North Carolina’s Fort Macon State Park host a monthly dark night astronomy program open to the public. With the help of the Crystal Coast Star Gazers Group, telescopes are set up for public viewing. In this photo, group member Fred Angeli”s headlamp leaves a streak of light as he approaches his ‘scope to focus on the night sky. Photo by Doug Waters.
Interested in astronomy, but not sure where to begin? A first step can be to seek out your local astronomy club. It consists of a roomful of willing and able amateur astronomers, whose telescopes may offer your first glimpse of the cosmos. The Astronomical League, an umbrella organization of 240 amateur astronomy clubs and societies in the U.S.
The Astronomical League also helps us create and maintain the list of events on this page. Click here to visit the Astronomical League’s website.
Know of an event that’s not on the list below? Contact us.
Do you have a great photo of a star party in your area? Submit here.
Looking for an astronomy club in your area? Click here.
Special thanks also to the Royal Astronomical Society of Canada for help with this list.
Jump below the photo for a list of upcoming events! If no web link is given, it’s because the information for the upcoming event hasn’t been posted yet. Check back.
Jim Elliott of Powell, Ohio, contributed this photo. He wrote: “The moon over Jupiter over Columbus, Ohio, at the OSU planetarium star party. April 16, 2016.”
Upcoming astronomy events …winter, 2018
February 3
Regional Gathering of Amateur Astronomers
(a.k.a. BoBfest) Catawba Science Center
Hickory, North Carolina
www.catawbasky.org
February 7–11
Orange Blossom Special International Star Party
Withlacoochee River Park
Dade City, Florida
http://ift.tt/1WnMXnm
Feb 12-18
Winter Star Party
Southern Cross Astronomical Society
Chiefland Astronomy Village (5450 NW 52nd Court Chiefland, Florida 32626)
http://ift.tt/2jrDU9A
March 3
TriStar 2018
Guilford Technical Community College
Greensboro Astronomy Club and the
Cline Observatory
Jamestown, North Carolina
observatory_gtcc.edu/tristar/
April 11–14
Mid-South Star Gaze and Astronomy Conference
French Camp, Mississippi
http://ift.tt/1KlyoA0
April 14–21
The OzSky Star Safari
(a.k.a. Deepest South Texas Star Safari)
Coonabarabran, New South Wales, Australia
www.ozsky.org
April 21–22
Northeast Astronomy Forum
Suffern, New York
http://ift.tt/1HMGVYK
Here is Dan Lewelyn at Deerlick Astronomy Village near Atlanta, Georgia. Photo by Dave Woolsteen.
Texas Star Party, one of the biggest public astronomy events of each year, drawing about 500 deep-sky enthusiasts and their telescopes to the Davis Mountains of West Texas. Image used with permission, via Todd Hargis and Ron Ronhaar.
Bottom line: List of astronomy and night sky events for the public, for 2018, compiled in cooperation with the awesome Astronomical League. Join in, and have fun!
North Carolina’s Fort Macon State Park host a monthly dark night astronomy program open to the public. With the help of the Crystal Coast Star Gazers Group, telescopes are set up for public viewing. In this photo, group member Fred Angeli”s headlamp leaves a streak of light as he approaches his ‘scope to focus on the night sky. Photo by Doug Waters.
Interested in astronomy, but not sure where to begin? A first step can be to seek out your local astronomy club. It consists of a roomful of willing and able amateur astronomers, whose telescopes may offer your first glimpse of the cosmos. The Astronomical League, an umbrella organization of 240 amateur astronomy clubs and societies in the U.S.
The Astronomical League also helps us create and maintain the list of events on this page. Click here to visit the Astronomical League’s website.
Know of an event that’s not on the list below? Contact us.
Do you have a great photo of a star party in your area? Submit here.
Looking for an astronomy club in your area? Click here.
Special thanks also to the Royal Astronomical Society of Canada for help with this list.
Jump below the photo for a list of upcoming events! If no web link is given, it’s because the information for the upcoming event hasn’t been posted yet. Check back.
Jim Elliott of Powell, Ohio, contributed this photo. He wrote: “The moon over Jupiter over Columbus, Ohio, at the OSU planetarium star party. April 16, 2016.”
Upcoming astronomy events …winter, 2018
February 3
Regional Gathering of Amateur Astronomers
(a.k.a. BoBfest) Catawba Science Center
Hickory, North Carolina
www.catawbasky.org
February 7–11
Orange Blossom Special International Star Party
Withlacoochee River Park
Dade City, Florida
http://ift.tt/1WnMXnm
Feb 12-18
Winter Star Party
Southern Cross Astronomical Society
Chiefland Astronomy Village (5450 NW 52nd Court Chiefland, Florida 32626)
http://ift.tt/2jrDU9A
March 3
TriStar 2018
Guilford Technical Community College
Greensboro Astronomy Club and the
Cline Observatory
Jamestown, North Carolina
observatory_gtcc.edu/tristar/
April 11–14
Mid-South Star Gaze and Astronomy Conference
French Camp, Mississippi
http://ift.tt/1KlyoA0
April 14–21
The OzSky Star Safari
(a.k.a. Deepest South Texas Star Safari)
Coonabarabran, New South Wales, Australia
www.ozsky.org
April 21–22
Northeast Astronomy Forum
Suffern, New York
http://ift.tt/1HMGVYK
Here is Dan Lewelyn at Deerlick Astronomy Village near Atlanta, Georgia. Photo by Dave Woolsteen.
Texas Star Party, one of the biggest public astronomy events of each year, drawing about 500 deep-sky enthusiasts and their telescopes to the Davis Mountains of West Texas. Image used with permission, via Todd Hargis and Ron Ronhaar.
Bottom line: List of astronomy and night sky events for the public, for 2018, compiled in cooperation with the awesome Astronomical League. Join in, and have fun!
In late November and early December, 2017, get up before morning dawn – say, around one and one-half hours before sunrise – to see the planet Mars pairing up with the bright star Spica, brightest star in the constellation Virgo, on the sky’s dome. Look east, and you can’t miss the dazzling planet Jupiter near the horizon. Mars and Spica are those two colorful starlike objects shining above Jupiter in the eastern, predawn sky.
As darkness gives way to dawn in late November and early December 2017, look also for the brilliant planet Venus near the eastern horizon. Venus, Jupiter and Mars (and it so happens, Spica) travel in our sky along the ecliptic, which is the plane of Earth’s orbit around the sun. Most planets and moons in our solar system move in this plane. And so – when you see them in the sky – most planets lie along this line across the sky, which is marked in green on our chart above.
By the way, please understand that our chart above is very fanciful. That’s because Mars is so faint that it’ll probably disappear from view by the time Venus rises into your sky.
If you see only 1 planet before dawn now, it’ll be Jupiter. Dennis Chabot of Posne Night Sky Astrophotography caught this photo of Jupiter on Saturday morning, November 25, 2017.
Mars and Spica should be close enough together to fit within the same binocular field for another week or so, at least. The actual conjunction date is November 29, 2017, when Mars passes some 3O north of Spica on our sky’s dome. Three degrees in the sky is approximately the width of your thumb at an arm’s length.
Spica, the brighter of these two starlike points of light, radiates blue-white while Mars glowers with a reddish hue. If you have difficulty discerning the contrasting colors of these close-knit celestial gems with the eye alone, try viewing them through binoculars.
At present, Mars resides in front of Spica’s constellation, Virgo, while Jupiter shines in front of the constellation Libra. Relative to the backdrop stars of the zodiac, both Mars are Jupiter are going eastward day by day. Mars is going eastward through Virgo, toward Jupiter, and Jupiter is going eastward through Libra, away from Spica and Mars.
However, Mars travels much more quickly through the constellations of the zodiac than Jupiter does. In the morning sky on January 7, 2018, Mars will finally catch up with Jupiter in front of the constellation Libra. It’ll be a stunning conjunction, with Mars passing less than one-quarter degree (0.25o = half the moon’s diameter) south of Jupiter on the sky’s dome.
And it’ll be a great time to note the contrast in the brightness of Jupiter and Mars … so that you can watch Mars brighten to around Jupiter’s brightness as 2018 progresses!
In fact, 2018 will be be the best year in many years to see Mars.
Bottom line: Now the view toward the east before dawn has entirely changed. Bright Jupiter is the 1st object you’ll notice. Venus can only be seen very shortly before sunup. Mars and Spica are fainter, but close!
In late November and early December, 2017, get up before morning dawn – say, around one and one-half hours before sunrise – to see the planet Mars pairing up with the bright star Spica, brightest star in the constellation Virgo, on the sky’s dome. Look east, and you can’t miss the dazzling planet Jupiter near the horizon. Mars and Spica are those two colorful starlike objects shining above Jupiter in the eastern, predawn sky.
As darkness gives way to dawn in late November and early December 2017, look also for the brilliant planet Venus near the eastern horizon. Venus, Jupiter and Mars (and it so happens, Spica) travel in our sky along the ecliptic, which is the plane of Earth’s orbit around the sun. Most planets and moons in our solar system move in this plane. And so – when you see them in the sky – most planets lie along this line across the sky, which is marked in green on our chart above.
By the way, please understand that our chart above is very fanciful. That’s because Mars is so faint that it’ll probably disappear from view by the time Venus rises into your sky.
If you see only 1 planet before dawn now, it’ll be Jupiter. Dennis Chabot of Posne Night Sky Astrophotography caught this photo of Jupiter on Saturday morning, November 25, 2017.
Mars and Spica should be close enough together to fit within the same binocular field for another week or so, at least. The actual conjunction date is November 29, 2017, when Mars passes some 3O north of Spica on our sky’s dome. Three degrees in the sky is approximately the width of your thumb at an arm’s length.
Spica, the brighter of these two starlike points of light, radiates blue-white while Mars glowers with a reddish hue. If you have difficulty discerning the contrasting colors of these close-knit celestial gems with the eye alone, try viewing them through binoculars.
At present, Mars resides in front of Spica’s constellation, Virgo, while Jupiter shines in front of the constellation Libra. Relative to the backdrop stars of the zodiac, both Mars are Jupiter are going eastward day by day. Mars is going eastward through Virgo, toward Jupiter, and Jupiter is going eastward through Libra, away from Spica and Mars.
However, Mars travels much more quickly through the constellations of the zodiac than Jupiter does. In the morning sky on January 7, 2018, Mars will finally catch up with Jupiter in front of the constellation Libra. It’ll be a stunning conjunction, with Mars passing less than one-quarter degree (0.25o = half the moon’s diameter) south of Jupiter on the sky’s dome.
And it’ll be a great time to note the contrast in the brightness of Jupiter and Mars … so that you can watch Mars brighten to around Jupiter’s brightness as 2018 progresses!
In fact, 2018 will be be the best year in many years to see Mars.
Bottom line: Now the view toward the east before dawn has entirely changed. Bright Jupiter is the 1st object you’ll notice. Venus can only be seen very shortly before sunup. Mars and Spica are fainter, but close!
Image via IceBridge Digital Mapping System/NASA.
NASA’s Operation IceBridge, now in its ninth year, is an airborne mission flown annually over both polar regions to map the ice. A few flights during the 2017 campaign took scientists and instruments over Antarctica’s newly reshaped Larsen C ice shelf.
One of the big changes the scientists observed was the calving of an iceberg from the Larsen C ice shelf. Nathan Kurtz, IceBridge project scientist, said in a statement:
We observed the crack across the shelf during the campaign last year; it has since broken through and produced a huge iceberg.
The iceberg from Larsen C, named A-68A, was photographed during a flight on November 12, 2017. The photo above was acquired by the Digital Mapping System (DMS), which as essentially a downward-looking digital camera pointed out a window on the belly of the aircraft. This image shows part of the giant iceberg’s edge (the side closest to the shelf) and open water.
