2016, October 28: Jupiter and the Moon


 On the morning of October 28, Jupiter passes the star Gamma Virginis and the waning crescent moon is about 1.5 degrees from Jupiter.  Look in the southeast at about 6:30 a.m. CDT in the Chicago area.  In your location check about 50 minutes before sunrise.

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2016, October 5: The Moon, Saturn & Mars


The crescent moon (overexposed in the image) appears near Saturn this evening as seen from the Chicago area.  This evening the moon is 5 degrees from Saturn with Mars 24 degrees farther to the east.  Tomorrow evening the moon is about 8 degrees to the upper left of Saturn.

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Study Predicts Next Global Dust Storm on Mars

Global dust storms on Mars could soon become more predictable — which would be a boon for future astronauts there — if the next one follows a pattern suggested by those in the past.

A published prediction, based on this pattern, points to Mars experiencing a global dust storm in the next few months. “Mars will reach the midpoint of its current dust storm season on October 29th of this year. Based on the historical pattern we found, we believe it is very likely that a global dust storm will begin within a few weeks or months of this date,” James Shirley, a planetary scientist at NASA’s Jet Propulsion Laboratory, Pasadena, California.

Local dust storms occur frequently on Mars. These localized storms occasionally grow or coalesce to form regional systems, particularly during the southern spring and summer, when Mars is closest to the sun. On rare occasions, regional storms produce a dust haze that encircles the planet and obscures surface features beneath. A few of these events may become truly global storms, such as one in 1971 that greeted the first spacecraft to orbit Mars, NASA’s Mariner 9. Discerning a predictable pattern for which Martian years will have planet-encircling or global storms has been a challenge.

Continue the story here.

2016, October 4: Venus and Moon


After several days and nights of cloudy and rainy weather, the sky cleared today for a display of Venus and the moon in the western evening sky after sunset.  Tonight the moon and Venus are separated by 12.5 degrees.  Look for the moon near Saturn tomorrow evening.

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2016, October: Sky Watching

Image Credit

Our images and charts collections are available here –> http://goo.gl/Sfp1ur

See our article about Venus’ evening appearance.

See our  article outlining the planets in the evening sky in 2016.

Sun During October


The sun rises and sets farther south along the horizons this month.  As seen from the Chicago area, the region loses nearly 80 minutes of daylight during the month. By Halloween, the sun is in the sky about 10 hours, 20 minutes.  The chart above shows the change in daylight each month.  The red curve indicates the length of daylight throughout the year.  The blue shaded area indicates the daylight for October.


NASA Photo

NASA Photo

Phase Date/Time Moonrise Moonset
First Quarter 10/08/16 (11:33 p.m.) 1:37 p.m. 11:38 p.m.
Full Moon 10/15/16 (11:23 p.m.) 6:13 p.m. 7:25 a.m. (10/16)
Last Quarter 10/22/16 (3:04 p.m.) 11:10 p.m. (10/21) 1:50 p.m.
New Moon 10/30/16 (12:38 p.m.) 7:04 a.m. 6:10 p.m.

Times are Central Daylight Time for Chicago, Illinois, from US Naval Observatory calculations.
(For mjb & afb)

Morning Planets


Bright Jupiter and Mercury appear in the eastern sky early in the month.  Mercury was a its greatest separation from the sun last month.  This article outlines Mercury’s appearance.


On October 11, Jupiter and Mercury rise at the same time, at the beginning of Nautical Twilight, the time when the horizon can be distinguished from the sky as daylight approaches.  They are less than one degree apart.  This chart is calculated for 30 minutes before sunrise when the sky is moderately bright.  Use binoculars to locate the planets.


Jupiter was at its conjunction with the sun on September 26 and is rising earlier each month.  See this article for more about Jupiter’s appearance.  On the morning of October 28, Jupiter passes the star Gamma Virginis and the waning crescent moon is about 1.5 degrees from Jupiter.

