In the early morning of Monday 5th, we will be just past a first quarter Moon and this is the optimum time to look for that clair-obscur visual effect known as the Lunar X and V.  At 1am on the Monday morning, the Moon will be located towards the west, with planet Mars a little below and to the right of it.

While you are trying to spot the "X" and "V" shapes, it will also be very easy to find the Sea of Tranquility to the right of them, where Apollo 11 made the first Moon landing back in 1969.

A good question I am sometimes asked is whether there is a telescope on the Earth powerful enough to see the descent state of the Lunar Landing Module or the American flag that Apollo 11 left behind.  The short answer is "no" unfortunately.  The smallest features we can see with a telescope are still several kilometers across at least and compared to that, the Apollo hardware is miniscule!

If you've brought your telescope out to see the "X" and "V", you could also aim it towards Mars and try to observe its polar ice cap.  You may notice that Mars is extremely close to the Beehive open cluster of stars, known as M44 in the Charles Messier catalogue.

The cluster contains about 1000 stars and is between 500 - 600 light years away from us.  It's existence has been known about since ancient times and the cluster was first observed by the Greek mathematician Ptolemy around 150AD.  Galileo made observations of it in 1609 with his basic telescope and Charles Messier added the cluster to his list in 1769.  Because the light takes so long to reach us, if you do observe the cluster next week, you will be seeing it how it was before Galileo was even born!  The cluster is about 600 million years old, so to be fair, its structure won't have changed much over the last few hundred years!

In the dawn twilight of Monday 28th, Venus will be an easy target to spot shining at a magnitude of -4.4 which is very bright.  Around 5am, Venus will be located towards the east, with a harder-to-see, magnitude +0.8 Saturn a little below and to the right of it.

Using a telescope will show Venus as a beautiful crescent shape, but please be careful, as the Sun will be rising in the same direction shortly afterwards and you mustn't risk catching an accidental glimpse of it in your eyepiece!

Sticking with crescent shapes, look towards the west as darkness falls on the evening of Wednesday 30th, around 9pm, to see a 13%-lit waxing crescent Moon, with a magnitude -1.8 Jupiter just below and to the left of it.  Further left and closer to the horizon will be the red giant star Betelgeuse in the constellation of Orion.

You may notice a bright star just above the Moon.  This is Elnath that is a blue-white giant star and the beta star (or second-brightest) in the constellation of Taurus.  Elnath has a magnitude of +1.65  making it the 27th brightest star in the night sky overall.  By comparison, Betelgeuse shines at an average magnitude of +0.5 and is the 10th brightest - remember the magnitude scale works backwards!

Finally there are three good opportunities to spot the International Space Station next week, but you will need to be an early riser!  Tuesday 29th April at 4.20am, Thursday 1st May at 4.20am and Saturday 3rd May at 4.21am.  In each case, the ISS will appear in the west and spend over five minutes passing almost directly overhead, before disappearing towards the east.

If you are an early riser on Monday morning 21st, a very bright planet Venus pops her head above the horizon to the east at 5am.  The planet will be shining at a magnitude of around -4.7 so very obvious to spot.

In exactly the same direction, Mercury puts in an appearance from 5.40am, shining at a magnitude of +0.5 so again, it should be easy to locate.  Please don't be tempted to use your telescope though, as the Sun will be rising shortly afterwards.

On Monday 21st, Mercury reaches is greatest western elongation, or in other words, its greatest visual separation from the Sun.

Tuesday 22nd is the time of the annual Lyrid meteor shower, but the actual peak is around 2pm when it will be daylight, so it's best to look for those elusive shooting stars on the Tuesday evening.  By 10pm, Vega, which is the alpha star in the constellation of Lyra, will have risen above the horizon towards the north east.  The radiant point of the meteor shower will be a little to the right of Vega.

If you fancy another early morning, look towards the east at 5am on Friday 25th.  Venus will be an easy spot again, with a 10%-lit waning crescent Moon just below it.  A little further below and to the right of that, Saturn should be visible at a magnitude of +0.8 but once again, please don't bother with your telescope, as that pesky Sun will be coming up and you must never risk catching (even a momentary glimpse) of it in the eyepiece!

If you look towards the west north west at 10.30pm on Wednesday 16th, Jupiter will be easy to spot.  Aim your telescope in that direction and you will see exactly what Galileo saw back in the 1600s when he realised that the Earth was not at the centre of everything - the four "Galilean moons" orbiting around the gas giant.  At this particular time on 16th, two of the moons, Ganymede and Callisto, will appear very close to Jupiter's southern pole.