Scientists estimate that the edges of the shelf and iceberg tower about 100 feet (30 meters) above the surface of the sea. Some mélange – a mix of ice types – appears attached to the iceberg, and blocks of ice have fallen away, giving the berg’s edge giving it an angular appearance.
John Sonntag, IceBridge mission scientist, shot this photo from a window of the P-3 research plane. The flight aimed to get a better understanding the Larsen system as a whole, and scientists made gravity measurements to “see” the shape of the seafloor and bedrock below the ice. Read more in this blog post. Photo via NASA/John Sonntag.
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Donate to EarthSky: Your support means the world to us
Bottom line: Photos of giant iceberg A-68A, that calved from Antarctica’s Larsen C ice shelf.
Read more from NASA’s Earth Observatory
Image via IceBridge Digital Mapping System/NASA.
NASA’s Operation IceBridge, now in its ninth year, is an airborne mission flown annually over both polar regions to map the ice. A few flights during the 2017 campaign took scientists and instruments over Antarctica’s newly reshaped Larsen C ice shelf.
One of the big changes the scientists observed was the calving of an iceberg from the Larsen C ice shelf. Nathan Kurtz, IceBridge project scientist, said in a statement:
We observed the crack across the shelf during the campaign last year; it has since broken through and produced a huge iceberg.
The iceberg from Larsen C, named A-68A, was photographed during a flight on November 12, 2017. The photo above was acquired by the Digital Mapping System (DMS), which as essentially a downward-looking digital camera pointed out a window on the belly of the aircraft. This image shows part of the giant iceberg’s edge (the side closest to the shelf) and open water.
Scientists estimate that the edges of the shelf and iceberg tower about 100 feet (30 meters) above the surface of the sea. Some mélange – a mix of ice types – appears attached to the iceberg, and blocks of ice have fallen away, giving the berg’s edge giving it an angular appearance.
John Sonntag, IceBridge mission scientist, shot this photo from a window of the P-3 research plane. The flight aimed to get a better understanding the Larsen system as a whole, and scientists made gravity measurements to “see” the shape of the seafloor and bedrock below the ice. Read more in this blog post. Photo via NASA/John Sonntag.
Enjoying EarthSky so far? Sign up for our free daily newsletter today!
Donate to EarthSky: Your support means the world to us
Bottom line: Photos of giant iceberg A-68A, that calved from Antarctica’s Larsen C ice shelf.
Read more from NASA’s Earth Observatory
Tonight and tomorrow night – November 26 and 27, 2017 – the moon is sweeping near the 8th planet Neptune on the sky’s dome. It’s even harder than usual right now to find Neptune because of the moon’s glare. Still, if you want to know Neptune’s location on the sky’s dome – maybe in order to find it when the moon has moved away – look at tonight’s moon. It is pointing the way.
What will you see? Only the moon shining in all its splendor. You can gaze at it and imagine Neptune nearby.
The image below is a spacecraft image of Neptune. It’s from Voyager 2, the only spacecraft that has ever visited Neptune. The spacecraft’s closest approach to the planet occurred on August 25, 1989. Neptune is the eighth planet out from our sun and outermost of the major planets.
It’s the only major planet in our solar system that you absolutely can’t see with the unaided eye.
Photo of Neptune taken by Voyager 2 spacecraft in August 1989.
Like the moon, Neptune is close to the ecliptic, or path the planets follow in front of the constellations of the zodiac. We see them travel on or near this great circle on the celestial sphere because the major planets in our solar system, and Earth’s moon, orbit the sun on almost the same plane.
Although the moon and Neptune are close together on the sky’s dome tonight, they’re nowhere close in space. The moon resides just over one light-second from Earth, whereas Neptune looms way out there at over four light-hours away. In other words, Neptune is over 11,000 times farther away than the moon in tonight’s sky.
Once the moon leaves the evening sky, starting the second week of December, Aquarius will easy to spot in a dark country sky. Then, if you’re armed with a telescope or powerful binoculars and a good sky chart, you might be able to glimpse Neptune.
