07/10/2015 – Ephemeris – The celestial scorpion crawls over the horizon
Ephemeris for Friday, July 10th. Today the Sun will be up for 15 hours and 21 minutes, setting at 9:28. The Moon, 2 days past last quarter, will rise at 2:44 tomorrow morning, and tomorrow the Sun will rise at 6:07.
The planet Saturn, this year, is on the right edge of the constellation of Scorpius the scorpion which is in the south at 11 p.m. Its brightest star is Antares in its heart, a red giant star. From Antares to the right is a star then a vertical arc of three stars that is its head. The Scorpion’s tail is a line of stars running down to the left of Antares swooping to the horizon before coming back up and ending in a pair of stars that portray his poisonous stinger. Scorpius looks huge lying on the southern horizon. But if you go south Scorpius will be higher in the sky, and will look smaller. Being close to the horizon from Michigan, Scorpius shares with the rising and setting sun and moon the illusion of increased size.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Scorpius from Traverse City/Interlochen at 11 p.m. on July 10, 2015. Created using Stellarium.
07/09/2015 – Ephemeris – The first stars to appear at night
Ephemeris for Thursday, July 9th. Today the Sun will be up for 15 hours and 23 minutes, setting at 9:29. The Moon, 1 day past last quarter, will rise at 2:05 tomorrow morning, and tomorrow the Sun will rise at 6:07.
Let’s check out all the bright stars in the evening sky, as it gets dark tonight. Low in the west are the planets Venus and Jupiter. High in the west is the bright yellow-orange star Arcturus. In the northwest is the Big Dipper, whose curved handle points to Arcturus. Straightening that curve to a spike will point to Spica a blue-white star low in the southwest. The planet Saturn is located in the south. Below and left of it is the red star Antares which usually twinkles merrily. High in the east is the bright white star Vega. To its lower right is Altair, and to its lower left the star Deneb. Vega, Altair and Deneb make the Summer Triangle, whose rising in the east signals the coming of summer.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
I talked about seeing the first stars a month ago. It seems that in holding star parties this time of year we spend a lot of time watching the first stars appear. I wanted to discuss the Summer Triangle, but it wandered off to what you see above. I’ll get there next week, I promise.
The first stars and planets to appear. See if you can located them from the text. Created using Stellarium for about 10 p.m., July 9, 2015.
07/08/2015 – Ephemeris – The bright planets are hanging around in the evening.
Ephemeris for Wednesday, July 8th. Today the Sun will be up for 15 hours and 24 minutes, setting at 9:29. The Moon, at last quarter today, will rise at 1:30 tomorrow morning, and tomorrow the Sun will rise at 6:06.
Lets take a look at the bright planets for this week. Our evening stars Venus and Jupiter are side by side in the west by 9:45 p.m. They both will set at 11:21 p.m.. Venus’ will slide down to the Sun faster and faster in the coming weeks leaving Jupiter behind for a while. Venus will take 5 weeks to slide past the Sun. Jupiter though will take 7 weeks, so Venus will pass it again around August 4th when both are too close to the horizon and Sun to spot. There’s a third conjunction of these two in October in the morning sky with Mars nearby. Saturn is in the south in the evening twilight. It will pass due south at 10:24 p.m. and will set at 3:16 a.m. Even small telescopes can see Saturn’s rings.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The evening planets at 10:30 p.m. July 8, 2015. Created using Stellarium.
Venus’ greatest brilliancy will be on Sunday the 12th. This is the point where Venus’ increasing size is countered by its decreasing phase. The brightness of Venus doesn’t change much over its orbit, and will be stay brilliant. However it will surrender to the brightening twilight as it sets closer and closer to sunset.
The evening planets as seen with the same magnification. Note that Venus is noticeably larger appearing than Jupiter. This is probably the time Venus’ crescent is visible in binoculars. Created using Cartes du Ciel (Sky Charts).
07/07/2015 – Ephemeris – New Horizons will resume science gathering after glitch July 4th.
