This is the Skywatch Line for Monday and Tuesday, April 25th and 26th.
The Sun sets at 7:49 PM; night falls at 9:38. Dawn begins at 4:08 AM and ends with the Sun rising at 5:56.
The twilight sky contains two planets. Jupiter is high in the southern sky. It is located near Leo’s hind leg and is best observed at 9:39 PM, when it is highest. With Jupiter rising later and also setting around Dawn, the chance for observing moon and shadow transits is reduced. The Great Red Spot, a giant storm, is visible to telescopic observers at 1:22 AM on Wednesday. Still, Jupiter is interesting for binocular observers to track the dance of its Galilean Moons.
Mercury is also up at twilight, about ten degrees above the western horizon. Mercury shines at magnitude 1.6 and about 17 percent illuminated. Mercury sets at 9:26. Mercury is now quickly fading and predicted to be lost by April 28th. This is the time for last looks.
Midnight sees the rise of Mars, Saturn, the star Antares and the Moon. Mars rises first in the dim constellation of Ophiuchus and glows at minus 1.3 magnitude. Thirteen degrees high at Midnight, it is best observed around 3 AM. Saturn and Antares rise next. Saturn is also in Ophiuchus and shins at zero magnitude, while red Antares simmers at first magnitude. First time sky watchers should compare the colors of Mars and Antares, the “Rival of Mars.” Saturn transits at 3:34 AM, when it is ideally positioned for observation.
The eighteen-day-old Moon follows Saturn in Ophiuchus on Tuesday night. It rises about Midnight and is best at about 4 AM. The Moon blazes at minus 11 magnitude, and washes out most the dim stars and deep sky objects in its neighborhood. Mars, Saturn, Antares and the Moon remain up the rest of the night. Mars, Saturn and the Moon make a straight line Tuesday morning.
Neptune rises at about 3:56 AM in Aquarius. However, it is quite low on the horizon at first. By 4 AM, the sky is becoming brighter and making discovery of this eighth magnitude planet difficult.
The first artificial satellite, Sputnik, was launched in 1957. A series of military and scientific satellites followed. However, long before Sputnik, Arthur C. Clarke, a novelist, screenwriter and physicist, had a dream. In 1947, he published a paper predicting that a satellite placed in a special orbit could act a relay for radio signals. Clarke said that, if you launched a satellite to orbit high above the Earth at the same speed as the Earth’s, the satellite would appear to be stationary in the heavens. In May 1960, NASA first launched Echo, a silvered Mylar balloon, which literally bounced signals across the Atlantic. On July 10, 1962, AT&T launched Telstar, a true relay station. Telstar received and retransmitted signals between the US and Europe. Today, many such satellites crowd our skies and make worldwide television, telephone and Internet service routine. Telstar also paved the way for commercial services like Dish TV and radio services.