#24O - I'm on Vacation but the Sky is Not! - Kepler's Spots and How to Do Like Him - Upcoming 4-Minute Eclipse
TGT 8/16/24: Sky Planning Calendar--Between Events, See the Moon Pass Three Worlds; For the Future--A Weird Eclipse Coming Up; Followup on Tycho--Kepler's Sunspots and Cameras Obscura's; Luna Biz's.
Cover Photo - Kepler’s Spots
In This Issue:
Cover Photo — Kepler’s Spots
Welcome to Issue 24O!
Sky Planning Calendar —
* Moon-Gazing - Moon Passes (Over) Saturn, Does Long Distance Flyby’s Mars and Jupiter
* Observing—Plan-et -
- Saturn Nearly All Night
- Venus and Mercury Enter Into Views on Opposite Sides of the Sky
* Border Crossings - Match! (briefly)
* For the Future - A 4-Minute Eclipse ComingTowards Cosmic Awareness
- Kepler’s Sunspots and the Camera ObscuraAstronomy in Everyday Life - Luna Businesses
Welcome to The Galactic Times Newsletter-Inbox Magazine #24O!
Your truly is taking an August break (as much as I can with a lot of Lafayette history talks — my other current writing genre—see https://www.hermograph.com/lafayette is you are interested) being arranged) and this issue will be shorter than usual and most of it “pre-written”. But a news article near the last minute encouraged me out of the Sun’s heat into A/C to write about….the Sun.
Same idea for the September 1st issue. I hope to add an astronomical travel piece when things resume on the 16th of September.
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We seem to be in between celestial activities of interest. As this issue comes out the Perseid meteor shower has all but become insignificant (there’s always a few late ones). After it expires at month end we will be awaiting the evening prominence of Saturn at opposition, visible all night, and a very weird partial lunar eclipse. See below.
Enjoy!
Publisher — Dr. Larry Krumenaker Email: newsletter@thegalactictimes.com
Sky Planning Calendar
Moon-Gazing
Moon passages by a star, planet or deep sky object are a good way to find a planet or other object if you’ve never located it before.
August 18 One calendar month until a partial eclipse of the Moon! See below.
August 19 Full Moon.
August 20 Saturn is a half-degree South of the Moon, and behind it in an occultation if you are in Europe, or South or Central America.
August 21 Perigee. A Super-Waning Gibbous Moon.
August 25, past midnight into the 26th, the Moon scrambles the Seven Sisters, flying through the Pleiades star cluster, and likely over some of them depending on where you are.
August 26 Last Quarter
August 27 In the AM North American time, you’ll find bright Jupiter near (but not too near, 6-degrees) and South of the Moon. In the early evening, Mars does almost the same trick, 5-degrees South.
August 29 Just barely before midnight, the Gemini twin star Pollux will be 1.7-degrees North of the Moon.
Observing---Plan-et
==Lunar Conjunctions with Planets are the Best Opportunities for Viewing==
==Venus and Mercury Begin to Be Better Visible, in Opposite Directions==
Mercury starts the this half-month in conjunction with the Sun on the 19th but rapidly zooms into view to rise 45 minutes before the Sun from August 24th onwards into September. By month’s end it rises nearly at the time twilight begins so you have some chance of seeing it in a not-yet-too-brilliant dawn.
Venus finally sets in the evening sky more than an hour after the Sun…on the 31st. Still not that easy to find with the ecliptic having a line roughly parallel to the horizon…. And just to make things interesting….Venus and Saturn are in opposition to each other, as Saturn is almost in opposition to the Sun. In other words, they are 180-degrees apart, one rising as the other is setting.
Mars is making its rapid get-away from the giant planet Jupiter, having been a third of a degree away on the 14th. The Moon passes distantly by on the 27th. Still not visible before midnight but that’s coming next month. But in fact, it is….
….Jupiter getting more prominent, being more westward, to Mars’ right, in sky and rising increasing earlier in the night. The Moon also passes by it distantly on the 27th. By month’s end, it rises 45 minutes before Mars, at midnight Daylight Saving Time on the 31st, now to enter status as an evening planet!
Saturn is 7 days away from opposition at month’s end, rising shortly after the Sun sets. The Moon passes distantly by on the 20th. Also, in the predawn and dawn hours it will be one of THREE bright planets AND ELEVEN first magnitude stars in the sky at the same time! Perhaps this year’s most brilliant gathering of night-sky-diamonds….
