Archive
03/14/11 – Ephemeris – The Lunar Jura Mountains
Ephemeris for Monday, March 14th. The sun will rise at 7:57. It’ll be up for 11 hours and 49 minutes, setting at 7:46. The moon, 3 days past first quarter, will set at 5:13 tomorrow morning.
On the moon tonight the gibbous phase and the terminator on the left side of the moon is revealing a large semi circular mountain range called the Jura Mountains that encloses a flat lava plain that looks like a bay in the margin of the Sea of Showers or Mare Imbrium. It is easily visible in binoculars this evening when the sunrise line is crossing the bay. The Jura Mountains will appear as a hook out of the upper left edge of the moon. That’s about the coolest sight that’s visible on the moon that can be seen with binoculars. It’s especially striking if seen in a small telescope. I’ve added these programs to my web log or blog and I can add images to illustrate what I’m talking about, as I did today. The blog’s address is bobmoler.wordpress.com.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Jura Mountains sticking up into morning daylight. Created from the Virtual Moon Atlas.
03/11/11 – Ephemeris – Time change again
Friday, March 11th. The sun will rise at 7:02. It’ll be up for 11 hours and 40 minutes, setting at 6:43. The moon, 1 day before first quarter, will set at 1:52 tomorrow morning.
This weekend we go back to Eastern Daylight Saving Time. It may be a boon to most folks, lengthening the evening daylight hours, but around here it makes stargazing difficult by pushing it to the late night hours, especially in June or July. In the old days noon was when the sun was due south in the sky. Railroad schedules were the impetus for the creation of standard time zones, one hour wide. Thanks to politics Michigan is in the eastern time zone, rather than the closer central time zone. We’re about 43 minutes behind Philadelphia, the eastern time meridian. With the imposition of daylight time, it pushes our time meridian 15 degrees of longitude farther east, out into the Atlantic Ocean. So late winter, or spring, forward Sunday morning.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
03/10/11 – Ephemeris – The moon will appear near the Pleiades tonight
Thursday, March 10th. The sun will rise at 7:04. It’ll be up for 11 hours and 37 minutes, setting at 6:41. The moon, 2 days before first quarter, will set at 12:54 tomorrow morning.
The fat crescent moon tonight will be near the Pleiades or Seven Sisters star cluster. The Pleiades can be seen above the moon. They will make a very beautiful sight in binoculars. They will be closest together near 2 in the morning. Some years the moon will even pass in front of the stars of the Pleiades. On the moon itself tonight, in binoculars, we can see the dark lunar seas of Crises, Fertility, Nectar, and Tranquility. With a telescope the crater Theophilus is visible near the terminator, the sunrise line a bit below center of the moon. It is a perfect circular crater with a central peak. The best crater visible now. That will change as the moons phase becomes fuller. It will appear washed out and indistinct. The moon needs shadows to delineate its features.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Blog addendum:
Pleiades and the moon 03/10/11, created using Cartes du Ciel.
Here’s a closer look at the moon courtesy of Virtual Moon Atlas.
Young moon with the crater Theophilus and four seas. From Virtual Moon Atlas
03/09/11 – Ephemeris – Where are the bright planets this week?
Ash Wednesday March 9th. The sun will rise at 7:06. It’ll be up for 11 hours and 34 minutes, setting at 6:40. The moon, 3 days before first quarter, will set at 11:53 this evening.
It’s Wednesday and time again to take a look at the whereabouts of the bright planets for this week. Mercury is marginally visible low in the west in twilight setting at 7:37. The planet Jupiter is low in the western sky in the early evening twilight. It will set at 8:25 p.m. The ringed planet Saturn will rise at 8:47 p.m. in the east southeast and will move due south at 2:34 a.m. In telescopes Saturn shows its rings which are a year and a half along their seven and a half year opening. Also visible in a telescope is Saturn’s moon Titan. Wait a couple of hours after Saturn rises for the clearest images. Venus is brilliant in the morning sky and will rise at 5:29 a.m. in the east southeast. It is really a beautiful sight in the morning twilight.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
03/08/11 – Ephemeris – The lunar sea of Crises
Fat Tuesday, March 8th. The sun will rise at 7:08. It’ll be up for 11 hours and 31 minutes, setting at 6:39. The moon, half way from new to first quarter, will set at 10:51 this evening.
The one feature that is prominent on the crescent moon tonight will be the dark sea Mare Crisium or sea of Crises. It appears easily in binoculars. It, as all the lunar seas, are really a large crater that was created about 3.85 billion years ago by an asteroid strike. It appears foreshortened because it’s near the moon’s limb. If you watched the proximity of Mare Crisium to the edge of the moon over time, you’d notice that sometimes it’s closer to the edge than at other times. The moon has a constant rotation, but its orbit isn’t circular, so the moon appears to rock back and forth slowly, and nods a bit too. The effect is called libration, and allows us to see 60% of the moon from earth.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Blog Addendum:
Below is an image from Virtual Moon Atlas pointing out Mare Crisium, the Sea of Crises. VMA is a free program. See the links for free programs on this blog.
Mare Crisium via Virtual Moon Atlas
03/07/11 – Ephemeris – Earthshine
Monday, March 7th. The sun will rise at 7:09. It’ll be up for 11 hours and 28 minutes, setting at 6:37. The moon, 3 days past new, will set at 9:49 this evening.
