Archive
10/21/2022 – Ephemeris – Lots of transient astronomical activity this weekend
This is Bob Moler with Ephemeris for Friday, October 21st. Today the Sun will be up for 10 hours and 41 minutes, setting at 6:48, and it will rise tomorrow at 8:07. The Moon, halfway from last quarter to new, will rise at 4:44 tomorrow morning. | We have several astronomical events happening tonight and over the weekend. The Orionid meteor shower may still be at peak, appearing tonight between 11 pm and moonrise tomorrow morning. Up to 20, and maybe more, meteors per hour may be spotted just prior to moonrise. Tomorrow Venus will be in superior conjunction with the Sun, the passing behind, though not directly behind the Sun, and thus entering the evening sky. It will be a month or so for Venus to separate itself from the Sun’s glare to be spotted in the early evening. Finally, on Sunday Saturn will end its retrograde or westward movement against the stars of Capricornus and resume moving eastward, its normal motion around our sky.
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 Orionid meteor shower radiant. The radiant rises at 11 p.m., so the meteors will be visible from then into morning twilight. Despite the location of the radiant, the meteors will b e seen all over the sky. However, true Orionids can be traced back to the radiant point. This chart is from another year. This year, bright Mars would be at the top center of the image. Created using Stellarium.
Venus near Superior conjunction through the Solar and Heliospheric Observatory (SOHO) LASCO C2 Coronagraph. The white circle inside the occulting disk is the diameter of the Sun’s photosphere, the disk we see of the Sun in white light. Launched in 1995, SOHO has been in halo orbit around the Sun-Earth L1 Lagrange point ever since.
Saturn stationary animation showing it with and without annotations. The fine, folded line with tick marks is Saturn’s path. The tick marks are at 10-day intervals. Saturn starts out in retrograde motion, heading westward or to the right. On October 23rd, it slows and stops that motion. It begins to head back eastward in its normal prograde motion to the left. Outer planets like Saturn, Jupiter, Mars and the rest exhibit retrograde motion when the Earth in effect passes them on the same side of the Sun. Click on the image to enlarge it slightly. Created using Cartes du Ciel (Sky Charts), LibreOffice Draw, and GIMP.
10/20/2022 – Ephemeris – Halley’s Comet returns… in little bitty pieces
This is Bob Moler with Ephemeris for Thursday, October 20th. Today the Sun will be up for 10 hours and 44 minutes, setting at 6:49, and it will rise tomorrow at 8:06. The Moon, 3 days past last quarter, will rise at 3:36 tomorrow morning.
Halley’s Comet is back! (Pronounced Hawley’s) Well sorta. In the form of the Orionid meteor shower. Bits of Halley’s Comet from previous passes by the Earth’s orbit make their twice-yearly show in our skies as these bits collide with the Earth’s atmosphere. Halley’s orbit passes close to the Earth’s orbit at points where the Earth is around May 6th and again near October 21st. Light dust and ionized gas get blown back into the tail of the comet. Heavier particles will roughly follow in the comet’s orbit. The radiant, a spot above the constellation Orion and below Gemini from which they will seem to come, will rise around 11 pm. So view them any time after that as their numbers will increase until the Moon rises both tonight and tomorrow nights.
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 Orionid Radiant is high in the south at 5 a.m. this weekend. Created using Stellarium.
Halley’s Comet orbit with the orbits of the inner planets showing the points at which the debris from the comet intersect with the Earth’s orbit, causing meteor showers. Click on the image to enlarge it. Diagram credit JPL Small-Body Database Browser with my annotations.
10/20/2020 – Ephemeris – The Orionid meteor shower reaches peak overnight
This is Bob Moler with Ephemeris for Tuesday, October 20th. Today the Sun will be up for 10 hours and 43 minutes, setting at 6:48, and it will rise tomorrow at 8:06. The Moon, 3 days before first quarter, will set at 9:44 this evening.
Halley’s Comet is back! (Pronounced Hall-ee’s) Well sorta. In the form of the Orionid meteor shower. Bits of Halley’s Comet from previous passes by the Earth’s orbit make their twice-yearly show in our skies as these bits collide with the Earth’s atmosphere. Halley’s orbit passes close to the Earth’s orbit at points where the Earth is around May 6th and again near October 21st. Light dust and ionized gas get blown back into the tail of the comet. Heavier particles will roughly following the comet’s orbit. The radiant, a spot above the constellation Orion and below Gemini from which they will seem to come will rise around 11 pm. So view them any time after that as their numbers will increase until morning twilight begins.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Orionid meteor shower radiant at 5 a.m. October 21st. The radiant rises at 11 p.m., so the meteors will be visible from then into morning twilight. Despite the location of the radiant, the meteors will be seen all over the sky. However true Orionids can be traced back to the radiant point. Created using Stellarium.
We get two meteor showers from Halley’s Comet. The Orionids, when Halley’s meteoroids are approaching the inner solar system, and the Eta Aquariids when they’re leaving. Created using my LookingUp program.
10/18/2018 – Ephemeris – Halley’s Comet returns as the Orionids
Ephemeris for Thursday, October 18th. The Sun will rise at 8:02. It’ll be up for 10 hours and 50 minutes, setting at 6:53. The Moon, 2 days past first quarter, will set at 2:32 tomorrow morning.
