Archive
12/30/2020 – Ephemeris – Let’s take our last look at the naked-eye planets for this year
This is Bob Moler with Ephemeris for Wednesday, December 30th. Today the Sun will be up for 8 hours and 51 minutes, setting at 5:11, and it will rise tomorrow at 8:20. The Moon, 1 day past full, will rise at 5:40 this evening.
Let’s take our last look at the naked-eye planets for this year. Jupiter and Saturn are both low in the southwestern sky around 6 pm. Jupiter is the very bright one. Below and right of it is the dimmer Saturn it by a degree or two moon widths. They crossed paths for us nine nights ago. They can still be seen in the same binocular field. Saturn will set first tonight at 6:57 pm with Jupiter following four minutes later. Quite high in the southeast will be Mars, still in Pisces. Mars’ distance is increasing to 82 million miles (132 million km) away. It will set at 2:29 tomorrow morning. Brilliant Venus will rise at 6:49 am in the east-southeast as it seems to retreat slowly toward the Sun, but actually it’s heading way around behind the Sun.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum

Mars with the stars of Taurus the Bull including Aldebaran with the “V” of stars that are the Hyades that mark the bull’s face and the Pleiades. Seen at 8 pm, December 30, 2020. Created using Stellarium.

The planets as seen in a telescope (north up) with the same magnification for the night of December 30/31, 2020. Times of the display are: Jupiter and Saturn, 6 pm; Mars, 8 pm; Venus, 7:30 am. Apparent diameters: Jupiter, 32.92″; Saturn, 15.26″, rings, 35.54″; Mars, 10.52″, and Venus 10.71″. Mars also displays an enlargement showing surface detail. Mars was closest to the Earth this go-a-round on October 6. The ” symbol means seconds of arc (1/3600th of a degree.) Planets whose diameters drop below 10″, or are too close to the direction of the Sun to observe will not be shown. Created using Cartes du Ciel (Sky Charts).

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on December 30, 2020. The night ends on the left with sunrise on the 31st. I’m afraid that the labels for Jupiter and Saturn will overlap, since the planets are very close. Click on the image to enlarge. Created using my LookingUp program.
12/25/2020 – Ephemeris – Did the “Star” of Bethlehem appear in 3 BC and again in 2 BC?
Merry Christmas, this is Bob Moler with Ephemeris for Christmas Day, Friday, December 25th. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:07, and it will rise tomorrow at 8:19. The Moon, halfway from first quarter to full, will set at 4:53 tomorrow morning.
Many writers of the 2nd and 3rd centuries AD place Jesus’ birth around 2 BC, which had to be before Herod the Great’s death, which I suggest was in 1 BC marked by to a total lunar eclipse. In 3 and again in 2 BC there were star-like conjunctions or apparent joinings of the planets Jupiter and Venus against the backdrop of the constellation of Leo the Lion. A lion is related to Judah, son of Jacob by a blessing the latter gave his 12 sons in Genesis. The first conjunction occurred in August of 3 BC in the morning sky. In June the next year the two planets got together again, this time in the evening sky, just after Jesus would have been born in the lambing season of spring.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum

Here is an animation created using Stellarium of Jupiter and Venus, the brighter of the two seeming to coalesce on August 12, 3 BC in the early morning twilight. The ghostly image popping up in the second frame is the thin crescent Moon showing earth shine. Created using Stellarium and GIMP.

On June 16th 2 BC, this time in the evening, Venus and Jupiter seem to coalesce as one, at least to the naked eye. Regulus (The Little King star) is the brightest star in Leo the lion. To the upper right of it is the Sickle, the front part of the lion and his head and mane. Created using Stellarium and GIMP.
12/23/2020 – Ephemeris – Let’s look for the naked-eye planets for this Christmas week
This is Ephemeris for Wednesday, December 23rd. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:06, and it will rise tomorrow at 8:18. The Moon, 2 days past first quarter, will set at 2:49 tomorrow morning.
Let’s look for the naked-eye planets for this week. Jupiter and Saturn are both low in the southwestern sky around 6 pm. Jupiter is the very bright one. Below and right of it is the dimmer Saturn it by a quarter of a degree or half a moon width. They crossed paths for us two nights ago, in 20 years, though not as close. They can still be seen in the same low power telescope field. Saturn will now set first tonight at 7:20 pm with Jupiter following a minute later. Quite high in the southeast and above the 9 day old Moon at that hour will be Mars, still in Pisces. Mars’ distance is increasing to 76 million miles (123 million km) away. It will set at 2:41 tomorrow morning. Brilliant Venus will rise at 6:33 am in the east-southeast as it seems to retreat slowly toward the Sun, but actually it’s heading way around behind the Sun.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum

Jupiter and Saturn in twilight at 6 pm or a bit less than an hour after sunset tonight December 23, 2020. Created using Stellarium.

