Monday 27th October to Sunday 2nd November 2025
 

This coming week, we have a period of occultations.  Sounds like some series of sinister black magic rituals, but in astronomy terms, an occultation occurs when one celestial body hides another.

 

On the evening of Wednesday 29th, our target is Saturn.  Aim your telescope towards the gas giant a bit before 8.30pm, when it will be located towards the south.

 
 

Although Saturn's dust rings are not currently well-placed for observing, a number of its many moons will be obvious.  Keep watching and you should be able to see the largest of Saturn's Moons, Titan, being gradually occulted by the planet.

 
 

The following evening, Thursday 30th, look towards the south west at 10pm to see a 62%-lit waxing gibbous Moon against the backdrop of the constellation Capricorn.  The Moon will be getting close to the magnitude +3.7 star Nashira in the constellation.  Just before 10.30pm, the Moon occults Nashira.

 
 
 

Remember that the Moon appears as a disc, but being in a gibbous phase, you can only see 62% of the surface facing us lit by sunlight.  This means that Nashira will disappear before the illuminated part of the Moon gets to it and at the beginning, it is occulted by the dark bit of the Moon's surface that you can't actually see!

 
 

You won't get this effect with the Titan occultation because planets that are further away from Sun than us don't exhibit phases and we always see them as single points of light.

 

 

Monday 20th to Sunday 26th October 2025
 

Tuesday 21st is the peak of the annual Orionids meteor shower, so named because the radiant point where the shooting stars appear to originate from is close to the constellation of Orion.

 

If you go outside from around 11pm. Orion will have risen above the horizon to the east and the radiant point of the shower will be a little to the left of the red giant star Betelgeuse.  While you are waiting for those streaks of light to appear, further to the left, Jupiter will be easy to spot.

 
 

As a bonus, that evening coincides with a New Moon, when the side of the Moon facing us is not illuminated at all by sunlight, so there will be no light pollution from our celestial neighbour to spoil the view.

 

Meteor showers are caused by the Earth scooping up the debris left by comets while they travel close to the Sun on their long journey from the outer reaches of our Solar System.  As we orbit around the Sun, these showers occur at the same time every year.  In the case of the Orionids, they are caused by bits left behind from comet Halley.

 

The shower has a zenithal hourly rate in excess of 20 meteors per hour, so you shouldn't be waiting too long before you see something and if you can't make Tuesday 21st, observing a couple of days before or after the peak should still produce some results.

 

Finally, an early reminder that the first of my astronomy talks and star parties for this season will be taking place at the Ham Hill Visitor Centre on the evening of Friday 28th November.  There will be a one-hour talk about the night sky at 7pm and then if it is clear, we venture outside.  Places always fill quickly, so booking is essential via the Ham Hill Rangers Office on 01935 823617.

 

 

Monday 6th to Sunday 12th October 2025
 

If you pop outside just as it's getting dark on the evening of Tuesday 7th, say around 7pm and look towards the east, a Full Moon will be rising above the horizon, with Saturn visible a little to the right of it.

 
 

A Full Moon reflects so much sunlight that it creates the ultimate natural light pollution and this will spoil your view of Saturn a bit.  It is also the worst possible time to go hunting for faint deep sky targets.

 

We have just passed the autumn equinox and as this Full Moon is the closest to that date, it is known as the 2025 Harvest Moon.  Coincidentally, this particular Full Moon occurs at perigee, when our celestial neighbour is closest to us in its orbit around the Earth.

 

In astronomy, there is no such thing as a perfect circle and all objects' orbits are elliptical (or egg-shaped) to a greater or lesser degree.  In the case of our Moon, at perigee our natural satellite is approximately 225,000 miles away from us, where at the opposite point in its orbit, known as apogee, it is more like 251,000 miles away.  This cycle repeats every 27 days, which is how long the Moon takes to go around us.

 
 

The Moon appears slightly larger when it is at perigee and the difference is size between the two extremes is about 14%.  If a Full Moon occurs at perigee, it is known as a Supermoon.  So on 7th, we really have a Harvest Supermoon!

 
 

Because the Moon will be close to the horizon when you view it, you may also witness that phenomenon known as "Moon Illusion" where your eyes play a trick on you and make it appear artificially large.

 

 

 

Monday 29th September to Sunday 5th October 2025
 

If you venture outside at 1am on Monday 29th September and look towards the east north east, Jupiter will have just risen above the horizon.  To the right of the gas giant, you should also be able to make out the constellation of Orion more towards the east and again, close to the horizon.

 
 

Why 1am specifically?  Well if you aim your telescope towards Jupiter at that time, it should be possible to witness the shadow of the planet's moon Io cast onto its surface, while at the same time, another of Jupiter's moons, Ganymede, is physically passing in front of the planet.  At 1am, Ganymede and the shadow of Io will appear to be either side of Jupiter's Great Red Spot.

 
 

The Great Red Spot is a giant storm in Jupiter's upper atmosphere that has been blowing for hundreds of years.  It measures about 10,000 miles across, so is about the size of the whole Earth and has wind speeds of over 250 miles per hour!  It keeps going because Jupiter has no planetary surface that would cause friction to slow it down.  Often, when you look at Jupiter through a telescope, you don't see the Great Red Spot at all.  This is because it only takes ten hours for the storm to rotate completely around the planet, so it's often round the other side!

