October Dark Skies

5^thClose approach of the Moon and Saturn (figure 1). The Moon will be 7 days old. They will be visible in the evening sky, becoming accessible approximately 19:07 (BST) as the dusk sky fades, 15° above the Southern horizon. Reaching highest point in the sky at 19:20, 15° above Southern horizon. Continuing to be observable until 21:59, when they drop below 8° above South West horizon. Close enough to fit within the field of view of a telescope, but also visible to the unaided eye or with binoculars. Both will be in the constellation Sagittarius (figure 2).

Figure 1: Moon and Saturn, close approach.

Figure 2: Constellation Sagittarius.

13^th: Full Moon (figure 3), reaching full phase. At this time the Moon lies almost directly opposite the Sun, placing it high above the horizon for much of the night. It can be found in constellation Pisces and will be at a distance of approximately 406000 km from Earth. Visible at all latitudes between 83°North and 76° South. Also known as the harvest Moon at this time of year.

Figure 3: Full Moon. Credit: NASA/Goddard Space Flight Centre.

21^st will see the Orionid meteor shower (figure 4). Active from 2^nd October to 7^th November, producing peak rate of meteors approximately 21^st/22^nd October. There will be a chance of seeing Orionid meteors whenever the shower radiant point, in the constellation Orion (figure 5), is above the horizon, with the number of visible meteors increasing the higher the radiant point is in the sky.

Not visible before approximately 22:06 each night, when the radiant point rises above Eastern horizon. It will then remain active until dawn breaks, approximately 07:17. The shower will possibly produce best displays around 06:00 BST, when the radiant point is highest in the sky.

At peak activity there will be approximately 20 meteors per hour.

Figure 4: Orionid meteor.

Figure 5: Constellation Orion.

31^st: Moon and Jupiter (figure 6) will share the same right ascension, with the Moon passing 1°18' to the North of Jupiter. The Moon will be 3 days old. Approximately same time, the two objects will make a close approach, called an appulse (when two or more astronomical objects, normally the planets or the Moon, appear close to each other in the sky.

They will become visible approximately 17:13 (BST) as dusk fades, 10° above South West horizon. They will then lower towards the horizon, setting 2h and 13 min after the Sun at 19:02. They will be too widely separated for viewing through a telescope, but will be visible through binoculars or to the unaided eye. The Moon will be approximately 379600 km from Earth and Jupiter will be   5.9 Astronomical Units from Earth.

1 AU = Distance between Earth and Sun.

1 AU = 150 000 000 km (93 000 000 miles).

Figure 6: Conjunction of the Moon and Jupiter.

WARNING: Never attempt to view through binoculars, telescope or any optical aid an object close to the Sun. Also, never attempt to view the Sun unaided, doing so may result in immediate and permanent blindness.  Always use astronomical approved viewing equipment.

The Stellarium software will assist greatly in locating objects in the sky.

Mark R Smith FRAS

Physicist

Nuclear Fusion Physics & Astrophysics