2023, March 17: Morning Moon, Mars Heads toward Gemini


March 17, 2023: The crescent moon is low in the southeast before sunrise.  After sundown, Mars, in front of eastern Taurus, marches toward Gemini.  Venus and Jupiter are in the west.

Photo Caption – 2022, March 16: Sunrise Approaches


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 6:59 a.m. CDT; Sunset, 6:59 p.m. CDT.  Check local sources for sunrise and sunset times for your location.  Times are calculated from the U.S. Naval Observatory’s MICA computer program.

At Chicago’s latitude, daylight and nighttime are equal at 12 hours.  This occurs four days before the equinox.

The equinox is defined to occur when the sun reaches specific celestial coordinates.  This is when the sun is at the origin coordinates of the system at 4:24 p.m. CDT, March 20.  From Earth, the sun is directly overhead as viewed from the equator where the sun’s light is most direct.  From this equinox until the autumnal event on September 23rd, the sun’s light is most direct in the northern hemisphere and daylight is longer.

Sunrise, with the added hour of daylight time, has returned to before 7 a.m. CDT.

Here is today’s planet forecast:

Morning Sky

Chart Caption – 2023, March 17: The crescent moon is low in the southeast before sunrise.

The crescent moon, 24% illuminated, is low in the southeast before sunrise.  Find an unobstructed view in that direction.

Photo Caption – 2022, January 29: Mars and the crescent moon in the southeast before sunrise.

The lunar orb is displaying earthshine, reflected sunlight from Earth’s oceans, clouds, and land, that gently illuminates the lunar night. The effect is visible is visible to the unaided eye and made clearer through a binocular or spotting scope.  Capture it with a tripod mounted camera with exposures up to a few seconds, depending on the camera’s characteristics.

The moon is at the New moon phase on the 21st at 12:23 p.m. CDT.  Then watch it move into the evening sky, passing Jupiter and Venus on the evenings of March 22nd through March 24th.

Mercury is at superior conjunction on the far arc of its solar orbit.  Mercury, Sun, and Earth are in a line, but the sun blocks the view of Mercury.  The solar system’s fastest planet moves into the evening sky for its best evening appearance during April.  The evening crescent moon is nearby on April 20th and 21st.

Saturn, rising over 50 minutes before the sun, is not high enough in the sky before sunrise to see yet.  Twenty minutes after rising, it is less than 5° above the horizon.

Evening Sky

Chart Caption – 2023, March 17: Venus and Jupiter are in the west as darkness falls.

Venus shines from the western sky after sundown.  Forty-five minutes after the sun sets, the Evening Star is nearly 25° up in the west.  It brightens as it seems to climb higher in the sky each evening.

This evening, Jupiter, less than 10° above the western horizon, is over 15° to Venus’ lower right.  Find a clear western horizon to see the two planets.  The Jovian Giant is slipping into bright sunlight.  After its solar conjunction next month, it reappears in the morning sky during May.

Venus steps eastward faster than Jupiter and widens the gap by over 1° each evening.  Earth’s Twin planet is about 12° to the lower left of Hamal, the brightest star in Aries, with the brightness of the stars in the Big Dipper. Venus passes the star in a wide conjunction in six nights.

Chart Caption – 2023, March 17: Mars is high in the southwest, east of the Bull’s horns.

Mars is higher in the sky, marching eastward in western Taurus, near the Gemini border.  The Red Planet is east of the constellation’s brighter landmarks, 4.8° to the lower left of Elnath, the Bull’s northern horn, and nearly the same distance to the upper left of Zeta Tauri, the southern horn.

Mars marches eastward at nearly 0.5° from night to night, about half the speed of Venus.  The Venus-Mars gap is over 55°.  How long will it take Venus to catch Mars?  This reads like one of those two-train distance problems from Algebra class.  Well, the solution is not quite that easy.  The answer is in the Venus article for this apparition or in the 2023 evening summary article.  For others, stay with these daily articles and watch the Venus-Mars gap close during the next several months.

Photo Caption – The Beehive or Praesepe star cluster (National Science Foundation Photo).

Use a binocular to locate Mars, then move the binocular so that the planet appears in the right portion of the field.  A star cluster, catalogued as Messier 35, is to the left in the view.  The stellar bundle is a galactic cluster, comprised of a few hundred stars and found in the arms of the Milky Way. It is near Gemini’s western boundary in our sky. The Twins appear to be standing on the glow of a spiral arm. 

Messier 35 is near Castor’s toe, Propus.  It appears to be about the diameter of the moon, but the cluster is about 30 light years across.  From a dark location, it is visible without optical assistance.  Through a binocular, it is easily visible, and with a telescope, use a low-power eyepiece, 80 power or less, to see all of it in the same field of view.

The cluster is thought to be less than 3,000 light years away, about seven times the distance to the Pleiades cluster that has many bright blue stars. Similarly, Messier 35 has several blue stars as well as some yellow and orange ones.  The two clusters are thought to be about 150 million years old.

During the next several evenings, watch Mars close in on the star cluster and seem to pass by on the 29th.



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