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Throughout October the two largest planets of the solar system will be visible in the southwest throughout the early evening. Read more

On Sept. 23 Earth experienced a biannual event, the equinox, marking the conclusion of the astronomical season of summer and welcoming the start of fall in the Northern Hemisphere.

The star family prominent in fall is Kalupeakawelo, or “the Kite of Kawelo,” referring to the Hawaiian chief Kawelo, who excelled at kite flying as a mischievous youth on Kauai. The stars that comprise a star family generally run north to south and enable today’s generation of oceanic voyagers to navigate by identifying specific stars through the order and relationship in which they appear with each other.

The northern section of this star line begins with ‘Iwakeli‘i (royal frigate bird), more commonly known as Cassiopeia, the Greek queen of Ethiopia.

This celestial grouping resembles a “W” and is associated with Cepheus to the north and Andromeda to the south. Cepheus was the king of Ethiopia and the husband of Cassiopeia; Andromeda was their princess daughter. Legend has it that Cassiopeia was exiled to the night sky after angering Poseidon with a boast that Andromeda was more beautiful than the Nereids, or sea nymphs. Andromeda was later rescued by the Greek hero Perseus. Andromeda is represented by the star Alpheratz, one of the four stars that make up the box-shaped “Lupe,” or kite, at the heart of the star family, also known as the Great Square of Pegasus.

The Great Square of Pegasus comprises three stars from Pegasus and one star from Andromeda forming a celestial square. One side of the square is made up of Scheat in the north and Markab in the south, followed by Alpheratz in the north and Algenib in the south.

Scheat-Markab and Alpheratz-Algenib are also meridian pointers, meaning they travel together to cross the celestial meridian, the imaginary line that runs overhead from celestial north to celestial south and in this instance points to the celestial north pole.

This is an important constellation for oceanic wayfinders to use in identifying the celestial north pole. Running to the south of this star line through Scheat and Markab are the stars Fomalhaut, Beta Grus and Alnair; and from Alpheratz and Algenib are the stars Diphda, Ankaa and Achernar. These form the guidelines that control Kawelo’s kite as it soars overhead between the eastern and western horizons.

FEATURED MAUNA KEA OBSERVATION

While we focus on hurricanes here on Earth, astronomers also watch turbulent storms on the other planets. In a recently published paper, an international team of astronomers used a variety of different observatories — including Subaru Telescope, Gemini North Telescope and the W.M. Keck Observatory here in Hawaii — to study the turbulent atmosphere of Jupiter and track the enormous storms disrupting the various layers in Jupiter’s atmosphere.

These observations are consistent with the moist convection theory, which predicts that upwelling winds in Jupiter’s atmosphere will carry ammonia and water vapor into the upper atmosphere, eventually creating plumes that will break through the uppermost layers of the atmosphere.

This research is helping planetary scientists understand the complex atmospheric dynamics on Jupiter. Our neighbor planets are not too different from our home, and in learning more about our planetary community, we can also gain insight into the atmospheric systems here on Earth.

EVENING OBSERVATIONS

Throughout October the two largest planets of the solar system will be visible in the southwest throughout the early evening.

Jupiter will stand out as the brightest object in the sky at that time (unless the moon is out). Through a good pair of binoculars or a telescope, observers will be able to see Jupiter’s largest moons as tiny dots around the planet. Saturn will appear toward the left of Jupiter; even though Saturn is significantly fainter than Jupiter, it will still stand out in the sky.

Rising up in the northeast during the early evening will be the “W” shape of ‘Iwakeli‘i, or Cassiopeia.

On dark and clear nights observers will be able to faintly make out a small, blurry smudge beneath this constellation (about 15 degrees south of ‘Iwakeli‘i’s brightest star).

The light you see from this small blurry smudge is the oldest light we can see from here on Earth: the Andromeda Galaxy, the closest galaxy to our Milky Way at only 2.5 million light-years away. This means the light that we see from Andromeda left the galaxy 2.5 million years ago and is now reaching Earth just in time for us to see it in our early evening sky.

In mid- to late-October, our sky will be decorated with meteors from the Orionid meteor shower, which will peak the evening of Oct. 21, with an estimated 20 shooting stars per hour. The shooting stars from this shower will propagate across the sky going from east to west, roughly originating from the constellation of Orion, which will rise at 10 p.m.

MORNING OBSERVATION

Early morning observers will see a different view of the sky. In October, dawn will start to color the sky at 5:30 a.m., and the sun will be rising around 6:30 a.m. For observers viewing the sky in these early morning hours, the bright star ‘A‘a, also known as Sirius, will be high in the southern sky. ‘A‘a is the brightest star that we see in the night sky and will easily stand out through the early morning hours.

Just above and to the east of ‘A‘a will be the recognizable shape of Heiheionakeiki, also known as Orion, and to the north and east of Heiheionakeiki will be the beautiful star cluster of Makali‘i, the Pleiades. Additionally, by mid-October observers with a careful eye will be able to catch Mars rising in the east around 5:30 a.m.

Chad Kalepa Baybayan (Kalepa.Baybayan@hawaii.edu) serves as navigator-in-residence and Emily Peavy (Emily.Peavy@hawaii.edu) as planetarium technician support facilitator at the ‘Imiloa Astronomy Center of Hawaii, a center for informal science education at the University of Hawaii at Hilo showcasing astronomy and Hawaiian culture as parallel journeys of human exploration.