The July 2024 New Moon occurs today, when Earth reaches its furthest point from the Sun, known as aphelion.
According to the U.S. Naval Observatory, the new moon will occur on July 5 at 6:57 p.m. Eastern Time (22:57 UTC), and two days later the young moon will pass Mercury in the evening sky.
Earth reached aphelion today, meaning we were farther from the sun than at any other time in its annual orbit. Earth’s orbit around the sun is slightly elliptical, or oval-shaped, meaning our distance from our star can vary by up to 3% over the course of a year. This small variation is not significant enough to be noticeable to most observers.
New moons occur when the moon is directly between the sun and the Earth; in many lunar calendar systems, they mark the beginning of the lunar month. Technically, the sun and moon are in conjunction, on the same north-south line that passes through the celestial pole. The timing of moon phases is measured by where the moon is relative to the Earth, so a given phase occurs at the same time everywhere on the planet. Any differences are due solely to the time zone one is in—in Melbourne, Australia, for example, the new moon occurs at 8:57 a.m. on July 6.
New moons are invisible unless there is a solar eclipse; solar eclipses do not occur every new moon because the orbits of the moon and Earth are not perfectly aligned; they are tilted about 5 degrees relative to each other. The moon’s shadow usually “misses” the Earth then. (The next solar eclipse is not until October 2, 2024.)
Mercury passes nearby
In the evening hours of July 7, the Moon will pass Mercury as it emerges from its new phase; the thin crescent will become slightly 3 degrees north of Mercury at 2:33 p.m. eastern timeaccording to the skywatching site In-the-Sky.org. At sunset, when the moon becomes visible, it will be about 16 degrees above the horizon; Mercury will be below the moon. But the planet won’t be truly visible until around 9 p.m. (sunset on that day is at about 8:29 pm. in New York; times are similar in cities like Chicago or Sacramento) and by then it will only be 8 degrees high, so from anywhere in the mid-northern latitudes the conjunction will be a challenge to see – you’ll need a flat, unobstructed, clear horizon.
Observing the conjunction becomes easier the closer you get to the equator. From lower latitudes (whether from the north or south), the ecliptic, or the plane of the Earth’s orbit as projected onto the sky, makes a steeper angle with the horizon. This means that the planets, all of which are within a few degrees of the ecliptic, tend to reach higher altitudes. (It’s also why tropical sunsets appear so short, while sunsets at higher northern and southern latitudes seem to linger — in the tropics, the Sun approaches the horizon almost straight down, while in more northerly or southerly latitudes it approaches at a gentler angle.)
From Miami, the conjunction will occur at 2:33 p.m. local time, but both the Moon and Mercury will be higher in the sky; sunset at 8:16 pm local time and at that time the moon will be 20 degrees high and Mercury 18 degrees above the western horizon. Around 20:30 Mercury should just become visible and will still be about 12 degrees high, so with a clear horizon with no obstructions you should be able to see it.
From Bridgetown, Barbados (and similar latitudes) the Moon appears to the right of Mercury, and at sunset, at 7:29 pm local timethe moon will be 18 degrees high in the west, at 7 p.m. it will still be 14 degrees above the horizon, as will Mercury, and both will be more visible than from the continental U.S.
In the Western Hemisphere, the conjunction itself occurs in the afternoon, during daylight, but as one moves east, the moment of conjunction moves into the evening. From Madrid, Spain, the observing challenges are similar to those in New York (the two cities are at nearly the same latitude), but the conjunction occurs at 8:33 p.m. local time.
In the Southern Hemisphere it is a little easier to observe – the days are shorter because it is the Australian winter. In Sao Paulo the sun sets at 17:22 local time and while conjunction occurs at 15:33, still during the day, the moon will be 18 degrees high in the northwest at sunset and Mercury will appear above and to the left of the moon. Mercury will not be visible until around 18:00 and will still be about 12.5 degrees high. In Cape Town, where conjunction occurs at 20:33 local time – sunset is at 5:51 pm and the Moon and Mercury set at 7:34 p.m.; about half an hour after sunset they will be about 13 degrees in the northwest.
