05/30/2023 – Ephemeris – The Terminator… No, not Arnold Swartzenegger

This is Ephemeris for Tuesday, May 30th. Today the Sun will be up for 15 hours and 17 minutes, setting at 9:19, and it will rise tomorrow at 6:01. The Moon, 3 days past first quarter, will set at 3:59 tomorrow morning.

The Moon tonight is getting to be a fatter and fatter gibbous phase, until Saturday, when it will be full. The Moon will be blindingly bright in telescopes of low magnification. As always the case with the Moon, the most detail is seen near the terminator. The terminator, in the case of the waxing moon, is the sunrise line. After full moon, the terminator becomes the sunset line. This is where the shadows are longest, showing the detail of the craters. Farther from the terminator, where the Sun is higher in the Moon’s sky, shadows are short or nonexistent. Giving the surface a flat appearance. Even lacking wind and water, there is still erosion on the Moon, coming from meteoroid and asteroid impacts and their ejecta. And the breakdown of rocks due to the extreme day-night temperature swings.

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 first quarter plus 3 day old Moon tonight at around 10 pm with labels of selected features. Gassendi is a great crater to check out with a telescope. It is only really visible when near the terminator. A hint: Mare (pronounced Mar-e) means sea. Created using Stellarium, LibreOffice Draw, and GIMP.

05/29/2023 – Ephemeris Extra – Clouds will cause the Star Party, tonight, to be canceled, however…

The Grand Traverse Astronomical Society members will not come out this afternoon and evening to The Dune Climb at Sleeping Bear Dunes National Lakeshore if it stays cloudy. However, the park rangers will be there unless it is raining with alternate activities.

The next scheduled Sun & Star Party will be May 27, the Saturday of the Memorial Day weekend.

03/21/2023 – Ephemeris Extra – Spring has sprung without me

Being in the hospital and now in inpatient rehab one loses a sense of time. So the vernal equinox snuck by me unnoticed. My view of the outside world is another part of the hospital, a part of the HVAC system, and a piece of sky.

Yesterday, the Sun passed over the Earth’s equator, heading northward. The Sun is gradually setting at the South Pole and rising at the North Pole. Folks like me who live in the Northern Hemisphere are experiencing longer daylight than those south of the equator, who are beginning autumn. The daylight hours will increase daily until June 21st, the summer solstice. In the Interlochen/Traverse City area, that will be 15 hours and 34 minutes.

The cause of the Earth’s seasons is not our varying distance from the Sun in our eliptical orbit of the Sun of 93 million plus or minus a million and a half miles.By the way, the Earth is currently moving away from the Sun. It will be farthest from the Sun around July 4th or 5th.

Our perception of the advance of spring, besides the gradully warming temperatures and increasing daylight hours, will be the height of the Sun’s path in the sky, and the position of the Sun’s rise and set points on the horizon. All these annual changes are angles having to do with one’s latitude (an angle), Earth’s position in orbit (an angle), and the tilt of the Earth’s axis to it’s orbit (more angles).

Bob

03/17/2023 – Ephemeris Extra – I’m now in Rehab

I’m hoping to be home by the end of the month. My daughter wants me to take some additional time before plunging back in. I don’t actually disagree with her.

A local event I’d like to preview is the Grand Traverse Astronomical Society’s part in International Astronomy Day, Saturday, April 29th. This annual event will be held at the Sleeping Bear Dunes National Lakeshore. I’ve been out of the loop on this, but the GTAS may be offering solar and night viewing. The sun has been unexpectedly active this year, and it is our star. Stay tuned.

Bob

02/14/2023 – Ephemeris Extra – Back in the hospital again

It’s the cost of getting old. I hope to get back soon. Happy St Valentine Day!

02/03/2023 – Ephemeris – Space Rocks with Joe Brooks

This is Ephemeris for Friday, February 3rd. Today the Sun will be up for 9 hours and 54 minutes, setting at 5:54, and it will rise tomorrow at 7:58. The Moon, 2 days before full, will set at 7:54 tomorrow morning.