 
 
Size comparison image courtesy of NASA
 

Look towards the south around 1am on 2nd October and Saturn will be an easy target to spot.  To the left of Saturn will be the large constellation of Cetus and with your telescope, you could try to find the dwarf planet Ceres that lives in the Asteroid Belt - it will be just to the right of Cetus with a magnitude of around +7.6

 
 

 

 

Monday 22nd to Sunday 28th September 2025
 

Monday 22nd is the autumn equinox.  This translates to "equal night and day" and is the point in our orbit around the Sun where the Earth's 23.5 degree tilt is sideways on to the Sun.  The same happens again six months later of course, when we have the spring equinox.  In between these times, the northern hemisphere is either pointing away from the Sun or towards it and we have winter or summer.

 
 

Last week, I mentioned about Saturn being viewable throughout the night as it appears to travel from east to west horizons.  This week, if you dig out your telescope to have a better look at the gas giant, it should also be possible to spot Neptune just above and to the left of Saturn.

 

Pop outside any evening next week, around 10pm - Saturn will be located towards the south east and easy to spot, shining at a magnitude of around +0.6 while Neptune will be a much harder target at a magnitude of only +7.7 making it invisible to the naked eye.

 
 
 

Venture back outside at 6am on Saturday 27th and Jupiter will be quite high in the sky towards the south east, with a very bright planet Venus rising above the horizon in the east.

 
 

Why have I chosen 6am on the Saturday specifically?  Well if you aim your telescope towards Jupiter then, it will be possible to see the shadow cast by two of Jupiter's moons, Io and Europa, at the same time.  How cool is that!

 
 

Please remember to pack your telescope away before the Sun rises though, as catching an accidental glimpse of that in your eyepiece would most definitely NOT be cool!

 

 

Monday 15th to Sunday 21st September 2025
 

We always associate astronomy with the night sky, but it is possible to observe some brighter objects during the day, with our Moon being the most obvious target.

 

Look towards the south west around 11am on Tuesday morning 16th and try to spot a 28%-lit waning crescent Moon with the naked eye.  It will be quite high in the sky - about 55 degrees above the horizon.  If you have brought your telescope out, just below and to the left of the Moon, Jupiter will be shining at a magnitude of -1.9

 
 

I will repeat my usual warning though, that the Sun will be shining very brightly at a magnitude of around -26.0 a little further south and you must never accidentally catch a glimpse of it in your telescope's eyepiece, as it would result in instant and permanent blindness!

 

Moving on to the morning of Friday 19th, look towards the east at 6am to see a 6%-lit crescent Moon.  Just below the Moon, Venus will be easy to spot at a magnitude of -3.8 and immediately below Venus, you should be able to see the magnitude +1.0 bright star Regulus.

 
 

Don't even bother risking your telescope for this one, as the Sun will be just about to rise above the horizon in the same place!

 

Finally, towards the end of the week, Saturn reaches opposition and it will actually be viewable the whole night, from dusk to dawn, as it appears to travel between east and west horizons.

 
 

 

 

Monday 8th to Sunday 14th September 2025
 

We will have had a Full Moon on Sunday 7th, so if you pop outside around 9pm on Monday 8th and look towards the east, you will see a 98%-lit waning gibbous Moon rising above the horizon, extremely close to Saturn.  The gas giant will be just below and to the right of the Moon.

 
 

I wouldn't bother bringing your telescope outside as, being so close to a Full Moon, the light pollution from it makes for poor viewing of those elusive faint deep sky objects.

 

One deep sky object that is always easy to spot though is the Pleiades open cluster of stars, also known as M45 in the Charles Messier catalogue and often called the "Seven Sisters" because of the seven prominent stars that can be seen with the naked eye.

 

If you look towards the east north east at 9pm on Friday 12th, a slightly gibbous Moon will have just risen above the horizon and as it does so, the Moon occults (or appears to pass in front of) the Pleiades.

 
 

The Pleiades is the closest Messier object to us and is only 440 light years away.  The bright blue stars that you see are relatively young and it is estimated that the cluster formed about 100 million years ago.  If you are looking at them, remember that you will be seeing the stars how they were 440 years ago, as the light from them has taken that long to reach us, travelling at the speed of light, which is 186,000 miles per second!

 

The stars are gradually drifting apart and in around 250 million years, the group will no longer be classed as a cluster, rather individual stars.

 

 

Monday 1st to Sunday 7th September 2025
 

The evening of Tuesday 2nd is the optimum time to spot the clair-obscur visual effects known as the "Lunar X and V", where sunlight falling on the Moon's surface reflects off particular features and creates recognisable shapes.

 

Look towards the south south west around 11pm and the Moon will be about to set below the horizon.  You will need your telescope to be able to spot the "X" and "V" shapes on the terminator between light and dark on the lunar surface.

 
 

A little to the right of the "V" you can find the dark area known as the "Sea of Tranquility" where Apollo 11 landed back in 1969.  Of course there isn't really any water on the Moon, but early astronomers thought that the large dark, flat areas must be oceans and the names stuck.

 
 

Sticking with our neighbour in the Solar System, but moving on to the evening of Sunday 7th, we have a lunar eclipse.  As the Moon rises above the horizon at sunset, it is fully immersed in the Earth's shadow.

 

Look towards the east at 7.45pm to catch the Moon popping its head above the horizon and at that time, it will appear quite dark because it is totally eclipsed - this is called "totality".

 
 

Gradually, over the following hour, as the Moon comes out of totality and rises in the sky, you will see more and more of its surface illuminated.  If you are still watching it at 8.15pm, you will also be able to notice Saturn rising above the horizon in the same place.