10/07/2022 – Ephemeris – Learn about the Sun tonight and view the Moon on Saturday

October 7, 2022 Leave a comment

This is Bob Moler with Ephemeris for Friday, October 7th. Today the Sun will be up for 11 hours and 24 minutes, setting at 7:12, and it will rise tomorrow at 7:49. The Moon, 2 days before full, will set at 6:08 tomorrow morning.

Tonight at 8 pm, the Grand Traverse Astronomical Society will have an in-person meeting at Northwestern Michigan College’s Rogers Observatory. The meeting will also be available via Zoom. The program will be presented by Mary Gribbin who has been observing the sun through her special solar telescope. She’ll describe the features visible with a solar telescope. If it’s clear, there will be a star party following the meeting. The observatory is located south of Traverse City off Birmley Road, between Garfield and Keystone roads. A Zoom link is available at gtastro.org. There will be a Moon and star party at the Sleeping Bear Dunes, Dune Climb tomorrow starting at 8 pm. That may be our last of the year out there. 2023 promises to have a full slate of star parties out there.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Excerpt from the Sleeping Bear Dunes National Lakeshore calendar posting:

“These events will be cancelled if the sky is not visible due to weather conditions. The decision to cancel is usually made either three hours in advance or by 4:30 p.m. the day prior to the event. Please call park rangers at 231-326-4700, ext. 5005, for a voicemail message with the decision. For the early morning and late evening astronomy events, bring a flashlight for the walk to and from the event. Park rangers and GTAS staff will wear red glow bracelets at the events. For more information about the Grand Traverse Astronomical Society, go to http://www.gtastro.org/.“

 

10/06/2022 – Ephemeris – Artemis I rescheduled

October 6, 2022 Leave a comment

This is Ephemeris for Thursday, October 6th. Today the Sun will be up for 11 hours and 27 minutes, setting at 7:14, and it will rise tomorrow at 7:48. The Moon, 3 days before full, will set at 4:52 tomorrow morning.

Artemis 1 was going to launch on September 27th, But Hurricane Ian had other plans, so the rocket was trundled back to the Vertical Assembly Building. There, a battery or components of the auto destruct mechanism had to be swapped out before they attempted to launch again. All rockets launched from the US are required to be equipped with a destruct package to blow up the rocket if it veers off course, to not endanger lives on the ground. There are other tweaks, including charging or replacing batteries in all the CubeSats that are on board. The next possible launch period runs from November 12th to the 27th, with four blackout dates within that period. The weather should be better, being the tail end of hurricane season.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Artemis I November launch calendar

Artemis I November launch calendar. Dates in green are possible launch dates. I’m not sure, but red dates are also forbidden because the Orion Capsule will experience more than 90 minutes in shadow at a time. It’s powered by solar panels. Light green dates allow a long mission of 1 1/2 orbits of the Moon in the distant retrograde orbit (DRO). The dark green dates can only have 1/2 a DRO. Source: NASA.

10/05/2022 – Ephemeris – Let’s search for the naked-eye planets for this week

October 5, 2022 Leave a comment

This is Ephemeris for Wednesday, October 5th. Today the Sun will be up for 11 hours and 30 minutes, setting at 7:15, and it will rise tomorrow at 7:46. The Moon, 3 days past first quarter, will set at 3:33 tomorrow morning.

Let’s search for the naked-eye planets for this week. The waxing gibbous Moon will be visible near Saturn tonight, with the ringed planet right and above our Moon. Super bright Jupiter is to the far right of the Moon at 9 pm in the east southeast, the brightest star-like object in the sky. Jupiter is seen against the stars of Pisces the fish, while Saturn is spotted in the eastern end of Capricornus the sea goat. I don’t think the stars will be visible with the bright Moon. One star in their direction may be visible and low on the horizon and in line tonight with Saturn and the Moon. It’s Fomalhaut, normally the loneliest star in the sky. Before seven tomorrow morning, the red planet Mars will be high in the south, above the winter constellation of Orion. At that hour, Mercury can also be spotted low in the east.cc

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Evening planets and the Moon tonight

Evening planets and the Moon tonight, October 5, 2022, at 9 pm. Click on the image to enlarge it. Created using Stellarium.

