Ephemeris: 02/19/2025 – All the naked-eye planets are seen in the evening this week

February 19, 2025 Comments off

Ephemeris: 02/19/2025 – Where have the naked-eye planets wandered off to this week?

This is Ephemeris for Wednesday, February 19th. Today the Sun will be up for 10 hours and 40 minutes, setting at 6:17, and it will rise tomorrow at 7:34. The Moon, 1 day before last quarter, will rise at 1:59 tomorrow morning.

Let’s take our weekly look at the whereabouts of the naked-eye planets. At 7 PM this evening four of the five naked eye planets will be out. Starting from the West we have Venus the brightest of all in the west southwest. Far below it, near the horizon, will be the much dimmer Saturn, which we are about to lose, or may already have, to the evening twilight. Jupiter, the second-brightest planet will be high in the south. It has reversed course and is heading back eastward now. Farther below it is the spectacular constellation of Orion the hunter. The fourth planet out is Mars, the third-brightest planet now, with its distinctive reddish hue, west of the stars Castor and Pollux in Gemini, and in the east-southeast.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

Addendum

A 7 PM February 19, 2025 planet panorama
A 7 PM February 19, 2025 planet panorama. Venus and Saturn are in the west-southwest, and Jupiter is in the south-southeast. Mars is in the east. This looks like the last time Saturn will be visible in the evening sky for a while. The in this projection the ecliptic (not shown) is a straight line, so the planets and Moon nearly line up, but the horizon is curved. Click or tap on the image to enlarge it. Created using Stellarium.
The Moon tomorrow morning
The Moon tomorrow morning, February 20, 2025, as it might appear in a small telescope at 6 AM, in the south. Selected features are labeled. Created using Stellarium, LibreOffice Draw, and GIMP.
Telescopic Venus, Jupiter and Mars
Telescopic Venus, Jupiter and Mars (north up) as they would be seen in a small telescope with the same magnification. All the planets are shown for tonight, 8 PM, February 19, 2025. Apparent diameters: Venus 42.4″ and rapidly growing as it approaches us, 22.9% illuminated, it now appears larger than Jupiter; Jupiter 40.8″; Mars, 11.8″. Planetary surface detail is more subtle than shown here. The ” means seconds of arc, or 1/3600th of a degree. Click or tap 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
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on February 19, 2025. The night ends on the left with sunrise on the 20th. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.
A low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow
This is a low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow, February 19 and 20, 2025. Some of the columns are self-explanatory, others not. The transit column is the time that the body crosses the meridian and is due south. Elong, for elongation, is the angle between the Sun and that body. RA is right ascension, which is the object’s east-west position on the celestial sphere in hours and minutes. Dec is declination which is the north-south position of the object on the celestial sphere in degrees and minutes. R is the distance of that object from the Sun in astronomical units. An astronomical unit is about 93 million miles or 150 million kilometers. And Delta is the distance of that object from the Earth, also in astronomical units. I omit the ‘m’ in am and pm for compactness. The data was generated using my LookingUp for DOS app and displayed as a table by my Ephemeris Helper app.
Categories: Ephemeris Program, Naked-eye planets, Observing, Planets Tags: , , , , ,

Ephemeris: 02/18/2025 – Finding Orion’s greater hunting dog

February 18, 2025 Comments off

This is Ephemeris for Tuesday, February 18th. Today the Sun will be up for 10 hours and 37 minutes, setting at 6:15, and it will rise tomorrow at 7:36. The Moon, 2 days before last quarter, will rise at 12:52 tomorrow morning.

The great winter constellation or star group Orion the Hunter, is located in the south-southeastern sky at 8 p.m. His elongated rectangle of a torso is almost vertical. In the center of the rectangle are three stars in a line that mark 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. There lies the brilliant star called Sirius, 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 M41, at the 5 o’clock position from Sirius, 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). Times will be different for other locations.

