The Geminids-2017

   A few hours after sunset local time, on Wednesday December 13th, look toward the west for ‘shooting stars’, or meteors coming from the area around the constellation the Gemini Twins. These are the annual Geminid Meteor Shower – one of the best meteor showers each year, and at times rivaling the August Perseid Meteor Shower. The calculated peak time for the meteors is December 14th at 7 UT (2 am CST), but this does not mean that is the only time to view them. The Geminid Meteor Shower is named for the constellation that the meteors radiate outward from. This is the same for all meteor showers, and the ‘spot’ in the sky is known as the radiant. The Geminid radiant is just above the ‘twin’ star Castor, and under ideal viewing conditions an average of about 70 meteors per hour could possibly be seen. This year without the interference of moonlight will increase the chances of seeing the meteors.
   Meteor showers result from the Earth’s orbital path intersecting areas of comet debris. Comets, as they orbit the Sun, leave behind pieces of their icy, dirty, selves. If these debris clouds happen to be along the Earth’s orbital path then the Earth will regularly pass through the comet debris cloud. As this happens the small comet pieces hit our outer atmosphere and vaporize from the friction generated heat. We then see these as the shooting stars that make up meteor showers.
   There are, however, two exceptions to this. The January Quadrantid Meteors and the Geminids each come from their own respective asteroid rather than a comet. The source for the Geminids is Asteroid 3200 Phaethon

   
   
   
   

Caution: Objects viewed with an optical aid are further than they appear.
Click here to go to the Qué tal in the Current Skies web site for more observing information for this month

Orinids Meteor Shower 2017

   The Orionid Meteor shower reaches its peak on the morning of Saturday October 21st. Best viewing is looking toward the east to south part of the sky after midnight and before sunrise. Look for the stars of Orion – most find Orion from the 3 bright stars forming his belt. Look to the left from the belt stars for the bright reddish-orange star Betelgeuse (often pronounced ‘beetle juice’) that represents Orion’s right shoulder. A little further to the left from Betelgeuse is the radiant, the area where the meteors or shooting stars will seem to be radiating outward from.
   All annular meteor showers, like Orionids, and the more well-known August Perseids, are named for the constellation the radiant is located within. Meteor showers are the result of several factors including the reaction between the comet’s dirty, icy surface with the Sun’s radiant energy and the orbital path the Earth and comets follow around the Sun. All comets leave behind clumps or clouds of comet debris, their surface material, as they come closer to the Sun’s heat energy. Some of this comet debris is left along the Earth’s orbital path such that the Earth regularly passes through these debris clouds. As the Earth passes through the debris the small bits of rock enter the Earth’s atmosphere and as they heat from friction and melt they glow briefly appearing as streaks of light. Some meteors leave a bright glowing trail, called a train, for a few moments. The Orionids average around 20 meteors per hour, however this year estimates are that that number may go up to as many as 60 per hour.
   How the number per hour can increase is based on the debris cloud and where the Earth passes through it. The debris is cloud-like in its shape and there are parts of the ‘cloud’ where the particles are more numerous – the thicker parts of the debris cloud. Meteor showers, like the Earth’s orbit are pretty well known so part of the equation for determining the number per hour is based on knowing what part of the debris cloud the Earth will pass through. This year we apparently pass through a thicker part of the debris cloud.
   Hang on to your hat!

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.

2017 Perseid Meteor Shower – Not A Good Year

   In reality this year’s annual Perseid Meteor shower will be affected by the Moon. The waning gibbous Moon will rise at about the same time as the constellation Perseus – the location for the meteors. With the bright reflected light from the Moon it will be nearly impossible to see any meteors.
   Also keep in mind that the numbers quoted for meteors per hour, the ‘ZHR’ or Zenith Hourly Rate, is an average not a guarantee that you will see that many. On a good peak night in some years I have seen 30 or 40 bright meteors per hour from dark skies. The best time is the few hours before sunrise as the Earth rotates your location into the direction the Earth is moving and sort of puts you face-on into the meteors.
(graphic source from Facebook with this URL: http://sci-techuniverse.com/) — link takes you to a non-existent web site, or to a Go-Daddy advertisement
Update: I did a search for the web site and found that the correct address is http://www.sci-techuniverse.com/, and after searching the web site I could not find this graphic. There is, however a write-up from last year about the Perseids.

