#24B - Drinking in the Moon - Mars Rivers - Lots of Solar Eclipse Articles - & 5 More Stories (corrected)
TGT 2/1/24: Japan's Lander from Orbit; Moon Brushes All Planets in 8 Days; AEL-- -Hic- Tasty Moon Drinks; This Just In--Habitable M-dwarf Exo's, Mars' Rivers, Old Smoker's and Heavy Metals, more...
Cover Photo - Blinking the Moon
Assuming this survives your email, you should be able to see the recently errant Japanese lunar lander SLIM that kerplunked nose down into the Moon, in a blinking pair of before and after photos from NASA’s Lunar Reconnaissance Orbiter.
In This Issue:
Cover Photo — Blinking the Moon
Welcome to Issue 24B!
Links to Solar Eclipse Articles in The Classroom Astronomer
Our First Paid Subscriber-Only Issue ComingThis Just In —
* Never Too Old to Smoke
* The Rivers of Mars Ran dry—When?
* Filtering M-dwarf Stars for Habitable Exoplanets
* Citizen Scientist Solar System DiscoveriesSky Planning Calendar —
* Moon-Gazing - Eight Days of Passing Planets
* Observing—Plan-et - Three Planets About to Wave Farewell
* Border Crossings - (Goat)-Fish Out of WaterAstronomy in Everyday Life - Drinking In the Moon
Welcome to The Galactic Times Newsletter-Inbox Magazine #24B!
If you look up … on our Substack newsletter homepage … you’ll see a new menu item: April Eclipse Links. Here you will find all the articles that were published in the various issues of The Classroom Astronomer, our sister publication (though it is still on hiatus). You can go into its Archive and seek the article issue number and read the articles of interest to you, if you are a past subscriber. But a 31-page PDF is also available via a direct link only here.
The Link articles are on traveling to the path of the eclipse, practical matters, photo tips, teaching ideas, experiments you can try. and so on. Use them to make your best plans because it will be around TWO DECADES before you see another one in the continental US (but we’ll talk more about upcoming solar eclipses in March issues of TGT). Enjoy!
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Our first Paid Subscriber-only issue is nearly ready. It will contain more Moon stuff, specifically a Deeper Look at Moon Music, some astro education reports, and more research items, plus another Deeper Look piece on…well, you’ll see. Sign up to read this Extra Supplement for slightly more than $1 an issue per year!
Meanwhile….
The Moon is a lonely place, but not for long. As seen in Moon-Gazing, beginning the 7th, then on for a week (if your week, like the Beatles’, is actually 8 days long) it begins to brush past all the planets, first in the dawn then in the early evenings. The peak meeting is with Saturn, on the 10th, a beautiful Crescent by the planet with Rings. But this all is Last Call as Mercury, Venus and Saturn begin to quickly hide in the twilight glare of the Sun for a while.
Yet the Moon is never forgotten in society. During the recent author’s medical hiatus he found a LOT of things with the word “Moon” or its equivalent “Luna”, more than any other single object, on commercial products. In Astronomy in Everyday Life, we’ll drink to the Moon!
This Just In reports on Old Smokers—stars puffing away in the center of the galaxy distributing heavy metals to to space—and the ages of Martian rivers in the past. Some asteroids have become comets, as found by citizen scientists, one of which gets somewhat close to Earth. Finally, if you are looking for an exoplanet, your best chance is around an M-dwarf star, just by sheer numbers. But can they survive the long youth period of the star to become habitable?
Enjoy!
Publisher — Dr. Larry Krumenaker Email: newsletter@thegalactictimes.com
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This Just In —
* Never Too Old to Smoke
There are always strange and sometimes new things in the heart of our galaxy. Oftentimes they are violent or new objects. Then….there are 21 red stars near the center of the Milky Way that showed unusual changes in brightness during a British 10-year survey.
Professor Philip Lucas talked about the quandary, as his team was looking at protostars in the nuclear region of our galaxy: "We weren't sure if these stars were protostars starting an eruption, or recovering from a dip in brightness caused by a disc or shell of dust in front of the star – or if they were older giant stars throwing off matter in the late stages of their life."
Analysis of the spectra for seven of these stars, compared with data from earlier surveys, concluded that they were in fact a new type of red giant star.
Co-researcher Professor Dante Minniti of the Andrés Bello University in Chile, founder of the survey, said: "These elderly stars sit quietly for years or decades and then puff out clouds of smoke in a totally unexpected way. They look very dim and red for several years, to the point that sometimes we can't see them at all."
What makes this discovery important is the fact that they are heavily concentrated in the innermost part of the Nuclear Disc, where stars tend to be richer in heavy elements than anywhere else. It makes these “old smokers” an easier source for dust particles to condense out of the gas in the cool outer layers of red giant stars. How? That puffing’s still a mystery. But it could change how elements get spread across space.