Addendum

An animated GIF Finder for Canis Major the great dog of Orion in three frames
An animated GIF Finder for Canis Major the great dog of Orion in three frames. First, the stars as you would see them in the sky; second with constellation lines and a pointer from the belt of Orion to Sirius; third with the fanciful figures of the constellations. Created using Stellarium, LibreOffice Draw, and GIMP.
Categories: Constellations, Ephemeris Program, Observing Tags: , ,

Ephemeris: 02/17/2025 – Follow the Drinking Gourd

February 17, 2025 Comments off

This is Ephemeris for President’s Day, Monday, February 17th. Today the Sun will be up for 10 hours and 35 minutes, setting at 6:14, and it will rise tomorrow at 7:38. The Moon, 3 days before last quarter, will rise at 11:47 this evening.

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 Great Bear’s tail and now up to the star Polaris in the Little Dipper. 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). Times will be different for other locations.

Addendum

Runaway slaves following the Drinking Gourd
“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. Via Daily Press, Newport News, VA.
Precession circle
The path of the north pole of the sky (celestial sphere) over time. The celestial north pole is still approaching Polaris. In the past the Big Dipper was closer to the north pole of the sky than it is now. Polaris will be it closest to the north pole around the year 2110. Source: taichifuture.com/cosmology.html.

Categories: Asterism, Astronomical History, Ephemeris Program Tags: , , , , , ,

Ephemeris: 02/14/2025 – A Valentine’s Day Rendezvous

February 14, 2025 Comments off
The Heart Nebula, IC 1805, photographed by GTAS member Daniel Dall’Olmo. Today’s topic is also related to Valentine’s Day: an asteroid named for the god of love and the spacecraft that kissed it.

This is Ephemeris for St Valentine’s Day, Friday, February 14th. Today the Sun will be up for 10 hours and 26 minutes, setting at 6:10, and it will rise tomorrow at 7:42. The Moon, 2 days past full, will rise at 8:34 this evening.

Twenty-five years ago to the day, the NEAR-Shoemaker* spacecraft entered into orbit of the near Earth asteroid 433 Eros. It wasn’t originally planned to enter orbit of the asteroid named after the Greek god of love on Valentine’s Day, 2000. It arose after an aborted course correction a year earlier. After solving the problem, a new course was plotted and NEAR-Shoemaker was gently inserted into orbit of this 21 mile long asteroid, shaped like a bent bread stick with a bite taken out of the center of it. The spacecraft spent almost a year orbiting Eros at various altitudes. The spacecraft ended its mission by gently dropping onto the middle of the asteroid, where it stayed alive for ten days before succumbing to the cold.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

* The spacecraft was launched as NEAR for Near Earth Asteroid Rendezvous. It was renamed en route NEAR-Shoemaker after Eugene Shoemaker’s death in 1997. Shoemaker was a geologist who trained Apollo astronauts and proved that the Barringer Meteor Crater was indeed an impact site and not a volcanic caldera, and that most of the Moon’s craters were also caused by impacts. He with his wife Carolyn and David Levy discovered Comet Shoemaker-Levy 9, which crashed into Jupiter in 22 pieces in July 1994, gaining worldwide attention.

Addendum

Six views of Eros as it tumbled
“These color images of Eros were taken by the NEAR probe on February 12, 2000, at a distance of 1,800 kilometers, during the final approach imaging sequence before insertion into orbit. The images show the approximate color of Eros as it would be seen with the naked eye.” Click or tap on the image to enlarge it. Credit
NASA/JPL/JHUAPL. Caption from: https://eros2019.imcce.fr/eros.html via Google Translate.
An Artist’s rendition of the Near-Shoemeker spacecraft resting on the surface of 433 Eros. Credit Johns Hopkins University Applied Physics Laboratory.

    Categories: Asteroid, Ephemeris Program, NASA, Near Earth Object Tags: , ,

    Ephemeris: 02/13/2025 – A personal story

    February 13, 2025 2 comments

    This is Bob Moler with Ephemeris for Thursday, February 13th. Today the Sun will be up for 10 hours and 23 minutes, setting at 6:08, and it will rise tomorrow at 7:44. The Moon, 1 day past full, will rise at 7:29 this evening.

