April 2018

 

 

Planet watching is best in the morning this month. Jupiter, actually rising in late evening, remains in the diamond of Libra moving retrograde (westward) toward Zubenelgenubi. If you’ve been watching Mars since the beginning of the year, you’ve seen it pass right on by Jupiter in January and Antares in February. In March, the red planet moved alongside the teapot lid of Sagittarius where much slower Saturn has been since January. Now Saturn and Mars are together at the start of April and easy to see for a few hours before the sun rises. Northern hemisphere viewers should look southeast. Mars doesn’t stay for a long visit, but the moon drops in on them on the 7^th. By the end of April, Mars is clearly heading out of Sagittarius on its way to Capricornus.

 

 

Evening stargazing features Venus ever bright but low in the western sky right after sunset. It holds steady night to night as the stars behind it drop into the sun’s glare. A thin crescent moon passes left of the planet on the 18^th. Watch the planet pass between the Pleiades and the Hyades on the 27^th.

 

 

Don’t expect to see much dimmer Mercury this month from the northern hemisphere. It starts April at inferior conjunction. And even though it’s at greatest elongation 27° west of the sun on the 27^th, it’s just not well positioned this time for the northern observer at the end of the month. But if you’re seeing it from 25° south, you have the best view with the planet rising about two hours before the sun!

In a sign that northern winter’s over, Orion is setting very early in the evening this month.

Moon phases in April: Last quarter on the 8^th, new on the 16^th, first quarter on the 22^nd, full on the 30^th.

The moon’s positions: southern lunistice on the 7^th, crossing the equator going north on the 14^th, northern lunistice on the 21^st, and going south again on the 27^th.

The moon is at apogee on the 8^th and perigee on the 20^th.

Saturn is at aphelion on the 16^th at 10.666 astronomical units from the sun. Mercury is at aphelion on the 23^rd with a distance of 0.467 a.u. from the sun.

Mercury resumes direct motion on the 14^th. Saturn begins retrograde motion on the 17^th.

The moon occults Aldebaran on the 19^th. The far northern parts of Greenland and Canada’s Northwest Territories are the visibility zone. Regulus is occulted on the 24^th. Northern parts of Russia are where to be to see it.

Notable conjunctions this month:

1^st Moon 6.9° north of Spica

1^st Moon 2.8° north of sun, inferior conjunction

2^nd Mars 1.3° south of Saturn

3^rd Jupiter 3.8° south of the moon

7^th Saturn 1.9° south of the moon

7^th Mars 3.1° south of the moon

13^th Neptune 1.8° north of the moon

14^th Mercury 3.6° north of the moon

16^th Uranus 4.4° north of the moon

17^th Venus 5.2° north of the moon

18^th Uranus 0.5° south of the sun

19^th Moon 1.0° north of Aldebaran

24^th Moon 1.2° north of Regulus

26^th Pluto 1.4° north of Mars

28^th Moon 6.9° north of Spica

30^th Jupiter 3.7° south of the moon