Annotated Gibbous Moon Animation for tonight

Annotated Gibbous Moon Animation for tonight, October 5, 2022, as it might in binoculars or a small telescope. Created using Stellarium, LibreOffice Draw and GIMP.

Translations of some lunar feature names according to Virtual Moon Atlas

Mare Crisium – Sea of Crises
Mare Fecunditatis – Sea of Fertility
Mare Frigoris – Sea of Cold
Mare Imbrium – Sea of Showers
Mare Nectaris – Sea of Nectar
Mare Nubium – Sea of Clouds
Mare Serenitatis – Sea of Serenity
Mare Tranquillitatis – Sea of Tranquility
Mare Vaporum – Sea of Vapors
Montes Apenninus – Apennines Mountains
Sinus Asperitatis – Golfe des Asperites
Sinus Iridium – Bay of Rainbows
Sinus Medii – Bay of the Center

Craters are generally named after astronomers, people of science, or explorers

Note that Mare is pronounced Mar-é

Morning planets Mars and Mercury at 7 am tomorrow

Morning planets, Mars and Mercury with the winter stars and Orion at 7 am tomorrow morning, October 6, 2022. Click on the image to enlarge it. Created using Stellarium.

Telescopic views of Saturn Jupiter and Mars

Telescopic views of Saturn Jupiter and Mars (north up) as they would be seen in a small telescope, with the same magnification. The image doesn’t show it, but the white north polar cap will appear at the top or north limb of Mars. Saturn and Jupiter are shown at 9 pm, Mars at 6 am. I do not show planets less than 10 seconds of arc in diameter. Apparent diameters: Saturn 18.00″, its rings 41.91″; Jupiter 49.69″. Mars 12.44″. Mars’ distance is 69.7 million miles (112.2 million kilometers). Mercury, which isn’t shown, is 7.51″ in diameter and 40.8% illuminated. The ” symbol means seconds of arc (1/3600th of a degree.) Click on the image to enlarge it. Created using Cartes du Ciel (Sky Charts).

Planets and the Moon on a single night

The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on October 5, 2022. The night ends on the left with sunrise on the 6th. Click on the image to enlarge it. Created using my LookingUp program and GIMP.

10/04/2022 – Ephemeris – DART does its job, now we wait and watch.

October 4, 2022 Leave a comment

This is Ephemeris for Tuesday, October 4th. Today the Sun will be up for 11 hours and 33 minutes, setting at 7:17, and it will rise tomorrow at 7:45. The Moon, 2 days past first quarter, will set at 2:14 tomorrow morning.

Last week Monday night NASA’s DART spacecraft successfully smashed into the tiny asteroid Dimorphos, which was slowly orbiting an asteroid named Didymos five times its size, and nearly a half mile in size. Dimorphos is too small and too close to Didymos to be seen in optical telescopes. Even the DART spacecraft’s telescope could only spot it in the last hour before the collision. Astronomers have found that they can see asteroid shapes and moonlets by radar. One technique was to send out radar pulses out from the Arecibo Observatory in Puerto Rico and receive them back with the Green Bank Telescope in West Virginia. Now that Arecibo has been destroyed, astronomers transmit from Goldstone, California.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Dimorphos collision from Hubble and JWST

Dimorphos collision from as seen from Hubble and JWST. The colors aren’t true. Credit: NASA, ESA, CSA, Jian-Yang Li, Cristina Thomas, Ian Wong, Joseph DePasquale, Alyssa Pagan. From CNET web site.

10/03/2022 – Ephemeris – There’s something on the Moon that’s straight and not circular

October 3, 2022 Leave a comment

This is Ephemeris for Monday, October 3rd. Today the Sun will be up for 11 hours and 36 minutes, setting at 7:19, and it will rise tomorrow at 7:44. The Moon, 1 day past first quarter, will set at 12:55 tomorrow morning.

