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This website has been created by and is supported by a group of Boston, MA - area amateur astronomers. It is intended to be a convenient site to access news and information about astronomy and space-related activities of interest to the community and the public.




Next Astronomy Course


Introduction to Astronomy


We sit around our campfires as the ancients did, and ponder. How did the Universe come into existence? How did life begin? Are we alone? But now we see a Universe around us containing black holes, dark matter, and expanding space. What does it all mean? In this course we’ll sit around our own campfire, and try to piece together the stories that modern astronomy is teaching us.  


One meeting will be at a local observatory.


No math or science background required!


Meets at the Cambridge Center for Adult Education, 8 Tuesdays: September 19 -  November 7, 2017, 7:45 PM - 9:15 PM.




September Astronomy-Related Events in the Boston Area  



Saturday, September 9, 2017, 7:30 PM - 10:30 PM

Sea the Stars Cruise

We wish upon them, gaze at them, aim for them, and sometimes even thank our lucky ones! For centuries, stars have fascinated us, guided us, and provided us with nighttime illumination and splendor. Sadly, the abundance of bright lights and tall buildings has made stargazing for city dwellers difficult at best and often pretty much impossible. But fear not, amateur astronomers and celestial connoisseurs, the Museum of Science and Boston Harbor Cruises have teamed up to bring you the Sea the Stars Cruise!

Onboard a high-speed catamaran, you'll travel to where the city lights and congestion are just a bright memory for a stargazing opportunity like no other in the city.

Cruise highlights include:

Three-hour cruise aboard a high-speed catamaran from Long Wharf, Boston

Expert commentary and star identification from Museum of Science Astronomy Educators

Narration on the history and importance of celestial navigation – how sailors used the stars

Related video and content

Plenty of outdoor viewing space

Comfortable indoor seating

Cash Bar and snacks available onboard

Please note: Stargazing is dependent on clear skies. If forecasts show that clouds or precipitation will rule out good viewing, the cruise will be cancelled. Decisions on any cancellation will be made by 2:00 pm on the day of the cruise. Ticket passengers will be notified and refunds will be made. If, during the cruise, visibility limits successful stargazing, passengers will receive a rain check to return for a future Sea the Stars Cruise.

For tickets and more information, visit

Sponsored by Boston Harbor Cruises.



Thursday, September 14, 2017, 8:00 PM - 10 PM

Amateur Telescope Makers of Boston (ATMoB) Monthly Meeting

Harvard-Smithsonian Center for Astrophysics

60 Garden St.

Cambridge, MA 02138

Topic and Speaker: "The Great American Eclipse"

Where were you on August 21, 2017? If you were an ATMoB member, you might have been anywhere along a 70-mile-wide path from Oregon to South Carolina taking in the totality of the Great American Solar Eclipse. If you weren’t able to travel to the “sweet spot,” you might have taken in the partial eclipse from your back yard or from the above-mentioned gathering at the ATMoB clubhouse. At our September meeting, we’ll celebrate the event with first-hand member accounts. Already scheduled are talks by Bernie Volz (the ATMoB Missouri total eclipse trip), Phil Levine (the Clubhouse partial eclipse party), and 8th-grade Project CATE participant Arianna Roberts (whose role in this Citizen Science solar eclipse project was funded to a great extent by ATMoB). Arrangements to add brief reports by other ATMoB eclipse chasers are still pending, so stay tuned!



Friday, September 15 - Sunday, September 17, 2017

Connecticut River Valley Astronomers Conjunction
Northfield Mountain Recreational and Environmental Center
Northfield, MA



Thursday, September 21, 2017, 7:30 PM

CfA Public Observatory Night

Harvard-Smithsonian Center for Astrophysics
60 Garden Street

Cambridge, MA 02138

Topic and Speaker: "We Have No Idea: A Guide to the Unknown Universe", Jorge Cham, creator of PhD Comics & PhD in Robotics, and Daniel Whiteson, particle physicist & researcher at CERN

There are so many things we don’t know about the Universe. For example, what is most of the Universe made of? What is dark matter? Where does dark energy come from? Why does the universe have a speed limit? What (or who) is attacking earth with tiny, super-fast particles? And for that matter…what is matter? After generations of human research, brilliant scientific minds, and crazy technological advances we can confidently answer all of these questions the same way: we have no idea. In their new book We Have No Idea: A Guide to the Unknown Universe, Cham and Whiteson investigate why a vast portion of our universe (read: most of it) is still a mystery, and what a lot of smart people are doing to understand it. After the talk, copies of Cham and Whiteson’s book "We Have No Idea: A Guide to the Unknown Universe" will be available for purchase and signing.