Of course, if you using an astronomical telescope, everything will appear to be upside-down, so the two moons will look like they are above the top of Jupiter rather than the bottom!

If you don't have your telescope with you, instead have a go a spotting different red things in the sky.  To the left of Jupiter will be the red giant star Betelgeuse in the constellation of Orion and above that, the "red planet" Mars.  You will see two other bright stars in the area, Procyon and Capella.  Procyon is not a red giant and the light coming from it will appear white in colour.  Interestingly, Procyon is one of the closest stars to us - only about 11 light years away.  Capella is much further away, at around 42 light years and it is classed as a yellow giant.

If you stay up later, into the early hours of Thursday 17th, an 85%-lit gibbous Moon will rise above the horizon towards the south east around 1am.  Above the Moon will be the red supergiant star Antares.

Antares is one of the largest stars visible to the naked eye and it is around 550 light years away from us.  The star is so massive, that if it was placed in the middle of our Solar System, it would extend all the way out to the asteroid belt and swallow us up!

I'm going to suggest that you pop outside with your telescope around 9pm on Wednesday 9th.  A waxing gibbous Moon will be located towards the south east, with the constellation of Leo "The Lion" above it.

Within the constellation is a group of three galaxies, about 35 million light years away, known as the "Leo Triplet".  The members are M65, M66 and NGC3628 and they all have a magnitude of around +10.0 so you are never going to see them with the naked eye!

Identify the star "Chertan" at (what would be) the lion's bottom and then aim your telescope a little down from the star to find the triplet of galaxies.

M65 and M66 will be the faint fuzzy blobs to the right, with the elongated NGC3628 to the left.  NGC3628 is sometimes known as the "Hamburger Galaxy" because of its shape, where a thick dust lane crosses the bright centre, resembling a burger sandwiched between two pieces of bun!

Now there will be a lot of light pollution from the Moon that is a little below the triplet, so why am I bothering to suggest taking this opportunity to find the galaxies?  Well at the moment, very close to the Hamburger Galaxy is the asteroid known as 8 Flora.

The asteroid will look like a tiny star, with a similar magnitude to the three galaxies.  The name "Flora" originates from the Latin goddess of flowers and the "8" identifies it as being the 8th asteroid ever discovered, back in 1847.  Would you prefer butter or Flora on your burger?

Now we have moved forward into British Summer Time, all the times I quote on Stars Over Somerset will be local, so you can just look at your clock and not worry about converting anything.

Venture outside at 9pm on Tuesday 1st April and look towards the west to spot a 16%-lit waxing crescent Moon.  Over the following couple of hours, the Moon will gradually occult (or cover-up) all the stars of the Pleiades open cluster.  The Pleiades is also known as the "Seven Sisters" because there are seven particularly bright stars within the cluster that are easy to spot with the naked eye.

The Pleiades is about 440 light years away from us, which converts to a little over 4000 trillion Km.  The Moon is only 360,000Km away at this point in its orbit around us, so it appears to move in front of the cluster and blocks the Seven Sisters from your view.

Open clusters of stars can vary from tens to thousands of stars that are all about the same age, as they were born in the same molecular cloud - I mentioned one of these "stellar nurseries" last week - the Great Orion Nebula.  You can also come across globular clusters that contain thousands to millions of stars, all kept together by their mutual gravity - a bit like a mini galaxy.  An excellent example is the Great Globular Cluster in Hercules, also known as Messier 13, that is around 22,000 light years away.

If you've brought your telescope out to see the occultation, around 11pm point it towards the north east instead.  Find the constellation of Lyra with the bright star Vega and Messier 13 will be a little above and to the right of Vega.

At the beginning of next week, the Moon is conveniently below the horizon, so it's an ideal time to go looking for those faint deep sky objects, as there will be no light pollution from it.  One good target would be the planetary nebula known as Messier 97 - the Owl Nebula.

First you need to locate the constellation of Ursa Major, that resembles a saucepan.  Around 1am on Tuesday 25th, Ursa Major will be towards the west north west, sitting above the constellations of Auriga and Gemini, with Mars visible in Gemini as a bonus.

M97 can be found a little above the beta star "Merak" of Ursa Major.

M97 has a magnitude of around +9.9 so you will definitely need a telescope.  A small telescope will show a fuzzy disc, but a larger telescope reveals two "holes" in the disc that resemble the eyes of an owl looking at you.....hence the name.

A large "emission nebula" like the Great Orion Nebula has active gas that gives off light and is where stars are born.  A "planetary nebula" is NOT where planets are born, rather the gas left behind by a dying star!  Early astronomers with basic telescopes used to think these nebulas were planets because they were small and round.....the name stuck!