On this program, I try to talk about celestial objects one can see or find with the naked eye. Once found, I do talk about what they would look like in binoculars or small telescope. For those wanting more information, consult my blog bobmoler.wordpress.com where my scripts are posted with more information, illustrations and charts. The thing I’m talking about today is a feature on the Moon that’s visible only two nights a month. The day after first quarter, and the day after last quarter. It’s the straightest thing on the Moon, called the Straight Wall, that’s 67 miles (110 km) long and 900 feet (300 m) high. It is close to the terminator, the Moon’s sunrise line, about halfway from the center of the Moon to the south edge. It’s the thinnest dark line you can imagine.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

The Straight Wall or, officially in Latin, Rupes Recta, is a rectilinear fault. It isn’t really a wall, but a 7 degree slope. Once the Sun rises past seven degrees in that location of the Moon, it disappears. Near local sunset, a day after last quarter, the low sun in its sky shines more on it than the flat ground, so it shows up bright. Click on the image to enlarge it. The information and images were created from Virtual Moon Atlas, which is free software for MS Windows. I have a link to it on this page.

10/02/2022 – Ephemeris Extra – NASA goes on the offensive

October 2, 2022 Leave a comment

Didymus and Dimorphos from DART

DART images of both Didymos, the big one, and Dimorphos, on approach. Credit NASA / JHAPL

This is a slightly revised version of my article in the Stellar Sentinel, the newsletter of the Grand Traverse Astronomical Society. Educators may receive a free PDF copy of this monthly publication via email, which covers astronomical topics and events visible from Northwest Lower Michigan. Send your request, stating your affiliation, to info@gtastro.org.

The score is: Asteroids-billions, NASA-1. It’s a bit unfair, since asteroids have been hitting the Earth for 4.567 billion years or so, and NASA has been around for 64 years before DART spacecraft collided with the asteroid Dimorphos. Hey, this was their first attempt at a small asteroid. As far as the 21st century destructive asteroid score is 1 to NASA’s 1, as far as I know.
That strike was in Chelyabinsk, Russia. That was February 15, 2013. We were all waiting on another asteroid making a close pass of the Earth, when the Chelyabinsk meteoroid exploded 14 miles above the city. Over a thousand people were injured by the blast wave. They saw the bright flash and rushed to the windows to see what it was. Then the blast wave hit, shattering the windows, causing glass cuts for over a thousand people. One building’s wall collapsed, and a fragment fell into a lake outside of town.
NASA’s record in attempting to hit a planetary object dates back to the early 1960s and the nine Pioneer missions to crash a probe on the Moon, sending back pictures all the way down. Back in the early 60s, just hitting a 2,100-mile (3380 kilometer) wide object a quarter of a million miles away was a dicey prospect. It’s one thing to miss the Moon on one side or the other, but to not have enough oomph to even make it all the way is downright embarrassing. NASA did much better by the end of the decade with the Apollo manned landings and bombarding the Moon with used space vehicles for seismic studies of its interior.
NASA actually collided a spacecraft into a comet. That was July 4, 2005, when the impactor part of the Deep Impact spacecraft hit Comet Tempel 1’s nucleus, attempting to study part of its subsurface. The non-impactor part was later renamed EPOXI and went on to fly by the dog-bone shaped Hartley 2 comet nucleus. Another reused comet explorer spacecraft Stardust after collecting cometary dust from Comet Wild 2 (pronounced Vilt 2), and possible interstellar dust penetrating the solar system, and after dropping the sample re-entry capsule back on Earth it ended in solar orbit. Later it was repurposed as the Stardust-NexT mission and flew by Tempel 1 six years later to study the crater the Deep Impact Impactor made in the comet.
To study the effect of a collision of a spacecraft from the Earth despite the fact that Dimorphos cannot be seen is a trick. However, the pair is an eclipsing binary from our point of view, so the brightness of the unresolved pair changes as they eclipse each other.
Before the collision, Dimorphos had an 11.9 hour orbit of Didymos. Dimorphos is a fifth the size of Didymos orbiting it at three times the primary’s radius. If the orbit is near circular, Dimorphos’ orbital velocity is only 0.39 mph (0.63 kph). It should be relatively easy to see a tiny change in Dimorphos’ orbital period.

Last frame Dimorphos fit in from DART

Last frame Dimorphos fit in from DART. Credit NASA / JHAPL.

Two images from the LiciaCube satellite

Two images from the LiciaCube satellite launched from the DART spacecraft 15 days before the impact, and trailing it to record the collision with its wide and narrow angle imagers. Dimorphos does appear to be a rubble pile asteroid from its appearance and the amount of ejecta caused by the impact. The ejecta adds to the effect of the spacecraft’s kinetic energy by pushing away from the asteroid by Newton’s third law of motion. Credit: Italian Space Agency.

