Archive
08/18/2016 – Ephemeris – Viewing the full Moon tonight
Ephemeris for Thursday, August 18th. The Sun rises at 6:49. It’ll be up for 13 hours and 53 minutes, setting at 8:42. The Moon, at full today, will rise at 8:54 this evening.
The full moon, contrary to what you’d think is a poor time to observe it. The moon is essentially gray on gray. And at full moon we are looking at the moon from about the same perspective as the sun, so there are no shadows to delineate its fine features. Since the actual instant of full moon occurred at 5:27 this morning, some shadows will be creeping in on the moon’s upper right face as it is seen in the evening. Full moon is the best time to see the maria or lunar seas, the dark areas that make up the man in the moon. In binoculars can be seen the bright rays* emanating from the crater Tycho near the south end of the moon. Other craters have rays too, but none so long and distinctive. Night by night for the next two weeks the moon’s illuminated landscape will wane.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
* Rays are caused by the ejecta from the impact that created the crater. They are thought to be small craters themselves which show up best at full moon because they have no shadows in them.
Addendum
The full Moon taken last night, 7 hours before to was officially full. The contrast was greatly enhanced to bring out Tycho’s ray system. Credit Bob Moler.
08/17/2016 – Ephemeris – Two groups of evening planets are visible
Ephemeris for Wednesday, August 17th. The Sun rises at 6:48. It’ll be up for 13 hours and 56 minutes, setting at 8:44. The Moon, 1 day before full, will set at 7:01 tomorrow morning.
Tonight we still have all the bright classical planets in the evening sky. Mercury, Venus and Jupiter are very low in the west and will set at 9:32, 9:34 and 9:51 p.m. respectively. Jupiter is above Mercury with Venus to the right or Mercury in the evening twilight. Mars, Saturn and the star Antares start the evening in the south-southwestern sky as a tightening triangle, moving to the southwest during the evening. Antares, whose name means Rival of Mars is below Saturn with brighter Mars to the right and closing in on Antares. In 6 days Mars will pass just above Antares with Saturn above all in a nearly straight line. Mars, moving rapidly to the east against the stars will set at 12:30 a.m. Saturn, is spectacular in telescopes, with its rings. It will set at 1:06 a.m.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Venus, Mercury and Jupiter at 9:18 p.m. (30 minutes after sunset), August 17, 2016. Created using Stellarium.
The planets, and Moon at 10 p.m., August 17, 2016. Created using Stellarium.
Saturn and some of its moons at 10 p.m. August 17, 2016. Created using Cartes du Ciel (Sky Charts).
The Moon as it might appear in binoculars tonight, August 17, 2016 at 10 p.m. Tonight the Moon is only a bit more than 7 hours from being full. Created using Cartes du Ciel (Sky Charts).
Planets at sunset and sunrise of a single night starting with sunset on the right on August 17, 2016. The night ends on the left with sunrise on August 18. Actually all the naked eye planets are in the evening sky. If you are using Firefox right-click on the image and select View Image to enlarge the image. That goes for all the large images. Created using my LookingUp program.
08/16/2016 – Ephemeris – Does Proxima Centauri have a planet? Also some information for southern observers about Mercury
Ephemeris for Tuesday, August 16th. The Sun rises at 6:46. It’ll be up for 13 hours and 59 minutes, setting at 8:46. The Moon, 2 days before full, will set at 5:53 tomorrow morning.
Proxima Centauri is the closest star to our solar system. It is a red dwarf star, and a distant third member of the Alpha Centauri star system. Recently the German weekly Der Spiegel announced that astronomers at the La Silla Observatory in Chile have detected a possible Earth-like planet at a distance that water may be liquid on its surface around this tiny star. Other than this one leak, no one is talking, and the European Southern Observatory is mum on the subject. There may be some kind of announcement at the end of the month. If true, this means that the closest earth-like planet orbits the closest star, only four and a quarter light years away. That’s nearly 25 trillion miles, and hundreds of years travel time with our current technology.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Chart showing the location of Proxima Centauri, labeled here HIP 70890. Alpha Centauri is labeled Rigel Kentaurus. Alpha Centauri is actually a catalog name in the style of Johann Bayer’s 1603 star atlas. Note also the alpha (α) Greek letter next to the star. Created using Cartes du Ciel (Sky Charts).
Note also the star labeled Agena. That is the more distant Beta (β) Centauri also known as Hadar.
A section of a photograph of part of the field of view of the chart above. Credit: Wikipedia user Skatebiker.
Extra
For our southern observers: Today Mercury reaches its greatest eastern elongation of 27 degrees. So it’s visible in the west with Venus and Jupiter.