Thursday, September 21 - Sunday, September 24, 2017    

Acadia Night Sky Festival
Acadia National Park, ME



Friday, September 22 - Sunday, September 24, 2017

Connecticut Star Party
Astronomical Society of New Haven
Goshen, CT



Saturday, September 23, 2017 - 3:00 PM - ??? 

Amateur Telescope Makers of Boston (ATMoB) Club Picnic

ATMoB Clubhouse

Millstone Road

Westford, MA, 01886




Plus (ongoing):        



Boston University

Boston, MA.
Open Night at Coit Observatory most Wednesdays 8:30 PM - 9:30 PM. 




Thursdays (every 3rd Thursday of month, Sept. - Nov.)

Harvard Smithsonian Center for Astrophysics

60 Garden St.

Cambridge, MA 02138




Fridays (until October 27), 8:30 PM - 10:00 PM

Guilliland Observatory

Museum of Science

1 Science Park

Boston, MA 02114





The Sky Report for the Month of September 2017


The September Equinox occurs at 4:02 PM EDT on September 22. This represents the instant the Sun crosses the celestial equator on its way south. By convention, it is considered the beginning of autumn in the northern hemisphere and of spring in the southern hemisphere.



Current Night Sky: At A Glance


            Phases of the Moon:                           



Full Moon

September 6

3:03 AM EDT

Last Quarter Moon

September 13

2:25 AM EDT

New Moon

September 20

1:30 AM EDT

First Quarter Moon

September 27

10:54 PM EDT



The Moon & Planets:



Planet Visibility:


In Evening (after sunset):

    Jupiter, in W

    Saturn, in S

    Neptune, in SE 


 At Midnight:

    Saturn, in W

    Neptune, in S

    Uranus, in SE


 In Morning (before sunrise):

    Neptune, in W

    Uranus, in S

    Venus, in E 

    Mars, in E

    Mercury, in E 






    •     There are no comets brighter than magnitude 8 visible this month.


  •     There are no notable meteor showers in September.





The asteroid 3122 Florence makes a close approach to Earth on September 1. There is NO chance of a collision; the object will pass safely about

4.4 million miles from Earth. (That is over 18 times the distance to the Moon.) Still, Florence, estimated to be 2.4 miles across, is the largest object

to make a close pass of Earth since NASA began detecting and tracking asteroids. It may get as bright as magnitude 8.5, making it an easy

target for backyard telescopes.  

(September 1, 2017 – 20:06 PM UT).





Neptune is at opposition on September 5th, meaning that it is making the year’s closest approach to Earth. It is also at its largest and brightest.

Nevertheless, at 2.7 billion miles distant, it appears little more than a tiny, faint disk in all but the largest telescopes.

(September 5, 2017 – 1:00 AM EDT)


On September 18, the Moon, Mercury, and Mars form a tight triangle; each planet is barely a degree from the Moon. The Moon as shown here

 is illuminated mostly by earthlight; only 2% of the disk is in sunlight. Of course, the proximity of the bodies in our sky is deceptive.

The Moon is only 235,000 miles away. Mercury is 104 million miles distant, while dimmer Mars lies 241 million miles away.

(September 18, 2017, 23:30 UT).


Cassini's Last Days


The Cassini spacecraft, launched from Earth in 1997, took up orbit around Saturn in 2004.


Now, after exploring Saturn, its rings, and its moons for 14 years, the mission is coming to an end. With the spacecraft running low on attitude-control fuel, NASA has decided to dispose of Cassini by directing it to burn up in Saturn’s atmosphere. This decision was made to avoid the chance – however remote – of the derelict spacecraft impacting on Titan or Enceladus. Since these bodies are now of interest as possible habitats for life, NASA wanted to insure against the even more remote chance that any long-surviving organisms that Cassini may carry will contaminate these worlds.