Space Rocks with Joe Brooks, will be presented by, the Grand Traverse Astronomical Society’s own meteorite expert, Joe Brooks, at this evening’s meeting of the Grand Traverse Astronomical Society at 8 p.m. at Northwestern Michigan College’s Rogers Observatory. He even has a meteorite of a type called Howardite, that the Dawn spacecraft, which orbited the asteroid Vesta, has determined to be from there. Everyone is welcome. And there is a Zoom component to attend remotely. A link and instructions will be found on the society’s website, gtastro.org. This year, again, the society will be teaming up with the Sleeping Bear Dunes National Lakeshore for star parties this late spring, summer, and early fall.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

02/02/2023 – Ephemeris – It’s Groundhog Day again

This is Ephemeris for Groundhog Day, Thursday, February 2nd. Today the Sun will be up for 9 hours and 51 minutes, setting at 5:52, and it will rise tomorrow at 7:59. The Moon, 3 days before full, will set at 7:16 tomorrow morning.

I’m not sure if Punxsutawney Phil will see his shadow this morning or not, but February 2nd was a special day to the ancients. It is also Candlemas day for the Catholic Church. It is also celebrated as a cross-quarter day. The middle of the season of Winter, though the exact date of the middle of winter is the 4th. And if Phil sees his shadow, and we do get 6 more weeks of winter, that’s OK too. By the calendar, it’s actually more like 6 ½ weeks to the vernal or spring equinox and the official end of winter. Of the other cross-quarter days, only one stands out today. It’s May 1st, May Day. The way this year has been going, winter has had a hard time getting started. The temperatures are above normal and the snowfall below normal.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

Poor Punxsutawney Phil, rousted out of his mid winter nap. They might be in the middle of a blizzard today. Credit: http://www.fuzzytoday.com

01/24/2023 – Ephemeris – The “green” comet’s designation is C/2022 E3 (ZTF)

This is Bob Moler with Ephemeris for Tuesday, January 24th. Today the Sun will be up for 9 hours and 29 minutes, setting at 5:40, and it will rise tomorrow at 8:09. The Moon, 3 days past new, will set at 9:26 this evening.

Yesterday, I began covering new comet that’s in our skies. I didn’t mention its name. It’s got an odd one. Its designation is C/2022 E3, which means it was discovered in 2022. E means that it was in the 5th half month of the year, which puts it in early March, and three is the third object in that period. The name that goes along with it is actually the initials ZTF which stand for Zwicky Transient Facility which is actually 2 observatory complexes, one in California and the other one in Chile which looks for things that go bump in the night. Basically, things that change their brightness or movement in the short period of time. They cover the whole sky eventually and get back and see what’s changed. The facility is named after astronomer Fritz Zwicky.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

The track of Comet ZTF from tonight at 9 pm to January 30, 2023. Two constellations are named. The unnamed constellation line running through the image is the tail of Draco the dragon. The red dots are galaxies, much dimmer than the comet. The depiction of the comet’s tail simply suggests the direction of the tail. Comet positions are set for 9 pm on the dates shown. For each position, the date and magnitude are shown as in “mm-dd mag”, the year is omitted. Magnitudes are very subjective.

01/04/2023 – Ephemeris – Let’s see where the naked-eye planets have wandered off to this first week of 2023

This is Ephemeris for Wednesday, January 4th. The Sun will rise at 8:20. It’ll be up for 8 hours and 55 minutes, setting at 5:15. The Moon, 2 days before full, will set at 7:41 tomorrow morning.

Let’s see where the naked-eye planets have wandered off to this first week of 2023. Very early after sunset, Venus might be spotted very low in the southwest, even by 5:45 pm. Mars, Jupiter and Saturn will be visible this evening, in the east to southwestern sky at 7 pm. Mars will be in the east-southeast. Jupiter is the brightest of the three in the south-southwest, while dimmer Saturn will be very low in the southwest at that time. Mars will be above Orion as it rises in the early evening. As Orion straightens up as it moves to the south later in the evening, Mars will be to the upper right of it in Taurus near the red star Aldebaran. Saturn, the westernmost of the bright planets, will set around 8:29 this evening.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

Venus, Saturn and Jupiter at 6 pm, or about 45 minutes after sunset. Created using Stellarium.

