(Image credit: NASA/SVS/Ernie Wright)
The new moon occurs September 25, at 5: 54 p.m. EDT (2154 GMT). The new moon happens a day before Jupiter reaches opposition, when the planet is visible all night.
The new moon occurs when the moon is directly between the sun and Earth. The two bodies 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 sky; during new moons, a line drawn from the pole star due south through the sun would also hit the moon.
When there is a new moon, the illuminated side of the moon faces away from Earth, making it invisible to ground-based observers. The exceptions are when the moon passes directly in front of the sun, which creates an eclipse. That won’t happen this time – the next one is due on October 25 of this year.
Moon phases occur at different times depending on one’s longitude, or time zone. So the new moon that occurs at 5: 54 p.m. in New York happens on Sept. 26 at 9: 54 a.m. Similarly, in Mexico City it is at 4: 54 p.m.
If you’re looking for binoculars or a telescope to see the full moon, our guides for the best binoculars and the best telescopes have options that can help. If you need photography gear, consider our best cameras for astrophotography and best lenses for astrophotography to prepare for the next planet sight.
Jupiter at opposition
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A day after the new moon, on Sept. 26, the planet Jupiter will reach opposition, when it is on the opposite side of the Earth from the Sun (hence the name). Oppositions can only happen for “outer” planets – Mars, Jupiter, Saturn, Uranus, and Neptune. At those times the Earth is closest to those planets and they tend to be brighter. They are also visible the entire night.
In this case the moment of opposition is at 3: 25 p.m. Eastern Time (opens in new tab), according to In-the-Sky.org. From New York City the planet rises at 6: 46 p.m. on the evening of Sept. 26 and sets the next morning at 6: 50 a.m (opens in new tab). The sun sets on Sept. 26 at the same time (opens in new tab), and rises at 6: 48 a.m. on the 27th (opens in new tab).
Jupiter will be in the constellation Pisces, the fishes, and so in city locations the planet will be the brightest star-like object in the eastern sky after sunset. How high Jupiter gets when it crosses the meridian – the line going through the zenith from north to south – depends on one’s latitude. From New York City (and other places in the mid-northern latitudes), Jupiter will be about 49 degrees high.
From near the equator, as in Quito, Ecuador, the planet will be almost directly overhead – at 12: 10 a.m. local time on Sept. 27 it will be 89 degrees high (opens in new tab) (and on the northern side of the sky, as opposed to the southern). From mid-southern latitudes – places like Cape Town – Jupiter will appear lower again, about 56 degrees (opens in new tab) above the northern horizon when it crosses the meridian at 12: 42 a.m. local time.
Other visible planets
Aside from Jupiter, the other naked-eye planets will be visible in succession over the course of the night. On the evening of Sept. 25 the first planet to rise is Saturn, at 5: 00 p.m. in New York (opens in new tab), and becomes visible about a half hour to 45 minutes after sunset, depending on how clear the sky is. (A good exercise is to see how soon after sunset one can spot the planet, which will be in the southeastern sky). By the time the sun is 12 degrees below the horizon at 7: 47 p.m. – the end of nautical twilight – Saturn will be about 24 degrees high. Saturn is in Capricornus, the Sea Goat, and as Capricornus is a fainter constellation the planet stands out.
More southerly locations will see Saturn higher in the sky; in Quito, Saturn rises at 4: 17 p.m. local time (opens in new tab) while the sun sets at 6: 08 p.m. (opens in new tab) on Sept. 25; nautical twilight ends at 6: 53 p.m. By that time the ringed planet will be about 51 degrees above the southeastern horizon. In Cape Town, Saturn rises at 3: 09 p.m. local time (opens in new tab) and nautical twilight ends at 7: 38 p.m. (opens in new tab) At that point Saturn will be 54 degrees high in the northeast.
Next to rise is Mars, in the constellation Taurus. From New York City the red planet will clear the horizon at 10: 20 pm. local time (opens in new tab), and by midnight will be about 17 degrees high in the east. The planet will appear to the left of Aldebaran, the brightest star in Taurus. Both are a reddish color, with Mars a more intense red compared to Aldebaran’s more white-orange. Unlike Aldebaran, Mars won’t twinkle the way stars do – as a general rule, planets shine with a steady light.
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Mars will appear lower in the sky as one moves southwards. In Quito, for example, Mars rises a bit later, at 11: 01 p.m. local time (opens in new tab), and by 11: 45 p.m. it will be only 10 degrees high in the northeast. Further south (and two time zones eastwards), in Buenos Aires, Mars rises at 12: 45 a.m. on Sept. 26 (opens in new tab), and by 1: 30 a.m. is only 7 degrees high.
