SKYWATCH HOTLINE # 3:  July 24 – 30, 2020

On July 24 the Sun will rise at 5:22 a.m. and set at 8:12 p.m, giving us 14 hours and 50 minutes of daylight, a 36 minute decrease since the summer solstice.  On July 30, the Sun will rise at 5:29 a.m. and set at 8:06 p.m, providing us with 14 hours and 37 minutes of daylight.  The Sun is passing through the constellation Cancer the Crab this week.  By week’s end it will almost be directly in front of the Praesepe Star Cluster.  At week's beginning the moon will be progressing through the waxing crescent phase.  The moon will reach the first quarter point on July 27^th.  On that date, the moon will rise at 1:25 p.m. and set at 12:17 a.m. the following morning. The moon will then pass through the waxing gibbous phase toward the end of the week.  The moon will be full on August 3^rd.

Mercury rises around 3:55 a.m at week’s beginning and will be visible briefly in the eastern pre-dawn sky before being obscured by the intensifying twilight, Mercury reached greatest western elongation on July 20^th and will now appear to move closer to the Sun. Venus, as always the brightest planet, currently occupies the Taurus constellation and will rise at 2:25 a.m. at week’s beginning. The optimal time to view Venus is between 3 - 5 a.m, when the brilliant planet remains visible against the pre-dawn glow. It was at its maximum brightness of the year on July 10th. Though slightly dimmer now at magnitude -4.3, Venus will still be 15 times brighter than Sirius.    Mars rises by 11:19 p.m.  As it is currently located almost precisely on the celestial equator within the constellation Cetus, Mars rises nearly due east and will remain an eastern evening sky object through the rest of the night. At magnitude -0.9, Mars is now brighter than any night sky star except Sirius, which is not currently visible.    Mars will continue to rise earlier and grow brighter as it approaches its next opposition on October 13, 2020.      Jupiter reached opposition on July 14^th and will now slowly move away from Earth and grow gradually dimmer.  However, at magnitude -2.6, Jupiter outshines all the stars and planets, save Venus. It will rise in the eastern sky at 7:30 p.m. at the beginning of the week and it will set just before 4:30 a.m.  Jupiter reaches opposition again on August 19, 2021. Saturn reached opposition on July 20^th and attained its maximum brightness at that time.   Saturn is also now moving away from Earth and will become dimmer as a consequence.   However, at magnitude 0.1, Saturn remains brighter than Vega and will rise at 7:54 p.m. at week’s beginning. Both Jupiter and Saturn are currently passing through the constellation Sagittarius the Archer.  

Yet again Comet NEOWISE is the celestial object of the week!  Named for the Near-Earth Object Wide-Field Infrared Survey Explorer that astronomers used to discover this icy interloper on March 27th.    Though dimmer at magnitude 2.5, Comet NEOWISE is higher in the northwestern evening sky and can be see south of the Big Dipper.  The Comet is fading as it moves away from Earth.   The comet reached perigee, its closest point to Earth, on July 23. On that date it passed 64 million miles from our home planet.  

We’re expecting the peaks of two minor meteor showers this week:  the alpha Capricornids on July 26^th and the July Gamma Draconids on July 28^th.    Both events should produce fewer than 10 meteors an hour at maximum.     The July Gamma Draconid radiant is located about 12 degrees north of Vega, the brightest star in Lyra the Harp.     The Perseid meteor shower has begun, but not in earnest.  The Perseids peak on August 11^th.  

The brightest fly over of the International Space Station occurs this week on July 28^th. 

The ISS will rise at 10:08:51 p.m. and attain its maximum altitude of 79 degrees at 10:14:19 p.m.  At that time the ISS will shine at magnitude -3.8, more than three and a half times brighter than Jupiter!   The International Space Station then will vanish into the shadow at 10:14:47 p.m.    During this passage, the ISS will appear to slice across the Big Dipper’s handle, Draco the Dragon and Cygnus the Swan.