The Moon, Jupiter, and Spica – Together Again


   Wednesday February 15th the 18-day old waning gibbous Moon will be within a few degrees from the planet Jupiter and the blue-white star Spica in Virgo the Harvest Maiden as they rise in the east a few hours before sunrise local time.
   All three will fit within the field of view of a pair of 7×50 binoculars as this graphic shows.

   
   
   
   
   
   
   
   
   
   
   
   

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.

January Moon at Ascending Node

15jan-ascending-node   Sunday January 15th the waning gibbous Moon will be crossing the plane of the ecliptic moving north relative to the ecliptic. This is known as the ascending node, one of two intersections the Moon’s orbital path has with the ecliptic. The ecliptic is actually the Earth’s orbit and the Moon’s orbit is inclined about 6o from the ecliptic. So there are two node intersections, the ascending and descending nodes.

   On January 15th the 16-day old waning gibbous Moon will come within about 1o from the star Regulus in Leo the Lion.

   Does our Moon actually go around the Earth as many graphics show? From our perspective on the Earth the Moon appears to circle around the Earth. However, in reality, the Moon orbits the Sun together with the Earth*

*Click here to read my 2006 Scope on the Sky column “The Real Shape of the Moon’s Orbit”. (PDF)

Read this very informative article about the Earth-Moon system and their orbital motions, written by Joe Hanson. “Do We Orbit the Moon?”

   
   
   

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.

December Moon at Ascending Node

19dec-ascending-node   Monday December 19th the waning gibbous Moon will be crossing the plane of the ecliptic moving north relative to the ecliptic. This is known as the ascending node, one of two intersections the Moon’s orbital path has with the ecliptic. The ecliptic is actually the Earth’s orbit and the Moon’s orbit is inclined about 6o from the ecliptic. So there are two node intersections, the ascending and descending nodes.

   On the morning of the 19ththe 20-day old waning gibbous Moon will be over the south-southwest horizon and will not set until close to 12 pm local time, after having risen during mid-evening local time the night before. The Moon is below Leo the Lion and above one of the longest, if not the longest, constellation. This is Hydra the many headed snake.

   Does our Moon actually go around the Earth as many graphics show? From our perspective on the Earth the Moon appears to circle around the Earth. However, in reality, the Moon orbits the Sun together with the Earth*

*Click here to read my 2006 Scope on the Sky column “The Real Shape of the Moon’s Orbit”. (PDF)

Read this very informative article about the Earth-Moon system and their orbital motions, written by Joe Hanson. “Do We Orbit the Moon?”

   
   
   

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.

Moon Passes Regulus

17-18dec
   The waning gibbous Moon rises near the front feet of the constellation Leo the Lion and over the next couple of days the Moon approaches and then passes by Leo’s alpha star Regulus. If you are at the right location then at 18 UT on the 18th the Moon will be slightly less than 1o from Regulus.
   The animated graphic is set for 10 pm CST on December 18th and 19th.

   
   
   

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.

Pollux Kicks it Back!


   Over the next couple of nights the 15 to 16 day old waning gibbous Moon will move past Pollux and Castor, the twin stars of Gemini, and Procyon the alpha star in Canis Minor, the Little Dog. With a little imagination or the animated graphic it’s not hard to picture Pollux kicking the Moon. Ok a lot of imagination, or the animated graphic!
Animated graphic shows the sky for December 15th and 16th a couple of hours after sunset.

   
   
   

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.

Bulls Eye? Bull’s Nose!

   Tuesday morning November 15th the just past full Moon, the waning gibbous Moon, will appear to be poking Taurus the Bull on the Nose. Ignore the illustration and this will be an interesting binocular viewing opportunity as the Moon will be within a few degrees from the reddish star Aldebaran in the V-shaped face of the Bull.
   Depending on your viewing location you may see the Moon come within 0.45o from Aldebaran. The closest approach will be at 17 UT, (11 am CST).

   
   
   

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.