Dimorphos ejecta from Atlas

A frame from a time-lapse video taken from the ATLAS Project’s South African observatory of the unresolved Didymos – Dimorphos pair and the expanding ejecta cloud. The asteroid pair developed a dust tail like a comet for a while.
ATLAS is an acronym for a rather apocalyptic title “Asteroid Terrestrial-impact Last Alert System”. Developed by the University of Hawai’i and funded by NASA. It has two telescopes in Hawai’i, one in Chile, and one in South Africa. Credit: NASA/UH.

Days later, Dimorphos was exhibiting a thin dust tail, like a comet.

Now we wait on Earth’s observatories to observe of the period of Dimorphos’ orbit. It should decrease the orbital time.

09/30/2022 – Ephemeris – View the Sun and Moon tomorrow in the Grand Traverse Area!

September 30, 2022 Comments off

This is Ephemeris for Friday, September 30th. Today the Sun will be up for 11 hours and 45 minutes, setting at 7:25, and it will rise tomorrow at 7:40. The Moon, 2 days before first quarter, will set at 9:57 this evening.

There are two observing sessions tomorrow in the Traverse City area with the assistance of the Grand Traverse Astronomical Society. First at the Dennos Museum Center grounds, from 2 to 4 pm, there will be telescopes to safely view the Sun. The Sun’s eleven-year sunspot cycle is getting active again. There will be telescopes to see those sunspots, and special solar hydrogen alpha telescopes to view the Sun’s chromosphere and any prominences above the Sun that day. From 8 to 10 pm, Northwestern Michigan College’s Rogers Observatory will be open for International Observe The Moon Night. There will also be a telescope on the 200 Block of East Front Street to observe the Moon during this time. Of course, all this is contingent on clear or mostly clear skies.

Update: It’s supposed to be nice this weekend, after a week of cold and rain.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Later today I’ll add a Moon Map for tomorrow evening and what the Sun looks like today, which should give a clue to what’s happening on the Sun now.

Sun in white light (How we normally see it with a solar filter)

Sun in white light

The Sun in white light, by the Solar Dynamics Observatory on September 30, 2022. What is seen is the photosphere, the visible “surface” of the Sun, where the energy transport from the interior changes from convection to radiation. The apparent roughness of the surface are the tops of the convection cells, called granules, which are usually about 600 miles wide that bubble up and recede. The numbers label active areas. The dark spots are sunspots, areas of intense magnetic activity. Brighter wispy or splotchy areas are faculae and are associated with sunspots or precursors of a new group forming.  The rotation of the Sun will move the surface features from left to right in this image with north up. Telescopes may show the image upside down or mirror reversed. Click on the image to enlarge it. Credit NASA/SDO.

Sun in the light of the Hydrogen Alpha wavelength. Light absorbed and emitted by the hydrogen atom.

The Sun in Hydrogen-Alpha light

The Sun in Hydrogen-Alpha light, taken at 10:19 EDT today, September 30, 2022. It is in the same orientation as the SDO image above, but may have been taken at a different time of the day. This image was taken from the web page https://gong2.nso.edu/products/tableView/table.php?configFile=configs/hAlpha.cfg I colorized the image to show how it would look in a Hydrogen-Alpha telescope, of which we may have several, both the society’s and personal. The images may be dim since they select one narrow frequency of light from the broad spectrum of white light coming up from the photosphere. Its temperature is 10,000 degrees F. The thin dark markings are called filaments. These are the same thing as the bright prominences seen off the edge or limb of the Sun. Brighter areas of the chromosphere are called plages and are associated with active regions. The Chromosphere is a thin layer of the Sun’s atmosphere lying above the photosphere only 3,000 miles thick, and slightly hotter than the photosphere, its appearance is rougher than the granules of the photosphere. It reminds me of uneven, red grass that hasn’t been mown in a few weeks. They grow and recede in minutes. Sometimes a bright spot will appear in a sunspot group. These are solar flares and are caused by magnetic disruptions in sunspot groups. They last only a relatively few minutes but emit x-rays, electrons and protons as the most energetic explosions in the solar system. The x-rays arrive at Earth in 8 and a half minutes at the speed of light, the particles a day or two later will affect the Earth’s magnetic field if aimed in our direction, causing the aurora (northern and southern lights), and possibly disrupt communications and the power grid. On Earth, it’s called a geomagnetic storm.

