The Galactic Times Newsletter #18 - February 15 - 28, 2022
News of the Current Sky--Moon Chronology, Where's Webb's First Star?, Alpha Centauri's Planets, Water for Mars...and Earth?, and More News!@; When Will We Have Evening Planets?
Cover Photo - Dayglow Saturn
In This Issue:
Cover Photo — Dayglow Saturn!
This Just In — Stories in the Current Night Sky
1. Full Moon Gazing….
2. Webb’s (Not So Pretty) First Photo, But How to Find That Star
3. Alpha Centauri - Once More
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What the (Infrared) Eye Can See of VenusDayglow Saturn
Wet Mars, Longer Time for Life?
Where was the Water Fountain? It was Already Here!
Sky Planning Calendar —
* Moon-Gazing - Jupiter Says Farewell….
* Observing—Plan-et — ….and the Evening will be Bereft of Planets until April…and June* For the Future — Mercury Points the Way Out to Saturn in March…and the Zodiac gets Weird Next Month
* Border Crossings — Something Fishy….The Classroom Astronomer Inbox Magazine Issue 19 Highlights
Welcome to The Galactic Times Inbox Magazine, #18 !
It may not be the most observable of times—with storm after storm and cold weather, and in some places, not the best of political circumstances to want to be outside. But the news has been hot and heavy and there has been a lot to cover. Some of it makes for good teachable moments if you just grab your telescope, binoculars, or eyeballs and head outside. Take a look at our first three This Just In articles. But if you want planets during your evening stroll, you’re pretty much out of luck after this weekend….until April….or late May….or June. Read all about it in Observing…Plan-et.
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Publisher — Dr. Larry Krumenaker Email: newsletter@thegalactictimes.com
This Just In—
* Stories in the Current Night Sky:
1. Full Moon Gazing….
When you look up at that Full Moon on the 16th, you get a complete look at every place where humans have taken a sample of lunar material and used it to get the chronology of the lunar surface. Part of how we do that is chemical, and we then relate it to counting craters. One of the problems has been that there’s a big gap in our chronology, between 1 and 3 Gigayears. The recent Chang’e 5 Chinese mission, which returned 1700 grams of lunar soil, has begun analysis of that materials, and it has filled in that gap.
In more detailed looks, comparing it to the highly used Neukum chrono-study that is utilized on Moon, Mercury and elsewhere from all the Apollo and other samplings, there is at most usually no more than a 0.25 Gigayear difference between ages determined by the two studies, per Kaichang Di, of the Chinese Academy of Sciences, in the February 14th issue of Nature. Science progresses forward….
* Webb’s (Not So Pretty) First Photo
This is what you get when you packed 18 mirrors and they got all shook up on your trip into space. The same star, and the mirrors are not aligned. Well, this was expected….
Still, it is historic and you might want to show the star to your friends or students. Get out your binoculars or telescopes….
The star is called HD84406 and it is not naked eye bright, magnitude 6.9. Bright enough for the Webb telescope to get an easy image and not so bright to have any competitors nearby to confuse the sensors. It is sitting on the back of the scruff of the neck of the Big Bear, Ursa Major. You’ll find the constellation in the early evening rising STRAIGHT up to the right of the North Star Polaris at 6PM local time:
That’s the Big Dipper rising straight up, most of its handle is above the barn, in this Stellarium simulation of 6 PM local time this week. Cassiopeia is in the upper left, Polaris above the N, and the star in the Webb Telescope’s first photo is circled. Then you have to draw a line along the top of the Big Dipper part of the Big Bear (a saddle on it?) and onwards along its emaciated upper body towards its nose to where we’ve circled the dim star in this close up (and we turned it 90-degrees to make it look a bit more familiar—you’ll have to rotate counter-clockwise to match the sky):
The star is 250 light-years away, plus or minus 10 depending on your source of data, but a close match to the Sun.
Alpha Centauri - Once More
Seems our nearest neighbor can’t stay out of the headlines (it was our Cover Story in the last Galactic Times!). It was recently announced that the red dwarf third member of the triple system…has a third planet. Let’s be careful here…….
