Dark Sky Maine Newsletter #4
What is the Stars Over Katahdin event?
By Nancy Hathaway
It’s the annual star party at Katahdin Woods and Waters National Monument.
Cassiopeia sits in her chair amidst the Milky Way; Sagittarius’ teapot spout pours steamy milky white stars into the Milky Way; Cygnus the Swan flies through the Milky Way overhead. In the autumn when folks gather at the Overlook off the Loop Road at Katahdin Woods and Waters National Monument, these are the usual constellations that are seen. As viewers look to the heaven during the annual star party either with unaided eyes, binoculars, or through telescopes, “ooohs” and “ahhhs” are constant sounds. Over Mount Katahdin, Arcturus is seen at the end of an imaginary arch from the tip of the Big Dipper’s handle.
Before the sky is dark enough for stars to be seen, Campfire Chats takes place around a campfire a short walk from the viewing area. Stories, having to do with the night sky or Katahdin, are told before viewing stars on the Overlook. Due to Covid, this year’s seventh annual Stars over Katahdin star party will be a Zoom event focusing on Campfire Chats.
This is the first-year Stars Over Katahdin will be held since the International Dark Sky Association designated Katahdin Woods & Waters as a Dark Sky Sanctuary, which is the first Dark Sky Sanctuary on the eastern seaboard. This designation recognizes the unusually dark nature of the night sky above the monument, which measures a 2 on the Bortle Scale. The Bortle Scale measures light pollution with a 1 rating representing an absolutely dark sky while a 9 designates a highly light polluted one. Only places as remote as Antarctica have darker Bortle ratings than can be found in Katahdin Woods and Waters.
This year Dark Sky Maine will co-host Stars Over Katahdin with its president, Colin Caissie beginning the event with banjo music. Following will be ‘campfire chatters’ – representatives of Friends of Katahdin Woods & Waters and the National Park Service, John Meader of Northern Stars Planetarium and Dark Sky Maine, Shawn Laatsch of Emera Astronomy Center and the Jordan Planetarium of the University of Maine, Larry Berz of the Francis Malcolm Planetarium, Kelly Beatty of Sky & Telescope Magazine, Nancy Hathaway of Dark Sky Maine, and John Dennis–a Wabanaki story-teller.
You are invited to join us.
Go to: https://www.friendsofkww.org/stars/ for more information and a ZOOM link when closer to the event that will take place on Thursday, October 15th @6:30 PM.
What’s in September skies?
Presented by Northern Stars Planetarium
Mercury will make a challenging evening appearance through much of September as it stays very close to the western horizon for northern observers.
Venus continues to dominate the eastern pre-dawn skies through September. It is high above the horizon, well ahead of the Sun.
Mars rises just before midnight, and by mid-September it will be seen within an hour after sunset. Mars will be at its closest approach to Earth October 6, the closest approach until 2035. Its brightness will double during this time, and by the end of September Mars will outshine even Jupiter. The coming months are an excellent time to explore the red planet.
Jupiter is already well above the horizon at sunset. Look for it shining brightly in the southern sky. Jupiter has been in retrograde motion (an illusion that makes it look like it is moving backwards to the west) since mid-May. On September 13 it will resume its normal eastward motion, bringing it very close to Saturn by December.
Saturn is 8° east of Jupiter and is already up in the south-southeastern sky after sunset. Look for a prominent yellowish-tinged star that is fainter than Jupiter. Telescopic views of both Saturn and Jupiter are improved the later in the night you observe them as they climb higher in the sky, when the atmospheric disturbances lessen and the seeing improves.
Uranus rises just before midnight, its visibility is fleeting as twilight each morning quickly obscures the dim planet. Look for it with a small scope about midway between Hamal, the brightest star in Aries, and Menkar, the brightest stars in Cetus.
Neptune rises soon after sunset in the eastern sky. Look for it just 2.5-3.0 degrees east-northeast of the 4th magnitude star Phi Aquarii. Look for a faint blue star.
The Planets of our Solar System.
Planet Season 2020
by Colin Caissie
One of the most challenging, and also rewarding, astronomical participations is the observing of the planets. This season, summer into autumn 2020 is especially fortunate in that over the course of the evening, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto are all placed for observation.
Observing the movements of the planets over time reveals the dynamics of the Solar System. It was these motions that unlocked the true arrangement of the Solar System...evolving from the apparent Earth-centered belief to the actual Sun- centered reality.
Most rare are sightings of Mercury and Pluto. Mercury is always very close to the Sun, and understanding where its orbit is in relation to our orbit—a so-called “inner planet”—reveals why it shows up as a Morning Star or an Evening Star, and why it is often invisible in the glare of the Sun.
Pluto is elusive in that it is so faint. I can claim that I have probably seen Pluto, but it was only a speck among other faint stars, and truly, I'd have to view it on several nights to untangle it from the background by its motion.
Currently, August through October, the brighter planets are putting on a show. In the early evening, white hued Jupiter is the bright unblinking steady object in the south, followed by a yellowish Saturn only a hands-width to the left with a fainter, yet also steady light. At about the time when Jupiter and Saturn cross the meridian, that is, due south at 9:30 p.m. around Labor Day, Mars rises in the East, and shows that typical planetary steady light, and a definite ruddy hue. Mars crosses the meridian at about 03:30 a.m. high in the pre-dawn sky.
Visible in this same sky will be Uranus, visible in binoculars, and Neptune, a telescopic object.