Mars, Jupiter, Saturn and the Moon at 8 pm tonight, January 4, 2023, in this panorama. Created using Stellarium.

The Moon tonight as it might be seen in binoculars or low power telescopes tonight, January 4, 2023. Labels of prominent features are alternately shown with the unlabeled chart. Created using Stellarium, LibreOffice Draw and GIMP.

Telescopic views of Saturn Jupiter and Mars (north up) as they would be seen in a small telescope, with the same magnification. The image of Mars doesn’t show it, but the white north polar cap will appear at the top or north limb of Mars. The planets are shown at 8 pm tonight, January 4, 2023. Apparent diameters: Saturn 15.70″, its rings 36.57″; Jupiter 38.86″. Mars 14.12″. Mars’ distance is 61.6 million miles (99.1 million kilometers). 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).

The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on January 4, 2023. The night ends on the left with sunrise on the 5th. Click on the image to enlarge it. Created using my LookingUp app and GIMP.

07/20/2022 – Ephemeris – Let’s search for the naked-eye planets for this week

This is Ephemeris for Wednesday, July 20th. Today the Sun will be up for 15 hours and 5 minutes, setting at 9:21, and it will rise tomorrow at 6:17. The Moon, at last quarter today, will rise at 1:13 tomorrow morning.

Let’s search for the naked-eye planets for this week. All but one of the naked-eye planets are in the morning sky, That one is Mercury, too close to the Sun to be seen in the evening. At 5:15 am tomorrow, the planets will be spread out from brilliant Venus low in the east-northeast to Saturn higher in the south-southwest. Mars will be a lot higher than Venus in the east-southeast. The waning crescent Moon will be just right of Mars. Jupiter is farther to the right in the southeast. Mars is dimmer than Jupiter, but is slowly getting brighter as the Earth creeps up on it. Saturn ends the line of planets lower than Jupiter in the south-southwest. Tonight, Saturn will rise about 10:30 pm, though it won’t be an official evening planet until it rises before sunset, which won’t happen until mid-August.

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 morning planets and the Moon at 5:15 am tomorrow morning, July 21, 2022. The planets and Moon actually appear in a straight line in the sky, being placed along the ecliptic, or path of the Sun in the sky. The ecliptic is a great circle on the celestial sphere. Click on the image to enlarge it. The span of the planets from Venus to Saturn is 129 degrees. Click on the image to enlarge it. Created using Stellarium.

Animated last quarter Moon at 5:15 tomorrow morning, July 21, 2022, with labels. Created using Stellarium and LibreOffice.

Translations

Mare Frigoris – Sea of Cold
Mare Humorum – Sea of Moisture
Mare Imbrium – Sea of Showers
Mare Nubium – Sea of Clouds
Mare Serenitatis – Sea of Serenity
Mare Vaporum – Sea of Vapors
Montes Apenninus – Apennine Mountains
Oceanus Procellarum – Ocean of Storms
Sinus Iridium – Bay of Rainbows
Sinus Medii – Central Bay

Note that Mare is pronounced Mar-é

Views of Saturn, Jupiter, and Venus (north up) as they would be seen in a small telescope, with the same magnification, tomorrow morning at 5:15 am, July 21, 2022. I do not show planets less than 10 seconds of arc in diameter. Apparent diameters: Saturn 18.56″, its rings 43.24″; Jupiter 43.47″. Mars is not shown, its apparent diameter is 7.84″; Venus 11.10″. 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).

The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on July 21, 2022. The night ends on the left with sunrise on the 21st. Notice that all the naked-eye planets except Mercury are in the morning sky now. Click on the image to enlarge it. Created using my LookingUp program.