Betelgeuse, Bright Jupiter, Saturn, Full Harvest Moon – What To Watch In The September Sky And When

September Astronomical Events: Early in September, one can observe Mars near the orange-coloured star Aldebaran. Over the course of the month, Mars will move eastward toward reddish Betelgeuse.

Over the course of September, Mars will move eastward from Aldebaran toward reddish Betelgeuse (top left), creating a "red triangle" in the evening sky. The Harvest Moon (top right) will appear on September 10. In the early morning sky, one can find Jupiter, Saturn, & the Moon (bottom)

Source : NASA

The September sky is full of astronomical marvels, including spectacular views of Betelgeuse, Mars, Saturn, and Jupiter. One can find Mars high in the south on September evenings. Early in September, one can observe the Red Planet near the orange-coloured star Aldebaran. This is the brightest star in the constellation Taurus, and is known as the "eye of Taurus the bull". People can also spot Jupiter's four large moons as star-like points in the sky.

Here is the list of cosmic objects stargazers can observe in the September sky. 

The “Red Triangle”

Over the course of September, Mars will move eastward from Aldebaran toward reddish Betelgeuse, creating a "red triangle" in the evening sky, according to NASA. Betelgeuse is the second brightest star in the constellation Orion, and is also known as Alpha Orionis. 

After this, Mars will stop moving eastwards, and instead, hang out in the red triangle for the next month. 

Therefore, the Red Planet forms a triangle of reddish objects in September, and into October, as it hangs near bright red stars Aldebaran and Betelgeuese in the evening sky. 

On September 11, one can spot the Moon just a couple of finger-widths from Jupiter in the evening sky. This will be a great viewing opportunity to observe the Moon and Jupiter together through binoculars. 

Bright Jupiter

In September, Jupiter is in opposition. This means that Jupiter appears directly opposite the Sun as seen from Earth. Therefore, Jupiter will be visible all night under clear skies. Also, this is the time of the year when the gas giant is at its biggest and brightest for telescope viewing. 

Jupiter’s Four Moons

Using a pair of binoculars, one can spot Jupiter's four large moons as little star-like points of light next to the gas giant. NASA's Jupiter-orbiting Juno spacecraft is slated to make a special, fast flyby of one of Jupiter's icy moons, Europa, on September 29. The Juno spacecraft will pass a little over 200 miles above Europa's surface, and return images and science data. 

In the morning sky, one can observe Saturn and Jupiter together as planetary companions for the entire month. 

Trio Of Jupiter, Saturn, And Moon

On September 9, Jupiter and Saturn will escort the Moon across the sky. In the early morning sky, one can find Jupiter, Saturn, and the Moon together in the southeast. Then, the trio will glide westward. By the end of September, Jupiter and Saturn will rise even earlier. Bright Jupiter will hang low in the sky. 

On the morning of September 9, the nearly full Moon will be escorted across the sky Jupiter and Saturn. 

September Equinox

This year, the September Equinox falls on September 23. The September Equinox marks the beginning of astronomical winter in the Northern Hemisphere, and the start of astronomical spring in the Southern Hemisphere. When Earth's tilt with respect to the Sun is the same for both hemispheres, an equinox occurs. The equinoxes occur twice every year. On the day of an equinox, both north and south receive the same amount of sunlight. 

Following is a list of celestial objects and the dates on which they can be seen in the sky. 

September 6: Mars and Aldebaran

September 7: Saturn and the Waxing Gibbous Moon 

September 10: The Full Harvest Moon

September 11: Jupiter and the Moon

September 14: Shortest Solar Day

September 16: Mars and the Waning Gibbous Moon

September 17: Third Quarter Moon

September 19: Moon at Apogee

September 20: Pollux and the Waning Crescent Moon

September 23: Autumn Equinox

September 23: Mercury at Inferior Conjunction

September 25: New Moon

Waxing Gibbous Moon, Waning Crescent Moon, Harvest Moon, Pollux, And More

The Waxing Gibbous phase of the Moon is between a half moon and full moon. It is the phase when the lit-up part of the Moon grows from 50.1 per cent to 99.9 per cent. 

The Waning Gibbous phase is when the lit-up part of the Moon shrinks from 99.9 per cent to 50.1 per cent, and falls between a full moon and a half moon.

The Harvest Moon is the full, bright Moon that occurs closest to the start of Autumn.

The Third Quarter or Half Moon is the seventh phase in the cycle of phase of the Moon, and the one during which the opposite half of the Moon is illuminated compared to the First Quarter.

The farthest point of the Moon from Earth is known as the Moon's Apogee. 

Pollux, which will appear in the sky on September 20, along with the Waning Crescent Moon, is the brightest star in the constellation Gemini. It is a reddish giant star, and is 33.7 light-years from Earth.

The Waning Crescent Moon phase is the one in which the lit-up part of the Moon decreases from 49.1 per cent to 0.1 per cent, and falls between the last quarter moon phase and the new moon phase. 

On September 23, Mercury will be at Inferior Conjunction. This means that Mercury will pass between Earth and the Sun.