Said Lucas, "Matter ejected from old stars (a.k.a. Old Smokers or dipping giants) plays a key role in the life cycle of the elements, helping to form the next generation of stars and planets. This was thought to occur mainly in a well-studied type of star called a Mira variable. However, the discovery of a new type of star that throws off matter could have wider significance for the spread of heavy elements in the Nuclear Disc and metal-rich regions of other galaxies."
Sources: The most variable VVV sources: eruptive protostars, dipping giants in the Nuclear Disc and others,and Spectroscopic confirmation of high-amplitude eruptive YSOs and dipping giants from the VVV survey, Monthly Notices of the Royal Astronomical Society.
* The Rivers of Mars Ran Dry—When?
Depending on whom you ask, early Mars was either “warm and wet” with an ocean, or it was “cold and icy” with massive ice sheets, and somewhere in there water flowed. There is evidence for river valleys and lakes and possibly oceans of water. But when did that watery era start and when did that end? Using impact craters as a dating tool, Planetary Science Institute Research Scientist Alexander Morgan has determined maximum timescales for the formation of Martian valley networks shaped by running water.
“The timescale over which these valleys formed has big implications for early Mars’ habitability, as long eras with stable liquid water would be more conducive to life,” said Morgan, sole author of “New maximum constraints on the era of Martian valley network formation” that appears in Earth and Planetary Science Letters.
The articles states that ‘Martian valley networks formed more than 3 billion years ago and have long been considered among the strongest pieces of evidence of liquid water on early Mars. Previous work has found that it took a minimum of tens of thousands of years to erode these valleys, but the frequency of flow events, and thus the total time era over which the valleys formed, has not been constrained.’
“In this study, I used craters that predate and postdate valley systems to place maximum bounds of hundreds of millions of years on the era over which these systems formed. Previous work had only determined minimum timescales, so these new results provide an upper bound on the timescale over which Martian valleys were active,” Morgan said. “Given what we know about erosion rates on early Mars, longer timescales imply that conditions permitting rivers were highly intermittent, with long arid periods interspersed with brief episodes of fluvial activity.” So both warm and wet and cold and dry are too general.
The results suggest that Mars’ rivers were eroding at a very slow rate, similar to parts of the Atacama Desert in Chile. The surface conditions for running water varied from strong to non-existent and back.
* Filtering M-dwarf Stars for Habitable Exoplanets
There are lots of known exoplanets now, and the vast majority, as is fitting, are around the vast majority type of star, the M-dwarf. Cooler and smaller than our Sun, M-dwarf stars last longer and make up perhaps 75% of the stars in the galaxy; the combination of greater numbers and longer lives would make them the ideal candidate for finding exoplanets. But are they habitable?
There are a variety of factors needed to answer that question. First, any such world has to be in the Habitable Zone, which will be extremely close to the star in order to generate any warmth for which water could be liquid and life as we know it exist. But that creates a new problem—most close-in worlds become tidally locked, with one side hot and the other frigid. And to make matters worse, M-dwarves are surprisingly active. They can vary greatly in brightness due to flares, and THOSE are are hand-in-hand with intense magnetic fields and huge coronal mass ejections. The latter can take an otherwise habitable world and make it a dead one by stripping its atmosphere away, sterilizing its surface, all due to massive X-ray and UV-emissions from the star.
So how can an exoplanet survive this onslaught. According to a study by Scott Engle of Villanova University, in the January 1st Astrophysical Journal, one factor has to be how long the onslaught lasts. As part of an interestingly-titled research program, Living with a Red Dwarf, Engle studied a large number of M-dwarf stars with coronal (X-ray), chromospheric (hydrogen and calcium emission lines in their spectra) and overall emissions from various catalogs, along with magnetic and rotational data in the stars; spectra and determined emission-age correlations.
It would appear that any exoplanet’s fate is at risk (other factors equal) in the star’s younger days, notably within the first 500-600 million years to 1.5 Gigayears, after which the radiation bath fades down by a factor of 1.5 orders of magnitude to possibly tolerable levels. These are not hard and fast age limits; some ‘saturation times’ can go as much as 2.5 Gyr. It is then possible that in some cases, a second atmosphere that is habitable can be outgassed from the planet’s interior, a second-life so to speak.
* Citizen Scientist Solar System Discoveries
Citizen science astronomy programs have become more than just monitoring variables, hunting supernovae or classifying galaxies. Some briefs from the December 2023 Research Notes of the AAS:
Two new active comets have been discovered, both belonging to Jupiter’s family of comets, meaning their orbits are controlled by the giant world, cross its orbit, then head back out to the Kuiper Belt. The first comet, originally an asteroid labeled 2012 UQ192 until the cometary activity was noted, now known as 2019 SN40 was found by the Active Asteroids Zooniverse Citizen Science program and gets active near perihelion. It will be close again in 2027 and it is suggested that it be observed for activity then.
