The new moon occurs on May 30, at 07:30 a.m. Eastern Daylight Time (1130 GMT), in New York, according to the U.S. Naval Observatory. This will be, for some regions, the second new moon of the month, sometimes called a "black moon." It will be a day after a close approach between Jupiter and Mars, so skywatchers on the night of the New Moon will still see them placed close together in the sky.
New moons occur when the moon is directly between the Earth and sun, and the two share their celestial longitude, a projection of the Earth's longitude lines on the sky. This position is also known as a conjunction.
If one could see the dark sky during the day, the moon would only be noticeable as it blocked out stars. But the sun is so bright that it makes that kind of observation impossible from Earth. (The exceptions are solar eclipses. in which the moon passes directly in front of the sun, but will not happen until October).
Because the moon takes only 28.5 days to make a circuit of the Earth, and May is 31 days long, some places will see the second new moon of the month. This is because the timing of lunar phases depends on the position of the Moon, so the local time a moon becomes new, full, or enters the quarter phases depends on one's time zone.
The last new moon was on April 30 for time zones in the Western Hemisphere (roughly from Hawaii to Baghdad) and on May 1 for time zones from Iran to New Zealand and the Pacific islands on the western side of the International Date Line. This full moon will be on May 30 for the entire world, so those places that got a May 1 new moon will get a second.
On the day of the New moon, the sun rises in New York at 5:28 a.m. local time; sunrise will be close to that in mid-northern latitudes generally (in Washington DC it will be at 5:45 a.m., and in Seattle sunrise is at 5:17 a.m.).
From New York, by about 4:30 a.m., one will see Venus, Jupiter, Mars, and Saturn forming a rough line from east to southeast. Venus will be the lowest (and brightest), at about 8 degrees above the horizon almost due east. Turning southwards (to the right) and moving upwards, one will spot a "double star" that is in fact two planets — Mars and Jupiter. Both will be about 21 degrees high.
Moving further up and to the right one will then see Saturn, nearly due southeast, about 30 degrees above the horizon. Jupiter and Mars will undergo a conjunction on May 28, passing within about 38 minutes of arc of each other — a bit more than a lunar diameter. Both planets will rise that day by about 2:41 a.m. in New York — the actual moment of conjunction isn't until later that day at 8:03 p.m., after both planets have set. While the two will be in conjunction on May 28, they will make a closer approach on May 29, at 6:26 a.m. Eastern Time, when they will be within 34 minutes of arc. This will be after sunrise for the eastern half of the U.S., but from Los Angeles, for example, the close approach will occur three hours earlier (3:26 a.m. Pacific Daylight Time) after the two planets have risen and well before sunrise (which is at 5:43 a.m.)
Mercury rises at 5:06 a.m. in New York, and it will be hard to spot as the sky brightens — the planet will only get 4 degrees above the horizon by sunrise. It is important to be very cautious when trying to catch planets (or other objects) close to the sun — looking through binoculars or opera glasses at the sun can burn retinas and cause permanent damage and even blindness. (This can happen even when using sun filters lifted from eclipse glasses because lenses intensify the light).
In the Southern Hemisphere, the planets will make a more "vertical" line in the predawn skies. In Cape Town, where the new moon occurs at 1:30 p.m. local time on May 30, sunrise is at 7:41 a.m. local time, so the sky will be dark enough to see stars until about 7:15 a.m. (nautical twilight, when the sun is between 6 and 12 degrees below the horizon is from 6:43 a.m. to 7:14 a.m.).
Venus, Jupiter, Mars and Saturn will all make a line that runs slightly northward from the east-southeastern horizon, towards the zenith. Venus is the last to rise, at about 4:43 a.m. local time, and by 6:30 a.m. it will be a full 20 degrees above the northeastern horizon. Looking further up and slightly to the left (northwards) one will see Mars and Jupiter, both about 46 degrees high and then Saturn, which will be 70 degrees high in the constellation Capricorn.
Constellations: Northern Hemisphere
In mid-northern latitudes, summer approaches, and it doesn't get fully dark until about 9:30 p.m. in New York City or Chicago (sunset is at 8:17 and 8:19 p.m. local time in those cities). In Madrid, daylight savings extends sunset to 9:37 p.m. local time, and in Istanbul, the sun sets at 8:28 p.m. (All of these cities are near 40 degrees north.)