    Whenever I hear the term DEI used by someone that questions the qualifications of a person, or they speak of being apprehensive when they see someone of color or a woman piloting an airplane or having great responsibilities, I get angry. As a not so amateur astronomer in the past I’ve worked in and lectured at planetariums though I didn’t have the academic qualifications for, or sheepskin to prove it. I’m not sure that a black person could get away with what I did. But one thing I did learn as an amateur astronomer and working on star parties such as the ones we have in the summer at Sleeping Bear Dunes, is that everyone is the same color under the light of the stars.

    The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

    Addendum

    A Grand Rapids Press clipping from my planetarium days
    A Grand Rapids Press clipping from my planetarium days, May 17, 1964. Click or tap on the image to enlarge it.
    AI generated image with Google's Gemini with editing.
    AI generated image of a group with telescopes under the stars, with Google’s Gemini with some editing.

    Categories: Ephemeris Program, Personal story

    Ephemeris: 02/12/2025 – Taking our weekly look at the whereabouts of the naked-eye planets

    February 12, 2025 Comments off

    This is Ephemeris for Darwin Day, Wednesday, February 12th. Today the Sun will be up for 10 hours and 20 minutes, setting at 6:07, and it will rise tomorrow at 7:45. The Moon, at full today, will rise at 6:21 this evening.

    Let’s take our weekly look at the whereabouts of the naked-eye planets. At 7 PM this evening four of the five naked eye planets will be out. Starting from the West we have Venus the brightest of all in the west southwest. Far below it, near the horizon, will be the much dimmer Saturn, which we are about to lose to the evening twilight. Jupiter, the second-brightest planet will be high in the south-southeast. It is reversing course and beginning to head back eastward now. Farther below it is the spectacular constellation of Orion the hunter. The 4th planet out is Mars, the third-brightest planet now, with its distinctive reddish hue, west of the stars Castor and Pollux in Gemini, and just about due east. The full Moon will be rising in the east.

    The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

    Addendum

    A 7 PM February 12, 2025 planet panorama
    A 7 PM February 12, 2025 planet panorama. Venus and Saturn are in the west-southwest, and Jupiter is in the south-southeast. Mars is in the east. The in this projection the ecliptic (not shown) is a straight line, so the planets and Moon nearly line up, but the horizon is curved. Click or tap on the image to enlarge it. Created using Stellarium.
    The Moon tonight, February 12, 2025, as it might appear in a small telescope at 7 PM
    The Moon tonight, February 12, 2025, as it might appear in a small telescope at 7 PM, shortly after rising. Since this is about 10 hours after the Moon was full, shadows are beginning to be visible in craters at the upper right edge. Selected features are labeled. Created using Stellarium, LibreOffice Draw, and GIMP.
    Telescopic Saturn, Venus, Jupiter and Mars as they would be seen in a small telescope with the same magnification
    Telescopic Saturn, Venus, Jupiter and Mars (north up) as they would be seen in a small telescope with the same magnification. All the planets are shown for tonight, 8 PM,February 5, 2025. Apparent diameters: Saturn 15.8″, its rings 36.8″, 2.2 degrees from edge on and closing; Venus 38.0″ and rapidly growing as it approaches us, 28.9% illuminated; Jupiter 41.8″; Mars, 12.7″. Planetary surface detail is more subtle than shown here. The ” means seconds of arc, or 1/3600th of a degree. Click or tap 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 February 12, 2025. The night ends on the left with sunrise on the 13th.
    The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on February 12, 2025. The night ends on the left with sunrise on the 13th. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.
    This is a low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow
    This is a low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow, February 12 and 13, 2025. Some of the columns are self-explanatory, others not. The transit column is the time that the body crosses the meridian and is due south. Elong, for elongation, is the angle between the Sun and that body. RA is right ascension, which is the object’s east-west position on the celestial sphere in hours and minutes. Dec is declination which is the north-south position of the object on the celestial sphere in degrees and minutes. R is the distance of that object from the Sun in astronomical units. An astronomical unit is about 93 million miles or 150 million kilometers. And Delta is the distance of that object from the Earth, also in astronomical units. I omit the ‘m’ in am and pm for compactness. The data was generated using my LookingUp for DOS app and displayed as a table by my Ephemeris Helper app.