Halley’s Comet is back! (Pronounced Hall-ee’s) Well sorta. In the form of the Orionid meteor shower. Bits of Halley’s Comet from previous passes by the Earth’s orbit make their twice-yearly show in our skies as these bits collide with the Earth’s atmosphere. Halley’s orbit passes close to the earth’s orbit at points where the Earth is around May 6th and again near October 21st. Light dust and ionized gas get blown back into the tail of the comet. Heavier particles, still affected by the pressure of sunlight and the gravitational pull of the Sun and planets end up roughly following the comet’s orbit. In the morning after the Moon sets should be the best time to see them. They will seem to come from a spot above Orion and below Gemini.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
10/19/2017 – Ephemeris – Bits of Halley’s Comet will rain down on Earth this weekend
Ephemeris for Thursday, October 19th. The Sun will rise at 8:03. It’ll be up for 10 hours and 47 minutes, setting at 6:50. The Moon is new today, and won’t be visible.
The Orionid meteor shower is ramping up. This is the second of two visits of bits of Halley’s* comet this year, and every year, really. These are particles shed by the comet in past visits to the inner solar system. They are pretty much evenly strewn out along its orbit. The comet itself is now out past Neptune, and will reach aphelion, its farthest distance from the Sun around 2024, poised to head back to the inner solar system in 2061. It was last spotted in 2003 when it was just inside Neptune’s orbit. Anyway the Orionid meteors will appear to come from above the left side of constellation of Orion, about where the tip of his club is. They are best seen this weekend, in the early morning sky, with a possible 20 per hour visible.
Orionid meteor shower Saturday a.m.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location
* A contemporary of Edmund Halley, Samuel Pepys, spelled his name Hawley. We presume he pronounced it that way.
Addendum
The Orionid meteor shower radiant at 5 a.m. October 21, 2017. The radiant rises at 11 p.m., so the meteors will be visible from then into morning twilight. Dispite the lication of the radiant, the meteors will b e seen all over the sky. However true Orionids can be traced back to the radiant point. Created using Stellarium.
10/20/2015 – Ephemeris – Halley’s Comet returns… in bits and pieces
Ephemeris for Tuesday, October 20th. The Sun will rise at 8:04. It’ll be up for 10 hours and 45 minutes, setting at 6:50. The Moon, at first quarter today, will set at 12:53 tomorrow morning.
Halley’s Comet is back! Well sorta. In the form of the Orionid meteor shower. Bits of Halley’s Comet from previous passes by the Earth’s orbit make their twice yearly show in our skies as these bits collide with the Earth’s atmosphere. Halley’s orbit passes close to the earth’s orbit at points where the Earth is around May 6th and again near October 21st. Light dust get blown back into the tail of the comet. Heavier particles, still affected by the pressure of sunlight and the gravitational pull of the Sun and planets end up roughly following the comet’s orbit. Tonight night after the Moon sets should be the best time to see them. They will seem to come from a spot above Orion and below Gemini.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Orionid Radiant
We get two meteor showers from Halley’s Comet. The Orionids, when Halley is approaching the inner solar system, and the Eta Aquariids when it’s leaving. Credit my LookingUp program.
05/05/2015 – Ephemeris – Eta Aquariids, an early visit of Halley’s Comet
Ephemeris for Tuesday, May 5th. Today the Sun will be up for 14 hours and 24 minutes, setting at 8:52. The Moon, 2 days past full, will rise at 10:29 this evening. Tomorrow the Sun will rise at 6:26.
The Eta Aquariid meteor shower will reach peak tomorrow morning. But the Moon will be bright, so only the brightest of them will be seen. However if you’re waiting to see the return of Halley’s Comet, you needn’t wait until the main body of the comet returns in 2061. Halley’s Comet has made many passes of the inner solar system in recorded history, and many more before that, returning to the inner solar system every 76 years or so, before returning to its frigid home beyond Neptune. It’s closest to the Sun, called perihelion is inside Venus’ orbit. On the way in and out it passes close to the Earth’s orbit. It has left a trail of debris, which we pass through in May and again in October.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Eta Aquariid radiant at 5 a.m. The radiant moves slowly to the east with time. Credit: My LookingUp program.
We get two meteor showers from Halley’s Comet. The Orionids, when Halley is approaching the inner solar system, and the Eta Aquariids when it’s leaving. Credit: My LookingUp program.
10/20/11 – Ephemeris – The Orionid meteor shower
Thursday, October 20th. The sun will rise at 8:03. It’ll be up for 10 hours and 46 minutes, setting at 6:50. The moon, 1 day past last quarter, will rise at 1:40 tomorrow morning. | The Orionid meteor shower will reach its peak tomorrow morning. Like most meteor showers, this is best seen just before dawn. As the name suggests the so-called shooting stars will seem to come from the constellation Orion the hunter. They will appear to come from above the rectangular torso of the giant. These meteors actually have nothing to do with Orion, but they are the light flashes from bits of rock that were once part of Halley’s comet, as they burn up in the earth’s atmosphere. In Halley’s many passes close to the sun, much of its solid material has been liberated by the evaporating gasses, leaving a trail of litter in its orbit. The earth passes through this debris every May and now, in October.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Orionid Radiant
10/03/11 – Ephemeris – More celestial events for this month
Monday, October 3rd. The sun will rise at 7:42. It’ll be up for 11 hours and 37 minutes, setting at 7:19. The moon, at first quarter today, will set at 12:10 tomorrow morning.
We have more celestial happenings this month than I could enumerate last Friday. Later on Saturday evening, if it’s clear the Grand Traverse Astronomical Society will join with astronomy groups, planetariums and observatories with International Observe the Moon Night with telescopes positioned on the 200 block east Front Street in Traverse City, near the Martinek clock. Going on that same evening will be the return of the Draconid meteor shower. Its a favorable return of a periodic shower but interferes with by the bright moon. However some bright meteors will be seen. I’ll have more information and background Thursday. Another meteor shower later this month will be the Orionids a morning shower related to Halley’s Comet.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Bob Moler's Ephemeris Blog 