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Ephemeris: 01/31/2024 – Where have the naked-eye planets wandered* off to this week?
This is Ephemeris for Wednesday, January 31st. Today the Sun will be up for 9 hours and 46 minutes, setting at 5:49, and it will rise tomorrow at 8:02. The Moon, 2 days before last quarter, will rise at 11:56 this evening.
Let’s find out where the naked-eye planets have wandered off to this week. Three of those five planets are now visible. Saturn and Jupiter are the evening planets. Saturn is getting harder to spot low in the west-southwest, nearly succumbing to evening twilight, setting at 7:59 pm. Jupiter will move from high in the south to low in the west by midnight, and will set in the west-northwest at 1:20 am. Venus, the brilliant morning star, will rise in the east-southeast at 6:18 am, and be a brilliant beacon in the morning, shining in the southeast before the bright morning twilight claims it around 7:45 am. As we advance through winter into spring Venus is going to be harder to spot before sunrise.
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 Greeks called the moving objects in the sky Planetes meaning Wanderers, from which we get the name Planet. In reality the planets do not wander, or move aimlessly, but move in orbits, discovered by Johannes Kepler, in accordance with the laws of gravitation discovered by Isaac Newton and Albert Einstein. The ancients considered the Sun and Moon planets, because they also moved against the “fixed” stars in the sky. This made seven, adding to the five naked eye planets we know today. These seven objects became the names of the days of the week in many countries. We have retained three of them: Sun’s day, Moon’s day, and Saturn’s day. The rest are named for Norse gods and a goddess.
Ephemeris: 01/30/2024 – The Winter Maker moves to center stage at midwinter
This is Bob Moler with Ephemeris for Tuesday, January 30th. Today the Sun will be up for 9 hours and 43 minutes, setting at 5:48, and it will rise tomorrow at 8:03. The Moon, 3 days before last quarter, will rise at 10:53 this evening.
As we approach midwinter looking in the south at about 9 pm we see the great constellation of Orion the hunter. For the Anishinaabek people, who are native to our Great Lakes area, that constellation is the Wintermaker. Instead of holding a club and a shield, as Orion does, he has his arms outstretched from Aldebaran in Taurus to Procyon in Canis Minor embracing all the winter constellations. I’ve first seen him as morning twilight started when I’ve stayed up all night to watch the Perseid meteor shower in August. We begin to see him on late November evenings, rising in the east, to herald the coming of winter, and we will lose him in April when he descends into the West in the evening twilight.
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
Ephemeris: 01/29/2024 – Canis Major, Orion’s larger hunting dog
This is Ephemeris for Monday, January 29th. Today the Sun will be up for 9 hours and 41 minutes, setting at 5:46, and it will rise tomorrow at 8:04. The Moon, halfway from full to last quarter, will rise at 9:50 this evening.
The great winter constellation or star group, Orion the hunter, is located in the south-southeastern sky at 9 p.m. His elongated rectangle of a torso is nearly 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 41, or M41, the Little Beehive Cluster, 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
Ephemeris: 01/26/2024 – In astronomy “dark” means we can’t see it
This is Ephemeris for Friday, January 26th. Today the Sun will be up for 9 hours and 33 minutes, setting at 5:42, and it will rise tomorrow at 8:07. The Moon, 1 day past full, will rise at 6:37 this evening.
What does the word “dark” mean? In astronomy the word dark means something we cannot see. In ages before 1959 we could not see the backside of the moon, so people got to calling it the dark side of the Moon. All changed in 1959 when a Soviet spacecraft went around behind the moon it took photographs of it. The two contenders for dark things in astronomy are now dark matter and dark energy. Dark matter is something that has a gravitational effect on the galaxies that it surrounds, but we can’t see it. Also, the expansion of the universe appears to be accelerating, where we would expect it to be decelerating because of gravitational forces of all the galaxies in it. We call that cause dark energy. And we don’t know what either is.
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
Two possible causes of Dark Matter are in the running, WIMPs, and of course MACHOs. WIMPs are Weakly Interacting Massive Particles, while MACHOs are the bit more tortured acronym Massive Astrophysical Compact Halo Objects. Whatever they are they don’t interact much with themselves or ordinary matter, neither emitting light or any other radiation, or block it. However, they have mass and warp spacetime, distorting the shape of galaxies seen behind them. They also make galaxies seem to be more massive than their starlight would make them appear, and other effects.
Ephemeris: 01/25/2024 – Where is the full moon in winter?
This is Ephemeris for Thursday, January 25th. Today the Sun will be up for 9 hours and 31 minutes, setting at 5:41, and it will rise tomorrow at 8:08. The Moon, at full today, will rise at 5:30 this evening.
The exact time that the Moon will be full, at least to the nearest minute is 12:54 this afternoon. Have you ever noticed the placement of the full moon in the sky between winter and summer? The full moon near the winter solstice moves very high at midnight, while the full moon near the summer solstice is seen quite low in the south. For the Moon to be full, it must be nearly opposite the Sun in the sky, so we see it fully illuminated as the Sun does. The Moon’s orbit is close to the Sun’s apparent path in the sky, the ecliptic, which is the projection of the Earth’s orbit of the Sun. So the Moon now is near, and actually a bit north of, where the Sun will be 6 months from now in mid to late July.