Evening Planets

Venus is easily see in the western sky during evening twilight. It is so bright it looks like lights on an airplane.  At the beginning of the month, it sets about 75 minutes after sunset. As it moves toward its greatest separation from the sun, it sets later each evening.  On Halloween, it sets nearly 2 hours after sunset.


Saturn and Mars appear to the left of Mars and higher toward the south.  On October 1, Mars and Venus are 52 degrees apart with Saturn in between them.  Venus is slowly moving toward Mars.  This article explains more about this planetary chase.


On October 3, the crescent moon appears with Venus.  They are separated by about 2.25 degrees.

Venus is nearly 3 degrees from the star Zubenelgenubi.  On ancient star maps this star and its neighbor, Zubeneschamli, were part of Scorpius.  Their names are translated as the Northern Claw and Southern Claw (of the Scorpion).  Today they are part of Libra, the only inanimate object that forms the background for the motion of the sun, moon, and planets.


A few nights later, the moon appears near Saturn.


As the moon moves farther east in its orbit and its phase increases, the waxing moon appears near Mars on October 7 and October 8.  On both evenings, the moon is about 8 degrees from Mars.  On the first night it appears to the upper right of Mars as shown in the image above and the upper left on the second night.


By month’s end, Venus and Mars have moved farther east compared to the starry background.  Venus appears to move between Saturn and Antares, the bright star in Scorpius.  On October 25, Venus passes 3 degrees north of Antares and 3 degrees south of Saturn five nights later.  At month’s end the separation between Venus and Mars decreases to 37 degrees.

Both the morning and evening skies provide excellent opportunities to view the planets.  Take a look.

2016: Late September Morning Sky


During September a congregation of bright stars shines from the southeastern sky during predawn hours.  Sirius, the Dog Star, is the brightest star among these.  It is the brightest star in the night sky, although Venus, Jupiter and Mars shine brighter than Sirius.  Procyon appears to the upper left of Sirius and the bright stars of Orion (Betelgeuse and Rigel) shine above Sirius.

Currently there are no bright planets in the morning sky.  Mercury (see article) and Jupiter (see article) appear in the morning  sky during the next several days.  Venus, Mars and Saturn are currently in the evening sky.


Nearly a year ago, Venus appeared in the morning sky.  It was close enough to Sirius that both fit into a camera frame.  That bright star in the morning sky in the southeast is Sirius.

Our images and charts collections are available here –> http://goo.gl/Sfp1ur

See our article about Venus’ evening appearance.

See our  article outlining the planets in the evening sky in 2016.

2016: Sidereal Signs of Autumn


The autumnal equinox occurs on September 22, 2016 at 9:21 a.m. CDT.  At this moment the sun’s rays are most direct at the equator.  Astronomically, the sun’s coordinates are at 12 hours of right ascension and 0 degrees of declination.  If you not into the technicalities of this event, there’s another way to note that autumn has arrived.  One way is to look toward the western horizon early in the evening.  Near the time of the start of autumn, the Big Dipper lies low in the northwest.  Perhaps trees or your neighbor’s house blocks its view.  Locate a clear horizon to see these stars.

 In North America, the Big Dipper is one of the first star patterns that children learn when they visit their local planetarium.  Its familiar seven stars are part of the formal group call Ursa Major, the Great Bear.  The handle of the dipper points toward Arcturus, a distinctly red-orange star in the western sky.  Follow the bend of the Big Dipper’s handle toward the star Arcturus, or as the familiar saying goes, “Follow the arc to Arcturus.”  Arcturus is part of a large constellation known as Bootes, the Herdsman, that resembles a kite.

As a large celestial calendar, the stars indicate the seasons as well as the sun’s location on the great sidereal sphere.  As the earth revolves around the sun, we see a distinct layout of stars in the night sky each season.  The Big Dipper and Arcturus in the western sky make a sidereal sign that autumn has arrived.