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Ephemeris: 07/31/2023 – August’s Blue Moon
This is Ephemeris for Monday, July 31st. Today the Sun will be up for 14 hours and 42 minutes, setting at 9:10, and it will rise tomorrow at 6:28. The Moon, 1 day before full, will set at 5:45 tomorrow morning.
In August, we are going to have two full moons this year and by most modern reckoning the second full moon is called a Blue Moon, even though that’s not the color of the Moon, which looks like normal although both of these moons in August will be supermoons, so they’ll be a little bit larger than average. However, there is nothing to compare them to, so there’s no way of determining this visually for yourself. The older definition of blue moon is the third full moon in a season that has four full moons. Being a purist, I prefer the latter definition, but I seem to be in a minority. The months of our calendar are a result of Roman politics and superstition, an arbitrary construct. So are time zones by modern politicians. Some time zones could have a blue moon, and some not.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.
Addendum
Ephemeris: 07/28/2023 – Sun and Star Party scheduled for tomorrow at the Sleeping Bear Dunes
This is Ephemeris for Friday, July 28th. Today the Sun will be up for 14 hours and 49 minutes, setting at 9:13, and it will rise tomorrow at 6:25. The Moon, 3 days past first quarter, will set at 2:19 tomorrow morning.
Tomorrow, the Sleeping Bear Dunes National Lakeshore and the Grand Traverse Astronomical Society will host a Sun and Star Party at the Dune Climb area of the park. There will be a solar viewing period from 5 pm to about 7 pm. The society has two hydrogen alpha solar telescopes to view the Sun’s chromosphere and prominences. Plus, some members also have solar scopes and white light filtered telescopes to view sunspots on the face of the Sun. Night viewing will start at 9 pm with the Moon featured, along with the brighter telescopic wonders of summer. The park rangers will leave at 11 pm, but society members will stay later to get a good view of Saturn as it moves higher in the sky. All this will happen only if clouds permit.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.
Addendum
There will be a pass of the International Space Station starting in the WNW at 9:48 pm, reaching maximum altitude at 9:52 pm of 63o in the SW, entering the Earth’s shadow at 9:55 pm. Note, these are specific times to the nearest minute for the Dune Climb, but close for the Grand Traverse area of Michigan. For other locations, go to: heavens-above.com.
Ephemeris: 07/27/2023 – See the Moon’s Bay of Rainbows at sunrise
This is Bob Moler with Ephemeris for Thursday, July 27th. Today the Sun will be up for 14 hours and 51 minutes, setting at 9:14, and it will rise tomorrow at 6:24. The Moon, 2 days past first quarter, will set at 1:38 tomorrow morning.
The moon tonight is a waxing gibbous phase, so it’s more than half illuminated by the Sun. The line between light and dark on the left side of the Moon is called the terminator, which before full is the sunrise line. It is where we can see the greatest detail because the Sun is low in the Moon’s sky there, and creates the longest shadows. Compare it to the right side of the Moon which is seen at nearly solar noon where no shadows are seen, so it has a very bland appearance. One of the cool features of the gibbous moon tonight is Sinus Iridium, the Bay of Rainbows, which is on the upper left part of the terminator. Part of the mountain range that partially rings it is seen in sunlight, while that floor of the bay is still in shadow.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.
Addendum
Ephemeris: 07/26/2023 – Let’s find out where the naked-eye planets have wandered off to this week
This is Bob Moler with Ephemeris for Wednesday, July 26th. Today the Sun will be up for 14 hours and 53 minutes, setting at 9:15, and it will rise tomorrow at 6:23. The Moon, 1 day past first quarter, will set at 1:08 tomorrow morning. | Let’s find out where the naked-eye planets have wandered off to this week. Venus is our hard to find Evening Star, seen very low in the west in evening twilight by 9:45 pm. It will set at 10:11 pm, Mercury might be spotted to Venus’ right and a bit above. The red planet Mars is pretty much lost in the evening twilight, above and left of Venus. Saturn will rise at 10:38 pm. And by 5:30 am, or a bit less than an hour before sunrise tomorrow, it will appear in the south-southwest, the brightest “star” in that direction. Its above the bright star Fomalhaut, normally the loneliest bright star in the sky. Jupiter will be in the east-southeast at that hour. Jupiter is the brightest star-like object in the morning sky now, near some of the bright stars of a winter’s evening.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.
