Amateur Astronomers love to watch the Terminator day after day.

No, no, not Arnold Schwarzenegger in that movie with the same name, but on our Moon.

Definition of Terminator – the dividing line between the illuminated and the unilluminated part of the moon’s or a planet’s disk. In plain language – the line dividing the day and night on the Moon.

It’s a well-known truth among amateur astronomers that the best place to look on the moon is along the line between light and dark. Many observers study the moon along the terminator, because the deep shadows there make crater rims and walls on the line pop in relief. Day by day the terminator changes position on the Moon, illuminating different craters, rilles and mountain ranges. When the sunlight appears on the Moon’s surface from a low angle, i.e. at sunrise or sunset interesting lighting effects are created, which can be observed quite well from the Earth.

A well-known effect is the so called “Golden Handle”. This is when the Jura Mountains (Montes Jura) are just illuminated 4 to 5 days before the full moon and appear as a bright arc, in front of the still darkened Sea of Showers (Sinus Iridum) of the Mare Imbrium. This is reinforced by the terminator, runs directly through this area at this time. The Golden Handle shines rather brightly, as one side is darkness, and on the other side is the relatively darker Sinus Iridium.

On Friday 11th February, 2022, when the Moon rises at in the afternoon from Manesar, it will be 9.83 days old. Around sunset the Golden handle will be in darkness, but by midnight it will be fully illuminated by sunshine. A spectacular transition in about 4-5 hours.

Aperture Telescopes is organising an evening observation on Friday, 11th February, 2022 to observe this spectacular transition on the terminator.

Would you like to learn how to photograph the Moon is great detail, USING YOUR OWN CELLPHONE? We will have a big telescope all set up for YOU to photograph the Moon using YOUR cellphone.

Do carry your best one along! See you on the 11th.

Ajay Talwar, Aperture Telescopes.