Neptune moves around the sun slowly in contrast to Earth. It takes 165 Earth-years to travel around the sun once, and thus it takes 165 years to travel completely around our sky. That means that Neptune has been hanging out more or less in the same location in our sky – in front of the constellation Aquarius, and near the star Lambda Aquarii – for a few years.
Sky chart of the constellation Aquarius, We label the star Lambda Aquarii, a 4th-magnitude star that is visible to the unaided eye in a dark sky.
For a stellar reference, learn how to star-hop to Lambda Aquarii, your guide star to Neptune. Neptune demands high-quality binoculars or a telescope, patience and a detailed star chart. Look for Neptune and the star Lambda Aquarii to take stage within the same binocular field.
Bottom line: On November 26, 2017, use your mind’s eye to envision the solar system’s most distant major planet – Neptune – near the moon.
Do you love stargazing? Order your EarthSky Planisphere today!
Tonight and tomorrow night – November 26 and 27, 2017 – the moon is sweeping near the 8th planet Neptune on the sky’s dome. It’s even harder than usual right now to find Neptune because of the moon’s glare. Still, if you want to know Neptune’s location on the sky’s dome – maybe in order to find it when the moon has moved away – look at tonight’s moon. It is pointing the way.
What will you see? Only the moon shining in all its splendor. You can gaze at it and imagine Neptune nearby.
The image below is a spacecraft image of Neptune. It’s from Voyager 2, the only spacecraft that has ever visited Neptune. The spacecraft’s closest approach to the planet occurred on August 25, 1989. Neptune is the eighth planet out from our sun and outermost of the major planets.
It’s the only major planet in our solar system that you absolutely can’t see with the unaided eye.
Photo of Neptune taken by Voyager 2 spacecraft in August 1989.
Like the moon, Neptune is close to the ecliptic, or path the planets follow in front of the constellations of the zodiac. We see them travel on or near this great circle on the celestial sphere because the major planets in our solar system, and Earth’s moon, orbit the sun on almost the same plane.
Although the moon and Neptune are close together on the sky’s dome tonight, they’re nowhere close in space. The moon resides just over one light-second from Earth, whereas Neptune looms way out there at over four light-hours away. In other words, Neptune is over 11,000 times farther away than the moon in tonight’s sky.
Once the moon leaves the evening sky, starting the second week of December, Aquarius will easy to spot in a dark country sky. Then, if you’re armed with a telescope or powerful binoculars and a good sky chart, you might be able to glimpse Neptune.
Neptune moves around the sun slowly in contrast to Earth. It takes 165 Earth-years to travel around the sun once, and thus it takes 165 years to travel completely around our sky. That means that Neptune has been hanging out more or less in the same location in our sky – in front of the constellation Aquarius, and near the star Lambda Aquarii – for a few years.
Sky chart of the constellation Aquarius, We label the star Lambda Aquarii, a 4th-magnitude star that is visible to the unaided eye in a dark sky.
For a stellar reference, learn how to star-hop to Lambda Aquarii, your guide star to Neptune. Neptune demands high-quality binoculars or a telescope, patience and a detailed star chart. Look for Neptune and the star Lambda Aquarii to take stage within the same binocular field.
Bottom line: On November 26, 2017, use your mind’s eye to envision the solar system’s most distant major planet – Neptune – near the moon.
Do you love stargazing? Order your EarthSky Planisphere today!
Should a healthy environment be a human right? These Norwegians think so
Greenpeace and the environmental group Youth and Nature are suing the Norwegian Government for granting Arctic oil drilling licenses.
Their argument is based on an article in the Norwegian constitution protecting the right to an environment that’s healthy and that long-term consideration be given to digging up natural resources.
Greenpeace Norway head Truls Gulowsen told Hack it all comes down to climate change and oil licenses.
"We had challenged the Norwegian state for handing out new licenses for drilling in the arctic in spite of the fact that they have signed the Paris Agreement," he said on his way to court.
