This is the Dudley Observatory Skywatch Line for Wednesday, August 8th, and Thursday, August 9th, written by Louis Suarato.
The 6% illuminated, waning crescent Moon rises at 3:44 a.m. Thursday in the constellation Gemini, to the lower right of its brightest stars, Castor and Pollux. Venus, Jupiter, Saturn and Mars continue to be the highlights of the evening sky. All four can be seen above their respective horizons before 9:47 p.m. when Venus sets. Mercury reaches inferior conjunction Thursday, and will be lost in the glow between the Sun and Earth. Mercury will return to the morning sky toward the end of the month..
Keep an eye out for some early Perseid meteors this week. The Perseid Meteor shower peaks Sunday night, but you may see a few meteors emanating out of Perseus, below Cassiopeia, above the northeastern horizon. While concentrating on that section of the sky, there are two bright binocular targets to see below Cassiopeia. Below the northernmost end of Cassiopeia are two groups of stars known as the Double Cluster. The Double Cluster, also known as Caldwell 14, are two open clusters, NGC 869, and NGC 884. The two clusters are comprised of more than 300 blue-white super-giant stars in each cluster, and are approximately 7,500 light-years away. To the lower right of Cassiopeia, look for our neighboring galaxy, Andromeda. The Andromeda Galaxy, known as Messier 31, is 2.5 million light-years from Earth. Astronomers using the Spitzer Space Telescope, estimate the Andromeda Galaxy contains a trillion stars, more than twice the amount of stars in the Milky Way. Use Cassiopeia to find 3.4 magnitude Andromeda by following the deeper V of the W shape of the constellation down about 15 degrees. The first written account of the Andromeda Galaxy was by Persian astronomer Abd al-Rahman al-Sufi, who documented it as a “nebulous smear” in his Book of Fixed Stars.