Archive
04/26/2023 – Ephemeris – Let’s find where the naked-eye planets have wandered off to this week
This is Ephemeris for Wednesday, April 26th. Today the Sun will be up for 14 hours even, setting at 8:41, and it will rise tomorrow at 6:39. The Moon, 1 day before first quarter, will set at 3:28 tomorrow morning.
Let’s find where the naked-eye planets have wandered off to this week. Venus is our blazing Evening Star, seen in the west all evening. It will set after midnight. It’s in Gemini, below the namesake stars of the twins Castor on the right and Pollux on the left. Pollux is a bit below and to the right of the Moon tonight. Mars is above and left of Venus. Venus is closing the gap between them, but will never quite reach Mars while they are in the evening sky. The closest they will get is three and a half degrees or 7 moon diameters apart, before Venus pulls back toward the Sun faster than Mars. They won’t cross paths until February of next year. Saturn is emerging from morning twilight, rising at 4:33 am in the east-southeast. Both Jupiter and Mercury are too close to the direction of the Sun to be seen.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –4 hours). They may be different for your location.
Addendum

Evening planets and stars looking westward at 10 pm tonight, April 26, 2023. Click or tap on the image to enlarge it. Created using Stellarium and GIMP.

The Moon, one day before first quarter tonight, April 26, 2023, with prominent features labeled. Created using Stellarium, GIMP and LibreOffice Draw.

Telescopic Venus and Saturn (north up) as they would be seen in a small telescope, with the same magnification. Apparent diameters: Venus 16.51″ and is 68.1% illuminated; Saturn 16.23″, its rings 37.80″. Mars is too small to be represented here. It is 5.5″ in diameter. Created using Cartes du Ciel (Sky Charts).
04/25/2023 – Ephemeris – The Moon is passing Mars today
This is Bob Moler with Ephemeris for Tuesday, April 25th. Today the Sun will be up for 13 hours and 57 minutes, setting at 8:40, and it will rise tomorrow at 6:40. The Moon, 2 days before first quarter, will set at 2:50 tomorrow morning.
Tonight, the Moon and the planet Mars will appear close to each other. The Red Planet will appear just below and left of the waxing crescent Moon. Mars is a lot dimmer than it was last December. That’s because it is a lot farther away than it was back then, 157 versus 51 million miles (253 versus 82 million kilometers). Mars is the planet with the greatest distance variation percentage over its synodic period, that is, from opposition to the next opposition. It also has the longest synodic period, at 26 months on average. That’s why opportunities to launch spacecraft only occur every 26 months. The least energy it takes to get to Mars occurs when a spacecraft is launched a few months before opposition, when Mars is at its closest, to arrive several months after opposition.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –4 hours). They may be different for your location.
Addendum
04/19/2023 – Ephemeris – Let’s find where the naked-eye planets have wandered off to this week
This is Ephemeris for Wednesday, April 19th. Today the Sun will be up for 13 hours and 40 minutes, setting at 8:32, and it will rise tomorrow at 6:50. The Moon, 1 day before new, will rise at 7:04 tomorrow morning.
Let’s find where the naked-eye planets have wandered off to this week. Since I left you in February, Jupiter passed behind the Sun 8 days ago and moved to the morning side of the Sun. Though it will be more than a month before it is far enough from the Sun to be spotted before sunrise. Venus is our blazing Evening Star, seen in the west all evening. It will set shortly after midnight. It’s in Taurus, with the bright star Aldebaran below and left of it and the Pleiades below and right of it. Mars is above and left of Venus. Venus is closing the gap, but will never quite reach Mars while they are in the evening sky. The closest they will get is three and a half degrees or 7 moon diameters apart, but won’t cross paths until February of next year. In the morning sky, Saturn is now visible by 6 am in the east-southeast.
Addendum

Evening planets Venus and Mars among the bright stars of winter at 9:30 pm with Mercury about to set, April 19, 2023. 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
02/01/2023 – Ephemeris – Let’s find where the naked-eye planets have wandered off to this week
This is Ephemeris for Wednesday, February 1st. Today the Sun will be up for 9 hours and 49 minutes, setting at 5:51, and it will rise tomorrow at 8:00. The Moon, halfway from first quarter to full, will set at 6:31 tomorrow morning.
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. Mercury is now in the morning sky. It has a few more days visibility around 7 am in the southeastern sky after reaching greatest western elongation from the Sun last Sunday.
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 low in the west-southwestern twilight at 6:30 pm tonight, February 1, 2023. Created using Stellarium.

Evening planets at 7 pm tonight, February 1, 2023. The orange line is the ecliptic, which is the plane of the Earth’s orbit. The sun appears on that line throughout the year. Notice that all the other planets are very close to that line. That is an artifact of the accretion disk from which the planets formed some 4 1/2 billion years ago. The planets still maintain the nearly same plane for their existence to this day. Click on the image to enlarge it. Created using Stellarium.