The Moon for Saturday evening during the International Observe the Moon Night

The Moon as it should appear at 9 pm EDT, October 1st, 2022

The Moon as it should appear at 9 pm EDT, October 1st, 2022. The telescopic image would be sharper than this. Created using Virtual Moon Atlas.

Download page of maps from the Official 2022 International Observe the Moon Night website.

Images in astronomical telescopes produce images of various orientations. They may be right side up or upside down, mirror reversed or both. Telescopes with an odd number of mirrors produce mirror images. Astronomers are used to it, though they have a preferred orientation… The one their favorable telescope produces.

Come on out!

09/29/2022 – Ephemeris – Previewing October skies

September 29, 2022 Comments off

This is Ephemeris for Thursday, September 29th. Today the Sun will be up for 11 hours and 48 minutes, setting at 7:26, and it will rise tomorrow at 7:39. The Moon, 3 days before first quarter, will set at 9:20 this evening.

Let’s take an early look at the skies for the month of October. Tomorrow I’ll talk about local observing events for Saturday, both afternoon and evening. Back to October. The Sun will still be moving south rapidly. Daylight hours in the Interlochen/Traverse City area and will drop from 11 hours and 42 minutes on Saturday the 1st to 10 hours, 13 minutes at month’s end. The altitude of the Sun above the southern horizon at local noon will be 42 degrees Saturday in the Interlochen area, and will descend to 31 degrees on Halloween. For the Straits of Mackinac area, the Sun will be a degree lower, and the daytime hours will be a bit shorter. The Orionid meteor shower, bits of Halley’s Comet, won’t be bothered by the bright Moon until the early morning on the 21st.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

October Evening Star Chart

October

Star Chart for October 2022 (9 p.m. EDT, October 15, 2022). Click on image to enlarge it. Created using my LookingUp app.

The planets and stars are plotted for the 15th at 9 p.m. EDT in the evening and 6 a.m. for the morning chart. These are the chart times. Note that Traverse City is located approximately 45 minutes behind our time meridian, West 75° longitude. (An hour 45 minutes behind our daylight saving time meridian during EDT). To duplicate the star positions on a planisphere you may have to set it to 1 hour 45 minutes earlier than the current time.

October Morning Star Chart

October morning star chart

Star Chart for October mornings, 2022 (6 a.m. EDT, October 15, 2022). Click on image to enlarge. Created using my LookingUp app.

For a list of constellation names to go with the abbreviations, click here.

  • Pointer stars at the front of the bowl of the Big Dipper point to Polaris, the North Star.
  • Leaky dipper drips on Leo.
  • Follow the arc of the handle of the Big Dipper to the star Arcturus.
  • The Summer Triangle is in red.
  • DracR – Draconid Radiant – Peaks the 8th – Zenithal Hourly Rate < 10 with rare outbursts of a thousand an hour. It’s hindered this year by the full moon.
  • OriR – Orionid Radiant – Peak 21st – Zenithal Hourly Rate = 20