07/15/2016 – Ephemeris – The end is near for ESA’s Rosetta spacecraft
Ephemeris for Monday, August 15th. The Sun rises at 6:45. It’ll be up for 14 hours and 1 minute, setting at 8:47. The Moon, 3 days before full, will set at 4:49 tomorrow morning.
In a month and a half the European Space Agency’s Rosetta spacecraft will end its mission to comet 67/P Churyumov-Gerasimenko or just 67/P for short. The end will come as the Rosetta spacecraft will make a slow crash onto the comet. A week ago the spacecraft shut down its link to the Philae lander, which itself didn’t stick its landing and bounced three times and found itself between ice and a hard place with no way for the Sun to reach it to recharge its batteries, and so had an abbreviated science mission before the batteries failed. The comet was closest to the Sun a year ago, and is heading back out to near the orbit of Jupiter. Last time it was out this far Rosetta had just been woken up out of a three-year slumber. This time though it will sleep forever after a job well done.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
An artist’s illustration of the European Space Agency’s comet-chasing Rosetta spacecraft. Credit: ESA – C. Carreau
An image of the Philae lander superimposed on its panorama photographs where it was wedged between ice and a hard place in the shadows November 2014. Credit: ESA/Rosetta.
Comet 67P and jets of dust, carried by sublimating ices. Credit: ESA/Rosetta
08/12/2016 – Ephemeris – Two events this weekend
Ephemeris for Friday, August 12th. The Sun rises at 6:42. It’ll be up for 14 hours and 10 minutes, setting at 8:52. The Moon, 2 days past first quarter, will set at 2:12 tomorrow morning.
Tomorrow the Grand Traverse Astronomical Society will close out the Port Oneida Fair which is held by and at the Sleeping Bear Dunes National Lakeshore. It will be held at the Thoreson Farm on South Thoreson Road off M22, just west of Port Oneida road. From 4 to 6 p.m. there will be observation of the Sun through white-light filtered telescopes and a hydrogen-alpha filtered solar telescope. Then from 9 to 11 p.m. there will be viewing of the Moon and the bright planets including Mars and Saturn, and depending on sky condition, Jupiter, Venus and Mercury. There may be a few bright stragglers of the Perseid Meteor Shower to be seen. All this requires clear skies, so if in doubt check with the park at 231-326-4700, ext. 5005 for a voicemail message.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Also tonight if weather permits the Grand Traverse Astronomical Society will participate in Friday Night Live on Front Street in downtown Traverse City. The society will be in its usual spot, in front of Orvis Streamside, a few stores west of the State Theater. The event will be from 5:30 to 9 p.m. where we will have exhibits and solar viewing if it’s clear. Telescopes will be available for viewing the Moon and Saturn after 9 p.m. if skies permit.
Star Party at the Sleeping Bear Dunes National Lakeshore, Thoreson Farm August 2013. Credit Eileen Carlisle.
Looking at the Moon. Friday Night Live after hours.
08/11/2016 – Ephemeris – The Perseid meteors will peak tonight!
Ephemeris for Thursday, August 11th. The Sun rises at 6:41. It’ll be up for 14 hours and 12 minutes, setting at 8:53. The Moon, 1 day past first quarter, will set at 1:31 tomorrow morning.
This evening and tomorrow morning we should see the peak of the Perseid Meteor Shower. There is the expected broad peak of the shower which for us is after sunrise. However the meteoroid stream isn’t monolithic. Each pass of the comet in the inner solar system superimposes its debris on the general stream, so we will have increased activity all night tonight and even into Saturday morning. In general Perseid meteors will be seen to come from the northeast. The evening view will be hampered by the Moon which will drown out the dimmer meteors. The best time to view is after the Moon sets at 1:31 tomorrow morning until morning twilight becomes noticeable around 5 a.m. when over 100 meteors might be spotted an hour.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Perseid meteor shower radiant a about 2 a,m, during the period of the shower. Created using my LookingUp program.
Here are some meteors seen in the 2007 Perseid meteor shower taken by Scott Anttila. The image is centered on Cassiopeia. The radiant is low and a bit left of center in the image. The Double Cluster is seen below center and the Great Andromeda Galaxy is seen on the right just above center.
My best Perseid photo. From the 70’s.
08/10/2016 – Ephemeris – The planets tonight
Ephemeris for Wednesday, August 10th. The Sun rises at 6:39. It’ll be up for 14 hours and 15 minutes, setting at 8:55. The Moon, at first quarter today, will set at 12:55 tomorrow morning.
