July 2017

Mercury and Mars are sunset objects for northern hemisphere observers at the start of July. Mercury gets a little easier to see but stays typically close to the horizon all month. Watch for it to pass the star Regulus around the 25th as the constellation Leo lowers in the sky evening after evening. Conveniently, a very thin crescent moon is close by on the 25th and 26th to guide you to the star and the planet. The messenger planet is at greatest elongation on the 30th. It’s 27.2 ° east of the sun and is thus somewhat easier to find than usual.


Mars continues going under with the sunset and eventually loses its evening object status. Don’t count on finding it after conjunction. It will still be too close to the sun at month’s end after conjunction on the 27th. The best views for both Mercury and Mars this month are close to the equator.


Jupiter stays prominent in Virgo. A first quarter moon passes the star Porrima just a little west of the big planet in the early hours of the 1st Universal Time. For viewers in eastern North America, this will be an occultation. Then the moon passes Jupiter a few hours later. It will pass Jupiter again on the 30th.


Saturn hangs at the south end of Ophiuchus this month. A nearly full moon passes the ringed planet on the 7th. Saturn is a nice sight all evening as it’s on the meridian when the sun sets for those in the northern hemisphere and a little east of it for those in the southern hemisphere.


Dim Uranus rises in Pisces not long after local midnight.


Much brighter Venus rises in Taurus a little later. Watch the goddess scoot toward the Hyades for a conjunction with Ain on the western end of the V on the morning of the 12th. Venus has passed north of the V for this month’s Venus-moon conjunction on the 20th. By the end of July, the planet’s destination for August is obviously Gemini now rising before the sun.


The moon’s phases this month: first quarter on the 1st, full moon on the 9th, last quarter on the 16th, new moon on the 23rd, and first quarter again on the 30th.


The moon will be farthest south on the 8th, over the equator heading north on the 15th, farthest north on the 21st, and going south across the equator on the 28th.


Lunar apogee is on the 6th with a center-to-center distance of 406,000 km. Perigee is on the 21st at 361,300 km.


This month’s lunar occultations: Porrima on the 1st at 02:02 for eastern North America and again on the 25th at 10:04 for northeast Russia, Aldebaran on the 20th at 00:01 for India and Pakistan, Mercury on the 25th at 08:48 for Japan, and Regulus on the 25th at 10:37 for western Indonesia and western Malaysia.


Earth’s farthest from the sun on the 3rd at 152.1 million km.


Pluto is at opposition on the 10th.

Leave a Reply

Your email address will not be published. Required fields are marked *