Mars will be seen above the Moon tonight. This is the appearance of both at 6 pm, tonight, December 23, 2020. Created using Stellarium.

The gibbous Moon as it might be seen in binoculars this evening at 6 pm December 23, 2020. Created using Stellarium.

Venus low in the southeast at 7:30 am December 24, 2020. The morning sky is not as friendly to morning planets as it was earlier in autumn. Created using Stellarium.

The planets as seen in a telescope (north up) with the same magnification for the night of December 23/24, 2020. Times of the display are: Jupiter, Saturn, and Mars, 6 pm; Venus, 7:30 am. Apparent diameters: Jupiter, 33.18″; Saturn, 15.32″, rings, 35.70″; Mars, 11.32″, and Venus 10.89″. Mars also displays an enlargement showing surface detail. Mars was closest to the Earth this go-a-round on October 6. The ” symbol means seconds of arc (1/3600th of a degree.) I will no longer show planets whose diameters drop below 10″, or are too close to the direction of the Sun to observe. Created using Cartes du Ciel (Sky Charts).

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on December 23, 2020. The night ends on the left with sunrise on the 24th. I’m afraid that the labels for Jupiter and Saturn will overlap, since the planets are very close. Click on the image to enlarge. Created using my LookingUp program.
12/16/2020 – Ephemeris – Let’s look for the naked-eye planets for this week
This is Bob Moler with Ephemeris for Wednesday, December 16th. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:03, and it will rise tomorrow at 8:14. The Moon, 2 days past new, will set at 7:09 this evening.
Let’s look for the naked-eye planets for this week. Jupiter and Saturn are both low in the southwestern sky from 6 to 7 pm. Jupiter is the very bright one. Above and left it by half a degree or one moon width will be dimmer Saturn. Below them tonight will be the thin crescent Moon. They will cross paths for us on the evening of December 21st and be seen in the same low power telescope field that evening. Jupiter will set first tonight at 7:40 pm with Saturn following four minutes later. Quite high in the southeast at that hour will be Mars, still in Pisces. Mars’ distance is increasing to 71 million miles (114 million kilometers) away. It will set at 2:55 tomorrow morning. Brilliant Venus will rise at 6:16 am in the east-southeast as it seems to retreat slowly toward the Sun, but actually it’s heading way around behind the Sun.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum

Evening planet panorama showing Mars, Jupiter, Saturn and the Moon setting at 6:30 pm December 16, 2020. Click on the image to enlarge. Created using Stellarium.

Venus low in the southeast at 7 am December17, 2020. Venus is all by its lonesome in the morning sky. No need for a panorama, so we’re zoomed in a bit. The morning sky has is not as friendly to morning planets as it was earlier in autumn season as we embark into winter next week. Created using Stellarium.

The planets as seen in a telescope (north up) with the same magnification for the night of December 16/17, 2020. Times of the display are: Jupiter and Saturn, 6 pm and Mars, 8 pm; Venus, 7 am. Apparent diameters: Jupiter, 33.49″; Saturn, 15.41″, rings, 35.90″; Mars, 12.20″, and Venus, 11.10″. Europa is transiting Jupiter and will be generally invisible. Mars also displays an enlargement showing surface detail. Mars was closest to the Earth this go-a-round on October 6. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on December 16, 2020. The night ends on the left with sunrise on the 17th. I’m afraid that the labels for Jupiter and Saturn will overlap, since the planets are getting very close. Click on the image to enlarge. Created using my LookingUp program.
12/09/2020 – Ephemeris – A look at the naked-eye planets for this week
This is Ephemeris for Wednesday, December 9th. Today the Sun will be up for 8 hours and 53 minutes, setting at 5:02, the earliest sunset, and it will rise tomorrow at 8:09. The Moon, 2 days past last quarter, will rise at 2:55 tomorrow morning.
Let’s look for the naked-eye planets for this week. Jupiter and Saturn are both low in the southwestern sky from 6 to 7 pm. Jupiter is the very bright one. Above and left it by one and a half degrees or three moon widths will be dimmer Saturn. They are slowly closing, so they will cross paths for us on the evening of December 21st and be seen in the same low power telescope field that evening. Jupiter will set first tonight at 8 pm with Saturn following at 8:08. Quite high in the southeast at that hour will be Mars, still in Pisces. Mars’ distance is increasing to 65.3 million miles (105.2 million km) away. It will set at 3:10 tomorrow morning. Brilliant Venus will rise at 5:58 am in the east-southeast as it retreats slowly towards the Sun, but actually it’s heading around behind the Sun.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum

The evening planets seen at 6:30 pm or about an hour and a half after sunset December 9, 2020. Animation showing non-annotated sky and then with annotations. Click on the image to enlarge. Created using Stellarium and GIMP.

The waning crescent Moon as it might appear in binoculars or a small telescope at 6:30 am December 10, 2020. Created using Stellarium.

The planets as seen in a telescope (north up) with the same magnification for the night of December 9/10, 2020. Times of the display are: Jupiter, Saturn and Mars, 6:30 pm; Venus, 6:30 am. Apparent diameters: Jupiter, 33.85″; Saturn, 15.51″, rings, 36.13″; Mars, 13.18″, and Venus 11.32″. Io is transiting Jupiter and will be generally invisible. Mars also displays an enlargement showing surface detail. Mars was closest to the Earth this go-a-round on October 6. The ” symbol means seconds of arc (1/3600th of a degree). Created using Cartes du Ciel (Sky Charts).

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on December 9, 2020. The night ends on the left with sunrise on the 10th. I’m afraid that the labels for Jupiter and Saturn will overlap, since the planets are getting very close. Click on the image to enlarge. Created using my LookingUp program.
12/02/2020 – Ephemeris – A look at the naked-eye planets for this week
This is Ephemeris for Wednesday, December 2nd. Today the Sun will be up for 9 hours and 1 minute, setting at 5:03, and it will rise tomorrow at 8:02. The Moon, 2 days past full, will rise at 6:51 this evening.
Let’s look for the naked-eye planets for this week. Jupiter and Saturn are both low in the southwestern sky from 7 to 8 pm. Jupiter is the very bright one. Above and left it by 2 degrees or 4 moon widths will be dimmer Saturn. They are slowly closing, so they will cross paths on the evening of December 21st and be seen in the same telescope field that evening. Jupiter will set first tonight at 8:20 with Saturn following at 8:32. Quite high in the southeast at that hour will be Mars, still in Pisces. Mars’ distance is increasing to 60.2 million miles (97.0 million km) away. Mars will set at 3:27 tomorrow morning. Brilliant Venus will rise at 5:40 am in the east-southeast as it retreats slowly towards the Sun, but actually it’s heading around behind the Sun.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum

The evening planets with the Mon rising at 7 pm tonight December 2, 2020. Click on the image to enlarge. Created using Stellarium.

The planets as seen in a telescope (north up) with the same magnification for the night of November 25/26, 2020. Times of the display are: Jupiter, Saturn and Mars, 7 pm; Venus, 6:30 am. Apparent diameters: Jupiter, 34.28″; Saturn, 15.63″, rings, 36.41″; Mars, 14.27″; and Venus, 11.57″. Mars also displays an enlargement showing surface detail. Mars was closest to the Earth this go-a-round on October 6. The ” symbol means seconds of arc (1/3600th of a degree.) Click on the image to enlarge. Created using Cartes du Ciel (Sky Charts).