"They acknowledge climate change is a problem, and they know that the world has already found more carbon, fossil carbon, than we can ever afford to burn."
He said Norway's constitution gives future generations the right to a healthy environment.
"[That] puts duties on the state to guarantee and safeguard those rights."
Brendan Sydes, lawyer and CEO of Environmental Justice Australia, says the strategy used by Greenpeace goes to a country’s legal foundation, instead of working with a country's environmental regulations.
Should a healthy environment be a human right? These Norwegians think so by Courtney Carthy, ABC News (Australia), Nov 23, 2017
Sun Nov 19, 2017
Mon Nov 20, 2017
Is Trump's Nasa Nominee Ready to Tackle Climate Change by Eric Niler, Wired, Nov 20, 2017
Tue Nov 21, 2017
Wed Nov 22, 2017
Thu Nov 23, 2017
Fri Nov 24, 2017
Sat Nov 25, 2017
Should a healthy environment be a human right? These Norwegians think so
Greenpeace and the environmental group Youth and Nature are suing the Norwegian Government for granting Arctic oil drilling licenses.
Their argument is based on an article in the Norwegian constitution protecting the right to an environment that’s healthy and that long-term consideration be given to digging up natural resources.
Greenpeace Norway head Truls Gulowsen told Hack it all comes down to climate change and oil licenses.
"We had challenged the Norwegian state for handing out new licenses for drilling in the arctic in spite of the fact that they have signed the Paris Agreement," he said on his way to court.
"They acknowledge climate change is a problem, and they know that the world has already found more carbon, fossil carbon, than we can ever afford to burn."
He said Norway's constitution gives future generations the right to a healthy environment.
"[That] puts duties on the state to guarantee and safeguard those rights."
Brendan Sydes, lawyer and CEO of Environmental Justice Australia, says the strategy used by Greenpeace goes to a country’s legal foundation, instead of working with a country's environmental regulations.
Should a healthy environment be a human right? These Norwegians think so by Courtney Carthy, ABC News (Australia), Nov 23, 2017
Sun Nov 19, 2017
Mon Nov 20, 2017
Is Trump's Nasa Nominee Ready to Tackle Climate Change by Eric Niler, Wired, Nov 20, 2017
Tue Nov 21, 2017
Wed Nov 22, 2017
Thu Nov 23, 2017
Fri Nov 24, 2017
Sat Nov 25, 2017
These are star trails, and one of the brightest trails here is Alpha Arietis, or Hamal. To learn which one, click here, then click on the image you find. This neat image is via Herb Raab on Flickr.
Hamal – also known as Alpha Arietis – shines as the brightest star in the constellation Aries the Ram. This star and two others – Sheratan and Mesarthim – make up the Head of the Ram. Aries is small. But the compact pattern of these three stars makes Aries relatively easy to find. As seen from mid-northern latitudes, Hamal lights up the eastern sky on autumn evenings, shines high in the southern sky on winter evenings, and sits in the west on early spring evenings. Hamal disappears from the night sky in April, then returns to the eastern sky before sunrise by late spring or early summer, to begin another cycle of visibility.
It’s fun to spot Hamal and its brother stars in the night sky. But this star also has a profound significance in the history of astronomy.
Most people see the constellation Aries as three stars in a compact grouping. The stars are Hamal, Sheratan, and Mesarthim.
If you could see the stars in daytime, you’d see the sun and Hamal in conjunction (lined up with one another, due north and south in right ascension) on or near April 24. What this means is that – when the sun appears due south at noon – Hamal is due south, too, though lost in the glare of the noonday sun.
April 24 – the date of Hamal’s conjunction with the sun – is a little more than one month after the March equinox, which always takes place around March 20. This is the Northern Hemisphere’s spring equinox, and it’s a time of renewal throughout the northern half of Earth. So of course this time of year had significance to our ancestors, who were much more aware than we are of their dependence on the land and sky.
