June 2021

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

The Calendar

An amazing annular solar eclipse takes place on 10 June. Earth is at a solstice on 21 June and Mars passes just south of Praesepe two days later.

The phases of the Moon in June 2021

Date Body Event
2 Moon last quarter
6 3 Juno opposition
7 Earth Arietid meteor shower
8 Moon apogee
9 Moon ascending node
10 Mercury aphelion
Earth, Moon annular solar eclipse
Moon new
11 Mercury inferior conjunction
12 Moon, Venus 1.5° apart
Venus perihelion
13 Neptune west quadrature
16 Jupiter maximum declination north
18 Moon first quarter
21 Earth solstice
Jupiter stationary point in right ascension: direct → retrograde
22 Mercury 1.8° north of Aldebaran
Neptune maxiumum declination north
23 Mercury stationary point in right ascension: retrograde → direct
Mars 0.3° south of the open star cluster M44 (known as Praesepe or the Beehive Cluster)
Moon descending node
Moon perigee
24 Moon full
26 Neptune stationary point in right ascension: direct → retrograde
27 Earth June Boötid meteor shower

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 Taurus

Mercury vanishes from the west early in the month and undergoes inferior conjunction on 11 June, the day after aphelion. It emerges in the east at dawn before the end of the month in what is a decent morning apparition for southern hemisphere observers. Second-magnitude Mercury passes 1.8° north of first-magnitude star Aldebaran on 22 June and ends retrograde motion the following day.

Venus TaurusGeminiCancer

The evening star appears 1.5° south of the waxing crescent Moon on 12 June, the same day on which the planet reaches perihelion. Venus is best seen from the southern hemisphere where it continues to gain altitude above the western horizon.

Earth and Moon

A ring of fire is seen on 10 June when the New Moon moves between Earth and the Sun, resulting in an annular solar eclipse. Earth reaches 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.

Mars GeminiCancer

Mars is less than 3° south of the waxing crescent Moon on 13 June. Ten days later it has a far closer encounter with M44, also known as Praesepe or the Beehive Cluster, when it passes only 0.3° south of the centre of that open star cluster. Mars is getting increasingly difficult to see from northern latitudes as it sinks deeper into the evening twilight but skies are still dark in the southern hemisphere when the red planet finally sets in the early evening hours.

Jupiter Aquarius

Jupiter reaches its most northerly declination of the year on 16 June and enters into retrograde motion five days later. Observers in southern latitudes are best placed to view the giant planet which rises during the evening. It is only now that northern planet watchers might see Jupiter rise before midnight but it never gains much altitude before the sky brightens in the morning.

Saturn Capricornus

Saturn rises in the early evening hours for astronomers situated in the southern hemisphere, allowing the planet plenty of time to gain significant altitude before midnight. The gas giant is finally an evening sky object for observers in northern temperate latitudes too, although it is best seen after midnight. Saturn is getting closer to Earth and the rings are opening slightly, resulting in the planet brightening from magnitude +0.6 to +0.4 over the course of the month.

Uranus Aries

Uranus is visible in the east before dawn. It is most easily viewed from the southern hemisphere where it gains considerable altitude before the sky brightens. The waning crescent Moon pays a visit on 7 June, passing 2.1° south of the planet.

Neptune Aquarius

A small telescope is necessary to view the most distant planet in the solar system and the best place to put that telescope is the southern hemisphere where Neptune rises during the mid- and late evening hours. The faint planet arrives at west quadrature on 13 June and reaches its farthest point north (in terms of declination) for 2021 nine days later. Neptune spends nearly half of the year in retrograde motion and this year it begins on 26 June.

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