Greetings from RFO (www.rfo.org), Mars and Saturn have a very close encounter in the morning sky early this month, and Jupiter is now very dominant and near its best as it nears opposition, rising in the late evening hours. There are several nice conjunctions of the moon with bright stars and planets and Venus, increasingly prominent in the west, passes near the Pleiades cluster late in the month. And then there are the Lyrid meteors on or around the morning of April 22, 2018.
APRIL ASTRONOMY EVENTS TO WATCH FOR
[Note: All times are local Pacific Time and calculated for the RFO site.]
* Use the "What's Up in the Night Sky" link on our website for additional events and details.
Moon - The moon is near Jupiter around 5:30am on 4/3. The moon is near Mars and Saturn around 5am on 4/7. Last Quarter is early on the morning of 4/8. New Moon is on the evening of 4/15. An ultra-thin 1.4% crescent moon is 4° almost exactly due west 30 minutes after sunset (or at 8:18pm calculated for the RFO site) on 4/16 (use binoculars). The crescent moon is near Venus with the Pleiades star cluster above Venus around 8:30pm on 4/17 (use binoculars to help spot the Pleiades in the twilight glow). Shortly thereafter on the same evening the moon will occult the moderately bright star ZC516 (see below). The moon is VERY near the bright red-orange star Aldebaran in Taurus around 9:30pm on 4/18. Use binoculars to appreciate this colorful event. First Quarter is on the afternoon of 4/22. Later that same night the moon will be near the large bright open star cluster M44 ("Praesepe" or the "Beehive") in Cancer, best around midnight. Use binoculars! The "Pink" full moon on the evening of 4/29. The moon is again near Jupiter around 4:30am on 4/30. And there is a challenging reappearance occultation that evening (see our website).
Mercury - Mercury is at inferior conjunction (between Earth and the sun) on 4/1 then has an extremely poor morning apparition late in the month, reaching a maximum altitude 45 minutes before sunrise of only 1.6° on 4/28, so not observable for most casual viewers. Greatest elongation west is on 4/29.
Venus - Venus is now very prominent in the evening sky, setting after twilight ends. The crescent moon is nearby around 8:30pm on the evening of 4/17 with the Pleiades cluster above Venus. Venus continues to approach the Pleiades, coming closest on the evening of 4/25.
Mars - Mars, in Sagittarius, is very near Saturn around 5am on 4/2 (us binoculars), and the moon passes nearby around 5am on 4/7. Mars rises around 2am mid-month and, being so far south, stays fairly low in the southern sky.
Jupiter - Jupiter, retrograde in Libra, is nearing opposition, rising before 10pm mid-month, and now at its best for observing. The moon is very near Jupiter around 5:30am on 4/2 and again near Jupiter around 4:30am on 4/30. Jovian satellite events are now readily observable starting in late p.m. hours and especially in a.m. hours. Details on these are on our website(*).
Saturn - Saturn, in Sagittarius, is in the southeast morning sky, rising around 1:30am mid-month. Mars draws very near Saturn around 5am on 4/2 and the moon joins in around 5am on 4/7. Saturn begins retrograde motion on 4/17.
Lyrid Meteor Shower - The shower peak may occur any time between about 3am and 2pm on 4/22. It usually has about 18 meteors per hour at peak though this varies. The first quarter moon sets around 2am on 4/22 so best observing is from around 2am to 5am that morning. The shower remains active for a few days around the peak so the mornings of 4/20 and 4/21 are also worth checking out, with less moonlight interference.
Occultation of ZC516 - At about 9:02pm on 4/17 the magnitude 6.9 star ZC516 will disappear behind the moon's dark limb 71° from the north cusp. ZC516 is an extremely close equal double with a time separation of 0.2 seconds predicted for the disappearance of the two components. (Calculated using Occult4 for the RFO site. Details will differ as distance from RFO increases.)
TIME SEQUENCE SUMMARY OF EVENTS:
Capitalized items refer to the sections above.
April 2 - MARS Very near SATURN
April 3 - MOON near JUPITER
April 7 - MOON near MARS and SATURN
April 8 - Last Quarter MOON
April 15 - New MOON
April 16 - 1.4% Crescent MOON in west
April 17 - Crescent MOON near VENUS, with Pleiades above VENUS
April 17 - OCCULTATION OF ZC516
April 18 - MOON very near Aldebaran
April 22 - LYRID METEOR SHOWER peaks
April 22 - First Quarter MOON
April 22 - MOON near M44 cluster
April 25 - VENUS near the Pleiades cluster
April 29 - "Pink" Full MOON
April 30 - MOON near JUPITER