Mercury has its best morning apparition starting on the 17th. During the last week of October it will be easily visible just before 6 am looking east.
Venus is finally becoming a brilliant evening “star”. All month it sets at 8:10 pm. It speeds past Antares on the 16th at 1 1/2 degrees distance. On the 29th, it is in greatest elongation from the sun at 47 degrees. It moves far south and thus sets further south of west than the sun does in December.
The Moon will be a thin crescent at dusk on the 7th. Two days later it will make a beautiful pair with Venus.
Jupiter and Saturn transit halfway up mid evening. They stop their retrograde motion and move prograde again in Capricornus. They reach their closest separation of 15 degrees at the end of the month. The next time they will be that close will be in 2040. Mondays will be the days to look for Ganymede’s shadow on Jupiter’s disk, on the 11th until 7:30 pm, on the 18th from 8-11:30 pm, just after Io’s shadow entered at 11:15 pm, and on the 25th starting just before midnight. A double transit will occur on the 20th until 8 pm with Io’s shadow and Callisto itself.
Uranus and Neptune are up most of the night in Aries and Aquarius, respectively.
Mercury is visible about 15 degrees to the lower right of Venus until September 21st. It is so low that it remains close to the limit of visibility (use extreme caution to avoid looking at the Sun). It passes Spica on the 21st. However, Spica definitely requires binoculars since it is one magnitude fainter than Mercury.
Venus is the obvious evening star until it sets after 8 pm. It passes Spica on the 5th. Venus is slowly brightening towards its best in December.
The two giant gas planets shine in the southeast during dusk. Their distance slowly decreases from 18 degrees at the beginning of September to 15 degrees at the end. They transit around 10 pm, perfect for telescope or binocular viewing.
The Galilean satellites’ orbits are very close to edge-on this month, so that conjunctions of two satellites become very close. The best shadow transit occurs on the 5th starting at 7:45 pm when the dark disk of Ganymede is already close to the center of Jupiter’s disk, so that two dark spots will be visible. The same occurs 7 days later, although Ganymede’s transit does not start until 9:20 pm with its shadow joining at 11:47 pm. Also, on the 17th, Callisto’s shadow can be seen until 8:13 pm.
Neptune comes into opposition in the constellation Pisces on September 14th. Uranus is one constellation further east in Aries.
The Moon might be just barely visible on September 7th (one day past New Moon), 10 degrees to the right of Mercury. Even if Mercury is difficult to spot, you will see it before you see the Moon. The three day old Moon has a beautiful pairing with Venus on September 9th. Three days later it passes Antares.
Our next VIRTUAL STAR PARTY is Friday August 27th from 7:30 – 9 pm Tucson, AZ time (PDT). We will stream live solar system and deep-sky viewing to our Facebook Page. Join us at: https://www.facebook.com/TucsonAstronomy
Mercury will start its visibility at dusk, but will never get very obvious. It remains close to the Sun.
Venus is the evening star during dusk. It passes Beta Virginis on the 13th at only 7 arc minutes in distance, similar to the distance between Jupiter and Saturn during the last winter solstice. But the faintness of the star will probably require binoculars to see it.
Saturn comes to opposition on August 2nd, when it rises at sunset. Around that time, its rings are very bright as compared to the planet.
Jupiter also comes to opposition this month on August 22nd. The evening before, the Full Moon will be right next to Jupiter.
On the evening of August 18th, the Moon occults Nunki, the second brightest star of the teapot asterism in Sagittarius. In Nogales, it will last from 7:47 to 8:01 pm, but in Tucson the Moon will not quite make it, although it will get very close to the star. In between there is a grazing occupation which is rare for such a bright star to get so close to us.
August is meteor month. The Perseids will peak on the night of August 11-12 when the Moon is next to Venus which sets early. It cannot be much better than that!! Look toward the east late evening or early morning toward the constellation Perseus.
Venus is slowly increasing its visibility at dusk, starting to get visible at 20 degrees altitude. At the summer solstice it passes by Pollux at 5 degrees distance.
Mars is also visible in the evening but setting much later than Venus. The distance between both planets decreases from 25 to 8 degrees during June. On July 12, Venus will pass Mars quite closely.
Jupiter and Saturn rise just before midnight and are transiting during dawn almost 45 degrees high. They remain separated by 20 degrees.
At the end of June, Mercury starts its morning apparition.
Vesta is still an easy binocular object in Leo during the early evening.
On July 10, there is an annular Solar Eclipse visible in eastern Canada moving over the North Pole. The next day, the thin crescent Moon will be visible at dusk just below Venus.
The messages from the TAAAA president have appeared in various forms over the years. They have appeared in the Desert Skies publications, in the TAAA Monthly Bulletin, and now appear in the revamped monthly Desert Skies TAAA Bulletin. For a period of TAAA history, the Notes were send as a stand alone message to members from 2018 to 2021. Those communications with summaries of the work of the TAAA board and important monthly accomplishments by the organization are listed below.
