This is the Skywatch Line for Monday and Tuesday, May 13th and 14th.
The Sun sets at 8:09 PM; night falls at 10:07. Dawn begins at 3:35 AM and ends with the Sun rising at 5:34.
Mars remains the sole planet in the evening sky. By Civil Dusk, it is moderately low in the southern sky, in Taurus. At that time, it is about 96% illuminated, about 4 arc-seconds in size, shining with about first magnitude and 23º high. The Red Planet sets at 11:07 PM.
The 10-day-old Moon inhabits Leo on Monday, appearing about 72% lit and blazing with minus 11th magnitude; it appears about 33 arc-minutes in size about 55º high. Tuesday finds it in Virgo fatter, slightly brighter and about 49º high. Monday’s Moon is best observed at 8:57 PM and sets at 3:35 AM. Tuesday’s Moon is best observed at 9:48 PM and sets at 4:05 AM.
Midnight sees Jupiter already risen in Ophiuchus. The giant gas planet glows with minus 2nd magnitude, is about 45 arc-seconds in size and is 13º high. It is best observed at 2:56 AM. The Great Red Spot, a giant storm on Jupiter, is best observed at 4:16 AM on Tuesday, and at 12:07 AM, Wednesday. Monday, the Jovian ice moon Europa can be seen beginning to cross Jupiter’s face at 11:12 PM; however, Jupiter is only 6º above the eastern horizon. At 12:22 AM on Tuesday, Europa’s shadow begins its trek across Jupiter; at 1:30 AM Tuesday, Europa disappears from Jupiter’s face.
Jupiter shares Ophiuchus with the Dwarf Planet 1Ceres, 11º east of the planet. Ceres glimmers with 7th magnitude, is a tiny 0.7 arc-seconds in size and abut 26º in the Southwest. It rises about 9:18 PM and is best observed at 2:15 AM. Finder charts are available from online astronomy websites.
Jupiter and 1Ceres are joined by Saturn, rising in southeastern Sagittarius at 12:42 AM. The Ringed Planet shines with zero magnitude and is a third of Jupiter’s apparent size. By Civil Dawn it is 25º high, affording nice views of its famous rings.
Neptune is next, rising in Aquarius at 3:04 AM. The blue-green planet twinkles 8th magnitude and appears about 2 arc-seconds in size. By Civil Dawn it is 20º high in the East.
Venus, in Pisces, is very low on the eastern horizon. Rising at 4:38 AM, it appears about 90% lit, and flashes with minus 4th magnitude, helping to locate it only 4º high.
Like its fellow outer planets: Jupiter, Saturn and Uranus,
Neptune is a gas giant, which means that it is a large ball of gas. It is seventeen times heavier and thirty times further than Earth. Neptune takes almost 164 years to circle the Sun. Neptune sports a faint ring system, visible only to space telescopes. Like Jupiter it has a “Great Dark Spot,” similar to Jupiter’s gigantic hurricane. But it is also different. It is warmer at its equator and poles than its middle. It has a chaotic weather system that permits storms to switch latitudes.