    Categories: Ephemeris Program, Naked-eye planets, Observing, Planets Tags: , , , , ,

    Ephemeris: 02/11/2025 – Newly discovered asteroid may have our number

    February 11, 2025 Comments off

    This is Ephemeris for Tuesday, February 11th. Today the Sun will be up for 10 hours and 17 minutes, setting at 6:06, and it will rise tomorrow at 7:47. The Moon, 1 day before full, will set at 8:06 tomorrow morning.

    Late last year a tiny asteroid was found because it was close to the Earth and given the designation 2024 YR4. After observing it for a month it was discovered that it had a 1½ % chance of hitting the Earth when it came around again in 2032. Remember the fireball that exploded over Chelyabinsk Russia almost exactly 10 years ago? It exploded high in the air, and caused flying glass injuries to over a thousand people who saw the flash and rushed to the windows to see it when the atmospheric shock wave arrived. This object appears to be about 3 times the size of that object, nearly a football field in diameter, and thus could be 27 times the mass and volume. It’s four year orbit of the Sun will bring it back close to Earth in 2028 for us to get a better look at it and its orbit, and the last chance to alter its orbit.

    The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

    Addendum

    The orbit of the asteroid 2024 YR 4 is shown with the orbits of the planets of the inner solar system in this plot from the Jet Propulsion Laboratory's Small Body Database
    The orbit of the asteroid 2024 YR 4 is shown with the orbits of the planets of the inner solar system in this plot from the Jet Propulsion Laboratory’s (JPL) Small Body Database. I’ve added the arrow to the orbit intersect point, where the orbits of this asteroid and the Earth cross each other. That is where the Earth is around December 22nd each year. The asteroid and the Earth will be in about the same position 4 years from now. It would be a good time if the asteroid is close enough to the Earth to get an accurate measurement of its diameter, which is currently estimated based on the asteroid’s brightness. Most asteroids have the reflectance, or what astronomers called albedo of something like a charcoal briquette. But it does vary from asteroid to asteroid based on their composition. If the asteroid gets close enough, radar measurements will tell us for sure its size and give us a more accurate position which will affect the accuracy of where the asteroid will come through in 2032. Currently the possible error in the predictions is an area larger the orbit of the Moon. The Moon is about 60 times the radius of the Earth away.

    Categories: Asteroid, Ephemeris Program, The Earth Tags:

    Ephemeris: 02/10/2025 – How old are the features on the Moon?

    February 10, 2025 Comments off

    This is Ephemeris for Monday, February 10th. Today the Sun will be up for 10 hours and 14 minutes, setting at 6:04, and it will rise tomorrow at 7:48. The Moon, 2 days before full, will set at 7:42 tomorrow morning.

    In dating Moon rocks scientists get a range of dates from 4.6 to 3.3 billion years. An age of a rock is determined by the decay of a radioactive element one of which is uranium 238 decaying to lead 206. So the ratios of these two elements gives a date when a rock was last solidified. This clock is reset when a rock was last melted either by volcanism or by asteroid impact. It turns out that the rocks of the highlands, the lighter area on the Moon where most of the craters are, date to close to 4.5 billion years, and are probably the original crust of the Moon. The rocks from the lunar maria or seas are younger from about 4.1 billion years down to 3.8 billion years. So they were thought to be caused by asteroid impacts from the Late Heavy Bombardment.