September will see the last days of Cassini. On the 11th, the spacecraft will make a flyby of Titan for a final time – the so-called “goodbye kiss” – using the moon’s gravity to alter its trajectory. On the 14th, a final image will be taken and transmitted to Earth. All subsequent data – which will include sampling of Saturn’s atmosphere during Cassin’s last moments - will be sent in real time.




Cassini’s last few days are outlined here. (Courtesy NASA/JPL-Caltech.)


On September 15th, Cassini will plunge into Saturn’s atmosphere. As the spacecraft starts to experience increasingly dense atmospheric density, its thrusters will be firing ever more strongly to keep the main antenna pointed at Earth. But it’s a losing game; it’s predicted that loss of signal will occur at 6:31 AM EDT. Because signals travelling at the speed of light will be taking 83 minutes to reach Earth, we’ll hear the last from Cassini at around 7:54 AM EDT our time. Moments later, the tumbling craft will burn up in Saturn’s atmosphere.




Cassini will faithfully transmit its data until the very end, as it burns up in Saturn’s atmosphere and becomes part of the planet.

 (Courtesy NASA/JPL-Caltech.)


 Since its mission began 20 years ago, Cassini has revolutionized our knowledge of the Solar System. Its revelations concerning Saturn, its rings, and its moons have provided a scientific bonanza. And its discoveries of methane seas on Titan and of water geysers on Enceladus have stirred the public imagination. It can only be hoped that follow-on missions to the Saturn system – at least a decade away, in any case – will not be delayed for much longer.  



September Major Astronomical Events       
Sept. 1 Fri. 4:06 PM EDT Asteroid 3122 Florence @ close approach (7,066,506 km / 4,390,923 miles / 18.383 L.D.)
Sept. 2 Sat. 9:17 AM EDT Cassini Orbit 291 Periapsis Dip # 4 (1660 km from Saturn, 6040 km from D ring) "Final Five"
Sept. 4 Mon. 8:00 PM EDT Mercury 3.2° SW of Mars
Sept. 4 Mon. 8:00 PM EDT Mercury, Mars, and Regulus within circle 3.19° in diameter
Sept. 5 Tue. 1:00 AM EDT Neptune @ opposition
Sept. 5 Tue. 7:00 AM EDT Jupiter 3° N of Spica
Sept. 6 Wed. 1:00 AM EDT Moon 0.8° S of Neptune
Sept. 6 Wed. 3:03 AM EDT Full Moon ("Full Corn Moon")
Sept. 9 Sat. 6:00 AM EDT Moon 4° S of Uranus
Sept. 9 Sat. 8:18 PM EDT Cassini Orbit 292 Periapsis Dip # 5 (1680 km from Saturn) "Final Five"
Sept. 10 Sun. 8:00 AM EDT Mercury 0.6° S of Regulus
Sept. 11 Mon. 3:04 PM EDT Final, distant Titan flyby (aka, the "goodbye kiss") closest approach (119,049 km / 73,974 mi.)
Sept. 12 Tue. 6:00 AM EDT Mercury @ greatest elongation (18°  W of Sun) in morning sky
Sept. 12 Tue. 9:00 AM EDT Moon 0.4° N of Aldebaran
Sept. 13 Wed. 2:25 AM EDT Last Quarter Moon
Sept. 13 Wed. 12:06 PM EDT Moon @ perigee (369,859 km / 229,820 mi)
Sept. 14 Thur. 7:00 AM EDT Saturn @ (eastern) quadrature
Sept. 15 Fri. 7:54 AM EDT Cassini Orbit 293 Atmospheric Entry / LOS / EOM
Sept. 16 Sat. 2:00 PM EDT Mercury 0.06° N of Mars
Sept. 17 Sun. 12:00 AM EDT Sun enters Virgo
Sept. 17 Sun. 9:00 PM EDT Moon 0.5° S of Venus
Sept. 18 Mon. 1:00 AM EDT Moon 0.09° N of Regulus
Sept. 18 Mon. 1:00 AM EDT Moon, Venus, Regulus fit in circle 2.36° across
Sept. 18 Mon. 4:00 PM EDT Moon 0.1° N of Mars
Sept. 18 Mon. 7:00 PM EDT Moon 0.03° S of Mercury
Sept. 19 Tue. 1:00 AM EDT Moon, Mercury, Mars fit in circle 1.83° across
Sept. 19 Tue. 7:00 PM EDT Venus 0.5° N of Regulus
Sept. 20 Wed. 1:30 AM EDT New Moon
Sept. 22 Fri. 4:00 AM EDT Moon 4° N of Jupiter
Sept. 22 Fri. 12:52 PM EDT OSIRIS-REx Earth flyby (~ 16,000 km / 10,000 mi)
Sept. 22 Fri. 4:02 PM EDT September Equinox
Sept. 25 Mon. 6:35 AM / 6:35 PM EDT September Equilux (day and night of equal length)
Sept. 26 Tue. 8:00 PM EDT Moon 3° N of Saturn
Sept. 27 Wed. 2:50 AM EDT Moon @ apogee (404,348 km / 251,250 mi)
Sept. 27 Wed. 10:54 PM EDT First Quarter Moon
Sept. 30 Sat. All day Fall Astronomy Day