Ephemeris for Tuesday, July 7th. Today the Sun will be up for 15 hours and 25 minutes, setting at 9:30. The Moon, 1 day before last quarter, will rise at 12:56 tomorrow morning. Tomorrow the Sun will rise at 6:05.
On July 4th, the New Horizons spacecraft, now one week from is flyby of Pluto, suffered a glitch and went into safe mode. It, however switched to its backup computer, and is now in contact with the Earth. Sunday night it was determined that the problem was a timing flaw in a command sequence preparing for Pluto encounter. Normal spacecraft operations will resume today. Two way communication time is now nearly 9 hours, almost half a day. Earth day that is. New Horizons is approaching Pluto at 31,000 miles an hour. The spacecraft will have only a few hours to observe Pluto and its moons at their closest next Tuesday. It’s getting down to crunch time for the little spacecraft.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
I wrote Tuesday’s program Sunday night before the announcement that the problem with New Horizons was found and the spacecraft would back to normal on Tuesday. I found that out just before recording the programs, and had to do a quick fix. With New Horizons problems found, I could write the July 13th program I had planned. I write and record 5 programs at a time – Tuesday through Monday.
Artist’s rendition credit NASA.
07/06/2015- Ephemeris – Today we are at our greatest distance from the sun.
Ephemeris for Monday, July 6th. Today the Sun will be up for 15 hours and 26 minutes, setting at 9:30. The Moon, 2 days before last quarter, will rise at 12:23 tomorrow morning and tomorrow the Sun will rise at 6:04.
This is the day the we are the farthest we can get from the Sun for the year. The point in the Earth’s orbit that it occurs is called aphelion. Earth is closest to the Sun in January at perihelion. The actual distance difference between perihelion and aphelion is 3 million miles out of roughly 93 million miles. So now we’re roughly 94 and a half million miles from the Sun or 152 million kilometers., and will swoop down to 91 and a half million miles(91.4) or 147 kilometers from the Sun in early January. Because Earth’s northern and southern hemispheres have different ratios and placement of land versus ocean I’m not sure you could correlate seasonal differences of the hemispheres with the Earth’s distance from the Sun. Anyway the approximate time we reach aphelion will be 3 p.m. EDT (19 hr UT).
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The orbits of the inner planets. (P)erihelion – (A)phelion
The above is a diagram from three years ago, so the planets other than the Earth will be in different positions today. The date of aphelion and perihelion move around over a greater range of dates than the equinoxes and solstices. I’m not sure why without researching it, but I suspect that the Moon has something to do with it.
07/03/2015 – Ephemeris – Astronomy in the Grand Traverse Region tonight
Ephemeris for Friday, July 3rd. Today the Sun will be up for 15 hours and 29 minutes, setting at 9:31. The Moon, 2 days past full, will rise at 10:33 this evening and tomorrow the Sun will rise at 6:02.
Dr. David Penney will investigate the structure of the Milky Way at this evening’s meeting of the Grand Traverse Astronomical Society at 8 p.m. at Northwestern Michigan College’s Rogers Observatory. The Milky Way is the band of light we see in the sky especially on summer and winter evenings. But it is more than a band of dim stars, it is what we can see of the huge disk of maybe 200 billion stars with an embedded pin wheel structure. Everyone is welcome. Also at 9 p.m. there will be a star party at the observatory. The astronomical objects of the evening will be the planets Venus, Jupiter and Saturn and the Moon later in the evening. The observatory is located south of Traverse City on Birmley Road.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Dr. Penney has a Ph.D. in Physiology and Biochemistry, and is pretty much retired spending his time between Michigan in the summer and northern Florida in the winter, where he is a member of several astronomy clubs. He gives many talks there also.
07/02/2015 -Ephemeris – A belated preview of July’s skies
Ephemeris for Thursday, July 2nd. Today the Sun will be up for 15 hours and 30 minutes, setting at 9:31. The Moon, 1 day past full, will rise at 9:48 this evening and tomorrow the Sun will rise at 6:02.
