Skywatch September 2017

Skywatch September 2017

The last Skywatch!

Aloha everybody,

This will be the final Skywatch article. I am delighted and a little wistful to announce that I have accepted the position of Planetarium Director at Liberty Science Center in Jersey City, New Jersey, across from the bright lights of lower Manhattan. Liberty Science Center is in the process of renovating its IMAX Dome into the largest planetarium in the western hemisphere, and I will become their new Planetarium Director as of September 5.

While Bishop Museum will not be able to continue this monthly column after I move east, much of the same content will continue to be available on our planetarium home page. This page includes such resources as the monthly star maps for Hawaii’s latitude; the yearly list of astronomy highlights with the timings given in Hawai‘i Standard Time; and other important content, such as Lahaina noon timings for various locations in the islands, and moon phases given in Hawaii Standard Time. Planetarium page:

Coming from Seattle to Bishop Museum in 1999, I discovered immediately that interpreting astronomy in the Hawaiian Islands – via a planetarium show, a Skywatch article or a ‘real astronomy’ special event – meant offering the public something they really, really wanted! Hawaii’s deep, strong connections to astronomy meant that resident and visitor alike were drawn to the stars over the islands. To this day, the Watumull Planetarium continues to draw 95,000 attendees a year, some seven times the average yearly attendance of an average theater of its size; Skywatch and its related Hawaii-latitude sky maps have been put to good use on beaches and stuck to refrigerators across the state; and our ‘real astronomy’ events have drawn big crowds throughout these last eighteen years. In terms of reaching an immediate and enthusiastic audience, I was spoiled by starting at Bishop Museum in the planetarium field. While the later experiences of being Education Director, Exhibit Director and Visitor Experience Director led to great new challenges and experiences, I never had such as easy ‘sell’ as promoting astronomy here: as witnessed by everything from the 3,000 people who flocked to ‘Mars Madness’ in August 2003 to the 2,200 who came to our daylong Transit of Venus Festival in June 2012. There has always been a special bond between the Museum’s planetarium and its audiences.

Due in part to this, I am sure, the state of Hawaii funded a complete renovation of the planetarium in 2012. The renovation brought our venerable dome in the 21st century with immersive full dome video and a state of the art star machine. That, in turn, allowed us to create astronomy experiences that now drew upon all the resources of a modern immersive dome, from creating the world’s first immersive full-dome video program on Pacific Navigation (The Wayfinders, 2013), to alternating live and ‘movie’ elements into a single show,  to incorporating lasers and live theater and live music into our planetarium programs. It’s been wonderful being able to write this column, to plan these astronomy events, to manage this dome here in Honolulu; it will also be an exciting challenge to extend the lessons learned in our island dome to the vast canvas of the new Liberty Science Center planetarium theater.


September Planets



Jupiter, shining brightly at minus 2 magnitude, has been our constant evening companion this summer; but its days are numbered. In early September, Jupiter is still clearly visible, but it’s already low in the west. Look for Jupiter about twenty degrees above the west horizon (the width of two palms) at dusk; the planet sets by 9 p.m. By mid-month Jupiter sets by 8 p.m.; and by the end of September the planet sets right as it gets dark, ending Jupiter’s long reign as king of the summer evening sky.  Jupiter will be missing in action for all of October, then return in mid-November as a morning object.


Saturn is high in the southwest at dusk in September. The yellow-white planet is about one fist’s diameter to the left of Antares, the orange Mars-like star that is the brightest star in Scorpius. Saturn sets in the west at midnight in early September.  By the end of the month, look for Saturn partway up in the southeast at dusk; it will set just before 10:30 p.m. While it’s nowhere near as bright as Jupiter, Saturn does shine nicely at 0.5 magnitude. Look for a wide crescent moon above Saturn on September 26.

Saturn will be in the news this September as the Cassini spacecraft, after a phenomenal mission to the ringed planet, will meet its planned demise on September 15 as NASA sends the craft into the planet’s yellow-white clouds.


In early September, Venus rises in the east right around 4 a.m. as is about 1/4 of the way up in the east at daybreak. By the end of the month, the planet does not rise till 4:40 a.m. Venus shines at minus 4 magnitude, many times brighter than even Jupiter. While it rises later and later, Venus will remain in this role as a predawn beacon all the way till the end of October 2017.


Mercury and Mars

Mars finally returns to the night sky in mid-September, low in the east at daybreak. While the planet is still very faint, it appears close to Mercury, and that can be your guide.

From September 10 – 15, with a flat eastern horizon, look for bright Mercury rising at 5 a.m. You’ll have only about 40 minutes to see it till daybreak washes it out, but Mercury does shine brightly at minus 1 magnitude.  This early in the game, you will probably only be able to catch Mars, just below Mercury but shining feebly at 2nd degree magnitude, if you scan the sky below Mercury with binoculars.

On the morning of the 16th, Mercury and Mars will appear very close together, Mars still tucked below Mercury and still much fainter. Search the eastern sky around 5:30 a.m., again looking over a flat horizon.  On the 18th of September, still around 5:30 a.m., a very, very old crescent moon will appear above the two planets.  By that morning Mars will have moved above Mercury.

As the month goes on, every morning Mars seems a little higher, and Mercury a little lower. On September 24, if you have good viewing conditions and a flat eastern horizon, you will be able to see the planets Mercury, Mars and Venus spaced out equally; Mercury just rising, Mars in the middle, blazing Venus on top.  After the 24th, it will become much harder to catch Mercury rise before day breaks.  Mars meanwhile seems every morning to draw nearer to Venus, heading for a beautiful gathering of the two planets in early October.


Autumn begins

Autumn begins at 4:22 a.m. on September 22 Hawai‘i Standard Time (14:22 Universal Time on September 22.)

September sky map

The map for September 2017 is good for 10 p.m. at the start of September, 9 p.m. in the middle of the month, and 8 p.m. at the end. The map is set for the latitude of Honolulu, 21 degrees N, but works fine for anyplace else in the islands.

On this map, the constellation of Scorpius the Scorpion is setting in the southwestern sky. These bright stars of Scorpius make a pattern that really does look like a Scorpion. Scorpius also really looks like Maui’s Fishhook, the hook that Maui used the pull the Hawaiian Islands from the bottom of the ocean.

Low in the southeast is Grus the Crane. Grus is the best example on the September map of a constellation to can see easily from the Hawaiian Islands but which can’t be seen from much of the continental US; if you live further north than Los Angeles (34 degrees north), you won’t see Grus in your home skies. In Hawaii the southern stars are higher than in the continental US, and we see stars that don’t rise above the south horizon in a place like New York or Chicago.

The tradeoff is that the northern stars are lower here. Thus the northern constellation of the Big Bear (Big Dipper) is so low in our island skies that it does rise and set, and is in fact entirely gone from our September map.

Overhead is the Summer Triangle. This triangle is made up of three bright stars from three different constellations. This includes Vega, the brightest star in the triangle, in Lyra the Harp; Altair, in Aquila the Eagle; and Deneb, the dimmest of the three bright stars, in Cygnus the Swan. We’ve shown both the individual constellations and the triangle on our map.

Moon phases (Hawaiian Time zone)

Full:  Sept 6
Third Quarter: Sept 13
New: Sept 20
First Quarter: Sept 28

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2017-08-26T10:36:22+00:00Monthly Astronomy Article|