The Night Sky This Month

April 2015

Lunar Eclipse4 April 2015. Full Moon, 13:05 UT. (The “Pink Moon”, “Egg Moon”, or “Grass Moon”).

4 April. A brief lunar eclipse occurs near today’s Full Moon just two weeks after last month’s total solar eclipse. Many lunar eclipses last an hour or more, but this one is unusually short. It lasts just under five minutes, from 11:58 UT to just past 12:02 UT. Observers in the eastern half of Australia and all of New Zealand and Hawaii can see the entire eclipse. In western North America, the total eclipse will be visible in the pre-dawn sky, but the Moon will set before the eclipse ends. Observers in eastern North America and most of South America will see the Moon set before the eclipse reaches totality.

8 April.  Early risers can see the waning gibbous Moon just 3º from the planet Saturn in the southern sky before dawn. Saturn still hovers above the three bright stars in the head of the constellation Scorpius. The planet grows larger and brighter as it moves towards opposition late next month.

8 April. Jupiter stops its nightly westward, or retrograde, motion and begins to move eastward from night to night in the constellation Cancer and back towards Leo. The planet is slowly appearing to dim and grow smaller, but it’s still a splendid sight in a telescope. It lies high in the southeastern sky as darkness falls. It far outshines all stars in the sky.

10 April. Mercury lies at superior conjunction and is lost in the Sun’s glare. It quickly moves into the evening sky in a few days and makes a respectable apparition after sunset for northern observers at month’s end.

11 April. Look for brilliant Venus near the lovely Pleiades star cluster in the southwestern sky as darkness falls. Venus is the dominant sight in the western sky after sunset all month. At magnitude -4.0, it outshines every object in the night sky except for the Sun and Moon and continues to move a little higher each day.

Venus and the Pleiades at nightfall looking southwest on April 11, 2015.

Venus and the Pleiades and Hyades star clusters in the constellation Taurus at nightfall looking west after sunset on April 11, 2015.

12 April. Last-Quarter Moon, 04:44 UT.

18 April. New Moon, 18:57 UT.

19-20 April. In the prettiest display of solar-system sights this month, the fingernail crescent Moon, Mercury, and faint Mars are visible together in the western sky after sunset. Have a look with binoculars after sunset.

22 April.  Look for the Lyrid meteor shower late on April 22nd and early on the 23rd. Meteors from the Lyrids appear to trace their paths back to a radiant about 10º southwest of bright blue-white Vega, a point which is actually in what’s now the constellation Hercules. The shower was named before the constellation boundaries were formalized in the early-20th century. The Lyrids are sandgrain-sized pieces of dust and ice left over from the long-period Comet C/1861 Thatcher. In dark sky, you might see 10-20 Lyrid meteors per hour anywhere in the sky.

Moon, Mars, Mercury, and Venus looking westward at sunset on April 20, 2015.

Moon, Mars, Mercury, and Venus looking westward at sunset on April 20, 2015.

26 April. First-Quarter Moon, 00:55 UT.

30 April. Look for Mercury low in the northwestern sky after sunset. Today, it’s just 2º southwest of the Pleiades and about 10º above the horizon after sunset in the northern hemisphere. In the southern hemisphere, the planet is much lower at this apparition and much harder to hard to see.

Mercury near the Pleiades after sunset looking north-northwest on April 30, 2015. The V-shaped Hyades star cluster is to the left.

Mercury near the Pleiades after sunset looking north-northwest on April 30, 2015. The V-shaped Hyades star cluster is to the left.