Similarly, minor planet 2008 QZ44 was noted to have a diffuse tail in 2008 and 2017.
Finally, minor planet 2018 VL10 is a Mars-crosser that has also been noticed to give off cometary debris emissions. This one can get to 0.5 Astronomical Units (AU) of Earth, roughly 46 million miles.
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.
February 1 The bright star 1.7-degrees south of the Moon is Spica, the sheaf of wheat, the brightest star in Virgo. Still a while before spring will be here to grow that stuff….
February 2 Last Quarter
February 4 The summer star Antares gets close and chummy with the waning Moon, just 0.6-degrees to the Moon’s south, a distance just barely larger than the Moon’s diameter. Which finger held at arm’s length fits between them? It is even closer if you are in the Eastern Hemisphere of Earth where the Moon actually glides over it in an occultation!
February 7 The two brightest night sky objects meet but not too closely. Venus is that bright ‘star’ 5-degrees from the Moon.
February 8 Mars is passed 4-degrees by the thin Crescent Moon, if you are not viewing them from the Americas. If you are, then instead that ‘star’ 3-degrees away is Mercury, but good luck with the twilight. Use binoculars.
February 9 If you see any stars near the Moon, you’re sleep deprived. The Moon is in New Moon phase…..
February 10 The evening thin crescent Moon is about as big as it can get! The Moon is in its Perigee location, as close to Earth as it will be in this orbit, a Super (Crescent) Moon! Not only that, but if you use your binoculars, you’ll find dimly in the twilight nearby the ringed planet Saturn (to the north or above left, depending on the time) and around midnight you’ll find dim Neptune 0.7-degrees North of the Moon. The latter is occulted for those spending the winter on some South Pacific beaches…..sigh…..
February 15 Have a giant post-Valentine’s Day by finding Jupiter 3-degrees south of the Moon in the well-before-dawn’s midnight sky, and then planet Uranus the same way just before the next evening’s midnight. Okay, it’s a stretch but that’s what giant planets and the Moon are for….
Observing---Plan-et
==Planets Beginning to Hibernate for Spring==
Mercury, despite being unusually bright, is falling into the even brighter twilight glare zone. It will rise 45 minutes before the Sun on February 5th and that interval gets shorter by the day. Shortly after this fortnight ends, it is gone from view but heading towards a good evening appearance. The 8-9th is pretty much your last easy chance this month—when it is not far from the Moon.
Venus, on the other hand, is hard to miss in the morning sky, to Mercury and Mars’ upper right. But it too is falling towards the Sun and entering the twilight zone on the 10th. It fights to remain visible until nearly summer, but…..
Mars, still low in the morning twilight, will be hard to see for some time. It just met up with Mercury last month, it will be passed by Venus in a couple of weeks. The Moon goes wide by it as a thin crescent on the 8th.
The King of the Planets, Jupiter, is king of the evening sky…completely. It is the only easy planet to find then and is visible ONLY in the evening, setting before midnight after the the 8th. Makes a pretty view with the Moon on the 15th.
If you want to see Saturn in a dark sky, look after evening twilight before February 7th. After that date it sets during evening twilight and will be gone by month’s end. The super thin—but large because of Lunar Perigee—crescent Moon will make a pretty sight—best lunar conjunction of the month!—on the 10th!
Border Crossings
A total mismatch. The newspaper says the Sun is in Aquarius this whole fortnight. In reality, the Sun is in Capricornus. I guess the Sun should feel like a goat-fish out of water?
Astronomy in Everyday Life
Drinking in the Moon
So many products love the Moon. In their names. Considering that the Moon is a very big rock, shouldn’t this be just a big unappetizing thing? (Has anyone seen Lunar Rock Candy? Just asking…) Yet the Moon has been a cultural influence since the first cave dweller looked out into the moonlight to see if any creatures wanted *in*…to the cave opening. Or eons later, the Moon would light the way to the still in the deep woods. Yes, buckets of moonshine (light) is needed to get to the place where buckets of moonshine (drink) are a-waiting.
In January, just a few days before this issue came out, we had the Full Moon called the Wolf Moon, presumably because of the animal’s howling in the cold air of winter. And, for the human animal, some appropriate antifreeze might be useful…
Actually, there are quite a few spirits for your moonlit nights available. One Internet search came up with several with Full Moon-based nomenclatures, among other lunar phrases, and spirit types…
And did I forget? There is commercial Moonshine!
Sorting through Moon-related libations for observing monthly librations can make one hungry. Here’s a treat for a Full Moon dinner! Full Moon BBQ (an eatery chain) sauce on steak, an Old-Fashion made with Wolf Moon Bourbon, and a sampling of (gulp!) Moon cheeses (actually, dehydrated popcorn-style cheese bits). Better on warm, not-wintry nights……
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