Twilight Limits, Nautical and Astronomical

EDT
Morning Twilight Evening Twilight Dark Night Moon
Date Astro. Nautical Nautical Astro. Start End Illum.
2022-10-01 6h09m 6h43m 20h29m 21h04m 22h45m 6h09m 0.41
2022-10-02 6h10m 6h44m 20h28m 21h02m 23h45m 6h10m 0.53
2022-10-03 6h11m 6h46m 20h26m 21h00m 6h11m 0.64
2022-10-04 6h13m 6h47m 20h24m 20h58m 0h56m 6h13m 0.75
2022-10-05 6h14m 6h48m 20h22m 20h56m 2h14m 6h14m 0.84
2022-10-06 6h15m 6h49m 20h20m 20h54m 3h34m 6h15m 0.91
2022-10-07 6h16m 6h50m 20h18m 20h52m 4h52m 6h16m 0.97
2022-10-08 6h18m 6h52m 20h17m 20h51m 6h08m 6h18m 0.99
2022-10-09 6h19m 6h53m 20h15m 20h49m 1
2022-10-10 6h20m 6h54m 20h13m 20h47m 0.98
2022-10-11 6h22m 6h55m 20h11m 20h45m 0.94
2022-10-12 6h23m 6h57m 20h10m 20h43m 0.88
2022-10-13 6h24m 6h58m 20h08m 20h42m 20h42m 21h00m 0.81
2022-10-14 6h25m 6h59m 20h06m 20h40m 20h40m 21h38m 0.73
2022-10-15 6h26m 7h00m 20h05m 20h38m 20h38m 22h24m 0.64
2022-10-16 6h28m 7h01m 20h03m 20h37m 20h37m 23h18m 0.55
2022-10-17 6h29m 7h03m 20h01m 20h35m 20h35m 0.45
2022-10-18 6h30m 7h04m 20h00m 20h33m 20h33m 0h18m 0.36
2022-10-19 6h31m 7h05m 19h58m 20h32m 20h32m 1h23m 0.27
2022-10-20 6h33m 7h06m 19h57m 20h30m 20h30m 2h29m 0.19
2022-10-21 6h34m 7h08m 19h55m 20h29m 20h29m 3h37m 0.12
2022-10-22 6h35m 7h09m 19h53m 20h27m 20h27m 4h45m 0.06
2022-10-23 6h36m 7h10m 19h52m 20h26m 20h26m 5h54m 0.02
2022-10-24 6h37m 7h11m 19h50m 20h24m 20h24m 6h37m 0
2022-10-25 6h39m 7h12m 19h49m 20h23m 20h23m 6h39m 0.01
2022-10-26 6h40m 7h14m 19h48m 20h21m 20h21m 6h40m 0.04
2022-10-27 6h41m 7h15m 19h46m 20h20m 20h20m 6h41m 0.1
2022-10-28 6h42m 7h16m 19h45m 20h19m 20h40m 6h42m 0.17
2022-10-29 6h44m 7h17m 19h43m 20h17m 21h37m 6h44m 0.27
2022-10-30 6h45m 7h19m 19h42m 20h16m 22h46m 6h45m 0.38
2022-10-31 6h46m 7h20m 19h41m 20h15m 6h46m 0.49

Twilight calendar was generated using Cartes du Ciel (Sky Charts).

See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2018/09/27/.

NASA Calendar of Planetary Events

Oct  1 	Sa            Venus: 5.8° W
     2  Su   3:32 pm  Moon South Dec.: 27.4° S
     2  Su   8:14 pm  First Quarter
     4  Tu   1:01 pm  Moon Perigee: 369,300 km
     5  We  11:51 am  Moon-Saturn: 4.1° N
     8  Sa   2:06 pm  Moon-Jupiter: 2.1° N
     8  Sa   4:59 pm  Mercury Elongation: 18° W (Morning elongation)
     9  Su   4:55 pm  Full Hunter's Moon
    11  Tu   5:49 pm  Moon Ascending Node
    12  We  11:46 pm  Moon-Pleiades: 2.9° N
    15  Sa  12:28 am  Moon-Mars: 4° S
    16  Su   2:12 am  Moon North Dec.: 27.5° N
    17  Mo   6:21 am  Moon Apogee: 404300 km
    17  Mo  11:41 am  Moon-Pollux: 2° N
    17  Mo   1:15 pm  Last Quarter
    21  Fr   1:39 pm  Orionid Shower: ZHR = 20
    22  Sa   4:47 pm  Venus Superior Conjunction. Enters evening sky
    25  Tu   6:49 am  New Moon
    25  Tu   7:00 am  Partial Solar Eclipse (Parts of Europe, Africa and Asia) 
    26  We   2:30 am  Moon Descending Node
    27  Th  10:48 pm  Moon-Antares: 2.3° S
    29  Sa  10:48 am  Moon Perigee: 368300 km
    29  Sa   9:04 pm  Moon South Dec.: 27.5° S
Nov  1  Tu            Venus: 2.6° E

All event times are given for UTC-4 hr: Eastern Daylight Saving Time.

Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html.

If you go to the above site, you can print out a list like the above for the entire year or calendar pages for your time zone.