Venus is a morning planet; if you are up early on Sept. 26 the planet rises at 6: 11 a.m. local time in New York (opens in new tab). However the sun rises only about a half hour later, and the planet will be lost in the glare before it becomes easily visible. Mercury is in a similar position (the planet rises at 6: 20 on Sept. 26) and is fainter than Venus is. The situation doesn’t change with one’s location – while the rising and setting time will differ, the distance from the sun (as measured across the celestial sphere) does not.
Constellations: Northern Hemisphere
September and October are when the Northern Hemisphere’s autumn constellations come out and are visible most of the night. In the early evening the summer stars are setting, and in the wee hours before dawn one sees the winter stars rising. Between those regions of sky are constellations such as Andromeda, Pegasus, Cetus and Perseus. In general, the fall constellations are not as bright, and much of the sky is taken up with the “west region” — a set of water-themed constellations in the south, notably Capricornus, Aquarius (the Water Carrier), Pisces, and Cetus, the Whale or Leviathan.
At about 10 p.m. on the evening of Sept. 25, looking towards the south (roughly in the direction of Jupiter and above it), one can see the Great Square, a group of stars that marks the head of Andromeda and the wings of Pegasus, the legendary flying horse. Alpheratz, the alpha star of Andromeda, will be on the right corner, while the other three stars are in Pegasus. Andromeda is made up of two curved lines of stars running roughly eastward. In a dark sky location one can see the Andromeda Galaxy, as a faint smudge of light; through binoculars the spiral shape is clearly visible. The Andromeda Galaxy is some 2.7 million light-years distant.
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Looking straight towards the horizon from the Great Square, one sees Jupiter, and if the sky is dark enough, to the right and above the planet is a small circle of stars that marks one of the two fish in Pisces. From the circlet one can follow a line of faint stars to the east and south (down and to the left) which makes a sharp turn upwards to the other circlet of stars, where the second of the two fishes are. That line represents the cord holding the fish together. Near the point where the cord bends happens to be where the march equinox is.
To the south of Pisces is Cetus, the Leviathan, the sea monster that was called up to eat Andromeda. Cetus can also be hard to see from urban areas, but looking below Jupiter, one can spot a “V” shape of stars that is the front end of the sea monster’s head. Often the constellation is drawn as a sperm whale. Cetus has one notable star, Mira, or Omicron Ceti, which is variable and the very first variable star to be discovered; it changes from magnitude 2 to 10 over the course of about 332 days. Its last maximum — the star was about one one tenth as bright as Saturn — was in July, which means it is still naked-eye visible, though fainter than in the summer.
Turning northeast, one can see Perseus, the hero who rescued Andromeda from Cetus. Perseus is a brighter group of stars, and makes a compact triangular shape. Near Perseus is Cassiopeia, the Queen and Andromeda’s mother. Cassiopeia will be above Perseus, and is shaped like a “W”. You can use Cassiopeia to find Polaris, similar to the Big Dipper: the open side of the “W” faces north, so turning in that direction leads right to Polaris. At about 10 p.m. in mid-northern latitudes the Dipper will be close to the horizon, facing upwards.
Rising in the east one will see Auriga, the Charioteer, and just to the right of it, Taurus the Bull.
Constellations: Southern Hemisphere
In the Southern Hemisphere, at the latitude of Buenos Aires or Melbourne, on Sept. 25 at about 10 p.m., the Southern Cross is in the south-southwest, low in the sky. The Cross points to the South Celestial Pole, but there isn’t a star like Polaris that marks the spot. The pole is about four times the length of the cross from the Cross itself.
To the right of the Southern Cross and above it is Rigil Kentaurus, otherwise known as Alpha Centauri, famous for appearing in myriad science fiction stories.
In the southeast and about halfway to the zenith (about 42 degrees up) is Achernar, the brightest star in the River, which starts in the Southern Hemisphere sky and ends near the foot of Orion, which starts to rise after midnight. Coming up over the southern horizon east of south is Canopus, the brightest star in Carina, the Ship’s Keel, which rises at 8: 51 p.m.
Cetus is rising in the northeast at that time, and in the south-southwest one can see an “upside down” Scorpius facing down to the horizon. From where Cetus is looking left (northwards) one encounters Pisces, Pegasus and Cygnus.
New moons and eclipses
New moons are not visible unless there is an eclipse; eclipses don’t happen every new moon because the orbit of the moon is tilted by about 5 degrees relative to the plane of the Earth’s orbit, and the node — the point where the orbits intersect — moves relative to the Earth’s surface. So the moon’s shadow “misses” the Earth most of the time. (The next solar eclipse isn’t until Oct. 25, 2022).
Editor’s Note: If you snap an amazing picture of the new moon and would like to share it with Space.com’s readers, send your photos, comments, and your name and location to email@example.com.