Updated July 21, 2017
Today marks one month and counting until the total solar eclipse. For more information, including finding circumstances of the eclipse for your specific region, visit our eclipse page.
Although the weather is at its hottest in the northern hemisphere, the days are getting shorter and the noon-time sun angle is starting to decrease. We probably will not feel the benefits of these for another month or two. With the setting sun, the first object to become visible is Jupiter, which is assuming a role as “evening star” high in the South Southwest at dusk. Much lower in the west is the planet Mercury, another “evening star” which will lie close to the star Regulus on the evenings of July 24-26. Binoculars, a clear sky and low western horizon will be essential for looking for this pair about 30 minutes after sunset. On the 24th, a very thin crescent moon will be visible below and to the right of the pair; it will be above and left of the pair the next evening.
The familiar Big Dipper asterism is high in the northwest after dark but it is beginning to turn upright to “scoop up water”, which it will continue to do through evenings of summer and early fall. Scorpius is in the southern sky and is easily identified (sometimes referred to as “the Orion of Summer”) because of the brightness of many of its stars and the prominent red supergiant Antares. July is the best month to see Scorpius in the evening sky, mainly due to its low declination. The tail of Scorpius curves low to the lower left of the bright head and main body of the Scorpion. How low the constellation curves depends on your latitude: the further south you are the higher the Scorpion appears in your sky. There are two stars especially close together in the tail and are sometimes referred to as “the Cat’s Eyes”. They are lambda and upsilon Scorpii. Lambda, also known as Shaula, is a blazing giant, this bright even from 3,000 light years away!
The Cat’s Eyes point west (right) by nearly 10 degrees or about the width of a fist held at arms length, toward mu Scorpii, a much tighter pair known as the “Little Cat’s Eyes”. Can you see both components of Mu without using binoculars? After twilight (unless you live north of about 52 degrees where twilight still lingers all night…) if you live or observe away from city lights, the Milky Way forms a beautiful arch very high across the entire eastern sky. It runs from below Cassiopeia the Queen in the north-northeast, up and across Cygnus the Swan and the Summer Triangle high in the east under the bright star Vega, then continues down past the spout of the Teapot asterism of Sagittarius the Archer in the south.
Mars is invisible behind the glare of the Sun. Saturn is visible to the left of Antares, near the tail of the Scorpion. Below and left of Jupiter you will notice a single star, which is the bright star Spica, of Virgo the Maiden. Looking above this pair, high in the West, is bright star Arcturus. The Moon swings past Jupiter and Spica on July 27-29, making its closest pass to Jupiter on the 28th when the two will be a lovely pair in the evening sky.
Following Scorpius and Saturn is the Sagittarius Teapot, visible in the south as darkness becomes complete. It is now tilting to pour from its spout on the right. As the summer evenings pass by it will continue to tilt more to pour out its contents–which it also does on a daily basis if you stay up late enough to watch it.
Venus continues to be that bright “morning star” visible in the predawn hours; it is below Aldebaran and Hyades star cluster as seen 90 minutes prior to sunrise. Orion has become visible lying along the eastern horizon, visible for those who have a low horizon and clear skies. As the mornings pass, Venus will more-or-less remain where it is at as the stars of winter slide upward behind the planet over the next several days and weeks. The predawn sky features the constellations of autumn and early winter, a preview of when the weather turns colder and the days get shorter later in the year.
The spacecraft Cassini continues its “Grand Finale” part of the mission, and continues its weekly dive between the planet and the rings. It is sending back some spectacular pictures of the planet, rings, and innermost satellites. The end of mission will happen on September 15, 2017. Find out more at saturn.jpl.nasa.gov.
More information on what can be seen in the sky on a weekly basis can be viewed at the website http://www.skyandtelescope.com/observing/ataglance. One can go directly to this week’s information by clicking on the link for this week’s (July 21 – 29, as of this writing) sky-at-a-glance. For subsequent weeks the most current week is at the top with earlier weeks archived in reverse chronological order.
Work on the upgrading of the Solar Observatory has begun! For updates on this progress check out http://www.pvamu.edu/pvso/. Also check out plans for the observatory expansion at https://sites.google.com/view/saganti-astro/home. Some of the proposed renovations and remediation work include an upgrade to the motors and optics of the main telescope. The expansion features the addition of two piers and two domes to house our Mead 14-inch and Meade 16-inch advanced telescopes. If everything runs according to schedule this new observatory could see first light as early as Fall 2018. Keep checking back for updates.
On July 10, Juno flew closer to the Great Red Spot on Jupiter than any spacecraft in history, and it continues to orbit around Jupiter. Pictures of this event have been released at this website: https://www.missionjuno.swri.edu/junocam/processing/. Also, for more information about this mission in general visit www.nasa.gov/juno. You can also visit http://www.cnn.com/2016/06/30/health/juno-jupiter/index.html which has some additional interesting facts about the mission.