Visible planets
Venus will appear in the evening sky, but will still be largely lost in the bright sunlight. At sunset, Venus will appear slightly higher in the sky as you approach the equator. By the time the sky darkens, however, the planet will be no higher than five or six degrees.
Saturn is the first planet to rise, at 11:40 p.m. on July 5 in New York City. It will be clearly visible in its region of the sky in the constellation Aquarius, a fainter group of stars than many others. When the sky begins to brighten around 4:30 to 5 a.m. (the morning of July 6), it will be about 41 degrees above the south-southeast horizon.
Mars will be prominent in the early morning hours; as the year progresses, it will rise later and eventually disappear into the Sun’s morning light. On the night of the new moon (July 5-6), the planet will rise around 2 a.m. in mid-northern latitudes—it will rise at 2:03 a.m. in New York City, and the time will be similar in cities such as Chicago (1:56 a.m. CDT), Denver (2:10 a.m. MDT), and Sacramento (2:18 a.m. PDT). Mars will be located in the constellation Aires and will be easy to see, as Aires is composed of fainter stars.
Jupiter rises after Mars, at 3:07 a.m. EDT in New York. Jupiter is in Taurus and is to the left and above Aldebaran, the brightest star in that constellation. Aldebaran is noticeably more orange and twinkling, making it easy to spot the planet, which is white-yellow and radiates a steady light.
This means that around 4:30 a.m. local time at mid-northern latitudes, the three naked-eye planets that are further from the Sun than Earth will form a sort of line in the sky from the eastern horizon to the right, starting with Jupiter and ending with Saturn.
In the Southern Hemisphere, for example in Melbourne, Australia (where the new moon is on July 6), the three planets also form a line, but this time upward and to the left (as one is looking north). Saturn is also higher in the sky. In Melbourne (and other locations at mid-southern latitudes), Saturn rises at 10:22 p.m. Australian Eastern Standard Time on July 6; when the planet crosses (crosses) the north-south line in the sky at 4:43 a.m. AEST on July 7, it will be a whopping 58 degrees above the northern horizon. Mars rises at 3:22 a.m. AEST, and Jupiter rises at 4:47 a.m. Jupiter’s position in the sky relative to Aldebaran is reversed, with Jupiter appearing below Aldebaran instead of above it (it still appears to the left).
Summer stars
For the Northern Hemisphere stargazers, around 10pm the Summer Triangle will be high in the eastern sky; the “top” star is Vega, the brightest star in Lyra the Lyre, and it will be near the zenith (about 70 degrees above the horizon). The other two stars in the Summer Triangle are Deneb and Altair, both of which are east (left) of Vega; from a dark site you can see the Milky Way in the Triangle. The three stars form a rough right triangle with Altair at the southern end.
If you go left – due north you will see the Big Dipper on your left (west) and just below Polaris, the North Star. Follow the “pointers” (the two stars on the front of the bowl of the Dipper, Dubhe and Merak) to Polaris and continue straight ahead, you will come across Cepheus, the King, and just below Cepheus is the “W” shape of Cassiopeia, which will be low in the northeast.
In the other direction, follow the handle of the big dipper and “bow to Arcturus” the brightest star in Bootes the Shepherd, and further down you will find Spica, the brightest star in Virgo. Turning south (to the left) you will see the bright red star Antares, the heart of Scorpio, and in dark places looking up (north) from Scorpio you will see Ophiuchus the healer, with Sagittarius and his “teapot” shape to the left of Scorpio.
In mid-southern latitudes, you’ll see the winter stars – darkness comes earlier. At 7pm, the sky is dark and the Southern Cross is high above the southern horizon, at about 65 degrees. To the left of the cross (east) is Alpha Centauri, also called Rigil Kentaurus, our nearest stellar neighbor. Further east and closer to the horizon is Scorpio, although upside down (from the perspective of a northern hemisphere observer) and very high in the sky; Antares is at a full altitude of 47 degrees at 7pm.
In the southwest, the ship’s keel, Puppis, sets and is marked by Canopus, about 20 degrees above the southwestern horizon. Canopus is the second brightest star in the night sky after Sirius. In the same region on the left (toward the south) are the Large Magellanic Cloud and the Small Magellanic Clouds, two satellite galaxies of the Milky Way.