    The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

    Addendum

    The Moon's geological eras in linear time
    The Moon’s geological eras in linear time. The numbers on the right are in millions of years ago, thus 4000 = 4 billion years. The word Mare is pronounced Mar-e and is Latin for sea, and is the same as basin, because these are depressions. Credit: the Planetary Society, diagram by Emily Lakdawalla after Tanaka & Hartmann 2012.
    The Moon's Geologic Time Scale (without numbers)
    The Moon’s Geologic Time Scale (without numbers) Brown “U”s are supposed to denote impact craters. Red marks individual impact basins. The brown splotch denotes ebbing and flowing of mare volcanism. Credit: The Planetary Society, Emily Lakdawalla after Tanaka & Hartmann 2012.

    The Late Heavy Bombardment is not accepted by all planetary scientists. The main evidence is the cratering and maria on the Moon.

    Categories: Ephemeris Program, History, The Moon Tags: ,

    Ephemeris: 02/07/2025 – GTAS meeting tonight – Earth’s Impact Craters

    February 7, 2025 Comments off

    This is Ephemeris for Friday, February 7th. Today the Sun will be up for 10 hours and 6 minutes, setting at 6:00, and it will rise tomorrow at 7:52. The Moon, 2 days past first quarter, will set at 5:36 tomorrow morning.

    The Grand Traverse Astronomical Society will host its February meeting tonight at 8 PM at Northwestern Michigan College’s Joseph H. Rogers Observatory. The talk for the evening will be given by Society President, and Observatory Director, Jerry Dobek on the topic of Earth’s Impact Craters. Unlike the Moon, Earth’s impact craters have been mostly hidden. After the meeting, about 9 PM if it’s clear, there will be viewing of the heavens through the observatory’s telescopes, featuring Jupiter, the Moon and the Great Orion Nebula, which will be hindered a bit by moonlight. The observatory is located on Birmley Road. South of Traverse City between Garfield and Keystone roads. All are welcome, free of charge.

    The meeting is also available on Zoom. The link is at gtastro.org

    The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

    Addendum

    Aerial view of the Barringer Meteor Crater in Arizona
    Aerial view of the Barringer Meteor Crater in Arizona. Credit: barringercrater.com.

    Categories: Ephemeris Program, GTAS Outreach Event, History

    Ephemeris: 02/06/2025 – The Moon tonight, two days after first quarter

    February 6, 2025 Comments off

    This is Ephemeris for Thursday, February 6th. Today the Sun will be up for 10 hours and 3 minutes, setting at 5:59, and it will rise tomorrow at 7:54. The Moon, 1 day past first quarter, will set at 4:30 tomorrow morning.

    Tonight the moon will be about a day and a half past first quarter it is showing some very nice craters for the binoculars or small telescope. Near the south end of the moon near the terminator, the sunrise line, is the crater called Clavius which has an arc of several craters within it, each of decreasing size. North or above that is the sharp-edged crater called Tycho which, during a full moon, shows several long ejecta rays across the face of the Moon, but are almost invisible now. Near the top edge of the Moon the flat floored crater called Plato is seen by the edge of the large sea Mare Imbrium or Sea of Showers. A mountain range at the opposite side of Imbrium is called the Apennines Mountains.

    The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

    Addendum

    The Moon tonight, February 6, 2025, as it might appear in a small telescope
    The Moon tonight, February 6, 2025, as it might appear in a small telescope. Selected features are labeled, including those mentioned in the program. Created using Stellarium, LibreOffice Draw, and GIMP.
    The crater Clavius as seen from above
    The crater Clavius as seen from above. It’s one of the largest on the Moon of 140 miles or 225 kilometers in diameter. It sports a curious arc of inner craters. It looks like 5 craters in an arc of decreasing size, moving counterclockwise from the 5 o’clock position on the crater wall. The largest crater looks like it’s older than the others. This is an image from the Virtual Moon Atlas a free software program.
    The crater Plato seen from overhead
    The crater Plato seen from overhead with the Virtual Moon Atlas, along with the Alps Mountains (Montes Alpes) . Plato is known as a walled plain some 63 miles in diameter or 101 kilometers in diameter. An interesting feature of the Alps mountains is the long gash called the Alpine valley.
    Categories: Ephemeris Program, Observing, The Moon Tags: ,