Month: December 2018

2019, January 30 and 31: Morning Star Venus, Jupiter, and the Moon

Brilliant Morning Star Venus, bright Jupiter, and the moon put on a second dazzling display during late January 2019.  The first occurred at the beginning of the month.  During the two mornings displayed below note the moon’s changing position during the two days.   The moon is heading toward its New Phase on February 4.

  • January 30: About an hour before sunrise, look in the southeast for Venus and Jupiter. Venus (m = −4.3) is 7.7° to the lower left of Jupiter (m = −1.9). The waning crescent moon (24.4 days old — past its New Phase, 24% illuminated) is 6.1° to the upper right of Jupiter.


  • January 31: An hour before sunrise, the waning crescent moon (25.6 days old, 16% illuminated) appears 2° from Venus with Jupiter 8.5° to the upper right of Venus. This morning the moon and Venus resemble the stylized rock art “supernova” petroglyph on an overhang in Chaco Canyon, New Mexico.  The unanswerable question is whether the artist was admiring a close conjunction of the moon and Venus or the moon and the supernova of 1054. (Or of some other bright star or planet near the moon’s ambling.)  Take a look and ponder the possibilities.


The Chaco Canyon, New Mexico, “Supernova” Petroglyph. Photo E. C. Krupp, Published in Scientific American Blogs


More about Venus and Jupiter:


2019: January 1-3: Morning Star Venus, Jupiter, and the Moon

The new year opens with brilliant Morning Star Venus, bright Jupiter, and the crescent moon in the southeast before sunrise.  Watch the moon appear lower in the sky each morning and its phase diminish as it heads towards its New Moon phase on January 5. Here’s what to look for:

  • January 1: At about an hour before sunrise, the waning crescent moon (25.3 days old — past its new phase, 19% illuminated) is 24° up in the southeast, with Venus (m = −4.6), 4.7° to the lower left of the crescent. The moon is nearly between Zubenelgenubi (Z1 on the chart) and Zubeneschamli (Z2). Venus’ rapid motion is carrying it toward a widely-spaced conjunction with Jupiter later this month.  Jupiter (m = −1.8) is about 18° to the lower left of Venus and 5.3° to the upper left of Antares.
  • January 2: Venus is 25° up in the southeast, about one hour before sunrise). It is 17.3° to the upper right of Jupiter, and slowly closing that gap. The waning crescent moon (26.2 days old, 11% illuminated) lies in between them.  The moon is 11.6° above Antares.  If you have a telescope look at Venus.  It has a phase, like the moon displays; the Venusian terminator (line that divides day and night) is slightly curved, indicating a very thick morning crescent phase; the half phase is only days away (January 6).
  • January 3: Again this morning an hour before sunrise, the waning crescent moon (27.2 days old, 6% illuminated) is 3.5° to the left of Jupiter. Brilliant Venus is 16.5° to the upper right of Jupiter.

The moon repeats it motion past these bright planets at month’s end.

More about Venus and Jupiter

2018, December 26: Morning Star Venus and Jupiter

With a waning gibbous moon high in the southwest, brilliant morning star Venus shines during morning twilight from the southeast.  Jupiter is emerging from its solar conjunction.  Find a clear horizon to see Jupiter.

This morning the Venus-Jupiter gap is nearly 23 degrees.  Venus passes Jupiter on January 22.  The conjunction gap is about 2.4 degrees.  Watch the separation close during the opening days of the new year.

More about Venus and Jupiter

2018, December 24: Morning Star Venus and Jupiter

With a bright waning gibbous moon in the west, Jupiter joins brilliant Morning Star Venus in the southeastern sky.  Venus passes Jupiter in a widely-spaced conjunction on January 22.  Watch Venus close the gap during the next month.

More about Venus and Jupiter

2019, January 20: Chicago’s View of A Lunar Eclipse



Lunar Eclipse (NASA Photo)

Update:  January 20, Lunar Eclipse Photo

On January 20, observers across North America see a total lunar eclipse.  Unlike a total solar eclipse that is only visible for a few minutes from a narrow strip of ground, a lunar eclipse is visible everywhere the moon is above the horizon.  That’s from half the planet.  Another difference is that the light of a lunar eclipse is safe to view.

A lunar eclipse occurs when the moon is near its full phase and it moves through our planet’s shadow.  The entire eclipse occurs over several hours.  The best part of this eclipse occurs for about an hour.  So if there’s cloudy weather, the eclipsed moon might be visible through a break in the clouds.

Our planet’s shadow is composed of a dark inner core where the moon is totally eclipsed.  This is called the umbra. Ringing the umbra is a shadow where sunlight still somewhat shines.  When the moon is in this penumbra, the moon dims only slightly.  Without special equipment to measure the moon’s brightness, most of us will not likely see much change.

The eclipse begins on the evening of January 20 and concludes early the next morning.  Here are the events of the eclipse as seen from Chicago:

  • Jan. 20, 8:35 p.m. CST:  The nearly full moon begins to move into the penumbra.  The lunar sphere is about halfway up in the eastern sky.  There’s not much change when the moon is in this part of the shadow.
  • 9:33 p.m.: The moon continues to climb into the eastern sky.  The moon begins to move into the umbra.  During the next several minutes, the lower left portion of the moon begins to darken as the moon moves into the umbra.  This partial eclipse continues for over an hour as the moon moves farther into the shadow.  Interestingly, the moon appears to be moving higher in the sky as the eclipse progresses from Earth’s rotation.  The moon is slowly revolving eastward into our shadow.
  • 10:40 p.m. – 11:43 p.m. CST: The moon is high in southeast when totality begins.  It is totally immersed in the earth’s shadow, appearing as the image shows at the top of of this article.  The moon appears a deep ruddy orange color.  Depending on the amount of dust in the atmosphere, the moon could be dimly illuminated, nearly disappearing.  The orange color is from some of the sun’s light streaming through Earth’s thin atmosphere into the shadow.  Without the atmosphere, the moon would be completely dark.  In today’s popular press, this is known as a “blood moon.”  This is the time to see eclipse.  The moon is high in the south when totality ends.
  • 11:12 p.m. CST: The moon is midway through the total eclipse.  The moon is near its perigee — closest point to earth.  This distance qualifies it as a “super moon” if the moon where full.  So this eclipse will be known popularly as a “super blood moon” or a “blood super moon.”  This is a total lunar eclipse, an elegant name without the popular descriptions.
  • Jan. 21, 12:51 a.m. CST, The moon, high in the south-southwest exits the umbra.  It is partially eclipsed.
  • 1:49 a.m. CST, The eclipse is finished with the moon high in the southwest.

The next lunar eclipse visible from mid-America is on July 5, 2020 when the moon only passes through Earth’s penumbra.  Another similar penumbral eclipse occurs on November 30, 2020.  Chicago sees part of a total eclipse on the morning of May 26, 2021, but the moon sets before totality sets in.

2018, December 18: Mars and the Moon

With the planetary dance occurring in the southeastern sky during early morning twilight, Mars is the lone bright planet in the evening sky.  It starts in the south near the end of evening twilight.  During the next several weeks, it climbs higher in the southern sky as it moves among the stars.  Here’s our summary of Mars in 2019 until it reaches its solar conjunction.

The waning gibbous moon, 11.7 days past its new phase and 83% illuminated, brightens the sky high in the east this evening.

More about Venus, Jupiter, and Mercury in the morning sky: