Archive
08/15/11 – Ephemeris – Preview of next month’s harvest moon
Monday, August 15th. The sun rises at 6:44. It’ll be up for 14 hours and 3 minutes, setting at 8:48. The moon, 2 days past full, will rise at 9:16 this evening.
Last Saturday night under partly cloudy skies at the Port Oneida Fair Star Party we saw the full moon rise and it reminded me that the next full moon will be the Harvest Moon. The next few nights will preview the coming harvest moon effect. That is that the moon will rise at nearly the same time for several nights in a row. On average the moon will rise or set 50 minutes later each night. Due to the geometry of the situation the harvest moon for several nights will only rise later by down to 20 minutes a night. Back before electric lights the bright moonlight augmented twilight to increase the daily time available to harvest the crops. This slowdown in the moon’s rise times is affecting us now, though the moon is definitely waning.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
08/12/11 – Ephemeris – Star Party at the Port Oneida Fair
Friday, August 12th. The sun rises at 6:41. It’ll be up for 14 hours and 11 minutes, setting at 8:52. The moon, 1 day before full, will set at 6:37 tomorrow morning.
The Grand Traverse Astronomical Society will be part of the 10th Annual Port Oneida Rural Arts and Culture Fair, an event sponsored by the Sleeping Bear Dunes National Lakeshore. Tomorrow night the society will bring their telescopes to the Thoreson Farm on Thoreson Road of M22 North of Glen Arbor for a Star party beginning at 9:30 p.m. Thoreson Road is a loop off M22. On tap will be the full moon, and Saturn if skies permit early. Even though the full moon skies will be bright, there are plenty of wonders still visible in the telescopes. Early on yours truly will be talking about the state and advancements of astronomy during the heyday of the Port Oneida community in the late 19th and early 20th centuries.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
08/11/11 – Ephemeris – Prospects for this year’s Perseid Meteor Shower
Thursday, August 11th. The sun rises at 6:40. It’ll be up for 14 hours and 14 minutes, setting at 8:54. The moon, 2 days before full, will set at 5:31 tomorrow morning.
In the next two nights the Perseid meteor shower will be at a peak. The problem this year will be that the moon is full, or full enough that the skies will not be dark all night. Hope is not completely lost, because there will be a few really bright meteors, a few an hour, rather than the 50 or more an hour visible in dark skies. The paths of meteors appear longer in the evening where the radiant point of the meteors lies low in the north northeast, when the bits of rock skip through our atmosphere at a very low angle. These bits of rock were liberated by comet Swift Tuttle on a prior pass of the inner solar system. It orbits the sun in 130 years, and its path takes it very close to the orbit of the earth, so this time of year we pass through its debris.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Perseid Meteor Shower radiant after midnight
The radiant is actually circumpolar for northern Michigan. At 10:30 p.m. it’s just east or the north compass point and very low on the horizon.
08/10/11 – Ephemeris – The bright planets this week
Wednesday, August 10th. The sun rises at 6:38. It’ll be up for 14 hours and 17 minutes, setting at 8:55. The moon, 3 days before full, will set at 4:24 tomorrow morning.
It’s Wednesday and time again to take a look at the whereabouts of the bright planets. The ringed planet Saturn will be visible in the west southwest as it gets dark. It’s near the bright star Spica to its left. Spica has a blue tinge, while Saturn is yellowish. It will set at 11:09 p.m. Saturn is a wonderful sight is a telescope with its rings. We are now slowly seeing Saturn slip into evening twilight. We have very little time of good viewing of Saturn before its image deteriorates by being too low in the sky. Jupiter will rise at 11:54 p.m. in the east northeast and is seen against the stars of the constellation Aries now. Mars will rise at 3 a.m also in the east northeast and is now passing through the constellation Gemini the twins.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
08/09/11 – Ephemeris – The moon tonight – musings
Tuesday, August 9th. The sun rises at 6:37. It’ll be up for 14 hours and 19 minutes, setting at 8:57. The moon, 3 days past first quarter, will set at 3:19 tomorrow morning.
The moon tonight is in its gibbous phase, as it has been since first quarter last weekend. This Saturday it will be full. So now most of the moon’s face is in sunlight. Besides the dark, lava filled dry seas of the moon, which give us the dark spots that some of us imagine as the face of the man in the moon, we can spot many craters and other formations in a telescope. Even as the moon has been accumulating spacecraft, rocket parts, rovers and Hasselblad cameras for the last 50 years none can be seen from the earth. The Lunar Reconnaissance Orbiter is taking photographs of the moon in unprecedented detail. They’ve already located the Apollo landing sites, and discovered a lost Soviet lunar rover. Who knows what else they’ll find.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
08/08/11 – Ephemeris – The lunar seas and the possible second moon theory
Monday, August 8th. The sun rises at 6:36. It’ll be up for 14 hours and 22 minutes, setting at 8:58. The moon, 2 days past first quarter, will set at 2:17 tomorrow morning.
