By Jonathan Powell, South Wales Argus astronomy writer

The display of the aurora borealis on May 10 was, without question, one of the finest one can ever hope to see.

I have been observing the skies since the early 1980s and I have never witnessed anything in the night sky in the same league as this.

For those fortunate to catch the northern lights, I think you will also agree, it was simply jaw-dropping. Great anticipation followed regarding the potential for a repeat display on Saturday May 11, but alas to no avail.

The northern lights virtually filled the skies with an ever-changing display that was easily seen with the naked eye and just as easily captured with smartphone technology. No one view of the aurora stayed the same for very long as it constantly morphed into different patterns and shapes.

May 10's display is thought to be one of the strongest shows of the northern lights for 500 years, and all of that stemmed from a group of sunspots.

The sunspots groups, catalogued as 3663 and 3664, were linked firstly to solar flare activity, then as they repeatedly erupted, Coronal Mass Ejections. These CMEs (which can travel up to 1,900 miles per second), occurred several days before the display we witnessed, with their charged particles travelling from the Sun toward Earth and interacting with our atmosphere to deliver that dramatic evening.

The array of colours seen within the curtains, arcs, and spirals denote the interaction between the solar particles and different gases, at different levels in our atmosphere.

The picture of the Sun, courtesy of Dave Eagle, shows the sunspot grouping around the time of the display and how more recently, their prominence has faded. As a rough idea of scale, singular sunspots obviously vary in size, but can be around the size of the Earth.

It's not impossible that given the Sun’s current active state that more displays are likely during 2024, but whether they will match May’s entertainment is uncertain.


Great expectations lay on the shoulders this year of Comet C/2023 A3 Tsuchinshan-ATLAS. Discovered late last year, there are some quarters in the science world already labelling it as “the [potential] comet of the century”.

However, given the notoriously unpredictable nature of these ice and rock visitors, that might be an overstatement.

The comet is currently sat in the constellation of Virgo, the Virgin, and is faint to observe to all but those with sufficiently sized telescopes. If the comet lives up to its forecasted brightness, we could be in for quite a spectacle this autumn.

Stars and constellations

On Saturday June 8, seek out a thin crescent Moon in the evening sky. Once you’ve located the Moon, sweep upward to find two bright stars spread apart. These will be Pollux to the left, and Castor to the right. Both stars reside in the constellation of Gemini, the Twins. On Sunday June 16, the Moon will appear close to another bright star, Spica, in the constellation of Virgo, the Virgin.

Where to look: northwest.


All the planetary activity is reserved for the morning sky. Rising at 1am is Saturn. On the morning of Thursday June 27 and Friday June 28, the Moon will appear close to the ringed planet. Rising at 2.30am is Mars, with Jupiter next, rising at around 3.30am. While both Saturn and Mars appear to be around the same regarding brightness, Jupiter will be easier to spot, dazzling in the pre-dawn sky.

Where to look: along the eastern horizon.

Noctilucent cloud

This month, watch for a phenomenon known as ‘noctilucent cloud’. Named from the Latin for "night shining", look above the northern horizon a couple of hours after sunset for wispy threads of cloud. Formed by sunlight reflected upon high-altitude ice clouds right on the edge of space, the formations make for a wonderful sight with the naked eye, appearing bluey-white in nature.

Where to look: north

June’s Strawberry Full Moon

The full Moon on June 22 is more commonly known as the "Strawberry Moon" given the ripening of the fruit during this time of year. Because of light scattering by the Earth’s atmosphere, the Moon will take on a "reddish" hint.

Summer Solstice

The Summer Solstice occurs in the Northern Hemisphere on June 20 at 9.51pm. This is the point in the year when the Sun reaches its most northerly position in the sky, marking the astronomical start of summer for the northern half of the globe, while in the Southern hemisphere, the day marks the astronomical start of winter.

Society meetings

Cardiff Astronomical Society. Thursday June 6. 7.30pm. Space Industry in Wales – Neil Monteiro, Space Forge. Cardiff University, Queen’s Buildings, The Parade, Cardiff, CF24 3AA.

Barry Astronomical Society. Monday June 17. 7pm. Summer Skies – Dave Powell. Meetings are usually held at Barry Community Centre, Cemetery Road, Barry, CF62 8BP.

Bridgend Astronomical Society. Wednesday June 19. 7pm. An Introduction to Radio Astronomy – Andrew Thomas. Bridgend Tennis, Squash, and Bowls Club, Halo Rec Centre, Angel Street, CF31 4AH.

Heads of the Valleys Astronomical Society. Tuesday June 25. 7pm. The Milky Way Galaxy – Wayne Jones. Learning Action Centre, 20 James Street, Ebbw Vale, NP23 6JG

Moon phases

New Moon June 6; First Quarter June 14; Full Moon June 22; Third Quarter June 28.

Sunrise/sunset times

Start of June: Sun rises at 4.59am. Sets at 9.20pm. End of June: Sun rises at 4.58am. Sets at 9.32pm.