View larger. | Geminid fireball caught by Eliot Herman in the Tucson, Arizona foothills, during the 2015 shower.
The Geminid meteor shower – a highlight of the meteor year – starts around the second week in December. Peak in 2017 is expected on the nights of December 12 and 13. The nights before and after might be good as well. Geminid meteors tend to be few and far between at early evening, but intensify in number as evening deepens into late night. This shower favors Earth’s Northern Hemisphere, but it’s visible from the Southern Hemisphere, too. Follow the links below to learn more about the Geminid meteor shower in 2017.
How to watch the Geminid meteors in 2017
An earthgrazer Geminid meteor possible at early evening
Why are these meteors called the Geminids?
What causes the Geminid meteor shower?
The waning crescent moon will slide past the morning planets, on the peak mornings on the 2017 Geminid shower. Notice Jupiter in the same binocular field of view with the star Zubenelgenubi in the constellation Libra the Scales. Look closely, and you’ll see that Zubenelgenubi is a double star – two stars in one!
The Geminids radiate from near the bright star Castor in the constellation Gemini, in the east on December evenings. Learn more about the Geminids’ radiant point.
How to watch the Geminid meteors in 2017. The Geminids are a particularly reliable and prolific shower, one of the finest of the year. In 2017, the light from a slender waning crescent moon won’t be much to worry about. Try watch the usually reliable and prolific Geminid meteor shower from mid-evening December 12 or 13 until dawn December 13 or 14.
These meteors tend to be plentiful, rivaling the August Perseids. They are often bold, white and bright. On a dark night, you can often catch 50 or more meteors per hour.
And here’s a plus! You can indeed watch this shower in the evening (late evening is best). But the greatest number of meteors will still fall in the wee hours after midnight, centered around 2 a.m. local time (the time on your clock no matter where you are on Earth), when the radiant point is highest in the sky. As a general rule, the higher the constellation Gemini climbs into your sky, the more Geminid meteors you’re likely to see.
You need no special equipment – just a dark, open sky and maybe a sleeping bag to keep warm. Plan to sprawl back in a hammock, lawn chair, pile of hay or blanket on the ground. Lie down in comfort, and look upward.
By the way, some people mistakenly think that, since meteor showers have radiant points, you should look in the direction of the shower’s radiant point to see the most meteors. Not so! The meteors will appear in all parts of the sky. It’s even possible to have your back to the constellation Gemini and see a Geminid meteor fly by. However, if you trace the path of a Geminid meteor backwards, it appears to originate from the direction of the constellation Gemini.
When you’re meteor-watching, it’s fun to bring along a buddy. Then two of you can watch in different directions. When someone sees one, they can call out “meteor!” This technique will let you see more meteors than one person watching alone will see.
Be sure to give yourself at least an hour of observing time. It takes about 20 minutes for your eyes to adapt to the dark.
Be aware that meteors often come in spurts, interspersed with lulls.
Painting of 1860 earthgrazer fireball by Frederic Edwin Church. Image credit: Wikimedia Commons
An earthgrazer meteor possible at early evening. You won’t see as many Geminid meteors when the constellation Gemini sits close to the eastern horizon during the evening hours. As night passes, the Geminid’s radiant will climb upward, so that the meteors will be raining down from a point that’s higher in the sky.
Even so, the evening hours are the best time to try to catch an earthgrazer meteor.
Earthgrazers are rarely seen but prove to be especially memorable, if you should be lucky enough to catch one. An earthgrazer is a slow-moving, long-lasting meteor that travels horizontally across the sky.
Meteor flying straight from Gemini’s two brightest stars, Castor and Pollux, during the 2012 Geminid meteor shower. Photo by EarthSky Facebook friend Mike O’Neal in Oklahoma.
Why are these meteors called the Geminids? If you trace the paths of the Geminid meteors backward, they all seem to radiate from the constellation Gemini, hence the reason for the meteor shower’s name.
In fact, the radiant point of this meteor shower nearly coincides with the bright star Castor. However, the radiant point and the star Castor just happen to be a chance alignment, as Castor lies about 52 light-years away while these meteors burn up in the upper atmosphere, some 60 miles (100 km) above Earth’s surface.
You don’t need to find the constellation Gemini to watch the Geminid meteor shower. These medium-speed meteors streak the nighttime in many different directions and in front of numerous age-old constellations. It’s even possible to see a Geminid meteor when looking directly away from the shower’s radiant point. However, if you trace the path of any Geminid meteor backward, it’ll lead you back to the constellation Gemini the Twins.
Orbit of Asteroid 3200 Phaethon, parent of the Geminid meteor shower
Orbital path of 3200 Phaethon, via skyandtelescope.com
What causes the Geminid meteor shower? Every year, in December, our planet Earth crosses the orbital path of asteroid 3200 Phaethon, a mysterious body that is sometimes referred to as a rock comet.
In periods of 1.43 years, this small 5-kilometer (3-mile) wide asteroid-type object swings extremely close to the sun (to within one-third of Mercury’s distance), at which juncture intense thermal fracturing causes this rocky body to crack and crumble, and to shed rubble into its orbital stream. Annually, at this time of year, the debris from 3200 Phaethon crashes into Earth’s upper atmosphere at some 130,000 kilometers (80,000 miles) per hour, to vaporize as colorful Geminid meteors.
View larger. | Geminid meteor as captured by Henry Shaw of SummersMagic Photography. Click here to learn from Henry Shaw how to take photos of meteors.
Bottom line: Geminid shower ahead! It’s typically best around 2 a.m. when the radiant point – in the constellation Gemini – is highest in the sky. Best nights to watch in 2017 are likely December 12 and 13. But try the nights before and after, too!
from EarthSky http://ift.tt/2h7t8D6
View larger. | Geminid fireball caught by Eliot Herman in the Tucson, Arizona foothills, during the 2015 shower.
