caused by Earth’s turbulent atmosphere.

The effect is particularly prominent with the stars Capella and Sirius because they are so bright.

Can you spot Capella? If so, notice that it’s a golden star. A star’s spectral type indicates its color. Capella is a G star, and, in that classification, it’s like our sun. Both our sun and Capella shine with a golden light.

Sirius, by the way – the sky’s brightest star, after the sun – is almost always described as a white star.

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The constellation Auriga in the northeast sky at nightfall in December. The brightest star in this constellation is golden Capella. The bright red star just above the horizon is Aldebaran in the constellation Taurus. Image via AlltheSky.com

The stars’ true colors are apparent when they climb higher in the sky and above the turbulence of Earth’s atmosphere. If you have good eyesight and a dark, clear sky, you should be able to detect hints of color with the brighter stars. If you have difficulty discerning star colors with the unaided eye, try looking at these stars with binoculars.

Also contrast golden Capella with the reddish star Aldebaran and the stars of the misty Pleiades cluster higher up.

The light of a star reveals many things, but most directly the stars’ surface temperatures. The yellowish color of Capella indicates a mid-range surface temperature, much like our sun. The red of Aldebaran is typical of the lower surface temperature of an older star, whereas the blue of the Pleiades reveals their high surface temperature and young age.

The blue-white star Elnath, by the way, is officially part of Taurus, but it typically is considered part of Auriga as well.

There is a whole spectrum of stellar color sparkling in the sky tonight, from cool red stars to hot blue-white ones, and middle range yellow stars!

The H-R diagram, showing the colors of stars. Image via Wikipedia

Bottom line: Winter is the perfect season for noticing the colors of the stars. Never noticed them? Our sky chart can help guide your eye.

Never miss another full moon. Order your 2018 EarthSky lunar calendar today!

Donate: Your support means the world to us

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

Top 9 EarthSky stories of 2019

Who could forget this image? It’s the first direct image of a black hole, in the galaxy M87, released in April 2019. This long-sought image provided the strongest evidence to date for the existence of supermassive black holes and opened a new window onto the study of black holes, their event horizons, and gravity. Image via Event Horizon Telescope Collaboration.

1. January 3, 2019: China’s Chang’e 4 spacecraft landed on the moon’s far side. The year started with a bang (or was it a bump?) when a Chinese spacecraft called Chang’e 4 became the first-ever mission to land on the side of the moon that faces continually away from Earth. We’re linking here not just to the announcement of the landing, but to a story published a few months later on what early results from Chang’e 4 revealed about this mysterious part of the moon.
2. Mid-January, 2019: A 2nd repeating radio burst from the depths of space. Astronomers announced that, of the more than 60 Fast Radio Bursts found so far, only one has ever been seen to repeat from the same source … until now.
3. February 22, 2019: Japan’s Hayabusa2 successfully lands on asteroid Ryugu. The Hayabusa2 spacecraft touched down briefly and successfully on asteroid Ryugu, 200 million miles (300 million km) from Earth. It successfully fired a bullet into the asteroid to puff up dust for sample collection.
4. March 24, 2019: Scientists gathered to contemplate the Great Silence. In other words … if advanced alien civilizations are out there, why haven’t we heard from them? Scientists call this Fermi’s Paradox – aka The Great Silence – and they gathered in Paris to discuss it.
5. April 7, 2019: Scientists closed in on mysterious Mars methane. For the first time, an in-situ measurement of methane on Mars – made by NASA’s Curiosity rover – was independently confirmed from orbit, by ESA’s Mars Express. Could it be a clue to Mars life?
6. April 10, 2019: Astronomers released the first real black hole image. Researchers unveiled a history-making image – the first ever – of the shadow of a supermassive black hole.
7. September 7, 2019: Contact with India moon lander lost, moments before touchdown. The Vikram lander was to have made India the 4th nation of Earth to soft land on the moon. It was heartbreaking when contact with the craft was lost just 1.3 miles (2.1 km) above the moon’s surface.
8. August 30, 2019: Astronomers spied a 2nd interstellar visitor. Astronomers realized the object they initially labeled C/2019 Q4 – later officially identified as a comet and re-labeled 2I/Borisov – came from a place far, far away. It’s only the 2nd interstellar object ever detected, after ‘Oumuamua in 2017. The link goes to an update on this object, in November 2019, after the first peer-reviewed paper about it.
9. October 31, 2019: A small asteroid paid a heavy price for nearly striking Earth: Earth’s gravity bent the trajectory of asteroid C0PPEV1 – also known as 2019 UN13 – as it swept only 3,852 miles (6,200 km) above Africa.