   The peak time for the Perseids is August 12th and 13th but more specifically during the predawn hours of the 13th as the constellation Perseus is rising.
   
   
   
   
   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.

2017 Quadrantid Meteor Shower

   The annual Quadrantid Meteor Shower reaches its peak Tuesday morning January 3rd officially at 15 UT (10 am CST). The Quadrantids are one of the best meteor showers of the year but does not get much attention possibly because it’s winter in the northern hemisphere, and this area of the sky is not easily seen from south of the equator.
   The ZHR (average hourly rate) for this meteor shower ranges from 60 to several hundred. Best time for viewing is before sunrise as your part of the Earth is rotating toward the east sort of putting you headfirst into the meteor shower. To find the radiant for this meteor shower look for the stars of the Big Dipper and then look below the end stars in the handle.

Boötes the Herdsman

Boötes the Herdsman

   The radiant is the area from where the meteors seem to radiate outward from. Meteor showers owe their name to the constellation region the radiant is located within, and as this graphic shows the radiant is within the boundary of the constellation Boötes the Herdsman. So why the name Quadrantids?
   On some of the older star charts there is a now ‘extinct’ constellation called Quadrans Muralis, the Mural. This was a constellation located between Boötes and Draco the Dragon that was created in 1795 by French Astronomer Jérôme Lalande. It is a picture, or mural, of a Quadrant that had been used to map the stars. The Quadrantids Meteor Shower was named for the no longer used constellation.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.

My Leonids — Not!

   Despite going to bed last night with a partially cloudy sky I was up at 3 am CST this morning setting up my camera for some timelapse sequences of the constellation Leo the Lion as it rose. I was hoping to be able to capture at least one Leonid by taking a picture every 45 seconds until the camera batteries ran out of power.
   The sky was clear enough when I started the picture taking sequence and Leo was well placed to the left of the large Oak tree in my back yard giving me enough space to capture at least a couple of hours of pictures. So with a camera set to 3-second exposure time, ISO at 800, and the aperture at f5.6 I wound up with almost 60 useable pictures. At those settings despite the clouds most of the stars of the backward question mark shape for Leo are apparent.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.

2016 Leonid Meteor Shower

   During the early winter months of A.D. 902, Chinese astronomers recorded what were probably the first written accounts of a meteor shower. This event was described as a time when the stars fell like rain.Click on graphic to see it full size. Centuries later, in November 1799, the stars again fell like rain during a spectacular display witnessed across the colonies by North American astronomers. The shower activity was also recorded by the famous German scientist and geographer Alexander von Humboldt while he was on an expedition in Venezuela. During one intense period, witnesses described seeing as many shooting stars as actual stars. Approximately 33 years later (November 12-13, 1833), the skies over eastern North America were streaked with so many meteors that during a nine-hour period, observers calculated the Zenith Hourly Rate (ZHR) to be a few thousand, totalling to about 240,000 meteors.

   Following the 1833 meteor storm, interest in and study of meteors increased tremendously. By studying records, astronomers noted that meteors originate from a specific area of the sky within a certain constellation; hence the Leonids, Perseids, and so on. Observers also noted that as the night wore on and Leo “moved” westward, the shower’s point of origin stayed with the constellation. Thirty years later, after much study, Yale astronomer Hubert Newton pieced together a history of the Leonid meteor storms.