What is the relationship of Hamal to the March equinox? If you could backtrack some 2,500 years, you’d find the annual conjunction of the sun and Hamal happening on the March equinox. In fact, if you could backtrack 2,200 years, we’d find the March equinox sun in conjunction with the star Sheratan. So you see that the location of the sun at the March equinox sun drifts in front of the stars. It moves westward in front of the backdrop constellations by about one degree (two sun diameters) every 72 years. This drifting is due to a well-known motion of Earth called precession, or sometimes the precession of the equinoxes.
The March equinox sun shone in front of the constellation Aries from about 2,000 to 100 BCE. At present, the sun shines in front of the constellation Pisces on the March equinox. Even so, many people pay homage to the Ram and still refer to the March equinox point as the First Point of Aries.
Bottom line: The star Hamal, also known as Alpha Arietis, is the brightest star in Aries the Ram. Thousands of years ago, the sun was in conjunction – or aligned north and south – with this star at the time of the March equinox. Nowadays, we see the sun in front of Pisces at the time of the March equinox. But people still refer to the sun’s location at the equinox as the First Point in Aries.
Sky chart of the constellation Aries the Ram
Nowadays the sun passes in front of the constellation Aries from about April 19 to May 13. Click here for a larger chart
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These are star trails, and one of the brightest trails here is Alpha Arietis, or Hamal. To learn which one, click here, then click on the image you find. This neat image is via Herb Raab on Flickr.
Hamal – also known as Alpha Arietis – shines as the brightest star in the constellation Aries the Ram. This star and two others – Sheratan and Mesarthim – make up the Head of the Ram. Aries is small. But the compact pattern of these three stars makes Aries relatively easy to find. As seen from mid-northern latitudes, Hamal lights up the eastern sky on autumn evenings, shines high in the southern sky on winter evenings, and sits in the west on early spring evenings. Hamal disappears from the night sky in April, then returns to the eastern sky before sunrise by late spring or early summer, to begin another cycle of visibility.
It’s fun to spot Hamal and its brother stars in the night sky. But this star also has a profound significance in the history of astronomy.
Most people see the constellation Aries as three stars in a compact grouping. The stars are Hamal, Sheratan, and Mesarthim.
If you could see the stars in daytime, you’d see the sun and Hamal in conjunction (lined up with one another, due north and south in right ascension) on or near April 24. What this means is that – when the sun appears due south at noon – Hamal is due south, too, though lost in the glare of the noonday sun.
April 24 – the date of Hamal’s conjunction with the sun – is a little more than one month after the March equinox, which always takes place around March 20. This is the Northern Hemisphere’s spring equinox, and it’s a time of renewal throughout the northern half of Earth. So of course this time of year had significance to our ancestors, who were much more aware than we are of their dependence on the land and sky.
What is the relationship of Hamal to the March equinox? If you could backtrack some 2,500 years, you’d find the annual conjunction of the sun and Hamal happening on the March equinox. In fact, if you could backtrack 2,200 years, we’d find the March equinox sun in conjunction with the star Sheratan. So you see that the location of the sun at the March equinox sun drifts in front of the stars. It moves westward in front of the backdrop constellations by about one degree (two sun diameters) every 72 years. This drifting is due to a well-known motion of Earth called precession, or sometimes the precession of the equinoxes.
The March equinox sun shone in front of the constellation Aries from about 2,000 to 100 BCE. At present, the sun shines in front of the constellation Pisces on the March equinox. Even so, many people pay homage to the Ram and still refer to the March equinox point as the First Point of Aries.
Bottom line: The star Hamal, also known as Alpha Arietis, is the brightest star in Aries the Ram. Thousands of years ago, the sun was in conjunction – or aligned north and south – with this star at the time of the March equinox. Nowadays, we see the sun in front of Pisces at the time of the March equinox. But people still refer to the sun’s location at the equinox as the First Point in Aries.
Sky chart of the constellation Aries the Ram
Nowadays the sun passes in front of the constellation Aries from about April 19 to May 13. Click here for a larger chart
Enjoying EarthSky? Sign up for our free daily newsletter today!