Bottom line: Top EarthSky news stories of 2019.

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Who could forget this image? It’s the first direct image of a black hole, in the galaxy M87, released in April 2019. This long-sought image provided the strongest evidence to date for the existence of supermassive black holes and opened a new window onto the study of black holes, their event horizons, and gravity. Image via Event Horizon Telescope Collaboration.

1. January 3, 2019: China’s Chang’e 4 spacecraft landed on the moon’s far side. The year started with a bang (or was it a bump?) when a Chinese spacecraft called Chang’e 4 became the first-ever mission to land on the side of the moon that faces continually away from Earth. We’re linking here not just to the announcement of the landing, but to a story published a few months later on what early results from Chang’e 4 revealed about this mysterious part of the moon.
2. Mid-January, 2019: A 2nd repeating radio burst from the depths of space. Astronomers announced that, of the more than 60 Fast Radio Bursts found so far, only one has ever been seen to repeat from the same source … until now.
3. February 22, 2019: Japan’s Hayabusa2 successfully lands on asteroid Ryugu. The Hayabusa2 spacecraft touched down briefly and successfully on asteroid Ryugu, 200 million miles (300 million km) from Earth. It successfully fired a bullet into the asteroid to puff up dust for sample collection.
4. March 24, 2019: Scientists gathered to contemplate the Great Silence. In other words … if advanced alien civilizations are out there, why haven’t we heard from them? Scientists call this Fermi’s Paradox – aka The Great Silence – and they gathered in Paris to discuss it.
5. April 7, 2019: Scientists closed in on mysterious Mars methane. For the first time, an in-situ measurement of methane on Mars – made by NASA’s Curiosity rover – was independently confirmed from orbit, by ESA’s Mars Express. Could it be a clue to Mars life?
6. April 10, 2019: Astronomers released the first real black hole image. Researchers unveiled a history-making image – the first ever – of the shadow of a supermassive black hole.
7. September 7, 2019: Contact with India moon lander lost, moments before touchdown. The Vikram lander was to have made India the 4th nation of Earth to soft land on the moon. It was heartbreaking when contact with the craft was lost just 1.3 miles (2.1 km) above the moon’s surface.
8. August 30, 2019: Astronomers spied a 2nd interstellar visitor. Astronomers realized the object they initially labeled C/2019 Q4 – later officially identified as a comet and re-labeled 2I/Borisov – came from a place far, far away. It’s only the 2nd interstellar object ever detected, after ‘Oumuamua in 2017. The link goes to an update on this object, in November 2019, after the first peer-reviewed paper about it.
9. October 31, 2019: A small asteroid paid a heavy price for nearly striking Earth: Earth’s gravity bent the trajectory of asteroid C0PPEV1 – also known as 2019 UN13 – as it swept only 3,852 miles (6,200 km) above Africa.

Bottom line: Top EarthSky news stories of 2019.

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Top 9 EarthSky images of 2019

Thanks to all who posted this year at EarthSky Community Photos. If you have a great recent photo of the Earth or sky, submit it here.

View larger at EarthSky Community Photos. | As 2019 began, the eastern sky before sunup featured 3 bright planets, Venus, Jupiter qnd Saturn. In late January and early February, the moon swept through. Karl Diefenderfer in Quakertown, Pennsylvania, caught the waning moon, with bright Venus above right, on February 1, 2019. He wrote: “Chilly start to the day at -4F.” Thank you, Karl. View more morning planet photos from early 2019.

