We've all had enough of the recent weather forecasts and storms, but did you know that scientists are also interested in what is called "Space Weather"?  It is a branch of space physics concerned with the effect that the Sun has on our planet - things like the radiation from solar flares and the Solar Wind.  Space weather can cause disruption to our radio communications and is also responsible for creating those visual Auroras that could (unusually) been seen from here in the UK this year - guess space weather can have extremes, just like our own weather!

Saturday 21st is the Northern Hemisphere's winter solstice - the time when the Sun reaches is most southerly declination or lowest maximum height above the horizon.  This represents the shortest day, so it will now start staying lighter in the evenings by about 4 minutes each day.  Everyone works on an Earth day being 24 hours long, but in reality it takes 23 hours 56 minutes and 4 seconds for the planet to rotate once, hence the difference of roughly 4 minutes.

Sunday evening 22nd sees the peak of the annual Ursids meteor shower.  The radiant point is located near the constellation of Ursa Minor, which is itself easy to find, because the constellation includes Polaris, the pole star, located towards true north.

Polaris is the alpha (or most significant) star in the constellation.  The radiant point of the shower is close to Kochab, which is the beta star.

Best to look for the shooting stars before 11pm as a 58%-lit gibbous Moon will then be rising above the horizon, creating some light pollution and spoiling your view.

Just after dark, say around 5pm, on Tuesday 10th, a waxing slightly-gibbous Moon will have risen above the horizon to the south east, with Saturn further to the right of it.

This is the optimum evening to have a go at spotting the clair-obscur lunar visual effect known as the Jewelled Handle.  Sunlight hitting the Montes Jura mountain range at an angle on the Moon's surface produces what looks like the shiny handle of a teapot!

Venture out again around 5pm on Friday 13th and a 96%-lit waxing very-gibbous Moon will now be located towards the east, extremely close to the Pleiades open cluster of stars.  Jupiter will be a little below and to the left of it.  Of course, light pollution from the almost-full Moon will spoil your view of the cluster.

A similar problem occurs on Saturday 14th when the Moon is just one day away from being full and it ruins the peak of the annual Geminids meteor shower.  If you do want to try and spot a few shooting stars, the radiant point of the shower is in the constellation of Gemini, which by 9pm on the Saturday evening, will be found towards the east.

Looking in that direction, you should also be able to see Jupiter and Mars while waiting for those elusive meteors to show up.  To the right of Gemini will be the obvious constellation of Orion with the bright stars Betelgeuse and Rigel, while above Orion you can find the constellation of Taurus with the bright star Aldebaran.

Take a look towards the south around 5pm on Thursday 5th to see a very bright magnitude -4.0 Venus setting below the horizon.  To the left of Venus, you will find a waxing crescent Moon.

You'll notice that the crescent shape, where sunlight is illuminating the lunar surface, is on the right.  This tells us that our celestial neighbour is "waxing", or in other words, heading towards the Full Moon on 15th December.  After the Full Moon, it is said to be "waning" and because of the angles between us, the Sun and Moon, the illuminated part will then appear to be on the left side of the Moon's surface.

If you look towards the south again at 5pm on Sunday 8th, Venus will be setting below the horizon once more, while further to the left and a bit higher in the sky, a magnitude +1.0 Saturn will also be easy to spot.  At the same time, a first quarter Moon will only be a few degrees away from Saturn.  Again, it will be the right hand side of the Moon's surface that is illuminated.

When you've finished observing them, a magnitude -2.0 Jupiter will be rising above the horizon to the east north east.  Above and to the left of Jupiter is the bright star Capella, while to the right you can find the Pleiades open cluster of stars.  All of these targets are easy "naked eye" objects, so no telescope or binoculars required!

My next astronomy talk and star party at the Ham Hill Visitor Centre is taking place at 7pm on Friday 6th December.  The last one filled very quickly, so if you'd like to come along, it is essential to reserve a place by contacting the Ranger's Office on 07973 887129.

If you look towards the east at 8pm on the evening of Tuesday 26th, the constellation of Orion will have just risen above the horizon, with Jupiter a little higher.

Around 8pm, Io will be passing (or transiting) in front of the planet and because of the angle that sunlight is illuminating the event, Io's shadow will be cast on the planet's surface.  See if you can make out what will look like a small black dot against the clouds of Jupiter's storms.

Io is the third largest of Jupiter's Galilean moons and a little larger than our own Moon.  It would be a pretty nasty place to live, with over 400 live volcanoes, making it the most geologically active object in our Solar System.  Being the closest moon to Jupiter, it is also constantly bombarded by magnetic radiation from the planet.  Io was the first moon identified by Galileo back in 1610 with his new-fangled invention called a telescope!

