The new moon occurs today (June 3), just two days before our natural satellite makes a close pass to Mars in the evening sky.
When the moon is directly between Earth and the sun, we call that a new moon. This happens about every 29.5 days, when the sun and moon share the same celestial longitude, an alignment also called a conjunction. (Celestial longitude is a projection of the Earth's own longitude lines on the celestial sphere.) Today, they reached conjunction at 6:02 a.m. EDT (1002 GMT), marking the exact moment of the new moon.
The new moon of June is significant to religious Muslims, because it marks the end of the holy month of Ramadan, when practitioners fast during the day. The holiday is called Eid al Fitr and begins today at sunset local time.
Related: 2019 Moon Phases Calendar
According to NASA's Skycal, the waning moon was in conjunction with Venus on June 1, and it will be in conjunction with Mars on June 5.
The two-day-old moon's close approach to Mars happens during the day, at 11:05 a.m. EDT (1505 GMT), but the pair will still appear close together by the time it gets dark outside. The moon sets at 10:48 p.m. local time in New York City, while Mars sets at 10:27 p.m. local time. At sunset, which occurs at 8:23 p.m., Mars will be about 21 degrees above the western horizon with the moon appearing to the left of it, according to the skywatching site Heavens-Above.com.
With a clear view of the horizon and a keen eye, on the night of the new moon one might also spot the planet Mercury, an elusive target for observers. Mercury is in the constellation Taurus in June. For observers in mid-northern latitudes, it will be just bright enough (magnitude -0.8) to see at about 9 p.m. local time, when the sun is about 6 degrees below the horizon. The planet will only be at about 5 degrees altitude, so the best places to see it will be those that have relatively flat horizons.
See Mercury and Mars after sunset on June 5, 2019.
Spotting Mercury is not much easier as one moves south; even though the sun sets earlier – sunset on June 3 is at 6:55 p.m. local time in New York – Mercury is only about 6 degrees above the horizon by the time it becomes visible about half an hour later. (The planet sets at 8:04 p.m. local time on June 3).
Southern Hemisphere observers will have even less favorable conditions for viewing Mercury. Though the Southern Hemisphere is in the middle of winter, and the sun sets early, Mercury appears even closer to the horizon. In Cape Town, for example, the sun sets at 5:45 p.m. local time, but Mercury is only 3 degrees above the horizon 30 minutes later.
Visible constellations
On the night of the new moon, observers in mid-northern latitudes will see the bright winter sky constellations almost completely set by about 9 p.m. local time. The constellation Orion will be below the horizon, and won't reappear until autumn. Mars, which is in the constellation Gemini, will be low in the west, as it sets at about 10:30 p.m. in New York City.
In the East, Jupiter rises at about 8:48 p.m. and marks the constellation Ophiuchus, the snake bearer, who stands just above Scorpio, the scorpion. By about 10 p.m. most of Scorpio is above the horizon, and Antares, the brightest star in Scorpio, can be seen to the right of Jupiter. Saturn rises at about 10:50 p.m. local time in New York City, and by 11 p.m. it will be low in the eastern sky to the left of the brighter stars in the constellation Sagittarius.
High in the eastern sky, by 10 p.m. local time Lyra, Cygnus and Aquila will show the asterism the Summer Triangle, consisting of Vega (Alpha Lyrae), Deneb (Alpha Cygni) and Altair (Alpha Aquilae). During the summer, Vega — one of the brightest northern hemisphere stars — reaches the zenith around midnight, and the asterism also frames part of the Milky Way. From a dark-sky site one can see it stretch from Sagittarius to the constellation of Cassiopeia in the north.
Cassiopeia is a legendary figure, representing a queen of Aethiopia who was married to king Cepheus. Cassiopeia boasted her daughter Andromeda was more beautiful than the sea-nymphs, the Nereids. This angered Poseidon, the god of the seas, who sent a monster to attack the coast. An oracle said that the only way to stave off the attacks was to sacrifice her daughter to a sea monster, often represented by the constellation Cetus. Andromeda was saved and the monster defeated by Perseus.
Cepheus and Cassiopeia are both visible in the sky together for most of the year in the Northern Hemisphere, as both are near the north celestial pole and Cepheus never sets north of about 45 degrees latitude. Just south of the "W" shape of Cassiopeia is her daughter Andromeda, which rises after midnight, and just east of Cassiopeia is Perseus, which follows and becomes visible by about 1 a.m. local time.
On the night of the new moon, since the sky will be free of any interfering moonlight, Andromeda offers a naked-eye view of the Andromeda galaxy, which can be spotted away from city lights as a smudge of light in Andromeda; one can find it by tracing a line between the leftmost stars of Cassiopeia southwards.
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