Sun and Moon Rising and Setting Events

LU              Ephemeris of Sky Events for Interlochen/TC
October 2022          Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Sat  1| 07:40a  07:23p  11:42 | 08:26p  06:37a |      Set  10:44p   39%|
+------+-----------------------+----------------+-----------------------+
|Sun  2| 07:42a  07:21p  11:39 | 08:24p  06:39a |F Qtr Set  11:44p   50%|
|Mon  3| 07:43a  07:19p  11:36 | 08:22p  06:40a |      Set  12:55a   61%|
|Tue  4| 07:44a  07:17p  11:33 | 08:20p  06:41a |      Set  02:14a   72%|
|Wed  5| 07:45a  07:15p  11:30 | 08:18p  06:42a |      Set  03:33a   82%|
|Thu  6| 07:46a  07:14p  11:27 | 08:16p  06:43a |      Set  04:52a   90%|
|Fri  7| 07:48a  07:12p  11:24 | 08:15p  06:45a |      Set  06:08a   96%|
|Sat  8| 07:49a  07:10p  11:20 | 08:13p  06:46a |      Set  07:22a   99%|
+------+-----------------------+----------------+-----------------------+
|Sun  9| 07:50a  07:08p  11:17 | 08:11p  06:47a |Full  Rise 07:19p  100%|
|Mon 10| 07:51a  07:06p  11:14 | 08:09p  06:48a |      Rise 07:39p   99%|
|Tue 11| 07:53a  07:05p  11:11 | 08:08p  06:50a |      Rise 08:02p   95%|
|Wed 12| 07:54a  07:03p  11:08 | 08:06p  06:51a |      Rise 08:28p   90%|
|Thu 13| 07:55a  07:01p  11:05 | 08:04p  06:52a |      Rise 08:59p   83%|
|Fri 14| 07:57a  06:59p  11:02 | 08:02p  06:53a |      Rise 09:37p   75%|
|Sat 15| 07:58a  06:58p  10:59 | 08:01p  06:54a |      Rise 10:23p   66%|
+------+-----------------------+----------------+-----------------------+
|Sun 16| 07:59a  06:56p  10:56 | 07:59p  06:56a |      Rise 11:17p   57%|
|Mon 17| 08:00a  06:54p  10:53 | 07:58p  06:57a |L Qtr Rise 12:18a   47%|
|Tue 18| 08:02a  06:52p  10:50 | 07:56p  06:58a |      Rise 01:22a   38%|
|Wed 19| 08:03a  06:51p  10:47 | 07:54p  06:59a |      Rise 02:29a   29%|
|Thu 20| 08:04a  06:49p  10:44 | 07:53p  07:01a |      Rise 03:36a   20%|
|Fri 21| 08:06a  06:48p  10:41 | 07:51p  07:02a |      Rise 04:44a   13%|
|Sat 22| 08:07a  06:46p  10:38 | 07:50p  07:03a |      Rise 05:53a    7%|
+------+-----------------------+----------------+-----------------------+
|Sun 23| 08:08a  06:44p  10:36 | 07:48p  07:04a |      Rise 07:04a    3%|
|Mon 24| 08:10a  06:43p  10:33 | 07:47p  07:06a |      Rise 08:18a    0%|
|Tue 25| 08:11a  06:41p  10:30 | 07:45p  07:07a |New   Set  06:53p    0%|
|Wed 26| 08:12a  06:40p  10:27 | 07:44p  07:08a |      Set  07:21p    3%|
|Thu 27| 08:14a  06:38p  10:24 | 07:42p  07:09a |      Set  07:55p    8%|
|Fri 28| 08:15a  06:37p  10:21 | 07:41p  07:10a |      Set  08:39p   16%|
|Sat 29| 08:16a  06:35p  10:18 | 07:40p  07:12a |      Set  09:36p   25%|
+------+-----------------------+----------------+-----------------------+
|Sun 30| 08:18a  06:34p  10:16 | 07:38p  07:13a |      Set  10:45p   36%|
|Mon 31| 08:19a  06:32p  10:13 | 07:37p  07:14a |      Set  12:02a   47%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

Generated using my LookingUp for DOS program.

09/28/2022 – Ephemeris – Searching for the naked-eye planets for this week

September 28, 2022 Comments off

This is Bob Moler with Ephemeris for Wednesday, September 28th. Today the Sun will be up for 11 hours and 51 minutes, setting at 7:28, and it will rise tomorrow at 7:38. The Moon, 3 days past new, will set at 8:51 this evening.