An Overview of Major 2017 Astronomical Events

Jan. 3 Tue. 7:14:38 AM EST Latest sunrise of year in Boston
Jan. 3 Tue. 9:00 AM EST Quadrantid meteors
Jan. 4 Wed. 9:00 AM EST Earth @ perihelion (0.98331 AU / 147,101,111 km / 91,404,393 mi)
Jan. 12 Thur. 8:00 AM EST Venus @ greatest eastern elongation (47.1° E); Evening "Star"
Jan. 12 Thur. 6:00 PM EST Venus 0.4° N of Neptune (21' 57" in Boston)
Jan. 17 Tue. 8:00 PM EST Vesta @ opposition (mag. 6.3)
Jan. 19 Thur. 1:00 AM EST Jupiter 2.7° S of Moon
Jan. 19 Thur. 5:00 AM EST Mercury @ greatest western elongation (24.1° W); Morning "Star"
Jan. 31 Tue. 6:00 PM EST Mars, Venus, and waxing crescent Moon fit into circle 6° in diameter
Feb. 11 Sat. 5:34 PM EST - 9:53 PM EST Penumbral Lunar Eclipse
Feb. 17 Fri. 2:00 AM EST Venus @ greatest illuminated extent
Feb. 26 Sun. 7:10 AM EST - 12:38 PM EST Annular Solar Eclipse (SW Africa. S. Atlantic, South America)
Feb. 26 Sun. 8:15 PM EST Mars 34' N of Uranus
Mar. 1 Wed. 10:00 PM EST Neptune @ solar conjunction
Mar. 12 Sun. 2:00 AM EST Daylight Saving Time begins
Mar. 20 Mon. 6:29 AM EDT March Equinox
Mar. 25 Sat. 6:00 AM EDT Venus @ inferior conjunction
Apr. 1 Sat. 6:00 AM EDT Mercury @ greatest eastern elongation (19.0° E); Evening "Star"
Apr. 7 Fri. 5:00 PM EDT Jupiter @ opposition
Apr. 12 Wed. 2:00 PM EDT Comet 41P/Tuttle-Giacobini-Kresak @ perihelion (mag. 5?)
Apr. 14 Fri. 2:00 AM EDT Uranus @ solar conjunction
Apr. 22 Sat. 8:00 AM EDT Lyrid meteors
Apr. 22 Sat.   Cassini Titan flyby begins Proximal Orbit Phase ("Grand Finale")
Apr.29 Sat. All day Astronomy Day (spring)
Apr. 30 Sun. 12:00 AM EDT Venus @ greatest illuminated extent
May 4 Thur. 9:00 AM EDT Eta Aquarid meteors
May 17 Wed. 7:00 PM EDT Mercury @ greatest western elongation (25.8° W); Morning "Star"
Jun. 2 Fri. 10:00 AM EDT Venus 2° S of Uranus
Jun. 3 Sat. 7:00 AM EDT Venus @ greatest western elongation (45.9° W); Morning "Star"
Jun. 3 Sat. 8:00 PM EST Moon 2° N  of Jupiter
Jun. 3 Sat. 10:24 PM EDT - 12:21 AM EDT Double shadow transit on Jupiter (Io, Ganymede)
Jun. 12 Wed. 4:00 AM EDT Comet C/2015 V2 (Johnson) @ perihelion (mag. 6?)
Jun. 14 Wed. 5:07:00 AM EDT Earliest sunrise of year in Boston