Today we turn from the small meteoroids that orbit the Sun that are producing the Perseid Meteor Shower to the larger members of the solar family, namely the bright planets. Venus and Mercury are very low in the west-northwest and will set at 9:44 and 9:50 p.m. respectively. Jupiter is in the west in the evening. It will set at 10:19 p.m. Mars, Saturn and the star Antares start the evening in the south-southwestern sky as a tightening triangle, moving to the southwest during the evening. Antares, whose name means Rival of Mars is below Saturn with brighter Mars to the right. The Red Planet is back in Scorpius. It will set at 12:46 a.m. Mars is moving rapidly to the east against the stars. Saturn is spectacular in telescopes, with its rings. Saturn will set at 1:34 a.m.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Venus, Mercury and Jupiter at 9:25 p.m. (30 minutes after sunset), August 10, 2016. Created using Stellarium.
The planets, Moon and constellations at 10 p.m., August 10, 2016. Created using Stellarium.
The Moon as it might appear in binoculars tonight, August 10, 2016 at 10 p.m. Created using Stellarium.
Saturn and its moons at 10 p.m. August 10, 2016. Created using Cartes du Ciel (Sky Charts).
Planets at sunset and sunrise of a single night starting with sunset on the right on August 10, 2016. The night ends on the left with sunrise on August 11. Actually all the naked eye planets are in the evening sky. Also shown is the Perseid meteor shower radiant. If you are using Firefox right-click on the image and select View Image to enlarge the image. That goes for all the large images. Created using my LookingUp program.
Also shown is the Perseid meteor shower radiant.
08/09/2016 – Ephemeris – A look at the Perseids progenitor
Ephemeris for Tuesday, August 9th. The Sun rises at 6:38. It’ll be up for 14 hours and 18 minutes, setting at 8:56. The Moon, 1 day before first quarter, will set at 12:23 tomorrow morning.
Comet Swift-Tuttle is the comet responsible for the Perseid Meteor Shower which is now ramping up and will reach its peak Thursday night and Friday morning. The comet was independently discovered by Swift and Tuttle in the summer of 1862. Based on three months of observations it was predicted to return after 120 years in 1982. After it failed to appear more work was done to refine the orbit, and to check for past appearances of the comet. Sure enough comets appearing to fit the orbit were found in 188 CE and 69 BCE, so a new prediction for the comet to reappear was made for 1992 by the late Dr. Brian Marsden of the Smithsonian Astrophysical Observatory. His revised prediction was only off by 17 days.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Orbit of Comet 109P/Swift-Tuttle. Blue line is the comet’s orbit, coming from above (North). Credit NASA / JPL / Applet by Osamu Ajiki (AstroArts), and further modified by Ron Baalke (JPL).
Orbit of Comet 109P/Swift-Tuttle. Blue line is the comet’s orbit, coming from above. That’s why the radiant is so far north. See yesterday’s post for the radiant point. Credit NASA / JPL / Applet by Osamu Ajiki (AstroArts), and further modified by Ron Baalke (JPL).
These were generated a couple of years ago. However the comet won’t be back until 2122 give or take.
08/08/2016 – Ephemeris – This week the Perseid meteors ramp up
Ephemeris for Monday, August 8th. The Sun rises at 6:37. It’ll be up for 14 hours and 20 minutes, setting at 8:58. The Moon, 2 days before first quarter, will set at 11:54 this evening.
The Perseid meteor shower will reach its peak for this year between 9 and 11:30 a.m. Friday morning, the 12th. There is some expectation that there will be an enhancement of meteor numbers on Thursday evening before midnight. Our problem is that the Moon will be out and bright Thursday evening and will set at 1:31 a.m. Friday morning. The bright Moon doesn’t preclude seeing meteors, but only the brightest ones will be visible. Also we have been seeing precursor meteors for the last three weeks, slowly ramping up to Friday morning’s peak. You’ll see them every night this week. The meteors are caused by the debris from Comet Swift-Tuttle whose 130 year orbit of the Sun over the millennia, has strewn meteoroids along its orbit.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Perseid meteor shower radiant is circumpolar for northern Michigan, so the meteors will be visible all night.
Perseid radiant at 10:30 p.m.
Perseid Meteor Shower radiant after midnight
Last night’s sunset was beautiful, but didn’t promise clear skies
Just after sunset from a hill top near Suttons Bay, MI. Credit Bob Moler.
The view is across most of the Leelanau Peninsula, the Manitou Passage, and North Manitou Island at the sunlit bottoms of the clouds just after sunset.
The event was the annual Grand Traverse Astronomical Society picnic and star party. Most of the evening was consumed by fleeting glimpses of Saturn and deep sky objects through the holes in the clouds by members telescopes and the society’s 25 inch “Dobinator” which was run by a crew headed by telescope “wrangler” Don Flegel. Before sunset the Sun provided some glorious prominences for us.
Bob Moler's Ephemeris Blog 