SkyEye

June 2018

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

The Calendar

Glorious Saturn comes to prominence in June, reaching opposition just before the end of the month. Tiny 4 Vesta, the only asteroid capable of reaching naked-eye visibility, also reaches opposition this month.

The phases of the Moon in June 2018

Date Body Event
1 Moon, Saturn 1.6° apart
2 Moon apogee
3 Moon descending node
4
5
6 Mercury superior conjunction
Mercury perihelion
Moon last quarter
7 Earth Arietid meteor shower
Neptune west quadrature
8
9
10
11
12 Moon occultation of Aldebaran — not visible
13 Moon new
14 Moon perigee
15
16 Moon 1.2° south of the open star cluster M44 (known as Praesepe or the Beehive Cluster)
Moon ascending node
17
18
19 Neptune stationary point: direct → retrograde
4 Vesta opposition
20 Venus 0.7° north of the open star cluster M44 (known as Praesepe or the Beehive Cluster)
Moon first quarter
21 Earth solstice
22
23
24
25
26
27 Earth June Boötid meteor shower
Saturn opposition
28 Moon, Saturn 1.8° apart
Moon full
Mars stationary point: direct → retrograde
29
30 Moon apogee
Moon descending node

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.

The position of the Sun and planets at mid-month

Sun TaurusGemini

Mercury TaurusGeminiCancer

This tiny planet is never far from the Sun. After undergoing superior conjunction on 6 June, Mercury reappears mid-month in the west at sunset. It soars relatively high above the horizon for observers in the southern hemisphere but those in the north get a much poorer view.

Venus GeminiCancerLeo

Southern hemisphere observers finally get the best views of the evening star as it continues to rise higher and higher above the western horizon after sunset. However, to those watching from the north, this bright planet actually gets lower in the sky as the month wears on.

Earth and Moon

The Earth is at solstice on 21 June. The word solstice means 'sun stands still' so that on this day, the solar declination reaches an extreme. In this case, the Sun appears directly over the Tropic of Cancer in the northern hemisphere. From now until the solstice in December, days will be getting shorter in the northern hemisphere and longer in the southern hemisphere. On 7 June, the waning crescent Moon could cause problems with observing the Arietid meteor shower. The radiant is close to the Sun and the shower primarily occurs during the day. Twenty days later, the waxing gibbous Moon definitely washes out the June Boötid meteor shower.

Mars Capricornus

Mars remains a difficult observing target for viewers in northern temperate latitudes, despite shining brightly at magnitude −1.3. It changes direction on 28 June, moving from direct to retrograde motion.

Jupiter Libra

Brilliant Jupiter was at opposition last month and is still visible most of the night. Viewers in northern latitudes are finally beginning to get a good look at the largest planet in the solar system as it appears ever higher in the sky.

Saturn Sagittarius

Because it is at opposition on 27 June, Saturn is visible all night. It has two close encounters with the Moon this month, appearing 1.6° south of our satellite on the first day and a little farther on the day after opposition.

Saturn at opposition in 2018

Uranus Aries

Uranus is now well away from the Sun. It rises before midnight for southern hemisphere observers, and midnight or later for those in northern temperate latitudes.

Neptune Aquarius

A small telescope is necessary to view the most distant planet in the solar system. At west quadrature on 7 June, Neptune rises around midnight. It reaches a stationary point on 19 June and goes into retrograde.

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