By 10 p.m., the brightest winter stars are fully below the horizon. Only Castor and Pollux, marking the heads of the famous Twins (Gemini), will still be visible low in the southwest. In the East, one will see Vega, the alpha star of Lyra the Lyre, and Deneb, the brightest star in Cygnus, the Swan, and Altair, the eye of the Eagle above the horizon. These three stars make up the asterism (a group of stars that isn't an official constellation) called the Summer Triangle. The trio makes a rough right triangle whose narrowest point faces southward, so it is a good direction finder especially as it gets higher in the sky, much like another asterism, the Big Dipper.
Looking southeast one will see Antares, the brightest star (the "heart") of Scorpius, the legendary scorpion that killed Orion, the Hunter. Above Scorpius from dark-sky sites is the fainter (but much larger) constellation Ophiuchus, the Serpent Holder or Healer. Ophiuchus can be recognized by a long trapezoid of medium-to-faint stars that extends above Scorpius; before midnight he will appear to be lying on his side.
On either side of Ophiuchus are the constellations Serpens Caput and Serpens Cauda, the head (Caput) and the tail (Cauda) of the serpents that Ophiuchus holds. Ophiuchus, also named Asclepius by the ancient Greeks, was the healer who brought Orion back to life after the Hunter was bitten by the Scorpion. According to legend, Orion claimed he could kill any living creature, and Gaia, the goddess of the Earth, sent a scorpion to kill him. Asclepius went to heal Orion, and was so skilled he brought the hunter back to life. Hades, the god of the underworld, complained to Zeus that humans had the potential to become immortal, so Zeus struck both Asclepius and Orion down and placed them among the stars. To this day, Asclepius (as Ophiuchus) stands above the Scorpion, and to prevent further trouble they are on opposite sides of the sky.
Looking north, by 10 p.m. one will see the Big Dipper in the upper left quadrant of the sky (to the west of north), with the bowl upside down and the two stars that point to Polaris, the pole star, on the left side of the bowl. The stars are called Dubhe and Merak, and Dubhe will be the one closer to Polaris. Following the handle of the Dipper one can "arc to Arcturus" — a sweeping motion along the curve of the handle gets you there, to the brightest star in Boötes, the Herdsman. If one draws a line between Arcturus and Vega, there are two constellations. One is Corona Borealis, the Northern Crown, just to the east of Boötes, and east of that is the "keystone" — the four stars that make up the body of Hercules.
Constellations: Southern Hemisphere
In the southern hemisphere, winter is approaching. In Cape Town, the sun sets early, at 5:45 p.m. local time on May 30, and in Melbourne, Australia, the sun sets at 5:10 p.m. local time. That means the sky gets dark enough to see stars by 6 p.m. By 7 p.m., observers in mid-southern latitudes can see the Southern Cross high in the southeast, and just below it, Alpha Centauri (Rigil Kentaurus), the brightest star in Centaurus the Centaur and the Sun's closest stellar neighbor. Scorpius — "upside down" from the point of view of Antipodeans — will be rising in the southeast lower to the horizon. A fainter constellation just above Scorpius and to the left (east) of Centaurus is Lupus, the Wolf.
In the southwest, as one looks to the right of the Cross and Centaurus are the constellations Puppis, Vela and Carina, respectively the Poop Deck, Sail and Keel of the legendary ship Argo (at one time the three constellations were seen as a single entity, called Argo Navis, but since then astronomers have divided them). The brightest star in Carina is Canopus. Below and to the left of Canopus is the Large Magellanic Cloud, a satellite galaxy of the Milky Way.
The South Celestial Pole is in the constellation Octans, the octant. There's no southern "pole star" — Polaris' alignment with the North Celestial Pole is happenstance. One way to locate the Pole is to use the "pointers" in Centaurus, Alpha and Beta Centauri. Centaurus is the constellation just below the Cross in the sky, and Alpha and Beta are its two brightest stars. One draws a line from halfway between those two and another bright star, Achernar, the end of the River. The halfway point marks the pole.
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