Topic: 2 days to go for First Quarter Moon - Astronomy Calendar(July 17)
July 17,Saturday- First Quarter Moon (at 10:10 GMT)
On Saturday, July 17 at 6:10 a.m (or 10:10 GMT) our moon will complete its first quarter around earth.
Quarter moon is a phase of the moon when it completes the first quarter of its orbit around the earth.
In this the moon will be 90 degree angle away from the sun. Due to this we will be able to see the moon in a half-illuminated state on its eastern side.
In the first quarter, the moon always rises around midday and sets around midnight, so it is also visible in the afternoon in day-time sky.
The evenings surrounding the first quarter are the best ones for seeing the lunar terrain when it is dramatically lit by low-angle sunlight, especially along the terminator, the pole-to-pole boundary between the lit and dark hemispheres.
Tomorrow’s Event :
Several times a year, for a few hours near its first quarter phase, a feature on the moon called the Lunar X becomes visible in strong binoculars and backyard telescopes.
When the rims of the craters Purbach, la Caille, and Blanchinus are illuminated from a particular angle of sunlight, they form a small, bright X-shape.
Lunar X is located on the terminator, about one third of the way up from the southern pole of the Moon (at 2° East, 24° South).
On Friday, July 16 the ‘X’ is predicted to start developing by about 7 p.m. EDT (or 23:00 GMT), peak in intensity at around 9 p.m. EDT (or 01:00 GMT on July 17), and then gradually fade out.
The peak will be during waning daylight for observers in the eastern Americas – but you can observe the moon in a telescope during daytime, as long as you take care to avoid the sun.
Lunar X will be visible anywhere on Earth where the moon is shining, especially in a dark sky, between 23:00 and 03:00 GMT on (July 17).