To announce the dawn, often called The Morning Star, Venus, is visible as the intense bright white object, unmistakable in its brilliance. Again, because it is an “inner planet”, it never wanders more than 45 degrees from the Sun, and pondering this will explain why it alternates as an Evening Star and later a Morning Star, and why sometimes as it passes in front of or behind the Sun it is not visible. Also in small telescopes it shows phases like the Moon. A moment of study, maybe with a piece of paper and pencil, will decipher this beautiful mystery.
The planets slowly move against the starry background in a generally easterly direction, rising progressively later each day than the stars in its neighborhood. However, there is a twist where a planet will appear to reverse its motion— retrograde—and then resume it as it passes opposition, when the Sun, Earth and Planet are in line. This is clear when viewing an “outer planet” like Mars, Jupiter and Saturn are easily observed doing this loop. This motion was observed in ancient times, but weird and baroque explanations were necessary to represent it. When it was finally seen that the Sun was at the center of the Solar System, this retrograde motion was immediately understood. Simply, as the Earth, in its faster, “inside lane” passes the slower outer planet, it looks like it is moving backwards, just as when overtaking a car on the highway makes it look like it's moving back. At some point, looking back it's clear that the other car has not backed up, but continues along behind.
This retrograde is also seen with the “inner planets”, partly because of this variation in orbital speed, and sometimes because the planet is actually swinging fast between its Evening Star location and the Morning Star side.
Most planetary details are invisible to the naked eye, other than changes in brightness. We can prove that the planets have a definite size, not just a point of light. When the Moon occults or moves in front of a planet, it takes a few seconds or minutes for the planet to be fully extinguished.
https://www.youtube.com/watch?v=6CuEf2mwONA
Jupiter is actually large enough to show a tiny disk and the 4 Galilean moons in binoculars. Because the moons shift hourly, one or more may be hidden or too close to Jupiter itself. Careful focusing and resting the binos on a solid support are necessary to enjoy this view. On the next night they will be in a different configuration.
Saturn's ring feature is beyond the limit of most binoculars, though you may get the sense that it is not a round object.
Uranus (green) and Neptune (blue) will show as a colored star when a star chart is used to locate them. Large telescopes will still not reveal surface details, but will show the moon systems.
For those with small telescopes, planetary observing is a challenge, but here are a few tips that will greatly enhance your ability to appreciate these wanderers.
A star chart. This will help locate objects in the sky and separate them from the starry background. I use the freeware program Cartes du Ciel found at: https://sourceforge.net/projects/skychart/. A few minutes learning this program will give you a definite advantage in finding the night sky's wonders and allow you to predict and prepare for events in the future. There are fancier and more beautiful graphic programs also available.
The steadiness of the atmosphere. A turbulent atmosphere will disrupt the image, witness heat waves off a warm roadway, and an indicator is the “twinkle” of the stars. Most stars will twinkle when low on the horizon due to the thicker atmosphere, but if stars are wildly twinkling all over, then perhaps another night is better for planetary viewing. Even with turbulence, Jupiter's moons, Venus' phases, Saturn’s rings can be appreciated.
Unobstructed and soft landscape. Viewing over warm pavement or rooftop will disrupt the air. Viewing over lawn or trees is best.
Low magnification at first. It is easiest to locate and study a planet or other object using the lowest magnification first. Atmospheric steadiness and clarity can be assessed then and magnification can be increased as needed. Usually the practical limit is about 25X power per inch of lens or mirror aperture. Occasionally that can be upped to 50x per inch, but usually a smaller crisper image is preferable to a big bloated fuzzy and wobbly one.
Patience and perseverance. Often the atmosphere will become very steady for seconds at a time, revealing a momentary glimpse of fine detail.
There are many planetary details that are accessible when the viewing is favorable. Some of my favorite viewing items include:
The cloud bands on Jupiter...two bands are visible in small scopes, more detail shows when conditions are right.
The Great Red Spot of Jupiter. Sometimes hard to see, it moves across the planet in about 3 hours. There are charts available for timing this. https://www.projectpluto.com/jeve_grs.htm#aug
Dance of Jupiter's moons. They change hourly and sometimes disappear in the shadow or when crossing the face. They also cast shadows when crossing in front. Again a chart lists all these events. https://www.projectpluto.com/jevent.htm#aug
Saturn's rings. It's possible to see that there are two rings separated by a dark division, just like the gap between song #1 and song #2 on an LP record. The rings can cast a shadow on the planets surface, and the planet will cast a shadow on the ring behind. Lately you can just barely make out Saturn's south pole peeking above the ring as it gradually tips back towards a less “open” attitude.
Saturn's largest moon Titan is easily visible and you may see as many as 5.
Mars is getting larger as the October 15 opposition is coming up. The south
polar cap shows as a white spot, and various markings are visible.
Venus is showing a gibbous phase now, and will gradually change to a full
moon shape as it swings to the far side of the Sun.
For Astronomical Weather forecasts, the Clear Sky Clock has numerous location- specific forecasts detailing the steadiness of the atmosphere, cloud cover, dew, and much more. http://www.cleardarksky.com/csk/index.html .
Meteoblue.com also will create a forecast for your location, as well as give info on favorable planets visible. https://www.meteoblue.com/en/weather/outdoorsports/seeing/whitefield_united -states-of-america_4982975
There is so much to explore in planetary observing and this 2020 season offers some great observing opportunities. A completely dark sky is not required, only a bit of knowledge and taking time to locate the planets, and if you want, use visual aid to study them in detail.
In all, it opens up the cosmic panorama and reveals in a profound sense of where you are in the big picture, and that is right there all around you.
