This week, start looking at the Ursid meteors, which reach their peak each year around the December solstice. In 2017, the peak will probably arrive on the solstice night, the night of December 21 (morning of December 22). Up to 100 meteors per hour have been seen, but only in short bursts. Usually, if you see the shower at its peak, you can expect to see 5 to 10 meteors per hour in a dark sky. The moon will be in a phase of increasing crescendo and absent from the sky during the best hours for observation, after midnight. This rain favors the northern latitudes in the northern hemisphere. And, even in the northernmost latitudes, it is generally a discrete production, not as exciting as the Geminid meteor shower of last week. Robert Lunsford at the American Meteor Society wrote about this year's Ursid rain:
Rates will be low at the beginning of the week, but will peak on Friday, December 22 [before dawn] when hourly rates reach 5- 10 per hour. At 33 km / sec. the Ursids would produce mostly medium-velocity meteors.
Ho hum? I waited. This is the good thing about this meteor shower. Some meteor showers, such as the Perseids in August, have been observed every year at the same time for many centuries. The shower Ursid is new. It was first observed in the late twentieth century, when an observer from heaven observed that some meteors seen at this time of year were not random in their direction of movement through the dome of our sky, but radiated near the star Kochab in the Little Dipper asterism bowl.
In addition, although the Ursid meteor shower has been observed for a single century, and although the rates are typically 5-10 meteors per hour, the Ursid have gained popularity in recent years due to their possible outbursts. In 1945 and 1986 there were bursts of around 100 meteors per hour. An unexpected increase of 30 per hour occurred in 1973.
So, once again, meteor observation is like fishing! You never know what you're going to get, but you're expected to catch a big one!
All meteors in annual showers have radiant points in the dome of our sky, and the showers take their names from the constellations in which the radiant points are located. The asterism of Little Dipper is in the constellation Ursa Minor the Bear Minor. Therefore, meteor shower Ursid.
Ursa Minor is the constellation that contains the polar star or polar star, called Polaris. Just from that, you know it's a constellation from the far north. For this reason, the Ursids are not easily visible to observers in the Southern Hemisphere; its radiant point is too far north.
If you want to see the Ursidas in 2017, look for a place in the country where you can camp. Dress for the cold! And plan to spend several hours reclining under a dark sky, sometime during the night of December 21 (morning of December 22).
In latitudes far to the north, for example, latitudes such as the north of the United States and Europe, the radiant shower is out all night. Should you try to observe the afternoon of December 21 or the night of December 22? It's up to you. Just know that the radiant point of the Ursid shower rises up all night, and reaches its highest point during the night just before dawn.
Incidentally, the meteors in annual rains almost all come from comets (the Geminids are a rare exception). Starting around the 1970s, astronomers found evidence that Ursids move in the same orbit as Comet 8P / Tuttle, which is now believed to be the source of meteors.
In short: we anticipate that the Ursid meteor shower will reach its peak in 2017 on the morning of December 22. Expect to see 5-10 meteors per hour in a dark sky. 100 meteor bursts per hour are also possible.
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EarthSky Meteor Shower Guide