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

03/19/2023 – Ephemeris Extra – Zodiacal light

This is the time of year when the faint glow can be seen in the west at the end of asttronomical twilight in the evening. It’s called zodiacal light. It is difficult to spot the first time. The final twilight glow tends to be horizontal, along the horizon, while źodiacal light has a thin pyramidal shape tilted to the left along the constellations of the zodiac. Right now, Venus appears in the heart of the glow.

Some of my older blog posts also cover zodiacal light with images of it I’ve taken, so search for zodiacal light in the spot provided.

On a personal note: I’m expected to be discharged from rehab by month’s end. I’m hoping that a couple of weeks after that, I can get back to a regular schedule. Here’s hoping.

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!

02/13/2023 – Ephemeris – Follow the Drinking Gourd

This is Bob Moler with Ephemeris for Monday, February 13th. Today the Sun will be up for 10 hours and 21 minutes, setting at 6:08, and it will rise tomorrow at 7:44. The Moon, at last quarter today, will rise at 2:51 tomorrow morning.

In the decades before the Civil War, runaway slaves would travel, often at night, northward from the slave states in the south to the northern free states and Canada over the metaphorical Underground Railroad following the Drinking Gourd, the Big Dipper as their compass. For millennia, the North Pole of the sky had been passing near the handle of the Big Dipper or bear’s tail. As an amateur astronomer, who loves the dark, starlit skies, I’ve noticed that everyone is the same color in the dark! This year the Grand Traverse Astronomical Society will, once again, team with the Sleeping Bear Dunes for more Sun and star parties.

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

“Follow the Drinking Gourd,” a show at the Virginia Living Museum’s Abbit Planetarium based on Jeanette Winter’s children’s book of the same name, tells the story of a slave family who used the stars to make their way north. Visitors can watch the free show Saturdays in February. (Courtesy of Virginia Living Museum) Via Daily Press, Newport News, VA.

02/10/2023 – Ephemeris – Finding Orion’s greater hunting dog, Canis Major

This is Bob Moler with Ephemeris for Friday, February 10th. Today the Sun will be up for 10 hours and 13 minutes, setting at 6:04, and it will rise tomorrow at 7:49. The Moon, 3 days before last quarter, will rise at 11:14 this evening.

The great winter constellation or star group, Orion the hunter, is located in the southern sky at 9 p.m. His elongated rectangle of a torso is vertical. In the center of the rectangle are three stars in a line that make his belt. As a hunter, especially one of old, he has two hunting dogs. The larger, Canis Major, can be found by following the three belt stars of Orion down and to the left. They point to Sirius, the brightest nighttime star, also known as the Dog Star. It’s in the heart of a stick figure dog low in the southeast facing Orion that appears to be begging. There’s a fine star cluster, called Messier, or M 41, at the 5 o’clock position from Sirius. It’s easily visible in binoculars or a small telescope.

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

Orion and Canis Major animation for earlier than 9 in the evening. Created using Stellarium and GIMP.

02/09/2023 – Ephemeris – Orion’s Belt stars

This is Ephemeris for Thursday, February 9th. Today the Sun will be up for 10 hours and 10 minutes, setting at 6:02, and it will rise tomorrow at 7:50. The Moon, halfway from full to last quarter, will rise at 10:07 this evening.

Orion’s belt of three stars is one of the most noticeable star groupings in the sky. There are no other groups of three bright stars in a straight line visible anywhere else in the sky. The star’s names from left to right are Alnitak, Alnilam and Mintaka. They are actually a bit farther away than the other bright stars of Orion. Alnilam, the center star, is over three times the distance of red giant Betelgeuse above them and over twice as far as blue white giant star Rigel below them. Alnilam is 375 thousand times brighter than the Sun according to the SIMBAD Astronomical Database. These three stars were also known as Frigga’s Spindle by the Norsemen. Frigga also known as Freya is the goddess from which we get the name of the day of the week Friday.

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

Orion’s named stars, including the belt stars. Created using Stellarium.

02/08/2023 – Ephemeris – Let’s find where the naked-eye planets have wandered off to this week

This is Bob Moler with Ephemeris for Wednesday, February 8th. Today the Sun will be up for 10 hours and 7 minutes, setting at 6:01, and it will rise tomorrow at 7:52. The Moon, 3 days past full, will rise at 9:02 this evening.

Let’s find where the naked-eye planets have wandered off to this week. Very early after sunset, Venus can be spotted low in the southwest by 6:30 pm. Mars, and Jupiter will be visible this evening by 7 pm. Mars will be above Orion in the southeast and is pulling away from the Pleiades. Jupiter will be in the southwest. Saturn is way below Venus now, so it’s gone until it reappears in the morning sky in a few months. It will make the crossing to the morning sky with its solar conjunction on the 16th. Jupiter will cross paths with Venus on March 1st. Mercury is now in the morning sky, but too close to the Sun to be visible.

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 naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on February 8, 2023. The night ends on the left with sunrise on the 9th. Click on the image to enlarge it. Created using my LookingUp app and GIMP.

02/07/2023 – Ephemeris – A new view on the creation of our Moon

Feb 7. This is Bob Moler with Ephemeris for Tuesday, February 7th. Today the Sun will be up for 10 hours and 5 minutes, setting at 5:59, and it will rise tomorrow at 7:53. The Moon, 2 days past full, will rise at 7:58 this evening.

Is this how the Moon came to be? After the Apollo missions, NASA decided to look at the crust of the Moon which apparently is much like the Earth’s and came up to the conclusion that the Moon was formed by a collision with the Earth by a Mars sized body that they’ve called Thea, named after the mother of the twins Apollo and Artemis. It crashed into the Earth at about a 45-degree angle, and caused a ring of debris around the Earth that would be maintained for a long time. In a newer simulation, the collision could actually create two blobs of material, a large one that became our Moon, in orbit, with about one percent of the Earth’s mass, and a smaller mass that fell back onto the Earth.

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

A new simulation on how the Moon formed. Credit: PBS.

02/06/2023 – Ephemeris – The Persephone Period is ending

This is Ephemeris for Monday, February 6th. Today the Sun will be up for 10 hours and 2 minutes, setting at 5:58, and it will rise tomorrow at 7:54. The Moon, 1 day past full, will rise at 6:53 this evening.

All over the Interlochen Public Radio broadcasting region, the Persephone period is ending. What’s the Persephone period? The Persephone period is a time when the daylight hours drop below 10 hours a day. Around here, this would affect natural lighted greenhouses, since our world is still covered in snow. This is because plants don’t grow very well with less than 10 hours of sunlight. It is named for the Greek goddess Persephone, who is goddess of crops that are sewn. She was kidnapped by her uncle Hades, the god of the Underworld, and was made his bride and became Queen of the Underworld. However, every time she went down to the underworld all the plants on the surface of the earth died, so Zeus made an arrangement with Hades that she could only be in the underworld for part of the year.

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

Statue of Persephone-Isis at the Heraklion Archaeological Museum, Crete. Credit: Wolfgang Sauber.

In the Interlochen/ Traverse City area, the Persephone period runs from about November 5th to about February 6th. Of course, we make up for it in late spring and early summer with up to 15 1/2 hours of daylight near the summer solstice.