View larger at EarthSky Community Photo. | Mike Mezeul II captured what’s called “firefall” at Yosemite National Park on February 17, 2019. He wrote: “For two weeks out of the year, a spectacular event known as the firefall takes place within Yosemite National Park. Hundreds if not thousands of photographers flock to the valley in hopes of capturing the elusive moment, that is, if the weather, snow and light cooperate. If Yosemite receives an ample amount of snowfall throughout the winter, and if the western horizon stays clear, the last few minutes of daylight fall perfectly upon Horsetail Falls and illuminate it in a vibrant orange and red. The waterfall glows so fiercely that it appears to be on fire. Yesterday, after the valley received several feet of snow for a few days, one last clearing snowstorm led to the perfect mix of ingredients. Water flowing from the beautiful Horsetail Falls and a dazzling mix of broken clouds floating past El Capitan as the sunset set the fall ablaze.” Thank you, Mike!

Jingyi Zhang and Wang Zheng captured this stunning dragon shape in an aurora over Iceland in early February 2019. The image ran as the Astronomy Picture of the Day for February 18, 2019, which wrote: “This iconic display was so enthralling that the photographer’s mother ran out to see it and was captured in the foreground.” View more aurora photos from that same awesome night.

View at EarthSky Community Photos. | It has been a quiet year for sunspots. We’re near the lowest ebb of the 11-year sunspot cycle. But, in April 2019, a magnificent solitary sunspot – AR2738 – made its way across the sun’s face over a period of a couple of weeks. Padraic Koen in Adelaide, Australia, caught this closeup of sunspot AR2738 on April 14, 2019. Thank you, Padraic. View more photos of AR2738.

View at EarthSky Community Photos. | The month of June always brings new sightings of noctilucent clouds – also called night-shining clouds – at northerly latitudes. These clouds are a seasonal phenomenon. Hans Van Boven wrote, “Beautiful noctilucent clouds were observed above the Netherlands in the night from 12 to 13 June 2019.” Thank you, Hans! View more photos of noctilucent clouds in 2019, along with an explanation of what makes these clouds.

View at EarthSky Community Photos. | Fred Walder captured this rainbow and waterfall on June 17, 2019, in California’s Yosemite National Park. The streaks in the sky above – captured in a long-exposure photo – are called star trails. View more star trails photos.

View larger. | July 2, 2019 brought a total eclipse of the sun. Here’s the scene on a beach during totality in La Serena, Chile – darkness during the daytime at mid-eclipse – as captured by our friend Eliot Herman. Thank you, Eliot! View more eclipse photos by Eliot, and still more eclipse photos, by other EarthSky community members. Thanks to all!

August, of course, is the month of the Perseid meteor shower. Astrophotographer Ruslan Merzlyakov wrote: “Proud to present the biggest project I have ever made! Perseid meteor shower 2019 over Scandinavia’s first dark sky park, the island of Møn [in Denmark]. Five nights. Two cameras. Fifteen hours of observation. Some 3000+ images. Over 70 GB of data.” Thank you, Ruslan!

View at EarthSky Community Photos. | Claire Shickora was at Blythe Island Regional Park, Brunswick, Georgia, on Thanksgiving evening – November 28, 2019 – when she caught this beautiful image. She wrote: “After a spectacular sunset at the marina, the clouds broke up enough for me to get this shot (from right to left) of Jupiter, Venus, the moon, and barely-visible Saturn. Passersby were awed as I pointed out exactly what I was photographing.” Thank you, Claire! View more photos of the moon and planets in the evening sky, around Thanksgiving.

Bottom line: Nine favorite EarthSky images in 2019. Of course … they’re all our favorites. Thanks to all who submitted photos in 2019! Visit EarthSky Community Photos, or submit your photo here.

from EarthSky https://ift.tt/2F1FVnR

Thanks to all who posted this year at EarthSky Community Photos. If you have a great recent photo of the Earth or sky, submit it here.