The Geminid meteor shower – a highlight of the meteor year – starts around the second week in December. Peak in 2017 is expected on the nights of December 12 and 13. The nights before and after might be good as well. Geminid meteors tend to be few and far between at early evening, but intensify in number as evening deepens into late night. This shower favors Earth’s Northern Hemisphere, but it’s visible from the Southern Hemisphere, too. Follow the links below to learn more about the Geminid meteor shower in 2017.
How to watch the Geminid meteors in 2017
An earthgrazer Geminid meteor possible at early evening
Why are these meteors called the Geminids?
What causes the Geminid meteor shower?
The waning crescent moon will slide past the morning planets, on the peak mornings on the 2017 Geminid shower. Notice Jupiter in the same binocular field of view with the star Zubenelgenubi in the constellation Libra the Scales. Look closely, and you’ll see that Zubenelgenubi is a double star – two stars in one!
The Geminids radiate from near the bright star Castor in the constellation Gemini, in the east on December evenings. Learn more about the Geminids’ radiant point.
How to watch the Geminid meteors in 2017. The Geminids are a particularly reliable and prolific shower, one of the finest of the year. In 2017, the light from a slender waning crescent moon won’t be much to worry about. Try watch the usually reliable and prolific Geminid meteor shower from mid-evening December 12 or 13 until dawn December 13 or 14.
These meteors tend to be plentiful, rivaling the August Perseids. They are often bold, white and bright. On a dark night, you can often catch 50 or more meteors per hour.
And here’s a plus! You can indeed watch this shower in the evening (late evening is best). But the greatest number of meteors will still fall in the wee hours after midnight, centered around 2 a.m. local time (the time on your clock no matter where you are on Earth), when the radiant point is highest in the sky. As a general rule, the higher the constellation Gemini climbs into your sky, the more Geminid meteors you’re likely to see.
You need no special equipment – just a dark, open sky and maybe a sleeping bag to keep warm. Plan to sprawl back in a hammock, lawn chair, pile of hay or blanket on the ground. Lie down in comfort, and look upward.
By the way, some people mistakenly think that, since meteor showers have radiant points, you should look in the direction of the shower’s radiant point to see the most meteors. Not so! The meteors will appear in all parts of the sky. It’s even possible to have your back to the constellation Gemini and see a Geminid meteor fly by. However, if you trace the path of a Geminid meteor backwards, it appears to originate from the direction of the constellation Gemini.
When you’re meteor-watching, it’s fun to bring along a buddy. Then two of you can watch in different directions. When someone sees one, they can call out “meteor!” This technique will let you see more meteors than one person watching alone will see.
Be sure to give yourself at least an hour of observing time. It takes about 20 minutes for your eyes to adapt to the dark.
Be aware that meteors often come in spurts, interspersed with lulls.
Painting of 1860 earthgrazer fireball by Frederic Edwin Church. Image credit: Wikimedia Commons
An earthgrazer meteor possible at early evening. You won’t see as many Geminid meteors when the constellation Gemini sits close to the eastern horizon during the evening hours. As night passes, the Geminid’s radiant will climb upward, so that the meteors will be raining down from a point that’s higher in the sky.
Even so, the evening hours are the best time to try to catch an earthgrazer meteor.
Earthgrazers are rarely seen but prove to be especially memorable, if you should be lucky enough to catch one. An earthgrazer is a slow-moving, long-lasting meteor that travels horizontally across the sky.
Meteor flying straight from Gemini’s two brightest stars, Castor and Pollux, during the 2012 Geminid meteor shower. Photo by EarthSky Facebook friend Mike O’Neal in Oklahoma.
Why are these meteors called the Geminids? If you trace the paths of the Geminid meteors backward, they all seem to radiate from the constellation Gemini, hence the reason for the meteor shower’s name.
In fact, the radiant point of this meteor shower nearly coincides with the bright star Castor. However, the radiant point and the star Castor just happen to be a chance alignment, as Castor lies about 52 light-years away while these meteors burn up in the upper atmosphere, some 60 miles (100 km) above Earth’s surface.
You don’t need to find the constellation Gemini to watch the Geminid meteor shower. These medium-speed meteors streak the nighttime in many different directions and in front of numerous age-old constellations. It’s even possible to see a Geminid meteor when looking directly away from the shower’s radiant point. However, if you trace the path of any Geminid meteor backward, it’ll lead you back to the constellation Gemini the Twins.
Orbit of Asteroid 3200 Phaethon, parent of the Geminid meteor shower
Orbital path of 3200 Phaethon, via skyandtelescope.com
What causes the Geminid meteor shower? Every year, in December, our planet Earth crosses the orbital path of asteroid 3200 Phaethon, a mysterious body that is sometimes referred to as a rock comet.
In periods of 1.43 years, this small 5-kilometer (3-mile) wide asteroid-type object swings extremely close to the sun (to within one-third of Mercury’s distance), at which juncture intense thermal fracturing causes this rocky body to crack and crumble, and to shed rubble into its orbital stream. Annually, at this time of year, the debris from 3200 Phaethon crashes into Earth’s upper atmosphere at some 130,000 kilometers (80,000 miles) per hour, to vaporize as colorful Geminid meteors.
View larger. | Geminid meteor as captured by Henry Shaw of SummersMagic Photography. Click here to learn from Henry Shaw how to take photos of meteors.
Bottom line: Geminid shower ahead! It’s typically best around 2 a.m. when the radiant point – in the constellation Gemini – is highest in the sky. Best nights to watch in 2017 are likely December 12 and 13. But try the nights before and after, too!
from EarthSky http://ift.tt/2h7t8D6
Aucun commentaire:
Enregistrer un commentaire