First, the Alpha Centauri system consists of three known stars, A, B and C. A and B are two solar-type stars, B slightly cooler than Sol, and orbit each other in 79 years in an eccentric ellipse ranging from as close in distance as Sun-Saturn to as far as Sun-Pluto. Star C is WAY WAY away from the bright pair, in what might be our Oort cloud at 11,000 Astronomical Units. Being slightly closer to us than the AB pair, star C was a century ago named Proxima Centauri, and is the nearest known star. As we noted last week, it is the object of a plan to send a fleet of stellar sailing craft as a probe mission. For a map of where Alpha Centauri is in the night sky, see the last TGT issue.
Second, if there are any planets orbiting in or around the AB system, we haven’t found them for certain though two or more candidates had been announced and either retracted or are still unconfirmed. Those bright stars have a lot of glare, and planets are more stable when there are single stars or more circularly orbiting pairs. But Proxima, being small, close to us, and dim, has been the ideal site to search for planets, and three MAY have been found.
Proxima b (note that exoplanet names start with “b”, not “a”, and are lower case) was found in 2016 and is fairly certain, extremely close in and earth-sized in Proxima’s habitable zone, such as it is, being a red dwarf.
Proxima c is larger than b, has a ring, and is farther out, found in 2019.
Planet d was just announced and is a subdwarf planet and very very close to the star, and is not yet confirmed….
* What the (Infrared) Eye Can See of Venus
The Parker Solar Probe was designed to, well, explore the Sun, especially its polar regions, but it does so from orbital pathways that take it not only close to the Sun but also out far with flybys by Venus. In doing so we get two explorations for the price of one. In a visit to Venus exactly a year ago, the probe looked at that world in the near-infrared, which we sense as heat, and visible light. Normally, that last would just show brilliant clouds and a few cloud details, but Parker was a “fly-by-night” — the whole Venusian night — when it was cooler (in a relative sense)—and actually got details through the clouds.
The light of the planet in the night is coming from a surface that is so hot that it glows. Don’t go barefoot on the planet named for the Goddess of Love…..
* Dayglow Saturn (Cover Photo)
Gawd, I’d like to see THIS as a poster! This reminds me of the 1960’s and 1970’s black light posters put on dormitory walls, and UV galleries in some planetariums (I’m looking at you, Hayden and Abrams Planetariums….). But this image shows Saturnian aurorae that are generated not only by magnetic fields and charged particles but by particles in swirling winds in Saturn’s own atmosphere! It also solves a puzzle—why astronomers couldn’t always get Saturn’s rotational period correct….
* Wet Mars, Longer Time for Life?
We know Mars probably hasn’t any life now, nor for a long time. If it had life, it was a long time ago…but maybe not so far back as we once thought.
A NASA study indicates that maybe Mars was inhabitable a bit longer than we thought. The usual time frame has it that Mars had a thick enough air to support an ocean up to about 3.5 billion years ago. But studies now may extend that to as ‘recent’ as 3 billion years back. That may not seem like much but to Martian life forms, that could have meant the difference in forming forms that we could now find perhaps fossilized or as other remnants. The planet might not have been either too warm nor frozen but what scientists call "cold and wet instead,” the NASA study states. “An ocean would have formed in the northern lowland basin where the atmosphere was denser and warmer. Water would evaporate from this ocean and return to the surface as rain or snow. In and near the ocean, it would be mainly rain, but in the southern highlands where the air was cold, it would be mostly snow. The snow would accumulate into extensive glaciers which would flow down to the lowland basin, returning the water to the ocean.
The model shows that the northern ocean could remain liquid even with global mean surface temperatures below the freezing point of water because ocean circulation can bring warm water from mid-latitudes to the pole, regionally warming the surface up to 4.5° Celsius (40 degrees Fahrenheit). Also, just as a dark asphalt parking lot is hotter than a white concrete sidewalk on a sunny day, liquid water is darker than snow and ice, allowing the ocean to absorb more heat from sunlight.”
* Where was the Water Fountain? It was Already Here!
A report in Nature Astronomy, February 3rd, from the French CNRS, indicates that before the Earth got pelted with water from comets or meteoroids to form our oceans, it was already in our solar nebula. Findings from studying some meteorites indicate “two gas reservoirs existed during the first 200,000 years of our solar system, even before the formation of the earliest planetary embryos. One of these reservoirs consisted of the solar gas in which all the matter of our solar system originated. With the meteorite, the scientists were able to measure its record directly for the first time ever. The second gas reservoir was enriched in water vapour and already had the isotopic signature of terrestrial water. It was created by a massive influx of interstellar water in the hot internal regions of the solar system, upon the collapse of the interstellar envelope and the formation of the protoplanetary disc. The early existence of this gas with Earth-like isotopic composition implies that Earth’s water was there before the accretion of the first constituent blocks of our planet.”
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 16 Full Moon
February 22 The waning Gibbous Moon occults (eclipses) the bright star Alpha Librae, Zubenelgenubi (say that 5 times fast and impress your friends) before dawn. The star is also an easy double star.
February 23 Last Quarter Moon.
February 24 The Moon passed the bright red star Antares before it rose before dawn.
February 26 Perigee.
February 27 Mars is 4 degrees North of the Moon, and Venus is 5 degrees further along that line.
February 28 Mercury takes its turn near the Moon, by 4 degrees, the Moon to the right, and later on in the day, Saturn is also 4 degrees away from the Moon, the first chance in a while (and first in the dawn) to find the Ringed Planet.
Observing---Plan-et….
The stars of the Evening Show…are all stars! You might find Jupiter in the WSW, very low, a little more than 40 minutes after sunset, but only until around February 20th, after which it is lost in twilight glow on its way to solar conjunction. After this there will be NO BRIGHT EVENING PLANETS until late in the spring! With one brief exception:
From the period April 10 to May 16, Mercury will be in the evening twilight and, for the only time this year, April 22 to May 4, it will set in darkness after evening twilight ends.
Saturn does not rise before midnight until either middle June if you are on daylights saving time, or end of May if you stay on standard time. It will be the first outer planet to reach opposition, rising at sunset and staying up all night….in August.
For now, Mercury reaches its maximum elongation from the Sun on the 16th in the dawn, great for the Southern Hemisphere observers, not quite so good but not too bad for Northerners. The planet makes a nice line with Alpha and Beta Capricorni, Alpha being a nice double star even for naked eye observers, and Alpha, Mercury, Mars and Venus make a nice equal-sides rectangle around then.
For the Future
Keep your eye on Mercury. When The Galactic Times returns on March 1st, it will be your guide to a very close approach to Saturn, exiting its solar conjunction. And….
Border Crossings - Something Fishy….
….Next month will be zodiacally much more interesting…..but meanwhile…
On the 16th, as well as a Full Moon, we have the Sun entering Aquarius, the Water Bearer. Like we need a heat source to melt more water and cause rain instead of more snow.
Of course, the horoscopes say the Sun has been Bearing water in Aquarius all this time….but will shine on the Fishes, that is, Pisces three days later, on the 19th. Anyone for smoked salmon?
The Classroom Astronomer Newsletter Issue 19 Highlights
This premium Inbox Magazine is a subscribers-only publication, though a free Lite version is available. Starting in January, it became a 30-issues per year publication, and the Lite version, now called the TCA Digest, became a monthly, on or before the last day of each month.
Welcome to Issue 19
Cover Photo - Measuring Lunar Distances with Google Earth Pro
Sky Lessons - Galactic Structure in the Winter Sky
Connections to the Sky -
- Your Hubble Birthday Image;
- It’s Nebulous to Me….The RAP Sheet – Research Abstracts for Practitioners
- Teachers’ Conceptions About Science and Pseudoscience Distinguishing Astronomy from Astrology
- Using Smartphone Photographs of the Moon to Acquaint Students with non-Euclidean Geometry- Elementary School Children’s Explanations of Day and Night;
An Interpretation Based on an Inferential Approach to Representations
Sign up for it here or visit its home page here….
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