Changing the subject, there is an excellent opportunity to spot the International Space Station during the early evening of Monday 24th.  The ISS will appear in the west at 7.15pm and spend seven minutes passing directly overhead, before disappearing towards the east.

We're going to stay close to home next week because Thursday 20th is the vernal or spring equinox.  What on Earth does that mean?

Our planet is tilted by 23.5 degrees or in other words, the north and south poles are not directly at the top and bottom.  If you've ever seen the classic globe in a classroom, you will notice that it is not mounted vertically on its base, but 23.5 degrees off-centre.

We take 23 hours 56 minutes and 4 seconds to rotate once on our axis and this is one Earth day, but it is rounded up to 24 hours to keep things simple.  It takes the Earth a year, 365 1/4 days, to orbit around the Sun, but again we keep it simple by calling a year 365 days precisely and every four years, take the extra quarters to create an extra day in February - a Leap Year.

As we orbit around the Sun, at one point our 23.5 degree tilt is angled towards the Sun and we have summer in the Northern Hemisphere.  The Sun appears a little higher in the sky as a result and the daylight hours last longer.  Six months later, the tilt is pointed away from the Sun and it is then winter in the Northern Hemisphere, with the Sun lower in the sky and the daylight hours correspondingly shorter.  Half-way between each of these points, our tilt is sideways-on to the Sun and we have periods of equal day and night - the spring and autumn equinoxes.

This explains why, when we have summer, the Southern Hemisphere has winter and vice versa, but what about the missing minutes each day where we have rounded up to 24 hours?  It's why the days get longer and shorter every day by approximately four minutes as we go through the seasons!

Venus is a very popular target in the early evening sky at the moment.  Look towards the west any evening next week to see it, but on Tuesday 11th in particular, a telescope will reveal the planet in a beautiful 5%-lit crescent phase.  If you are looking west at 7pm, there is also the chance to spot Mercury just below and to the left of Venus.

Venus is currently shining very brightly at a magnitude of around -4.0 and this is a good opportunity to explain the magnitude scale in a bit more depth.  Imagine a reference star has a brightness magnitude of zero to start with.  The scale works backwards, so anything brighter than the reference star will have a negative number and the fainter an object is, the more positive its number will be.

The brightest star in the night sky is Sirius with a magnitude of -1.44 and around 7pm next week, Sirius can be found to the south.  Above and to the left of Sirius is another bright star, Procyon, that has a magnitude of +0.4 or in other words, not quite as bright as Sirius.  Above and to the right of Sirius you will find the constellation of Orion, with its red giant alpha star Betelgeuse shining at +0.45 (similar to Procyon) and the young beta star Rigel at +0.12 which is a bit brighter.

To put all this into context, our own Sun has a magnitude of -26.74 which is why you never try to look at it through binoculars or a telescope!  With the naked eye, from a dark location, you can see objects down to a magnitude of about +6.0 so things like the Great Orion Nebula in the sword of Orion at +2.9 can just be identified.  Anything with a magnitude more positive than +6.0 requires binoculars or a telescope.

The late evening of Tuesday 4th into the early morning of Wednesday 5th sees an unusual event - a chance to witness the shadows of two Galilean moons as they simultaneously transit across Jupiter's surface.  Just before midnight, Jupiter will be located towards the west and the transits of Ganymede and Europa can be observed with your telescope until about 2am on the Wednesday morning.

Pop back outside and look to the west again around 10pm on the Wednesday evening to see Jupiter once more, with a 42%-lit waxing crescent Moon just to the right of it.  The constellation of Orion will be to the left of the pair.

The Moon is "waxing" because it is heading towards a Full Moon later in the month on 14th.

Repeat the exercise around 10pm on Saturday 8th and the Moon will be higher in the sky and located more towards the south west.  This time it will appear very close to planet Mars.  The illumination of the Moon will have passed the "First Quarter" phase and you will now observe it as a 70%-lit waxing gibbous Moon.

This is the optimum time to spot the Clair-Obscur visual effect known as the "Jewelled Handle" on the Moon's surface. 

In the art world, the technique known as "Chiaroscuro" refers to the use of strong contrasts between light and dark.  In the astronomy world, the French translation of "Clair-Obscur" refers to extreme contrasts on the lunar surface where sunlight falling on the landscape produces obvious shapes at certain times of the month, when the Moon is in a particular phase and light from the Sun is hitting it at a specific angle.

Screenshots courtesy of Stellarium

Copyright Adrian Dening and Radio Ninesprings 2025