Jun. 15 Thur. 5:00 AM EDT Saturn @ opposition
Jun. 19 Mon. 10:06 PM EDT - 10:38 PM EDT Double shadow transit on Jupiter (Io, Europa)
Jun. 21 Wed. 12:25 AM EDT June Solstice
Jun. 27 Tue. 8:25:22 PM EDT Latest sunset of year in Boston
Jul. 3 Mon. 4:00 AM EDT Earth @ aphelion (1.01668 AU / 152,093,193 km / 94,506,329 mi)
Jul. 10 Mon. 12:10 AM EDT Pluto @ opposition
Jul. 26 Wed. 9:00 PM EDT Mars @ superior comjunction
Jul. 28 Fri. 9:00 PM EDT Moon 2° N of Jupiter
Jul. 30 Sun. 12:00 AM EDT Mercury @ greatest eastern elongation (27.2° E); Evening "Star"
Aug. 7 Mon. 11:50 AM EDT - 4:50  PM EDT Partial Lunar Eclipse (Eastern Hemisphere)
Aug. 12 Sat. 3:00 PM EDT Perseid meteors
Aug. 21 Mon. 11:46 AM EDT - 5:04 PM EDT Total Solar Eclipse (Partial 9:28 AM EDT - 11:59 PM EDT in Boston)
Sept. 5 Tue. 12:00 AM EDT Neptune @ opposition
Sept. 12 Tue. 6:00 AM EDT Mercury @ greatest western elongation (17.9° W); Morning "Star
Sept. 15 Fri. 8:07 AM EDT Cassini enters atmosphere of Saturn, burns up
Sept. 16 Sat. 2:00 PM EDT Mercury 0.03° N of Mars (3.2' in Pacific, 18' in Boston)
Sept. 22 Fri. 12:52 PM EDT OSIRIS-REx Earth flyby (~ 16,000 km / 10,000 mi)
Sept. 22 Fri. 4:02 PM EDT September Equinox
Sept. 30 Sat. All day Astronomy Day (fall)
Oct. 5 Thur. 9:00 AM EDT Venus 0.2° N of Mars
Oct. 7 Sat.   Mars @ aphelion
Oct. 19 Thur. 1:00 PM EDT Uranus @ opposition
Oct. 26 Thur. 2:12 PM EDT Jupiter @ solar conjunction
Nov. 5 Sun. 2:00 AM EDT Daylight Saving Time ends
Nov. 5 Sun. 9:03 PM EST - 9:59 PM EST Moon occults Aldebaran
Nov. 13 Mon. 1:00 AM EST Venus 0.3° N of Jupiter
Nov. 17 Fri. 12:00 PM EST Leonid meteors
Nov. 23 Thur. 7:00 PM EST Mercury @ greatest eastern elongation (22.0° E); Evening "Star"
Nov. 28 Tue. 5:00 AM EST Mercury 3° S of Saturn
Dec. 8 Fri. 4:11:42 PM EST Earliest sunset of year in Boston
Dec. 14 Thur. 1:00 AM EST Geminid meteors
Dec. 21 Thur. 11:29 PM EST December Solstice
Dec. 21 Thur. 6:00 PM EST Saturn @ solar conjunction
Dec. 22 Fri. 10:00 AM EST Ursid meteors
Dec. 30 Sat. 7:28 PM EST - 8:21 PM EST Moon occults Aldebaran




    Supernova Style Science News  with Ms. Julie Seven Sage



September 15, 2017 - 10:00 PM EDT