Border Crossings
Astronomically the Sun is in Leo all this fortnight. Astrologically, too (woo hoo!), will, until the 22nd when it enters Virgo.
For the Future
There is an upcoming partial lunar eclipse one month from now, on September 17th North American dating. It is not a very exciting one but at least we have it! The Moon will only barely enter the central umbral shadow, about a 10% of the way into it (3-minutes of arc—barely a size the average human eye can differentiate), something that will barely look darker than the deepest part of the outer penumbral shadow. Partial phase will last a whopping 4 minutes of time. Don’t close your eyes or you might miss it.
The peak, such as it is, will be centered at 10:44PM Eastern Daylight Time, and the eclipse will be visible, weather permitting, from the longitudes of the Mediterranean Sea to California’s.
Towards Cosmic Awareness
Kepler in Prague Provides Sunspot Data with His Camera Obscura
The Tycho stories in the last issue of The Galactic Times seems to have a followup. CNN and the New York Times both had a story from the Astrophysical Journal Letters about Tycho Brahe’s assistant-turned-inheritor of his data, Johannes Kepler. Seems Kepler did some solar observing, seeing some dark spots on the face of the Sun which he thought was the planet Mercury. On the rare occasions when the first planet does transit the Sun’s face, it is done in a matter of hours, but Kepler’s observations were over days. What the scientific result of re-using the drawings he made had to do with the sunspot cycle, and the Maunder Minimum, a decades-long time in the 1600 when few sunspots were ever visible.
But that’s not the story to be done here. Kepler’s observations were made in 1607, just before the beginning of the telescopic period or his own telescopic observations in his different from Galileo’s type of scope, called the Keplerian telescope, invented in 1611. Kepler used a method called the camera obscura that can be duplicated today.
The camera obscura is essentially a pinhole projector in which the pinhole acts like a lens and produces an image best at a far away wall in an otherwise darkened room. Ever notice the shadows of persons or moving images of cars on your room’s walls? That’s the same principle, the light coming through slits on your blinds or holes in a shade, or just very narrow passages in your window or door that let light through.
It is also, somewhat, the same thing as making pinhole projectors to view the phases of a solar eclipse. The difference here is that your pinhole crescent Sun during an eclipse need not throw the light very far to see the shape. But to see spots on the Sun (or planets like Mercury or Venus in a transit across its face) you need to greatly enlarge that image. Without actual optics, like lenses or mirrors that gather light and make focused images, you can really only observe the Sun this way at sunrise or sunset.
Sunspots have been known for thousands of years, though not what they were until the last couple of them. The only way back then to see spots without a telescope was when the Sun’s extreme brilliance could be cut way down, with fog or smoke or clouds, and then the spot had to be a super large one, rare, and rarer outside of solar max. Or have enough length in a place to project a large enough solar image that the spots can be see. When the Sun is higher than a few degrees, it is hard to get such an image with a horizontal length to view it.
Three ways for educators and public outreach to do this:
Have a room in the right direction available you can black curtain out, other than a pinhole in the curtain, near sunrise or sunset.
Have some kind of first-surface mirror—metal, glass first surface like a telescope mirror only flat, or other reflecting surface like thin clear glass, and aim a reflection of the Sun into a room, or put a pinhole like cover on a glass mirror to narrow the throw of light.
Use tiny mirrors, without a pinhole but thus act like one. A popular such one this past April for the Great American Eclipse was using those of a disco ball.
With a long enough throw of light, not only is the Sun enlarged but also any spots.
Oh, and if you want to observe a transit of Mercury like Kepler thought he had, you only have 8 years to wait. November 13, 2032, to be exact. Good luck. Get prepped….
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Kepler did this in two places we mentioned last issue in Prague. One was in his house on Karlova Street, in which he discovered some of his Planetary Laws of Motion. But this house’s front door faces North so he would have had to use the upper floor or attic to look east or west to see the low rising or setting Sun. [Turns out this place isn’t nameless, it is called the French Crown. No idea why but that’s what this writer learned out of the article!] The other was in a workshop in the Emperer’s Prague palace, Hradcany. The exact location of that isn’t clear but it was, and is, a BIG castle and could undoubtedly have suitable windows in any direction.
Kepler’s place at 4 Karlova Street, has markers about it. Kepler’s apartment building had a small museum but that has been closed.
Astronomy in Everyday Life
Eclipses deal with the Moon. So do many stores. As expressions of diversity, here’s a pair of them weird ways we use the Moon in commerce.
While traveling in Georgia, came across this store sign.
And this one in Alabama:
