#24L - The Art of Astronomy Data - Comet Olbers in the Evening - Planet Events Worth Seeing, Teaching - Watch Spica Disappear! - Seasons, Earth Motions, Planet Effects.
TGT 7/1/24: AstroVizicist Robert Hurt; Mars Catching Up With Red Stars and Lines Up With Two Giant Planets; Two Moons Shadows; Watch a Bright Star's Occultation; Earth Motions and Seasons.
Cover Photo - AstroVizicist Art
In This Issue:
Cover Photo — AstroVizicist Art
Welcome to Issue 24L!
Sky Planning Calendar —
* Moon-Gazing - Watch the Moon Cover Bright Star Spica Easily
* Observing—Plan-et -
- Mars Challenge—Compare Brightness and Color With Two Nearby Red Stars
- Mars Catching Up to Jupiter—and Two Moons Cast Shadows on the Giant Planet
- Comet Olbers in the Evening Sky
* Border Crossings - No CrossingsThis Just In
* AAS: The Astronomical Art of Robert Hurt, AstroVizicist
Welcome to The Galactic Times Newsletter-Inbox Magazine #24L!
Back ‘from’ Toulouse, France, heading ‘to’ Padua, Italy. Had a Georgia (USA) speaking gig last Saturday so the time shifting has been a killer. Who says you can’t get jet lag from Zoom meetings (or whatever software the conference uses!)?
Other reports from the American Astronomical society (AAS )went out in Issue 24K Xtra for Paid Subscribers, as promised. Still some more to do, and will be adding from the French CAP (Communicating Astronomy with the Public) meeting after this issue 24L. Annual subscribers pay roughly $1.25 per Galactic Times Issue and get the Xtras. Your support is very welcome; you get extra issues that lower that cost! Subscribe with the button at the end of this newsletter.
Note that we are taking off for a summer break in August so there will be no August 15th or September 1st issues. At least, not ‘live’ ones. Contemplating sending out pre-written/pre-scheduled versions of the Sky Planning Calendar and some Astronomy in Everyday Life columns I’ve been holding on to, just to keep you abreast of sky happenings.
I am very happy to welcome the mass of folks who joined The Galactic Times community this past weekend from Will Dowd’s wonderful Lunar Dispatch newsletter on Substack (get there from the Recommendations section of TGT’s website), both the newsletter subscribers and the Notes folks. My ‘lunatic’ friend was mentioned in Substack Reads and that reflected also over to The Galactic Times.
Three interesting sky events this half-month: 1) The Moon will pass over the bright star Spica on the 13th North America time, a rare chance to literally watch a BRIGHT star get approached by the dark leading edge of the Moon and wink out in an instant for the unaided eye, 2) Mars in the pre-dawn enters Taurus and passes a few degrees (slowwwwly) by the red star Aldebaran, the eye of the Bull (and not too far from Orion’s red giant Betelgeuse—a chance to learn to compare brightness and colors of the three objects, and figuring out when they match in brightness, and 3) Mars is gaining on Jupiter and Jupiter, for small telescope users even, will have a rare evening when there are TWO Galilean Moons casting their shadows on the giant planet’s face.
We have information on a comet that is sneaking into public view in the evening.
And finally, a look at the gorgeous astronomical artistry of Robert Hurt, as featured in an AAS Plenary.
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.
July 1 The dawn Moon is 4 degrees to the north of Mars (to its right).
July 2 The Moon shifts over to stand next to the Pleiades….and only 0.3-degrees to the upper left of Uranus.
July 3 Moving with rapidity towards a date with the Sun, the Moon passes Jupiter, though a good 5-degrees away. You can’t miss Jupiter—brightest star near Luna which is to the right of the planet.
July 5 New Moon.
July 7 Entering the evening sky, the Moon passes 3-degrees to the North of Mercury (and from the Northern Hemisphere, Mercury will be directly above the Moon during evening twilight, a few hours after the Moon’s closest approach, invisible in the day sky).
July 12 Apogee, the Moon is at the farthest part of its orbit around Earth, and with the Earth having reaching aphelion just on the 5th, farthest point in ITS orbit around the Sun, this makes the Moon exist about as far from the Sun as it can get!
July 13 First Quarter. Additionally, the Moon is 0.9-degrees north of blue-white Spica, unless you are in North or Central America or the Caribbean where Spica is an easy show to watch get occulted—the Moon passes not North but OVER the star. As the Moon’s phase is only half-lit, you can watch Spica twinkling away in front of the half-moon….until the dark part of the Moon makes it vanish in an instant!
The timing of this occultation, Spica’s winking disappearance to its difficult to view reappearance on the Moon’s bright following edge, varies with geographic location. In astronomer parlance, the disappearances take place generally between 2:18 and 3:48 UT on July 14th, but translated to US time zones, that’s 9:18 PM to 10:48 PM on the 13th. It is even earlier in the evening if you are in Canada or the US West Coast, and earlier yet if you are farther South. Best thing to do to enjoy this rare show of a bright star getting covered up by the Moon’s dark edge is to start watching as soon as you can see the brightest stars near the end of evening twilight. THEN, as 2 or 3 AM UT approaches in your time zone, DON’T BLINK or you might miss it.
Reappearances happen generally 1 hour and 13 to 22 minutes after the disappearance. However, if you are in Montreal, Toronto, Winnipeg, Massachusetts, or Miami (or places in that triangle of areas) the Moon will set before Spica reappears.
Observing---Plan-et
==Earth and Sun Separate as Far as They Can.==
==Mars and Uranus Have a Team Meeting. Mars Joins a Red Star Duo.==
==Why It Is Summer When Earth is Farthest Away?==
You can look at this in two ways. On July 5th, EDT and farther into the Atlantic, or evening of the 4th for Central and zones West, either the Sun is its absolute smallest size in the sky as it can get, or the Earth is at aphelion, its farthest distance in its orbit as it can get from the Sun. In either case, they are about 94.5 million miles apart, half outwards of the roughly 3% eccentricity of Earth’s deviation from a circular orbit, and its average distance, which defines the Astronomical Unit, the meter stick value for all orbits in the Solar System.
Some persons may actually be surprised at this, especially considering the extreme heat many parts of the world are having. We’re HOT HOT HOT! But we’re also at our farthest distance? Huh? Don’t you get hotter when you move closer to a heat source, like your barbecue or campfire? Yes, true, however, when you only vary your distance from the fire by 3% (think of this as being by a campfire, 93 feet away, and your distance on one side is 94.5 feet and the opposite side is 91.5 feet—does that 3-foot distance really make a difference to your trying to stay warm?
No, the reason for the (HOT) season is because the Earth is a tilted sphere. Different parts of the Earth’s surface, your latitudes, get different amounts of solar energy per square foot (or meter). Those directly in line between Earth’s center and the Sun (right now about latitude 23-degrees north of the equator) get the highest concentration, those farthest from that line (in July, the South Pole) get far less energy per square area. That difference in energy concentration is a FAR bigger difference than what happens with Earth’s changing distance, the latter a piffle compared to effects of our planet’s tilt.
Mercury is entering the evening sky for its best Southern Hemisphere evening appearance, but the Northerners aren’t getting TOO bad a deal. Mercury starts bright and slowly fades even as it moves more out of the solar glare, starting at a mere 18- degrees at month’s start, and and maxing out at 27-degrees from the Sun on the 22nd, yet fainter in brightness. Look for it best when it is setting more than 90 minutes after Sunset from the 5th to the 13th. Still in twilight but easier.
Venus. Reluctant to end its long spring vacation in the solar glare, she drags her planetary feet into the evening sky, setting only as late as 45 minutes after Sunset after the 13th. Yet, then it is still not an easy thing to find even if it is the brightest planet.
Mars is getting more interesting, closer to us, a tiny bit brighter, and about to enter view in evening hours. It enters the winter constellation of Taurus and brings interest because of its brightness and color. Why so? It is approaching magnitude +1.0, bright but not spectacular, but its red color and brightness are close to those of two bright red giant stars in the area.
The closest is Aldebaran, the eye of Taurus the Bull. Observationally fun, watch the two every few pre-dawns and check….which one is brighter (i.e., when does Mars match Aldebaran in brightness?).
Note that star brightnesses get brighter as magnitude values get smaller, e.g. Mag 1 is not as bright as mag. 0.5. Aldebaran officially is magnitude 0.86 while Mars enters the month of July as 1.0. The other red star, south east of Aldebaran is Betelguese in Orion. It is brightest of the three, at 0.42. One should after this start to see when does Mars match or surpass THAT red star in brightness!
Mars is approaching even brighter Jupiter, starting to rise into the sky an hour and a half before the Big World at month start, but that will rapidly reach just a 45-minute gap at the end of the month. Given that time-speed (minutes per day!) when do you think you will see the two planets in conjunction together in the sky?
Mars also makes a VERY close passage by the planet Uranus, about 0.6-degrees, on the 15th. Uranus will be above Mars in the dawn sky but visible in small telescopes with low power eyepieces easily.
Jupiter rises in the East about one hour and bit more on the 1st before morning twilight. More interesting to sky-gazers is it making a three-planet line-up-Jupiter lowest, Uranus to the upper right in binoculars (thought technically it COULD be spotted with the unaided eye in a dark place) and then Mars, or at least before the 15th (see above) when Mars and Uranus switch places in the order.
A telescopic fun event: there will be two Galilean moon shadows on Jupiter’s Earth-facing side simultaneously for a while on the 13th.
Saturn, king of the evening sky (barely, it rises just after midnight Daylight Saving Time on the 1st but edges into the 11 PM’s minutes after that) begins to retrograde. That means instead of moving eastward as per normal in front of the stars, it starts to go the other way on June 30th-July 1st. We are literally heading in the direction of Saturn in our orbit but then, moving faster than Saturn, we start to pass it by, like a billboard on the side of the road we are traveling. Neither the billboard nor Saturn actually move behind us, it is just illusion, but one that thoroughly puzzles astronomers until either Copernicus or Kepler figured it out…..
Comet Olbers
I will refrain from referring to Olber’s well known historical contribution to astronomy and logic….
But this comet has sneaked into a bit of prominence by being brighter than expected, an easy binocular object, in terms of brightness but a not-so-easy target in twilight.
First, the finding information. Below are two charts, top, July 1 about 8:45 PM CDT in Alabama. It will be higher if you are further north in latitude. The lower chart is its path in the stars during June.
Comet Olbers is considered a Halley-type comet, and also a Near Earth Asteroid. It goes from beyond Neptune to almost past Earths orbit in 69 years. It does have tail and is at its closest point to the Sun as this is written. Currently just a bit below the naked eye limit, magnitude 7 1/2 (had been predicted to be a dimmer object, by a full magnitude, so binoculars are needed. In the twilight, the tail may be lost but you might see it as a tiny fuzzy cloud.
Border Crossings
Same half-month, different interpretations. The Sun is in Gemini this whole period, since it had its solstice moment. Astrologers say uh uh, it is in Cancer. Yawn…..
This Just In
AAS: The Astronomical Art of Robert Hurt, AstroVizicist
One of THE most delightful plenaries I have ever witnessed was done by Robert Hurt of Caltech’s IPAC Center, where he is in the Communications and Education Team. Sounds dull, huh? He began professional life like almost every other astrophysicist: Bachelor’s, Ph.D., post-docs. But before he went to university he was motivated to astronomy by three things this author, and doubtless many TGT readers, were influenced by: Star Trek, Carl Sagan’s Cosmos, and the famous Space Art book featuring Chelsey Bonestall, pre-NASA but surprisingly realistic sci-fi art that wasn’t weird spaceships and bug-eyed monsters (it is still on my book shelf). As an amateur he took up painting astronomical scenes and objects.
But now, Dr. Hurt is not an astrophysicist. He calls himself an AstroVizicist, a visual artist of astronomical scenes, using real data from space missions and other observations. And he enthralled his audience of hundreds of AAS astronomers, from amateurs to emeriti.
“Illustrations are always guided by — and can deeply effect — our mental geography of the Universe,” said Hurt. “Illustrations built upon scientific understanding count as a form of data visualization,” hence the term AstroViz. Effective illustration for Social Media, or mainstream or scientific media, serves three purposes: Grab attention, Illustrate Ideas from a Story, and Lead Audiences to an Article. A large part of his work involves these tasks. And it all varies depending on your audience—Education (schools), Informal Education (planetariums and museums) or Communications (the above media).
For his sake, and the reader/observer’s and also the communications and education people, there are three criteria to evaluating a piece of astro visualization:
The astrovizicists must take all these evaluation techniques and create knowing there are known facts, and known falsehoods (and sometimes unknowns of both) and possibilities. That last, to him, is a scientific hypothesis done in Art based upon the other two points, or as many of them that fit—not all lend themselves to visualization.
Hurt showed the audience some examples; there is only room here for three:
The Milky Way
Back in 2005, four years after starting on his artistic journey, he produced an image (all digital and all that way now, no painting) of our galaxy from Spitzer Mission data as it was best understood at the time. It was published EVERYWHERE. It was also over-promising, he said.
Three years later he had more data—maser locations, spiral arm models, gas simulations and more just plain observations—and thought he could do a better job. This illustration is also widely used, and has labels of the various parts of the galaxy.
Interestingly, the part of our galaxy that is directly blocked by the Galactic Center was an Art Hypothesis, no data at all. And yet….data that same year came out that verified the hypothesis!
Black Holes
Black Holes have been known for a century or more. They are popular tropes in science fiction but their portrayals had been more simplified, falling into three types: Bowling balls surrounded by debris and stuff, Bathtub trains in which everything falls in in swirls, and other strange things—a miscellaneous category. Hurt explained that gravitational lensing may not have been seen early on but was a known effect of relativity, caused by the huge gravity of the hole. It was the basis of Einstein’s famous photograph experiment showing that stellar positions during an eclipse of the Sun were changed by the Sun’s gravity. Lensing is just more extreme. But hard to do, graphically or even on computers, until now.
Exoplanets
One of the neatest techniques Hurt demonstrated was to illustrate the 7-planet system of Trappist-1. He used older techniques of using marbles as models, and photography as well as digital imaging, but in laying out the ‘geography’ of the orbits of the planets he showed the conditions of temperature, zone where water could exist, and so on from the scientific data.
In Summary:
The skills that Hurt developed and uses are not found in your usual BS/MS/PhD pathway for astronomers. In fact, Hurt related that he had been told that experimentation in non-traditional techniques was something you stopped doing once you got into graduate school. Hurt today proposes otherwise:
“Students need traditional skills but they need room to cultivate non-traditional skills as well.”
For more information and superb pictures by Hurt and others, this graphic gives you some resources:
More reports from the AAS were sent out in TGT 24 Xtra to Paid and Education Professional subscribers. More of them, and from the Communicating Astronomy with the Public conference, will be coming out in upcoming Free and Paid issues. In July yours truly will attend the European Astronomical Society and Royal Astronomical Society’s annual meetings. Want to read all these meeting reports and news, and educational tips? Upgrade!