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on December 2, 2020. The night ends on the left with sunrise on the 3rd. I’m afraid that the labels for Jupiter and Saturn will overlap, since the planets are getting very close. Click on the image to enlarge. Created using my LookingUp program.
11/25/2020 – Ephemeris – Let’s look for the naked-eye planets for this week
This is Ephemeris for Wednesday, November 25th. Today the Sun will be up for 9 hours and 12 minutes, setting at 5:06, and it will rise tomorrow at 7:54. The Moon, 4 days past first quarter, will set at 3:58 tomorrow morning.
Let’s look for the naked-eye planets for this week. Jupiter and Saturn are both low in the southwestern sky from 7 to 8 pm. Jupiter is the very bright one. Above and left will be dimmer Saturn. They are slowly closing, so they will cross paths on the evening of December 21st and be seen in the same telescope field that evening. Jupiter will set first tonight at 8:41 with Saturn following at 8:56. Off in the southeast at that hour will be Mars above the bright gibbous Moon tonight. Mars’ distance is increasing to 55.6 million miles (89.6 million kilometers) away. Mars will set at 3:47 tomorrow morning. Brilliant Venus will rise at 5:21 am in the east-southeast as it retreats slowly toward, but actually around the back of the Sun.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum

Evening planets and the Moon for 7 pm tonight November 25, 2020. Click on the image to enlarge. Created using Stellarium.

The gibbous Moon as it might be seen in binoculars this evening at 7 pm November 25, 2020. Created using Stellarium.

Venus and the morning constellations at 6:30 am tomorrow November 26, 2020. Created using Stellarium.

The planets as seen in a telescope (north up) with the same magnification for the night of November 25/26, 2020. Times of the display are: Jupiter and Saturn, 7 pm; Mars, 10 pm; Venus, 6:30 am. Apparent diameters: Jupiter, 34.76″; Saturn, 15.76″, rings, 36.72″; Mars, 15.45″, and Venus 11.85″. Mars also displays an enlargement showing surface detail. Mars was closest to the Earth this go-a-round on October 6. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on November 25, 2020. The night ends on the left with sunrise on the 26th. I’m afraid that the labels for Jupiter and Saturn will overlap, since the planets are getting very close. Click on the image to enlarge. Created using my LookingUp program.
11/17/2020 – Ephemeris – Let’s look for the naked-eye planets for this week
This is Bob Moler with Ephemeris for Wednesday, November 18th. Today the Sun will be up for 9 hours and 26 minutes, setting at 5:11, and it will rise tomorrow at 7:45. The Moon, halfway from new to first quarter, will set at 8:24 this evening.
Let’s look for the naked-eye planets for this week. Jupiter and Saturn are both low in the southwestern sky 7 to 8 pm. Jupiter is the very bright one. Above and left it will be the somewhat dimmer Saturn. They are near the Moon tonight. They are slowly closing, so they will cross paths on December 21st and be seen in the same telescope field that evening. Jupiter will set first tonight at 9:02 with Saturn following at 9:21. Off in the southeast at that hour will be Mars. Its distance is increasing to 51.5 million miles (82.9 million kilometers) away. Mars will set at 4:10 tomorrow morning. Brilliant Venus will rise at 5:03 am in the east-southeast as it retreats slowly toward the Sun. Close to ending its morning appearance now is Mercury which will rise at 6:15 am in the east.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum

Jupiter, Saturn and Moon low in the southwest at 7:30 pm tonight, November 18, 2020. Created using Stellarium.

Evening planets, Moon, ecliptic and zodiac at 7:30 pm tonight November 18, 2020. Click on the image to enlarge. Created using Stellarium.

Venus and Mercury with the star Spica, the ecliptic (path of the Sun) and the constellation Corvus at 6:30 tomorrow morning November 19, 2020. Created using Stellarium.

The planets as seen in a telescope (north up) with the same magnification for the night of November 18/19, 2020. Times of the display are: Jupiter and Saturn, 7:30 pm; Mars, 10 pm; Venus, 6:30 am. Apparent diameters: Jupiter, 35.30″; Saturn, 15.91″, rings, 37.06″; Mars, 16.72″, and Venus 12.15″. Mars also displays an enlargement showing surface detail. Mars was closest to the Earth this go-a-round on October 6. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on November 18, 2020. The night ends on the left with sunrise on the 19th. I’m afraid that the labels for Jupiter and Saturn will overlap, since the planets are getting very close. Click on the image to enlarge. Created using my LookingUp program.
11/11/2020 – Ephemeris – Let’s look for the naked-eye planets for this week
This is Ephemeris for Veteran’s Day, Wednesday, November 11th. Today the Sun will be up for 9 hours and 43 minutes, setting at 5:18, and it will rise tomorrow at 7:36. The Moon, 3 days past last quarter, will rise at 4:00 tomorrow morning.
Let’s look for the naked-eye planets for this week. Jupiter and Saturn are both low in the southwestern sky at 8 pm. Jupiter is the very bright one. Above and left it will be the somewhat dimmer Saturn. They are closing slowly, so they will cross paths on December 21st and be seen in the same telescope field that evening. Jupiter will set first tonight at 9:24 with Saturn following at 9:46. Off in the southeast at that hour will be Mars. Its distance is increasing to 47.7 million miles (76.9 million km) away. Mars will set at 4:35 tomorrow morning. Brilliant Venus will rise at 4:46 am in the east as it retreats slowly toward the Sun. Making a morning appearance this week is Mercury which will rise at 5:52 am in the east.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum

Evening planet finder animation for 8 pm November 11, 2020. The orange line is the ecliptic, the plane of the Earth’s orbit projected on the sky, and the path of the Sun through the year. All the planets can be found near that line. The zodiacal constellations from Taurus on the left to Capricornus on the right are shown without labels. Click on the image to enlarge. Created using Stellarium and GIMP.

Mercury, Venus, and the Moon tomorrow morning November 12, 2020 at 6:30 am. The orange line is the ecliptic, the plane of the Earth’s orbit. It is the path of the Sun in the sky, The Moon is a crescent, and displayed at twice its apparent size. Over the next week Venus and Mercury will slide downward along the ecliptic in relation to the stars. Created using Stellarium.

The thin crescent Moon as it might appear in binoculars with earthshine at 6:30 am, November 12, 2020. The very dark crater visible is Grimaldi a 134 mile or 222 kilometer diameter crater named after Francesco Grimaldi a 17th century Jesuit astronomer and physicist. Created using Stellarium.

The planets as seen in a telescope (north up) with the same magnification for the night of November 11/12, 2020. Times of the display are: Jupiter and Saturn, 8 pm; Mars, 11 pm; Venus, 6:30 am. Apparent diameters: Jupiter, 35.90″; Saturn, 16.07″, rings, 37.43″. Mars, 18.04″, and Venus 12.49″. Mars also displays an enlargement showing surface detail. Mars was closest to the Earth this go round on October 6. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on November 11, 2020. The night ends on the left with sunrise on 12th. Click on the image to enlarge. Created using my LookingUp program.
11/04/2020 – Ephemeris – Let’s find the naked-eye planets for this week
This is Ephemeris for Wednesday, November 4th. Today the Sun will be up for 10 hours and 1 minute, setting at 5:26, and it will rise tomorrow at 7:26. The Moon, half way from full to last quarter, will rise at 8:04 this evening.
Let’s find the naked-eye planets for this week. Jupiter and Saturn are both low in the southwestern sky at 8 pm. Jupiter is the very bright one. Above and left it will be the somewhat dimmer Saturn. They are closing slowly, so they will cross paths on December 21st and be in the same telescope field that evening. Jupiter will set first tonight at 9:42 with Saturn following at 10:07. Off in the southeast at that hour will be Mars. Since the it was closest 29 days ago its distance has increased to 45.0 million miles (72.4 million kilometers) away. Mars will set at 5:04 tomorrow morning. Brilliant Venus will rise at 4:29 am in the east as it retreats slowly toward the Sun. Beginning to make a morning appearance now will be Mercury rising at 5:52 a.m. in the east.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum

The evening planets and the Moon at 8 pm, just before the Moon will rise, tonight, November 4, 2020. Created using Stellarium.

The waning gibbous Moon as it might be seen in binoculars or a small telescope at 9 pm tonight November 4, 2020. Created using Stellarium.

The morning planets Venus and Mercury visible tomorrow at 6:30 am, November 5, 2020 with some of the stars of morning. Click on the image to enlarge. Created using Stellarium.

The planets as seen in a telescope (north up) with the same magnification for the night of November 4/5, 2020. Times of the display are: Jupiter and Saturn, 8 pm; Mars, 10 pm; Venus, 6:30 am. Apparent diameters: Jupiter, 36.55″; Saturn, 16.24″, rings, 37.83″. Mars, 19.34″, and Venus 12.87″. Mars also displays an enlargement showing surface detail. Mars was closest to the Earth this go-a-round on October 6. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).