Just one day after the Earth passed its perihelion, the closest point to the Sun in its orbit, the American Astronomical Society was having its annual meeting online, the United States Congress was validating the results of the 2020 national election, and Wendee and I were settling in for a civics lesson about the way the United States Government works. The day did not turn out as we expected.
Shortly before noon, as we watched our television set a news ticker appeared. It announced that two buildings in the Library of Congress (LC), the James Madison, and quickly afterwards the Adams and Jefferson buildings, were being evacuated. That news sent an ugly chill through me. The LC is one of the finest libraries in the entire world. It contains more than 170 million books, of which more than thirty are books I wrote entirely or those for which I penned the foreword. It also includes all of the more than two hundred “Star Trails” columns I wrote for Sky and Telescope magazine between 1988 and 2008, and dozens more I wrote for other magazines and journals. Only the British library, with over 200 million books, is larger.
This evacuation was quite personal for me. A few minutes later, when the entire Capitol complex was stormed, it was personal for all of us. All of us had reactions to this, but in addition to the feelings I had, I felt a major conern for the library.
How many books does it take to make a library? When I was a child in 1963, a teacher told me his answer: “two books.” To me, a library– any library– is every bit as priceless as a dark sky. The wisdom of the ages is contained in each library- from the LC to a child’s collection. I have never gone into a library without feeling better when I exited. The idea that this magnificent collection was threatened that day was terrifying.
I have read many books over my lifetime, from The Cat in the Hat to my boxed set of Lord of the the Rings. One small treasure, Jene Lyon’s Golden book Our Sun and the Worlds Around It, opened a door to a lifetime of stargazing. (That gem, by the way, also lives in the LC). What is more, I have never encountered a really bad book. When an author places her or his thoughts on paper in a book, that book immortalizes those thoughts.
I hope that Capitol Hill and the Library of Congress are never threatened again. They belong to we the people, and stand beautifully in Washington, D.C. to govern us, teach us, and encourage us to follow our dreams and reach for the stars.
Our annual Astronomy Festival will be virtual this year and will stream to Facebook and YouTube Saturday April 17, 2021 from 3 – 7:30 pm Tucson Arizona Time (MST or PDT, UTC-7). It will include Solar Observing, nighttime observing, A Walk Around the Night Sky with Native and Star Lore, and activities and video’s about various astronomy topics. Tune in to watch it all or any portion. The festival will also be available to view later at the below links.
3.00-3.05 pm: Introduction 3.05-3.22 pm: Solar Observing Part 1 (Observe Sunspots, Prominences, and other activity on the Sun) 3.22-3.35 pm: Magnetic Sun (Learn about activity on the Sun like Prominences, Flares, Filaments, Sunspots, and more) 3.35-4.16 pm: Sorting the Universe (Learn how astronomers makes sense out of the Universe) 4.16-4.32 pm: Our Place in Our Galaxy (Where we fit in our Galaxy) 4.32-4.50 pm: Solar Observing Part 2 (Observe Sunspots, Prominences, and other activity on the Sun)
From here to the end if viewing on Facebook, add 5 minutes to the start and stop times (it will be aired under Part 2). Otherwise, for YouTube, the below times are still current.
4.50-5.07 pm: Why Do Eclipses Happen (How and why Eclipses happen and when the next ones will occur) 5.07-5.19 pm: Pocket Solar System (Make your very own Pocket Solar System) 5.19-5.31pm: Videos What is a Nebula Flight Through the Orion Nebula Losing the Dark 5.31-5.52 pm: TAAA Overview (Learn the benefits of becoming a member of the Tucson Amateur Astronomy Association, our Dark Sky Observing Sites, Special Interest Groups, Telescope & Book Library and lots more) 5.52-6.21 pm: Walk Around the Night Sky (Native American and Ancient Star Lore of the Night Sky) 6.21-7.22 pm: Nighttime Star Party (Observe galaxies, nebulae, star clusters, double stars, and lots more) 7.22-7.26 pm: Conclusion
Next Year’s Astronomy Festival is planned for April 9, 2022 at Brandi Fenton Park in Tucson Arizona. The Festival will go from 3 – 9 pm.
Mars is the only evening planet. During dusk it becomes visible in the west 45 degrees high and sets just before midnight. It passes the M35 cluster on the 26th within half a degree.
Our two giant gas planets continue to separate from their close passage last December, from 12 degrees to 15 degrees distance during the month. They rise just before the morning twilight in the southeast and get up to 20 degrees high once dawn gets bright.
On the morning of the 2nd, Jupiter will appear to have an extra satellite because 44 Capricorni sneaks exactly into the line of Galilean satellites with just the right magnitude.
No other planet will be easily visible during April. Specialists may find Uranus after dusk during the first week and Mercury and Venus during dusk at the end of the month. Both planets will be only separated by 1 degree on the 25th. By the 30th, Mercury will appear 5 degrees above Venus and getting to be easier to spot. Both planets will stay together will visible for most of May.
The Full Moon on the evening of the 26th will be during perigee which makes for a large bright Full Moon. Last Quarter Moon is April 4 New Moon is April 11, and First Quarter April 19.