Lets preview July’s skies a day late. Sorry, it’s been a busy week.. The sun, having reached its northern solstice, is beginning to slide southward again, at first imperceptibly, then with greater speed. The daylight hours will decrease from 15 hours and 30 minutes Today to 14 hours 44 minutes at month’s end. The daylight hours will be slightly shorter south of Interlochen, and slightly longer to the north. The altitude of the sun at local noon, when the sun is due south will decrease from 68 degrees Now to 63 degrees at month’s end. The sun will be a degree lower in the Straits area. Despite the warmth, the earth will reach its greatest distance from the sun on Monday the 6th. The range of the earth’s distance from the sun is 3 million out of 93 million miles.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Star Chart for July 2015. Created using my LookingUp program. Click on image to enlarge.
The Moon is not plotted.
The planets and stars are plotted for the 15th at 11 p.m. EDT. That is chart time. Note, Traverse City is located 1 hour 45 minutes behind our time meridian. To duplicate the star positions on a planisphere you may have to set it to 1 hour 45 minutes earlier than the current time.
Evening Astronomical twilight ends at midnight. EDT on July 1st, decreasing to 11:14 p.m. EDT on the 31st.
Morning astronomical twilight starts at 3:32 a.m. EDT on July 1st, and increasing to 4:42 a.m. EDT on the 31st.
Add a half hour to the chart time every week before the 15th and subtract and hour for every week after the 15th.
For a list of constellation names to go with the abbreviations click here.
The green pointer from the Big Dipper is:
- Pointer stars at the front of the bowl of the Big Dipper point to Polaris the North Star.
- Drill a hole in the bowl of the Big Dipper and the water will drip on the back of Leo the Lion.
- Follow the arc of the Big Dipper’s handle to Arcturus
- Continue with a spike to Spica
- The Summer Triangle is shown in red
Calendar of Planetary Events
Credit: Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC)
To generate your own calendar go to http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html
Times are Eastern Daylight Time on a 24 hour clock. Some additions made to aid clarity.
Conjunctions like the Moon-Jupiter: 4.5° N means Jupiter will appear 4.5° north of the Moon.
Date Local Event
Time
Jul 01 We 02:48 Moon South Dec.: 18.4° S
01 We Venus: 42.4° E
01 We 22:20 Full Moon
05 Su 14:54 Moon Perigee: 367100 km
06 Mo 08:59 Aphelion: 1.0167 AU
07 Tu 20:07 Moon Descending Node
08 We 16:24 Last Quarter
12 Su 13:55 Moon-Aldebaran: 0.9° S
14 Tu 00:24 Moon North Dec.: 18.4° N
14 Tu 17:35 Venus-Regulus: 2.3° S
15 We 21:24 New Moon
18 Sa 13:34 Moon-Jupiter: 4.5° N
18 Sa 21:06 Moon-Venus: 0.5° N
21 Tu 07:02 Moon Apogee: 404800 km
21 Tu 15:32 Moon Ascending Node
23 Th 15:18 Mercury Superior Conjunction with the Sun
24 Fr 00:04 First Quarter
26 Su 04:43 Moon-Saturn: 2.4° S
28 Tu 10:23 Delta Aquarid Meteor Shower: ZHR* = 20
28 Tu 13:34 Moon South Dec.: 18.3° S
31 Fr 06:43 Full Moon
Aug 01 Sa Venus: 21.5° E
*ZHR – Zenithal Hourly Rate: Approximate number of meteors per hour when the shower radiant is at the zenith. For more information on this and other meteor showers in 2015 see the International Meteor Organization website calendar section: http://www.imo.net/calendar.
07/01/2015 – Ephemeris – Jupiter, Venus and Saturn grace our evening sky
Ephemeris for Wednesday, July 1st. Today the Sun will be up for 15 hours and 31 minutes, setting at 9:32. The Moon, at full today, will rise at 8:58 this evening and tomorrow the Sun will rise at 6:01.
Lets take a look at the bright planets for this week. Our brilliant evening star Venus and Jupiter are close together in the west by 9:45 p.m. They will set around 11:45 p.m.. Venus’ will slide down to the Sun faster and faster in the coming weeks leaving Jupiter behind for a while. Venus will take a month and a half to slide past the Sun. Jupiter though will take 2 months, so Venus will pass it again around August 4th when both are too close to the horizon and Sun to spot. There’s a third conjunction of these two in October in the morning sky with Mars nearby. Saturn is in the southeast in evening twilight. It will pass due south at 10:53 p.m. and will set at 3:41 a.m. Even small telescopes can see Saturn’s rings.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The evening planets and the Moon at 10:30 p.m. July 1, 2015. Though their images overlap Jupiter is above right of Venus. Click on the image to enlarge. Created using Stellarium.
The evening planets and the Moon with their satellites to scale at 10:30 p.m. July 1, 2015. Created using Stellarium.
Mercury is officially in the morning sky now, but it is not a favorable appearance for northern hemisphere observers.
06/30/2015 – Ephemeris – Tonight’s close conjunction of Jupiter and Venus will be visible in the west after sunset
Ephemeris for Tuesday, June 30th. Today the Sun will be up for 15 hours and 31 minutes, setting at 9:32. The Moon, 1 day before full, will set at 5:49 tomorrow morning and tomorrow the Sun will rise at 6:00.
Tonight the planets Venus and Jupiter will appear at their closest in the western sky after sunset. Dimmer Jupiter will appear just above Venus by 20 minutes of arc or two-thirds of the width of the Moon. They can both be seen in the same telescope field using low power. It’s interesting that Jupiter, is over 11 times the diameter of Venus, but because Venus is so much closer to us, it now appears to be the same size as Jupiter, and it will continue to grow. It’s 48 million miles away and closing to 27 million on August 15th when it passes between the Earth and the Sun. Astrologers think a conjunction like this means something, while astronomers like me see two bright planets which happen to be beautifully aligned along our line of sight.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Jupiter-Venus approach animation June 11 to July 1, 2015 at 10:30 p.m. Created using Stellarium and GIMP. Click on image to enlarge.
A telescopic view of what we expect the positions of Jupiter and Venus at 10:30 p.m. EDT June 30, 2015 (2:20 UT July 1, 2015). Created using Stellarium.
06/29/2015 – Ephemeris – Did tomorrow’s conjunction between Venus and Jupiter happen before?
Ephemeris for Monday, June 29th. Today the Sun will be up for 15 hours and 32 minutes, setting at 9:32. The Moon, 2 days before full, will set at 4:56 tomorrow morning and tomorrow the Sun will rise at 6:00.
Tonight the planet Jupiter will be a bit more than the width of the Moon away from Venus. Tomorrow that distance will be cut in half as Jupiter will pass directly above Venus. This is a second of two conjunctions that are a near repeat of two conjunctions that some, including myself have speculated as being what the Magi reported as the Star of Bethlehem in 3 and 2 BC. On August 12th 3 BC in the predawn sky Jupiter and Venus were a third of a moon width apart, Then on June 17th 2 BC they were in conjunction again but even closer . Last year we had a close conjunction of the two on August, 18th and the two will be in conjunction, and again tomorrow. Neither are as close as they were in 3 and 2 BC.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Jupiter and Venus at 10:30 tonight June 29, 2015, one day before their conjunction. Created using Stellarium.
The orbits of Venus and Jupiter for the conjunction of June 30, 2015. The bright star to the upper left is Regulus. Created using Stellarium.
A telescopic view of what we expect the positions of Jupiter and Venus at 10:30 p.m. EDT June 30, 2015 (2:20 UT July 1, 2015). Created using Stellarium.
The orbits of Venus and Jupiter for the conjunction of June 17, 2 BC. The bright star to the lower right is Regulus. Created using Stellarium.
Venus appeared among Jupiter’s moons on August 12, 3 BC. Of course no one had a telescope back then. Created using Stellarium.
I’ve written about the Jupiter-Venus conjunctions of 3 and 2 BC. You can see it here from my Ephemeris website..
