SkyEye

May 2019

Welcome to SkyEye, your guide to this month's celestial events.

The Calendar

Look out for the η Aquariid meteors during the early part of the month when the skies are dark. The waxing crescent Moon passes through the open cluster M44 (Praesepe) on 11 May.

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Date Body Event
1
2
3
4 Moon new
5
6 Earth η Aquariid meteor shower
7
8 Mercury, Uranus conjunction: 1.3° apart
9 Moon ascending node
10
11 Moon 0.0° north of the open star cluster M44 (known as Praesepe or the Beehive Cluster)
12 Moon first quarter
13 Moon perigee
14
15
16 Mars maximum declination north
17
18 Venus, Uranus conjunction: 1.1° apart
Moon full: seasonal Blue Moon
19 Mercury ascending node
20 Moon, Jupiter 1.7° apart
21 Mercury superior conjunction
22 Moon descending node
Moon, Saturn occultation of Saturn — visible from South Africa and Antarctica
23
24 Mercury perihelion
25
26 Moon apogee
Moon last quarter
27
28 1 Ceres opposition
29
30
31

The Solar System

The word planet is derived from the Greek word for 'wanderer'. Unlike the background stars, planets seem to move around the sky, keeping mostly to a narrow track called the ecliptic, the path of the Sun across the stars. Dwarf planets and small solar-system bodies, including comets, are not so constrained, often moving far above or below the ecliptic.

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Sun AriesTaurus

Mercury PiscesAriesTaurus

Mercury soon disappears from the dawn sky. Observers in southern latitudes may be able to view the close pairing of Mercury and Uranus on 8 May but both planets will be very low in the sky. Superior conjunction occurs on 21 May and Mercury reaches perihelion three days later.

Venus PiscesAries

The morning star continues to dazzle southern hemisphere observers, shining at magnitude −3.9 and rising as much as two hours before the Sun. Planet watchers in tropical and southern latitudes will have the best chance of seeing bright Venus and faint Uranus together in the sky on 18 May when they come within 1.1° of each other.

Earth and Moon

The light from the very young crescent Moon poses no problems for observing the η Aquariid meteor shower on 6 May and the nights either side. On 11 May, the waxing crescent Moon occults M44, Praesepe, also known as the Beehive Cluster. Seven days later, the Moon is full, making it the third Full Moon of four in an astronomical season. This is a traditional Blue Moon as originally defined in eighteenth-century farmers' almanacs.

Mars TaurusGemini

Mars reaches maximum declination north this month. It is best viewed from northern latitudes but sets before midnight.

Jupiter Ophiuchus

Jupiter and the Moon have another close call this month, with our satellite passing less than 2° north of the planet on 20 May. With opposition in June, Jupiter continues to brighten and reaches magnitude −2.5 this month. It rises before midnight and is best seen from southern latitudes and equatorial regions.

Saturn Sagittarius

The lunar occultations keep coming, with the Moon gliding in front of Saturn at about 20:00 UT on 22 May. This gas giant is slowly brightening and reaches magnitude +0.3 by the end of the month. Still a morning sky object for observers in northern temperate latitudes, Saturn now rises before midnight for those seeking it from the southern hemisphere.

Uranus Aries

As Uranus emerges from the Sun's glare into the dawn sky, it first passes Mercury on 8 May and then Venus ten days later. However, at magnitude +5.9, this green ice giant may be too faint to see in the twilight of the eastern horizon.

Neptune Aquarius

A small telescope is necessary to view the most distant planet in the solar system. Tropical and southern latitudes have the best views of eighth-magnitude Neptune where it is high above the eastern horizon before sunrise.

The Celestial Sphere

Constellations are patterns of stars in the sky. The International Astronomical Union recognises 88 different constellations. The brightest stars as seen from the Earth are easy to spot but do you know their proper names? With a set of binoculars you can look for fainter objects such as nebulae and galaxies and star clusters or some of the closest stars to the Sun.

Descriptions of the sky for observers in both the northern and southern hemispheres are available for the following times this month. Subtract one hour from your local time if summer (daylight savings) time is in effect.

Local Time Mid-month Northern Hemisphere Equator Southern Hemisphere
1730 hours (1830 hours summer time) 60° N 50° N 40° N 30° N 20° N 10° N 10° S 20° S 30° S 40° S
1930 hours (2030 hours summer time) 60° N 50° N 40° N 30° N 20° N 10° N 10° S 20° S 30° S 40° S
2130 hours (2230 hours summer time) 60° N 50° N 40° N 30° N 20° N 10° N 10° S 20° S 30° S 40° S
2330 hours (0030 hours summer time) 60° N 50° N 40° N 30° N 20° N 10° N 10° S 20° S 30° S 40° S
0130 hours (0230 hours summer time) 60° N 50° N 40° N 30° N 20° N 10° N 10° S 20° S 30° S 40° S
0330 hours (0430 hours summer time) 60° N 50° N 40° N 30° N 20° N 10° N 10° S 20° S 30° S 40° S
0530 hours (0630 hours summer time) 60° N 50° N 40° N 30° N 20° N 10° N 10° S 20° S 30° S 40° S