Let’s search for the naked-eye planets for this week. The thin sliver of a waxing crescent Moon may be visible very low in the southwest at 8 pm. We’re back to two naked-eye planets in the evening sky. Jupiter was in opposition from the Sun on Monday, and closest to the Earth. As it gets darker, Jupiter will be seen first low in the east. At that time, Saturn can be seen in the southeast. Jupiter is seen against the stars of Pisces the fish, while Saturn is spotted in the eastern end of Capricornus the sea goat. At 6:45 tomorrow morning, Mars will be high in the south, above the winter constellation of Orion, and Jupiter will be very low in the west. Venus will rise in the east at 7:02 into bright twilight.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Three day old Moon in twilight

What the three-day-old Moon might look like in binoculars in twilight at 8 pm tonight, September 28, 2022. Illumination of the night part of the Moon will be provided by the bright gibbous Earth in its sky. The phenomenon is called earth shine. Created using Stellarium.

Evening planets finder animation

Evening planet finder animation by showing Jupiter and Saturn with and without the constellation lines. For 9 pm this evening, September 28, 2022. Click on the image to enlarge it. Created using Stellarium and GIMP.

Morning planets and bright winter stars

Morning planet Mars with the last gasp of the new evening planet Jupiter and bright winter stars at 6:45 tomorrow morning, September 29, 2022. Click on the image to enlarge it. Created using Stellarium.

Telescopic views of Saturn Jupiter and Mars

Telescopic views of Saturn, Jupiter and Mars (north up) as they would be seen in a small telescope, with the same magnification. The image doesn’t show it, but the white north polar cap will appear at the top or north limb of Mars. Saturn and Jupiter are shown at 10 pm, Mars at 6 am. Apparent diameters: Saturn 18.17″, its rings 42.33″; Jupiter 49.86″. Mars 11.01″. Mars’ distance is 73.8 million miles (118.7 million kilometers). The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).

One surprising thing about Mars in a telescope is how bright it is. That’s because it’s much closer to the Sun than Jupiter or Saturn, even thought it has a lower albedo (reflectance) than those planets.

Planets and the Moon on a single night

The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on September 28, 2022. The night ends on the left with sunrise on the 29th. Click on the image to enlarge it. Created using my LookingUp program and GIMP.

09/27/2022 – Ephemeris – Finding the constellation of Perseus the hero

September 27, 2022 Comments off

This is Ephemeris for Tuesday, September 27th. Today the Sun will be up for 11 hours and 54 minutes, setting at 7:30, and it will rise tomorrow at 7:37. The Moon, 2 days past new, will set at 8:28 this evening.

Close to the horizon, but rising in the northeast in the evening, is the constellation of Perseus the Greek hero, holding as his prize the severed head of Medusa. To me, the stars don’t seem to match the figure in the stars. It’s either the Greek letter pi (π) tilted to the left or the cartoon roadrunner running up the sky. Perseus’ brightest star is Mirfak in the middle of the top of the letter π, or back of the roadrunner. Using a pair of binoculars to look towards Mirfak, one can see many more stars, just below naked eye visibility near it. It’s a very loose star cluster called the Alpha (α) Persei Association, α Persei being a catalog designation for Mirfak. And Mirfak is actually in the association. Unlike some bright stars, who are just foreground stars.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

For my take on the mythology featuring Perseus, see The Great Star Story of Autumn. It’s way too long for my short radio program. For Hollywood’s treatment of the story, see Clash of the Titans.

Perseus finder animation

Perseus finder using the animated GIF to show the star field, constellation lines and names, and Perseus as art. Cassiopeia is included as a means to find the dimmer Perseus below it on autumn evenings. Algol, another important star and the second-brightest star of Perseus, is also labeled. I normally cover it around Halloween, but if you can’t wait, type Algol in the search box at the upper right. Created using Stellarium, LibreOffice Draw, and GIMP.

Alpha Persei Association

The Alpha Persei Association. The brightest star is Mirfak (Alpha Persei). This is a small section of a photograph taken February 18, 2017, Canon EOS Rebel T5, 121 seconds, f/3.5, 18 mm fl., ISO 3200. Credit Bob Moler.