June 15, 2023: Three planets and the moon are in the sky before sunrise. Venus sparkles in the western sky after sundown.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 5:15 a.m. CDT; Sunset, 8:27 p.m. CDT. Check local sources for sunrise and sunset times for your location. Times are calculated by the U.S. Naval Observatory’s MICA computer program.
Summaries of Current Sky Events
SUMMARY FOR VENUS AS AN EVENING STAR
Here is today’s planet forecast:
This morning Jupiter, Saturn and the crescent moon are in the eastern sky before sunrise. Saturn is easiest to see. An hour before sunrise, it is over 30° above the south-southeast horizon. While, not dazzlingly bright like Venus and Jupiter, the Ringed Wonder is among the brightest stars in the sky.
Through a telescope, Saturn’s rings are easily visible. Its largest moon, Titan, is to the west of the planet this morning.
The star Fomalhaut is near the horizon and about 20° to the lower right of Saturn.
Bright Jupiter, over 15° above the eastern horizon, continues to rise earlier and appear higher in the sky at this hour. It is slowly moving eastward in front of Aries. The Jovian Giant is 11.2° to the lower right of Hamal, the constellation’s brightest star.
Look carefully for the thin crescent moon, 8% illuminated. It is nearly 10° above the east-northeast horizon and over 15° to the lower left of Jupiter. Find a hilltop or elevated structure to see across any potential obstructions.
Continue to watch the moon during the next several minutes. The brightening sky begins to overwhelm the moon. By thirty minutes before daybreak, Mercury is low in the east-southeast and nearly 15° to the lower left of the lunar crescent. Mercury, Moon, and Jupiter are along a diagonal line beginning at the east-northeast horizon and extending nearly 35° to Jupiter. Use a binocular to see the participants in this morning’s scene.
Tomorrow, the crescent moon is in the same binocular field with Mercury.
Brilliant Venus sparkles in the western sky during evening twilight. Setting less than three hours after nightfall, the planet leaves the sky before midnight in the eastern regions of time zones and later farther westward in the time dividers.
Venus steps eastward in front of Cancer’s dim stars that are washed out by outdoor lighting. It is closing the gap to Mars, 5.9° to the Evening Star’s upper left.
Through a telescope, Venus is growing in size. Its phase is an evening crescent, 43% illuminated. The planet continues to brighten, beginning its phase of greatest brightness in two weeks. On moonless nights in dark locations, away from all outdoor lighting, the planet can cast shadows.
Mars continues its eastward March through Cancer. It is nearly 3.5 times farther away than Venus. While Mars does not get as bright as Venus, its brightness is from its increasing distance from Earth. On November 30, 2022, Mars was closest to Earth and brightest in the sky. As Earth moved away, the planet dimmed from the increasing distance.
Venus does not close the gap to Mars. The chase ends at month’s end, when Venus gets to within 3.6° of the Red Planet.
A conjunction would occur if Venus passed Mars, when they share the same celestial longitude. The sky as several coordinate systems that work like terrestrial latitude and longitude. One system uses the plane of the solar system as its 0° line, like Earth’s equator. The planets appear along this plane, either above it or below it. Perpendicular to celestial latitude is longitude, like terrestrial longitude, east and west of the Prime Meridian. In the sky, longitude is measured eastward from the vernal equinox.
When a faster moving planet, like Venus, passes one of the outer planets, like Mars in this case, a conjunction occurs when they share the same celestial longitude. This year Venus does not reach the same celestial longitude as Mars. The next Venus-Mars conjunction occurs February 22, 2024.
Not everybody sees the two planets when they share the same celestial longitude. For specific locations, the conjunction is named when the two planets are visible and closest.
Further, planets can have conjunctions with stars that seemed to be fixed in the coordinate systems. Mars passed Pollux, a Gemini Twin, on May 23rd. Venus passed by nearly a week later. Several months ago, Mars passed by several bright stars in Taurus.
Through a binocular, Venus is to the upper left of the Beehive star cluster. While the two planets fit into the same field of view, this leaves out the Beehive. Place Venus at the center of the field of view, the stellar bundle is to the lower right.
Watch this planet dance continue in the evening sky as Venus reaches its maximum brightness.