There are a couple of potentially excellent International Space Station passes next week if the skies are clear: Tuesday 26th at 6.17pm and Wednesday 27th at 5.28pm.  In both cases, the ISS appears in the west and spends several minutes passing almost directly overhead, before disappearing towards the east.

Finally, a reminder that my next astronomy talk and star party at the Ham Hill Visitor Centre is taking place at 7pm on Friday 6th December.  The last one filled very quickly, so if you'd like to come along, it is essential to reserve a place by contacting the Ranger's Office on 07973 887129.

If it's a clear evening, Wednesday 20th is when it's all happening next week.  If you look towards the south south west around 8pm, Saturn will be an easy target to spot.  Aiming a telescope towards the planet will reveal the shadow of Saturn's moon Titan as it passes in front of the planet.  The transit begins a little before 8 o'clock and will be all over by 11 o'clock.

When you've had enough of Titan, take a look towards the north east and a 70%-lit waning gibbous Moon will be rising above the horizon at 9pm, with Mars just below and to the right of it.

Further right, towards the east, will be the constellation of Orion, with Jupiter above it.  Orion is great for teaching astronomy, with lots of interesting things to see.  Betelgeuse is a great example of a giant red star, while on the opposite side of the constellation, Rigel is a much younger star that appears to have a blueish tint because it is much hotter.

If you still have your telescope out, the Orion Nebula (Messier 42) is a stunning target that can be found half-way down the "sword" of Orion.  The nebula's gas, where stars are being born, is around 1600 light years away, so if you look at it on Wednesday evening, you will be seeing the gas how it was 1600 years ago because its light has taken that long to reach us!

The best pass of the International Space Station next week occurs at 6.16pm on.....guess when.....Wednesday 20th, when it will appear in the west and spend about 4 minutes travelling almost directly overhead before disappearing towards the east.

The evening of Monday 11th sees the peak of the Northern Taurids meteor shower.  At 11pm, the radiant point (where the shooting stars appear to originate from) will be located towards the south east, just below the Pleiades open cluster of stars.  A little below and to the left of the radiant point you will find the bright star Aldebaran and planet Jupiter.  Below them, the constellation of Orion will be easy to spot.

If you look towards the south west at 11pm the following evening, Tuesday 12th, a 79%-lit waxing gibbous Moon will be an easy find.  Below and to the right of the Moon, Saturn will be about to set below the horizon.  Halfway between the two, telescope or binocular users should be able to spot a magnitude +7.7 planet Neptune.  Immediately beside Neptune is a star HIP117614 with about the same brightness and the pair could be confused for a double star system.

The HIP number refers to the Hipparcos Catalogue that was the result of the European Space Agency's Hipparcos mission in the early 1990s.  The Hipparcos satellite made high-precision measurements of almost 120,000 stars during its four-year life.

The evening of Friday 15th sees a Full Moon.  By 7pm, the Moon will have risen nicely to the east, with the Pleiades to the left of it and further left, Jupiter will just be poking its head above the horizon.  This Full Moon is known as a Supermoon because it occurs near perigee, when the Moon is closest to Earth during its orbit around us.  At this time, the Moon appears 14% larger and 30% brighter than when it is furthest away from us - a point called apogee.  An easy way to remember which is which is to think that at apogee, something is "apologising" for being further away!

First of all, a bit of a visual challenge just as it's getting dark on Monday 4th.  Look close to the south west horizon around 4.30pm and see if you can spot a thin 9%-lit waxing crescent Moon.  A little above and to the left of the Moon will be a very bright planet Venus, shining at a magnitude of about -4.0 so easy to find against the dusk sky.

If you look towards the south west any evening next week in the late evening, Saturn will be easy to spot with the naked eye at a magnitude of around +0.8 but it is not a great time to observe the rings of dust around the planet because their current "end-on" angle to us makes them appear to be very thin.

However this works to your advantage as Saturn's many moons are in the same plane as the rings, so appear to be nicely spaced out in their orbits around the gas giant.

At different times next week, three of Saturn's moons pass in front of the planet and cast a shadow on its surface.  Of course you will need a telescope to be able to observe what will look like a tiny black dot on the face of the planet.  The offending moons are Titan from 9pm on Monday 4th, Rhea from 11.30pm on Tuesday 5th and Dione from 7pm on Thursday 7th.  Because the time is a little earlier on the Thursday, Saturn will be more towards the south that evening.

Saturn is known to have 146 moons and their orbital periods (or the time they take to go around the planet) vary considerably, depending on how far they are away from the planet.  If you look at Saturn on the different evenings, the moons will therefore all appear to be in completely different places each time.

Screenshots courtesy of Stellarium

Copyright Adrian Dening and Radio Ninesprings 2024