GARRETT COUNTY SKIES
By Dr. Bob Doyle, Frostburg State Planetarium
Sun closest on July 3, Moon-Planet Encounters and two interesting star groups in the South
On July 1, Oakland’s sunrise is at 5:54 a.m. with sunset at 8:49 p.m. Daylight then lasts 14 hrs. and 55 min. In mid July, sunrises are about 6:04 a.m. with sunset about 8:44 p.m. The sun then peaks about 72 degrees altitude in the South at 1:24 p.m. On July 31, sunrise is at 6:16 a.m. with sunset at 8:32 p.m. Sunlight then lasts 14 hrs. and 16 min. During July, the amount of sunlight each day drops by 39 minutes. The above times are within a minute or two from any other location in Garrett County.
On July 3, the Earth is farthest from the sun. Our seasons are due to the tilt of the Earth’s axis. In late spring and early summer, out part of the world is tipped towards the sun. This causes the sun to have a high sky track and to be visible for over 14 hours. In late fall and early winter, we are tipped away from the sun, resulting in a low sky path and less than 10 hours of daily sunlight. The 3 % variation in the Earth-sun distance doesn’t change the sunlight striking the ground very much compared to the height of the sun in the sky.
July opens with the evening moon a little over half full. Early July will be fine for spotting lunar craters and features with a telescope. Lunar sunrise will then be along the left lighted edge of the moon, making the craters and elevations there stand out. On July 1, the moon will appear to the left of the planet Jupiter, the brightest point of light on July evenings. On the evening of July 6, the moon will appear above the planet Saturn, which matches the brightest evening stars in brightness. The moon is fullest on the evening of July 8. The best features visible at full moon are the lunar grey plains or Maria, huge lava fields formed from asteroid impacts on the thin lunar crust early in the moon’s history. These lava fields have long cooled and form the ‘man or lady’ in the moon seen by eye. In mid July, the moon is in the morning sky and will appear half full in the southern dawn on July 16. A crescent moon will appear below the brilliant planet Venus in the eastern dawn on July 20. The moon passes North of the sun on July 23, shifting from the morning to the evening sky. By July 25, the moon will reappear as a slender crescent in the western dusk. On July 28, the moon will appear above and to the left of the planet Jupiter. On July 30, the evening moon will appear half full and at its best for spotting craters with a telescope.
In July, evening sky watchers look southward for the planets Jupiter and Saturn and two of the best zodiac star groups, Scorpius and Sagittarius. The scorpion resembles a letter ‘J’ with bright stars near the top of the ‘J’ and bright stars near the curled end of the ‘J’. The brightest star of the scorpion is Antares, a pinkish star on the upper part of the ‘J’. The three moderately bright stars to the right of Antares mark the claws of the scorpion. The close bright stars at the end of the ‘J’ are known as ‘cat’s eyes’. To the right of the scorpion is Sagittarius, the archer centaur (upper half of a man and lower half of a horse). The brighter stars of Sagittarius form an old fashioned tea kettle with the handle to the right and the pouring spout on the left. In the steam of this imaginary tea kettle is the center of our Milky Way galaxy. On clear, moonless evenings, the Milky Way can be seen as a delicate glow running across the sky from the Northeast horizon, peaking in the East and flowing downward into Sagittarius. To be sure of seeing the Milky Way, avoid streetlights and bright outside lights. You need to give your eyes a few minutes to be dark adapted. Then the black pupils in the middle of each eye will expand fully to let in more light so you can see fainter sky features. The Milky Way glow is caused by the light of many faint stars clumped together along the central plane of our galaxy.
Next month, there will be partial solar eclipse visible in this area. The eclipse will be total in a 70 mile wide strip that runs from the Oregon coast, through some Mountain states, the lower Mid west, the upper South and down to South Carolina. The eclipse along this track will last several minutes. While one can drive hundreds of miles in an attempt to see the total eclipse, there’s no guarantee that the typical summer clouds won’t spoil your view. My August column will detail some ways to witness the partial eclipse safely here. These involve a small mirror, paper, a still puddle of water and the partially eclipsed sun shining through openings in the leaves of a tree.