This is what Mercury might look like in the southeast around 7:20 tomorrow morning, February 2nd from Interlochen/Traverse City. At that time, it’ll be 5 degrees above a sea horizon, which is half the width of a fist held at arm’s length. Any trees of course will reduce it. Created using Stellarium.
01/30/2023 – Ephemeris – Two planetary events are happening today
This is Ephemeris for Monday, January 30th. Today the Sun will be up for 9 hours and 44 minutes, setting at 5:48, and it will rise tomorrow at 8:03. The Moon, 2 days past first quarter, will set at 4:34 tomorrow morning.
Today, the planet Mercury was seen as far away from the Sun as it can get for this time of year in the morning sky. It’s called “greatest western elongation”, and it’s distance from the sun and angle is 25 degrees. It’s going to stay pretty close to that for about the next week or so, it’ll be visible if it ever clears up. This is about the latest time one can see Mercury morning elongations this for this time of year. We’re running out of the correct angles for it. This evening, if it’s clear, the planet of Mars will appear near the waxing gibbous Moon. Early on in the evening Mars will be to the upper left of the Moon, which will be approaching it by about its own diameter every hour, until about 1 o’clock in the morning when Mars will it’s closest above the Moon it should be a striking sight.
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
01/25/2023 – Ephemeris – Let’s see where the naked-eye planets have wandered off to this week
This is Bob Moler with Ephemeris for Wednesday, January 25th. Today the Sun will be up for 9 hours and 32 minutes, setting at 5:41, and it will rise tomorrow at 8:08. The Moon, 3 days before first quarter, will set at 10:42 this evening.
Let’s see where the naked-eye planets have wandered off to this week. Very early after sunset, Venus might be spotted very low in the southwest by a little past 6 pm. Mars, and Jupiter will be visible this evening, in the east to southwestern sky by 6:30 or 7 pm. Mars will be above Orion in the east-southeast and is pulling away from the Pleiades. Jupiter is brighter than Mars, and will be in the south-southwest, and tonight it’s directly above the crescent Moon. Saturn is below Venus now, so it’s pretty much gone until it reappears in the morning sky in a few months. Mercury is now in the morning sky, after it passed inferior conjunction with the Sun on the 7th, that is, it passed between the Earth and the Sun. It should be briefly visible before sunrise by month’s end.
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




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01/19/2023 – Ephemeris – Gemini, twins with a secret
This is Ephemeris for Thursday, January 19th. Today the Sun will be up for 9 hours and 19 minutes, setting at 5:33, and it will rise tomorrow at 8:13. The Moon, 2 days before new, will rise at 7:38 tomorrow morning.
Another famous winter constellation is Gemini. The constellation of Gemini the Twins is visible halfway to the zenith in the east, at the top and left of Orion the hunter, at 9 pm. The namesake stars of the two lads, are the two bright stars at the left end of Gemini, and are high and are due east. Castor is on top, while Pollux is below. From them come two lines of stars that outline the two, extending horizontally toward Orion. In Greek mythology the lads were half brothers, Castor was fathered by a mere mortal, while Pollux was fathered by Zeus, but were born together as twins. When Castor was killed during the quest for the Golden Fleece, Pollux pleaded with Zeus to let him die also, so Zeus placed them together in the sky.
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

Gemini finder animation for the second half of January 2023. It’s dated because Mars is dawdling in Taurus near the Pleiades. Mars is now back to heading eastward once again, after being in retrograde or westward motion as the Earth passed it in early December. Mars will officially enter Gemini in March. Created using Stellarium, and GIMP.
01/18/2023 – Ephemeris – Let’s see where the naked-eye planets have wandered off to this week
This is Ephemeris for Wednesday, January 18th. Today the Sun will be up for 9 hours and 17 minutes, setting at 5:32, and it will rise tomorrow at 8:14. The Moon, 3 days before new, will rise at 6:28 tomorrow morning.
Let’s see where the naked-eye planets have wandered off to this week. Very early after sunset, Venus might be spotted very low in the southwest by 6 pm. Mars, Jupiter and Saturn will be visible this evening, in the east to southwestern sky by 6:30 or 7 pm. Mars will be above Orion in the east-southeast and near the Pleiades. Jupiter is the brightest of the three and will be in the south-southwest., while dimmer Saturn will be very low in the southwest at that time. Saturn, the westernmost of these bright planets, will set around 7:42 this evening. It’s a bit above and left of Venus. Mercury is now in the morning sky, after it passed inferior conjunction with the Sun on the 7th, that is, it passed between the Earth and the Sun. It should be briefly visible before sunrise by month’s end.
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 and Saturn low in the southwest at 6:15 pm tonight, January 18, 2023. Saturn will probably not be visible yet, but Venus should be plenty bright enough. Created using Stellarium.

All the evening planets before Venus sets are in this panorama looking southward from east to west at 7:15 tonight, January 18, 2023. I dropped lines from some of the dimmer constellations. Click on the image to enlarge it. Created using Stellarium.

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 7 pm tonight, January 18, 2023. Apparent diameters: Venus 10.77″ and is 93.5% illuminated; Saturn 15.52″, its rings 36.16″; Jupiter 37.32″. Mars 12.25″. Mars’ distance is71.6 million miles (114.4 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).
12/28/2022 – Ephemeris – Taking a look at the bright planets for the last week of the year
This is Ephemeris for Wednesday, December 28th. Today the Sun will be up for 8 hours and 49 minutes, setting at 5:09, and it will rise tomorrow at 8:19. The Moon, 1 day before first quarter, will set at 11:46 this evening.
Let’s see where the naked-eye planets have wandered off to this week. Mars, Jupiter and Saturn will be visible this evening, in the east to southwestern sky at 6:30 pm. Mars is in the east. Jupiter is the brightest of the three in the south, while dimmer Saturn is low in the southwest at that time. Mars is above Orion as it rises in the early evening. Saturn, the westernmost of the bright planets, will set around 8:52 this evening. Venus and Mercury are also in the evening sky, but too close to the setting Sun to be easily spotted. At 6 pm, both will be very low on the southwestern horizon, with Mercury just above Venus by three moon-widths. There are now no bright morning planets, though Mars won’t set until 6:32 am in the northwest.
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 Moon at 8 in the evening tonight, December 28, 2022. Created using Stellarium.

Waxing crescent Moon as it might appear in binoculars or low power telescope tonight, December 28, 2022. 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, December 28, 2022. Apparent diameters: Saturn 15.82″, its rings 36.84″; Jupiter 39.72″. Mars 15.06″. Mars’ distance is 57.8 million miles (93.0 million kilometers). The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).