   The Leonid meteor storms (periods during a meteor shower of intense meteor activity) have been recorded approximately every 33 years dating as far back as the A.D. 902 shower observed by Chinese astronomers. Hubert Newton and other renowned astronomers predicted that another meteor storm would occur during November of 1866 or 1867, 33 years after the recorded meteor activity in 1833. Coincidentally, in 1865-66, two astronomers working independently, Ernest Tempel and Horace Tuttle, discovered a faint comet, the source of Leonid activity, which was named Comet 1866I (now referred to as Comet 55P{Tempel-Tuttle). Comet Tempel-Tuttle’s orbital period around the Sun was determined to be about the same as that of the Leonids, 33 years.

leonid-meteor-storm   The Leonid shower’s spectacular peak nights during November of 1866 and 1867 validated the two astronomers’ prediction. (Different portions of the Earth may encounter Comet Tempel-Tuttle’s meteor trail in two consecutive years because of the Earth’s changing position.) In 1866, sky observers in Europe noted that the shower’s intensity reached an average of 5,000 meteors per hour; in 1867, observers in North America counted an average of 1,000 meteors per hour. Because Tempel and Tuttle had so accurately predicted the source of the 1866/1867 Leonid meteor storm, the storm of 1899 was much anticipated and promoted by the astronomical community. Unfortunately, the Leonids did not display spectacularly that year. As a result, public interest in the storm waned tremendously. Ironically, the following year, 1900, brought storm displays with peak ZHRs of 1,000. During November 1901, the Leonids averaged about 2,000 meteors per hour.

   The Leonids’ return in the 1930s was also disappointing. Astronomers were concerned because the source comet had not been sighted since its 1866 passage. This suggested that perhaps the comet had broken apart and that the comet debris cloud would no longer be refreshed providing the source for the meteors. However, peak night averages during the 1930s were still impressive with hourly averages in the hundreds.

comet-temple-tuttle   During the early 1960s, the Leonid meteor showers started showing an increase in the hourly rate, similar to the intensity of the showers during the 1800s. In 1965 Comet Tempel-Tuttle was rediscovered. That year the shower’s intensity climbed to over 100 meteors per hour. One year later on November 17, 1966, the most intense meteor storm recorded in history occurred over the Midwestern United States-its average intensity was several thousand per hour, and at one point the storm rates were estimated at more than 100,000 meteors during a 20-minute period.

   So here it is 2016, and we are about mid-way through the 33-year period for the Meteor Storm. So no storm this year or for the next several years. Expect to see only a few meteors streaking outward from the radiant within the backward questions mark shaped asterism of Leo. Unfortunately the waning gibbous Moon will be brightening the sky and will dim out all but the brightest meteors. And remember that all meteor showers have a span of time before and after the peak when meteors will be visible. This year the activity for the Leonids is for about 2-3 weeks centered on the peak time calculated for November 17th at 11 UT (5 am CST). The radiant is near the hook part of the ‘backward question mark’ shape, near the 3rd magnitude star Aldhafera.
   Best viewing for a meteor shower is during the hours before sunrise as the part of the Earth you are on is turning into the direction that the Earth is moving as it revolves around the Sun. In effect you are moving ‘head first’ into the cloud of cometary debris. In the Midwest United States where I live Leo rises after midnight so the timing for viewing the Leonids around 94o west longitude is pretty good, unless like this year when the Moon is high in the sky.

cleardarkskieschart   Use this web site to see a forecast for how clear the skies will be for your location.
   Click here to see the skies for Lee’s Summit Missouri.
   
   
   

Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Perseid Hydro-Meteor Shower

   I was in Tucson Arizona this past week and was hoping, while there, to be able to take advantage of the darker skies for some night photography including the Perseid Meteor Shower. However this time of year is the monsoon season for Arizona so the nights for the meteor shower were a mixture of clouds, fog, and drizzle. A hydro-meteor shower! So my photography attempts were limited to pictures of a rain and lightning storm over the Catalina Mountains from my brother’s house.
   The camera was set to take an exposure every second and out of more than 500 pictures I was able to get a few pictures of lightning.

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Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to go to bobs-spaces.