The moon tonight will appear as a thin sliver, with not much visible on the thin illuminated portion. However if as you look at the moon tonight you have the funny feeling that the whole moon is visible, you are right. It’s easily confirmed with a pair of binoculars or a small telescope. What is illuminating the dark part of the moon is earthshine. The earth is big and bright in the moon’s sky, and nearly full from its vantage point. The effect used to be called by the term “Old moon in the new moon’s arms”. The effect was first explained by Leonardo DaVinci some 500 years ago. The effect will disappear in a few days as the moon gets brighter and the earth less so in the moon’s sky. Earthshine will appear again when the moon appears as a waning crescent in the morning.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Update:
Earthshine is notoriously hard to photograph. Here’s one of mine from 1991. Part of a planetary conjunction picture with a short focal length telephoto lens. I’ve cropped out the planets. The sunlit side of the moon is vastly overexposed causing the blooming in the photograph.
Earthshine on the crescent moon
03/04/11 – Ephemeris – Local astronomy events in Traverse City
Friday, March 4th. The sun will rise at 7:15. It’ll be up for 11 hours and 18 minutes, setting at 6:33. The moon is new today, and won’t be visible.
A look at the forgotten planets Uranus and Neptune will be given by Chris Snyder of the Northwestern Michigan College Astronomical Association at this evening’s meeting of the Grand Traverse Astronomical Society at 8 p.m. at Northwestern Michigan College’s Rogers Observatory. These two planets were last closely studied by the Voyager 2 spacecraft in the 1980’s, though the Hubble space telescope and other telescopes have been keeping tabs on them. Tomorrow night both groups will host a public viewing night starting at 8 p.m. On tap will be the planet Jupiter early, and the Great Orion Nebula, a place where stars are even now forming, and a look at the rising planet Saturn later on. 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.
03/03/11 – Ephemeris – The constellation Cancer
Thursday, March 3rd. The sun will rise at 7:16. It’ll be up for 11 hours and 15 minutes, setting at 6:32. The moon, 1 day before new, will rise at 6:46 tomorrow morning.
At 9 this evening, the faint constellation, and member of the Zodiac, Cancer the crab will be located in the south southeast half way between the bright stars Castor and Pollux of the constellation Gemini, high in the south and the bright star Regulus in Leo the lion in the east. Cancer is very dim, looking like an upside-down Y. In the center of Cancer is a fuzzy spot to the unaided eye. In binoculars or a low power telescope this fuzzy spot becomes a cluster of stars. It is the Beehive cluster. At 577 light years away, it is one of the closest star clusters, but more distant than the Pleiades and Hyades the face of Taurus the bull. Of the three the Pleiades is the youngest at 100 million years The Beehive is 7 times older.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Cancer rising in the southeast
Created using Stellarium. Constellation art by Johan Meuris.
Praecepe is the old name for the Beehive star cluster possibly before the invention of the telescope. Praecepe means “Manger”. Below is the Beehive as seen in binoculars.
The Beehive star cluster (M44) as it would appear in binoculars.
Chart created using Cartes du Ciel.
03/02/11 – Ephemeris – The bright planets this week
Wednesday, March 2nd. The sun will rise at 7:18. It’ll be up for 11 hours and 12 minutes, setting at 6:31. The moon, 2 days before new, will rise at 6:25 tomorrow morning.
It’s Wednesday and time again to take a look at the whereabouts of the bright planets for this week. The planet Jupiter is low in the western sky in the early evening twilight. It will set at 8:44 p.m. The ringed planet Saturn will rise at 9:17 p.m. in the east southeast and will move due south at 3:03 a.m. In telescopes Saturn shows its rings which are a year and a half along their seven and a half year opening. Also visible in a telescope is Saturn’s moon Titan. Wait a couple of hours after Saturn rises for the clearest images. Venus is brilliant in the morning sky and will rise at 5:30 a.m. in the east southeast. It is really a beautiful sight in the morning twilight. Mercury is now too close to the direction of the sun to be seen, as is Mars which is now in the morning sky.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
03/01/11 – Ephemeris – The constellation Puppis
Tuesday, March 1st. The sun will rise at 7:20. It’ll be up for 11 hours and 9 minutes, setting at 6:29. The moon, 3 days before new, will rise at 6:01 tomorrow morning.
Located south and east of Canis Major, the great hunting dog of Orion and it brilliant star Sirius in the south is a dim constellation of Puppis, the poop deck of the old constellation Argo Navis, the constellation that depicts the ship Jason and the Argonauts used in their search for the Golden Fleece. This huge constellation has been subdivided. Only Puppis and Pyxis the ship’s compass are visible from Michigan. The rest of the ship are Carina the keel, and Vela the sail require traveling south at least to the southern United States. Three other constellations also related to this expedition are Gemini with Castor, who died on the expedition and Pollux. Hercules was also aboard and was the physician of the constellation Ophiuchus.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Update:
The constellation Puppis the poop deck of the good ship Argo
Above, Puppis from northern Michigan.
Below, the entire ship Argo, the old constellation Argo Navis. It contains the modern constellations Puppis, the poop deck, Pyxis the compass, Vela the sail, and Carina the keel.
The old constellation Argo Navis
These images were created using Stellarium. Constellation art by Johan Meuris.