Addendum
Ephemeris: 07/25/2023 – Is the universe twice as old as we think?
This is Ephemeris for Tuesday, July 25th. Today the Sun will be up for 14 hours and 55 minutes, setting at 9:16, and it will rise tomorrow at 6:22. The Moon, at first quarter today, will set at 12:44 tomorrow morning.
Is the universe twice as old as we thought? That’s a conclusion of a study printed in the monthly notices of the Royal Astronomical Society by Rajendra Gupta from the University of Ottawa, in which he postulates that the structure and chemical composition of very early galaxies found by the James Webb Space Telescope turn out to be more developed than one would expect for objects so soon after The Big Bang. The problem with hypothesizing an older universe is to explain what we see currently that have shown that the universe is 13.8 billion years old. One of the things he hypothesized was something called tired light, where light loses energy and is red-shifted not just because of the expansion of the universe but over time and distance. Stay tuned.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.
Addendum
Timeline of the universe. A representation of the evolution of the universe over 13.77 billion years. The far left depicts the earliest moment we can now probe, when a period of “inflation” produced a burst of exponential growth in the universe. (Size is depicted by the vertical extent of the grid in this graphic.) For the next several billion years, the expansion of the universe gradually slowed down as the matter in the universe pulled on itself via gravity. More recently, the expansion has begun to speed up again as the repulsive effects of dark energy have come to dominate the expansion of the universe. The afterglow light seen by WMAP was emitted about 375,000 years after inflation and has traversed the universe largely unimpeded since then. The conditions of earlier times are imprinted on this light; it also forms a backlight for later developments of the universe. Public Domain.
Diagram is from Wikipedia. Above is the expansion of the universe as commonly understood. Not mentioned in the program script above, is the requirement, according to Gupta’s hypothesis, that the basic constants of the universe change over time. As Carl Sagan explained, “Extraordinary claims require extraordinary evidence.” So more evidence is needed. His hypothesis won’t be the only explanation put forth, so there will be more to test. That’s job security for astrophysicists and cosmologists.
Ephemeris: 07/24/2023 – The Moon appears to wobble a bit
This is Ephemeris for Monday, July 24th. Today the Sun will be up for 14 hours and 57 minutes, setting at 9:17, and it will rise tomorrow at 6:21. The Moon, 1 day before first quarter, will set at 12:24 tomorrow morning.
The Moon tonight is nearly half illuminated. In binoculars the dark oval spot visible on the Moon’s right edge is the Sea of Crises or Mare Crisium a small dark lava plain. The Moon’s rotation is quite uniform, however its orbit isn’t circular, so the Moon’s motion in its orbit slows as it moves farthest from the Earth, called apogee, and is sped up when closest, at perigee, So its face seems to rock a bit back and forth over the month. It’s an effect called libration. And one way to track that is to note how close the Mare Crisium (Sea of Crises) is to the edge of the Moon. It appears close to the right edge now. A week from now, that sea will appear to move away from the edge. Unfortunately, by then the Moon will be full, and night will soon fall on that little sea.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.
Addendum
Ephemeris: 07/21/2023 – Antares just looks weird
This is Ephemeris for Friday, July 21st. Today the Sun will be up for 15 hours and 3 minutes, setting at 9:20, and it will rise tomorrow at 6:18. The Moon, halfway from new to first quarter, will set at 11:34 this evening.
We’ve had our Fourth of July fireworks over two weeks ago, but there’s one star still celebrating as a sparkler. That’s Antares in Scorpius the scorpion low in the south tonight. We in Michigan always see Antares low in the south. It’s a bright red giant star which twinkles mightily, and since it’s low in the sky, it spits and sputters all kinds of colors due to our atmosphere’s turbulence, and the fact that we’re looking through so much of it at Antares. At it’s highest, due south, we are seeing it though 3 times more atmosphere than we would be if it was overhead. The more magnification one uses with binoculars or a telescope, the greater the sparkler effect. It is even called in sometimes as a UFO.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.