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
Ephemeris: 01/24/2024 – Where have the planets wandered off to this week?
This is Ephemeris for Wednesday, January 24th. Today the Sun will be up for 9 hours and 29 minutes, setting at 5:39, and it will rise tomorrow at 8:09. The Moon, 1 day before full, will set at 8:36 tomorrow morning.
Let’s find out where the naked-eye planets have wandered off to this week. Three of those five planets are now easily visible. Saturn and Jupiter are the evening planets. Saturn is getting harder to spot low in the west-southwest, setting at 8:19 pm. Jupiter will move from high in the south to low in the west by midnight, and will set in the west-northwest at 1:40 am. Venus, the brilliant morning star, will rise in the east-southeast at 6:09 am, and be a brilliant beacon in the morning, shining in the southeast before the bright morning twilight claims it around 8 am. Mercury, which rises by 7:03 am might just be visible below and left of Venus by 7:30 am.
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
Ephemeris: 01/23/2024- The “dark” side of the Moon is its brightest side
This is Ephemeris for Tuesday, January 23rd. Today the Sun will be up for 9 hours and 27 minutes, setting at 5:38, and it will rise tomorrow at 8:10. The Moon, 2 days before full, will set at 8 o’clock tomorrow morning.
In a couple of days the far side of the Moon will become the dark side for real. It’ll be night when the near side of the moon becomes fully illuminated, the far side will be a night. The far side of the moon actually gets more sunlight than the near side of the moon because it does not suffer solar eclipses. The lunar solar eclipse occurs when we see a lunar eclipse. The Sun is blocked from shining on the Moon. The totality of a lunar solar eclipse lasts much longer than a few minutes that we get when the Moon totally blocks the Sun, the length of totality for the Moon’s solar eclipse can last several hours. The far side of the moon does not see eclipses, and when fully illuminated at what we call new moon it is a quarter of a million miles closer to the Sun than 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
Ephemeris: 01/22/2024 – The Dog Star’s little buddy
This is Ephemeris for Monday, January 22nd. Today the Sun will be up for 9 hours and 24 minutes, setting at 5:37, and it will rise tomorrow at 8:11. The Moon, 3 days before full, will set at 7:14 tomorrow morning.
Sirius is the brightest nighttime star and is located low in the southeast at 9 p.m. below and a bit left of Orion the Hunter. We’ve visited Sirius on Tuesday, but there is another star in the Sirius system that is practically invisible due to Sirius’ dazzling glare. Its name is Sirius B, nicknamed the Pup, alluding to Sirius’ Dog Star title. The tiny star was suspected as far back as 1834 due to Sirius’ wavy path against the more distant stars in the sky. Sirius and the Pup have 50-year orbits of each other. The Pup was first seen in 1862. It was the first of a new class of stars to be discovered, white dwarfs. The Pup is a dying star with the mass of the Sun, collapsed down to the size of the Earth after running out of hydrogen fuel in its core.
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
Ephemeris: 01/19/2024 – Finding the Dog Star
This is Bob Moler with Ephemeris for Friday, January 19th. Today the Sun will be up for 9 hours and 18 minutes, setting at 5:33, and it will rise tomorrow at 8:13. The Moon, 2 days past first quarter, will set at 3:59 tomorrow morning.
In the evening, the great constellation of Orion the hunter can be seen to slowly move from the south-east to the south. Its large rectangle of bright stars is easily visible, even with a full moon. The three stars in a straight line, his belt, tilt downward to the left to a very bright star merrily twinkling lower in the sky. This star is called Sirius, also known as the Dog Star because it’s in the heart of Orion’s larger hunting dog, Canis Major. It is an arc light white star as seen in binoculars or telescope. It is the brightest star in the night sky, and a neighboring star, just twice the distance of the closest star to the Sun at 8.6 light years. Its name, Sirius, has nothing to do with a dog, but is from the Greek meaning scorching for its brightness and sparkling, due to its intense twinkling.
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
Ephemeris: 01/18/2024 – A quick guide to Jupiter for the small telescope
This is Ephemeris for Thursday, January 18th. Today the Sun will be up for 9 hours and 16 minutes, setting at 5:31, and it will rise tomorrow at 8:14. The Moon, 1 day past first quarter, will set at 2:43 tomorrow morning.
Jupiter is the largest planets and is generally the largest appearing planet in a telescope. Venus appears a bit larger than Jupiter only for about four months when it’s the closest it gets to us. There’s always something going on with Jupiter and its 4 Galilean moons which appear to shuffle back and forth from one side to the other of the planet. Jupiter has cloud bands which run parallel to its equator and to the plane of the moon’s orbits. And it has the Great Red Spot, but that spot is not easily visible in small telescopes. Back in the 1950s it was big and brick red. It is since lost a great deal of its redness and size. The moons can hide behind Jupiter or in its shadow or cross in front of the planet. Tonight Jupiter will appear below and right of the Moon.
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
Bob Moler's Ephemeris Blog 