Skywatch Line for Friday, April 17, through Sunday, April 19, written by Sam Salem
This is Dudley Observatory’s Skywatch Line for Friday, April 17, through Sunday, April 19, written by Sam Salem.
On Friday, Sun rises at 6:10am and sets at 7:40pm; Moon rises at 5:54am and sets at 8:22pm.
New Moon occurs on Friday at 7:52am. This is the first of 5 new supermoons in a row. It’ll be 226,299 miles away. The average moon distance is 238,900 miles. New Moons rise and set with the Sun.
In the western-northwestern sky during twilight on Saturday evening, the slender crescent Moon is positioned 4 or 5 degrees to the right or lower right of Venus. Use Binoculars to view Earthshine gently illuminating the Moon. Both Venus and the Moon will set shortly after the complete darkness of nightfall.
The crescent Moon is approximately 2.5 days old on Sunday and situated approximately 11 degrees above Venus. Venus, at magnitude –3.9, glows low in the western evening twilight. Fifty minutes after sunset, you’ll find it about a fist at arm’s length above horizontal. Venus sets soon after the end of twilight. As twilight descends, observe the emergence of the Pleiades constellation.
Mercury, Mars, Saturn, and Neptune sit very low in the glow of sunrise. There is a slight possibility of observing Mercury and even Mars this weekend. Saturn is emerging to join Mercury and Mars as potentially visible with optical aid, particularly as dawn brightens. On Monday morning, the three planets will align closely.
Use the crescent Moon to guide you as Venus and Uranus will be 5 degrees south of Moon on Sunday. Uranus, magnitude 5.8 in the constellation Taurus and 4° south of the Pleiades, is about 16 degrees high in the west right after the end of twilight. In a telescope,
Uranus is a tiny non-stellar dot, 3.5 arcseconds wide. Use a detailed finder chart to identify the planet among similar-looking faint stars.
Jupiter, magnitude –2.1, shines very high toward the west at nightfall. Jupiter swings lower through the evening. It sets around 2 am. on the west-northwest horizon.
In a telescope Jupiter is down to 38 arcseconds wide. It’s shrinking and fading as Earth pulls farther ahead of it in our faster orbit around the Sun.
The moonless Friday night is an opportunity to look for the zodiacal light after dark. This glow is produced by sunlight scattering off dust that has settled along the plane of the solar system. This dust is left behind by comets as they traverse the inner solar system, where they are heated by the Sun and expel gases and small grains from their nuclei in the process. Over time, the dust accumulates into orbits along the ecliptic, creating a cone-shaped glow in our nighttime sky. During the Spring season, this glow can be observed after dark in the western sky. At this time of year, the ecliptic ascends upward toward the left when viewed from the western horizon. After the fading of twilight, seek
lingering light in the sky, characterized by a wider base and pointed apex terminating in Gemini or Cancer. This is the zodiacal light.