The fundamentals of astronomy for beginners
EXPLAINER
Spend a month with the Moon
Scott Levine follows Earth’s natural satellite and jumps off to spot nearby targets
We all need some help when we’re new to the skies Fortunately, we have an incredibly handy tool to guide us on our way: the Moon. As it orbits and its phase changes, we can use it to hop off to the amazing objects it passes on its way. So use this article as inspiration this month, as you head outside and let the Moon guide you through the night.
Most of what we will talk about here are objects we can see with the unaided eye, but we’ll visit some deep-sky objects too. Before you start, however, remember to give your eyes time to adjust to the dark and preserve your night vision with a red filter on a torch, or by using a mobile phone’s night mode. Now we are ready, let’s get started on our month’s tour with the Moon!
New to first quarter Moon
The Moon was at its new phase on 30 May, lying between the Sun and Earth, which means that as June gets underway it starts to leave the Sun’s glare. On 1–2 June, you will find an eyelash-thin crescent under five stars arching just above the western horizon. With the summer solstice only about three weeks away, twilight lingers deep into the evening, so these may be tough to see.
From left to right (south to north), they are Procyon (Alpha (α) Canis Minoris), Pollux (Beta (β) Geminorum), Castor (Alpha (α) Geminorum), Menkalinan (Beta (β) Aurigae) and Capella (Alpha (α) Aurigae). Sound familiar? In the cold parts of the year, we’re used to seeing them along the left-hand edge of the Winter Hexagon, but the seasons have whittled them down to this subtle and delicate arch. This part of the sky is the opposite direction to the galactic centre: as we look towards the Moon, our gaze races through the twilight and off into the vast emptiness of the open Universe.
Let’s see if we can spot the first quarter Moon in the south in the late afternoon on 7 June (see box ‘Viewing the Moon in the day’). After sunset, the Moon appears to be about halfway between the stars Spica (Alpha (α) Virginis) and Regulus (Alpha (α) Leonis), within the sprawling Spring Triangle. Try to spot orange-red Arcturus (Alpha (α) Boötis), the third of the Triangle’s corners, northeast of the Moon.
Full Moon and Sagittarius
Look for June’s full Moon on the 14th in Sagittarius, where the brightest of the Archer’s stars form its famous ‘Teapot’ asterism. It’s about two weeks – about half a lunar orbit – since we saw the Moon near the galactic anti-centre. Now, we’re facing inwards, towards the Galaxy’s centre, which is thousands of lightyears behind the Teapot’s spout. A few Messier objects are in this part of the sky, including the Butterfly and Ptolemy Clusters, M6 and M7, and the Lagoon Nebula, M8, but the full Moon makes them tricky to see.
Waning Moon and planets
After full Moon, its late-night, waning phases begin. Over the next few nights the Moon meets up with four of our Solar System’s bright planets: on 18–19 June it glides past Saturn; and then, on 21 June, on the night of the summer solstice, the last quarter Moon shines with Jupiter. From there, it meets Mars in the morning twilight on the 22nd, and a whisper-thin crescent greets Venus on the 26th.
We see these conjunctions because the planets all orbit the Sun in roughly the same plane, which we see as a path across the sky called the ecliptic. The ecliptic also represents the Sun’s path across the sky. The Moon’s orbit is tilted by 5° relative to the ecliptic, so the Moon usually appears to pass near the Sun and planets, but only blocks them out from time to time.
The Moon is new again on 29 June. So, we’ve made it all the way back to where we started, ready to see what July brings.
We hope you’ll enjoy using our nearest neighbour as your guide as you discover some amazing sights in the night sky.
Viewing the Moon in the day
Top tips on spotting the Moon’s phases in daylight hours
We often think the Moon is a fixture of the night, but we can also see it during the day. Since the Moon travels all the way around Earth as it orbits, it spends half its time on Earth’s daytime side.
We can see all the phases during the day, but it’s easiest to start around first quarter (7 June). This phase rises around noon and sets around midnight, so we’ll see it towards the south in the late afternoon.
The Moon rises 50 minutes later each day, and inches deeper into the night before it slides into the early mornings. Last quarter phase (21 June) sees it due south in the mid-morning. Spotting a full Moon in the day is tricky because it rises around sunset. Try and catch it just before it sets around sunrise.
Scott Levine is an astronomy writer and naked-eye observer based in New York’s Hudson Valley