Addendum
The name of the star Antares means “Rival of Mars”. “Ant” meaning anti, “Ares”, the Greek equivalent to the Roman god Mars. The reason is their similar reddish color. Antares is red because it is a cool star, a red giant. Mars is red due to its red dust, colored by iron rust. The planet passes Antares about every 23 1/2 months. Mars will next pass Antares on December 8th, 2023. However, the event will not be visible, because both the star and the planet will be too close to the Sun in the morning sky then. Their next meeting, or conjunction, after that, on November 17th, 2025 will be in the evening sky, but still too close to the Sun to be spotted. The conjunction after that will be in the evening sky, again rather close to the Sun, on October 28, 2027. For these three encounters, Mars will be north or above Antares, and dimmer than the star.
Ephemeris: 07/20/2023 – How Boötes and Ursa Major got into the sky
This is Ephemeris for Thursday, July 20th. Today the Sun will be up for 15 hours and 5 minutes, setting at 9:21, and it will rise tomorrow at 6:17. The Moon, 3 days past new, will set at 11:16 this evening.
Seen in high in the west-southwest at 10:30 this evening is the kite shaped constellation of Boötes (pronounced Bo-o-tees) the herdsman. The bright star Arcturus is at the bottom of the kite. It is pointed to by the arc of the handle of the Big Dipper, part of Ursa Major, the Great Bear, over toward the northwest. Boötes represents a young hunter named Arcas, son of Callisto, a beautiful young lady who had the misfortune of being loved by Zeus, the chief of the Greek gods. Zeus’ wife, Hera, found out about it, and since she couldn’t punish Zeus, turned the poor woman into a bear. Arcas, many years later, unaware of the events surrounding his mother’s disappearance, was about to kill the bear when Jupiter intervened and placed them both in the sky to save her. Arcas still pursues her across the sky nightly.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.
Addendum
Ephemeris: 07/19/2023 – Let’s find out where the naked-eye planets have wandered off to this week
This is Ephemeris for Wednesday, July 19th. Today the Sun will be up for 15 hours and 7 minutes, setting at 9:22, and it will rise tomorrow at 6:16. The Moon, 2 days past new, will set at 10:55 this evening.
Let’s find out where the naked-eye planets have wandered off to this week. Venus is our blazing Evening Star, seen very low in the west in evening twilight. It will set at 10:31 pm, and by four minutes earlier each night. The red planet Mars is now pretty much lost in the evening twilight. We’ll see it in the morning sky in a few months. Venus too will soon leave the evening sky. Saturn will rise shortly after 11 pm. And by 5:15 am, or an hour before sunrise, it will appear in the south-southwest, the brightest “star” in that direction. It’s above the bright star Fomalhaut, normally the loneliest bright star in the sky. Jupiter will be in the east-southeast at that hour. Jupiter is the brightest star-like object in the morning sky now.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.
Addendum
Ephemeris: 07/18/2023 – Vega, the brightest star of the Summer Triangle
This is Ephemeris for Tuesday, July 18th. Today the Sun will be up for 15 hours and 9 minutes, setting at 9:23, and it will rise tomorrow at 6:15. The Moon, 1 day past new, will set at 10:30 this evening.
Vega, in the constellation Lyra the harp, is the highest bright star In the east and brightest star of the Summer Triangle also rising in that direction. It is an important and much studied star, first as a standard for brightness for the magnitude scale at almost exactly zero. In 1983 the Infrared Astronomy Satellite, IRAS, discovered an excess of infrared radiation coming from the star. It seems now that there are two orbiting rings around the star, an inner warm ring and an outer cold ring. This is somewhat like the two disks of material the Sun has: The asteroid belt between Mars and Jupiter and the Kuiper belt, beyond Neptune. No planets have yet been discovered around Vega, but I wouldn’t bet against it.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.
Addendum
Bob Moler's Ephemeris Blog 