NASA’S James Webb Space Telescope is about to enter its final stage of instrument preparation as it gears up toward opening its eyes on the universe this summer.

Much is expected of the JWST, replacing the Hubble Space Telescope as the most powerful space telescope to date.

The HST can see objects 60,000 times fainter than the human eye.

JWST will be able to see objects nine times fainter than Hubble currently can!

Total eclipse of the moon

May sees a total eclipse of the Moon and it’s a case of being prepared to get the best out of the event.

The eclipse takes place in the early hours of the morning of Monday, May 16, with totality, (the moment when the moon is completely covered by the earth’s shadow), taking place just before the moon sets below the horizon.

May’s eclipse explained

On average, there are about three lunar eclipses per year, (not all total eclipses).

These sorts of eclipses would occur more regularly if the Moon’s orbit around the Earth was on a flat plane. However, it’s angled at five degrees, and this means the Moon often goes below or above the Earth’s shadow.

A lunar eclipse occurs when the Earth comes between the Sun and the Moon, and the shadow cast by the Earth covers the Moon.

For the spectacle to happen, there must be a Full Moon and the alignment between the Moon, Sun, and Earth must form a line. In astronomy, this type of alignment is referred to as syzygy, taken from the Greek word and basically meaning being paired together.

The shadow cast by the Earth can be separated into three different parts:

  • The first part is the umbra, the darker central part of the shadow.
  • The second is the penumbra, the outer part of the shadow.
  • The third is the antumbra, the partly shaded area beyond the penumbra.

While all three come into play, for May’s eclipse, we shall be concentrating on the umbra and penumbra.

When the Sun, Earth and Moon form a direct line, a total lunar eclipse occurs. When the Sun, Earth, and Moon are aligned in such a way that the Moon is partly covered by the Earth’s umbra, a partial lunar eclipse will take place.

However, if the outer part of the Earth’s shadow covers the Moon, then a penumbral lunar eclipse occurs.

During the morning of May 16, we can expect the Moon to be totally covered by the Earth’s shadow and in doing so, take on a distinctly reddish guise.

Even though the Earth will be totally blocking out the sunlight reaching the lunar surface during the eclipse, we will still be able to see the Moon with the naked eye. This is because the Earth’s atmosphere bends sunlight and indirectly lights up the lunar surface.

As this refraction takes place, colours with shorter wavelengths become filtered out, while the likes of orange and red, both of whom have longer wavelengths, are left to ‘colour’ the Moon, hence the reference to a ‘Blood Moon’.

Eclipse timings

Make sure you have a good view of the south-west portion of the sky. Also, remember, that this is a naked eye event, so binoculars or a telescope are not required. However, this is a perfect opportunity for astrophotography!

  • 2.32am – The penumbral phase of the eclipse commences as the lunar surface enters the outer part of the Earth’s shadow. This part of the eclipse may well be difficult to spot at first but as the Moon moves deeper into the shadow the transition will become more and more apparent. Keep an eye on the western limb of the moon for the shadow moving across the lunar surface.
  • 3.27am – The Moon enters the umbra, the darker part of the Earth’s shadow. This will be more noticeable than the penumbra. At this point, the Moon will also be starting to take on a reddish appearance.
  • 4.29am – The total eclipse begins as the moon takes on a becomes completely reddish in appearance. At this point, the Moon is also heading toward the horizon, which is why having a good view of the south-western horizon is important.
  • 5.11am – This is the point of greatest eclipse, when the Moon is closest to the centre of the shadow cast by the Earth. However, the Moon is now very close to the horizon and depending on your vantage point, it may be tricky to actually spot the eclipse any further. A bright Full Moon can be spotted in these circumstances when it’s near to the horizon, but an eclipsed Moon will be difficult to see.
  • 5.21am – At this point, the Moon will set but there’s a strong possibility that it may already be lost from view.

There next total lunar eclipse visible from the UK will be on March 14, 2025.

Planets

Mercury is on view in the evening sky. Gazing in a west-northwest direction, look for a point of light above the horizon. Mercury will be on view for around two hours at the start of the month, dropping to under one hour by mid-May when the planet will then become increasingly difficult to spot in the evening twilight.

The morning sky sees the bulk of planet activity with Venus, the brightest of all, on view in the east, rising about one hour before the sun at around 4am. During the early part of May and having located Venus, look for Jupiter nearby, not as bright, but still easily spotted.

Mars too can be sighted early in the month if you sweep at an increasing upward angle to the right of Venus and Jupiter. Saturn can also be found if you continue the angled sweep upward to the right.

On Wednesday, May 25, Mars and Jupiter, (having moved quite considerably position-wise since the start of the month), will be near to a waning crescent moon in the morning sky. On Sunday, May 29, Mars will appear very close to Jupiter.

Society meetings

Barry Astronomical Society. Monday, May 30. 7.15pm. Tom Easton: The Moons of Mars. Barry Community Centre

Bridgend Astronomical Society. Wednesday, May 18. 7.30pm. Dr Sarah Roberts: Stardust Hunters. Bridgend Tennis, Squash, and Bowls Club.

Free online talks

Astronomy at Home for Teens – May’s Lunar Eclipse. Saturday, May 14. 6pm. To register free go to: www.eventbrite.co.uk/e/astronomy-at-home-for-teens-mays-lunar-eclipse-tickets-264634919167?aff=ebdssbonlinesearch&keep_tld=1

Moon phases

  • First quarter: May 9;
  • Full Moon: May 16;
  • Third quarter: May 22;
  • New Moon: May 30.

Sunrise/sunset times

  • Start of May: sun rises at 5.43am. Sets at 8.35pm.
  • End of May: sun rises at 5.01am. Sets at 9.19pm.

Jonathan Powell is a contributor to the BBC Sky at Night magazine, with articles also published in Astronomy Now. He has written three books on astronomy, Cosmic Debris; Rare Astronomical Sights and Sounds (which was selected by Choice magazine as an Outstanding Academic Title for 2019); and From Cave Art to Hubble, all of which are available from Amazon. Jonathan worked at BBC Radio Wales as their astronomy correspondent and is currently astronomy and space correspondent for The National, (an online newspaper for Wales), and a columnist at the South Wales Argus. He is a presenter on Astro Radio UK and also a contributor to CAPCOM, an online magazine which promotes astronomy and spaceflight to the general public. He has also presented on commercial radio at Sunshine FM in Worcester, Brunel FM in Swindon, and Bath FM. He is currently at 107.9 GTFM in South Wales. He has also written a book on castles, Fortress Wales, and was part of the writing team for the BBC Television show, The Fast Show, which won a BAFTA.