With the announcement last week that the earth may have had two moons, we’d kind of look at our surviving moon in a new light. Tonight the terminator, the line between light and dark on the moon, really the sunrise line crosses through the Sea of Clouds or Mare Imbrium. Telescope will reveal the crater Copernicus near the moon’s equator that will come into sunlight an hour from now as you listen to this. Two astronomers from the US and Switzerland propose that the collision of the earth that created the moon also created another moon. After a time this second, smaller moon crashed into our moon and created the dark seas on the side that faces the earth. The far side of the moon only has one small sea, the Sea of Moscow, discovered by the Russians in 1959 with their Lunik 3 spacecraft.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
08/05/11 – Ephemeris – Viewing night tommorrow at the Rogers Observatory
Friday, August 5th. The sun rises at 6:33. It’ll be up for 14 hours and 29 minutes, setting at 9:03. The moon, 1 day before first quarter, will set at 11:53 this evening.
Tomorrow night the Grand Traverse Astronomical Society and the NMC Astronomical Association will host a public viewing night at Northwestern Michigan College’s Rogers Observatory starting at 9 p.m. featuring, if it’s clear the planet Saturn early and the moon. Some of the brighter wonders of the summer sky can be seen as it gets darker, though the moon will interfere somewhat. There are sparkling binary stars and star clusters including the Wild Duck Cluster and at least one bright nebula, the Ring Nebula, the expanding envelope of a dying star. The observatory is located south of Traverse City, on Birmley Road between Garfield and Keystone roads.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
08/04/11 – Ephemeris – The moon’s Sea of Tranquility
Thursday, August 4th. The sun rises at 6:32. It’ll be up for 14 hours and 32 minutes, setting at 9:04. The moon, 2 days before first quarter, will set at 11:18 this evening.
In binoculars the center of the of the moon and clipped by the terminator, the moon’s sunrise line is the landing area of the first humans on the moon The Sea of Tranquility. It is a circular basin 424 miles in diameter with a flat floor. It was formed in the first 600 million years of the moon’s existence after the worst of the cratering was over. The moon appears to have been formed by a glancing collision of a Mars sized body with the earth during the formation of the solar system. The debris circled the earth and condensed to form the moon. It is from studying the rocks brought back by the Apollo astronauts that this origin scenario was first put forth. The origin of a huge satellite for the earth had baffled astronomers before this discovery..
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Sea of Tranquility emerging into sunlight - Virtual Moon Atlas
08/03/11 – Ephemeris – The bright planets for this week
Wednesday, August 3rd. The sun rises at 6:30. It’ll be up for 14 hours and 34 minutes, setting at 9:05. The moon, 3 days before first quarter, will set at 10:47 this evening.
It’s Wednesday and time again to take a look at the whereabouts of the bright planets. The ringed planet Saturn will be visible in the west southwest as it gets dark. It’s near the bright star Spica to its left. Spica has a blue tinge, while Saturn is yellowish. It will set at 11:35 p.m. Saturn is a wonderful sight is a telescope with its rings. We are now slowly seeing Saturn slip into evening twilight. We have a couple of more weeks of good viewing of Saturn before its image deteriorates by being too low in the sky. Jupiter will rise at 12:24 a.m. in the east northeast and is seen against the stars of the constellation Aries now. Mars will rise at 3:08 also in the east northeast and is now entering the constellation Gemini the twins at Castor’s foot.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
08/02/11 – Ephemeris – The constellation of Aquila the eagle
Note: this is a repeat due to Internet problems for the July 25th program with one alteration.
Tuesday, August 2nd. The sun rises at 6:29. It’ll be up for 14 hours and 37 minutes, setting at 9:06. The moon, 3 days past new, will set at 10:19 this evening.
The southernmost star in the Summer Triangle of three bright stars is Altair, high in the south southeast in the evening. It’s in the head of the constellation Aquila the Eagle. Altair is flanked by two stars, the eagle’s shoulders, and farther out are the wing tips. Other stars to the lower right are in its body and a last three in its tail. Near the tail binoculars will show a fuzzy spot that telescopes show as a compact star cluster, sometimes called the Wild Duck Cluster for its nearly triangular shape. Aquila is flying northeastward through the Milky Way, where it is split in two by a cloud of gas and dust, the edges of which can be seen in binoculars. According to mythology the Trojan boy Ganymede was taken to heaven at the behest of the god Zeus by this eagle.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Finder chart for M11, the Wild Duck Cluster, Created using Stellarium.