View larger at EarthSky Community Photos. | As 2019 began, the eastern sky before sunup featured 3 bright planets, Venus, Jupiter qnd Saturn. In late January and early February, the moon swept through. Karl Diefenderfer in Quakertown, Pennsylvania, caught the waning moon, with bright Venus above right, on February 1, 2019. He wrote: “Chilly start to the day at -4F.” Thank you, Karl. View more morning planet photos from early 2019.

View larger at EarthSky Community Photo. | Mike Mezeul II captured what’s called “firefall” at Yosemite National Park on February 17, 2019. He wrote: “For two weeks out of the year, a spectacular event known as the firefall takes place within Yosemite National Park. Hundreds if not thousands of photographers flock to the valley in hopes of capturing the elusive moment, that is, if the weather, snow and light cooperate. If Yosemite receives an ample amount of snowfall throughout the winter, and if the western horizon stays clear, the last few minutes of daylight fall perfectly upon Horsetail Falls and illuminate it in a vibrant orange and red. The waterfall glows so fiercely that it appears to be on fire. Yesterday, after the valley received several feet of snow for a few days, one last clearing snowstorm led to the perfect mix of ingredients. Water flowing from the beautiful Horsetail Falls and a dazzling mix of broken clouds floating past El Capitan as the sunset set the fall ablaze.” Thank you, Mike!

Jingyi Zhang and Wang Zheng captured this stunning dragon shape in an aurora over Iceland in early February 2019. The image ran as the Astronomy Picture of the Day for February 18, 2019, which wrote: “This iconic display was so enthralling that the photographer’s mother ran out to see it and was captured in the foreground.” View more aurora photos from that same awesome night.

View at EarthSky Community Photos. | It has been a quiet year for sunspots. We’re near the lowest ebb of the 11-year sunspot cycle. But, in April 2019, a magnificent solitary sunspot – AR2738 – made its way across the sun’s face over a period of a couple of weeks. Padraic Koen in Adelaide, Australia, caught this closeup of sunspot AR2738 on April 14, 2019. Thank you, Padraic. View more photos of AR2738.

View at EarthSky Community Photos. | The month of June always brings new sightings of noctilucent clouds – also called night-shining clouds – at northerly latitudes. These clouds are a seasonal phenomenon. Hans Van Boven wrote, “Beautiful noctilucent clouds were observed above the Netherlands in the night from 12 to 13 June 2019.” Thank you, Hans! View more photos of noctilucent clouds in 2019, along with an explanation of what makes these clouds.

View at EarthSky Community Photos. | Fred Walder captured this rainbow and waterfall on June 17, 2019, in California’s Yosemite National Park. The streaks in the sky above – captured in a long-exposure photo – are called star trails. View more star trails photos.

View larger. | July 2, 2019 brought a total eclipse of the sun. Here’s the scene on a beach during totality in La Serena, Chile – darkness during the daytime at mid-eclipse – as captured by our friend Eliot Herman. Thank you, Eliot! View more eclipse photos by Eliot, and still more eclipse photos, by other EarthSky community members. Thanks to all!

August, of course, is the month of the Perseid meteor shower. Astrophotographer Ruslan Merzlyakov wrote: “Proud to present the biggest project I have ever made! Perseid meteor shower 2019 over Scandinavia’s first dark sky park, the island of Møn [in Denmark]. Five nights. Two cameras. Fifteen hours of observation. Some 3000+ images. Over 70 GB of data.” Thank you, Ruslan!

View at EarthSky Community Photos. | Claire Shickora was at Blythe Island Regional Park, Brunswick, Georgia, on Thanksgiving evening – November 28, 2019 – when she caught this beautiful image. She wrote: “After a spectacular sunset at the marina, the clouds broke up enough for me to get this shot (from right to left) of Jupiter, Venus, the moon, and barely-visible Saturn. Passersby were awed as I pointed out exactly what I was photographing.” Thank you, Claire! View more photos of the moon and planets in the evening sky, around Thanksgiving.

Bottom line: Nine favorite EarthSky images in 2019. Of course … they’re all our favorites. Thanks to all who submitted photos in 2019! Visit EarthSky Community Photos, or submit your photo here.

from EarthSky https://ift.tt/2F1FVnR