October Sky Notes

Rather than heading directly towards Jupiter and its icy-ocean moon, Europa, the Clipper is now on its way to Mars. Here it will swing around the planet in a couple of close flybys, picking up energy as it goes, and then get catapulted off towards the Earth. This is known as a Gravity Assist or “Slingshot” manoeuvre and was used by Apollo, Voyager, Galileo and many other deep-space probes in the past.

Europa Clipper will make a similar, but not quite so close, flyby of the Earth where it will finally gain enough momentum to be flung out towards Jupiter.

On arriving at Jupiter, the opposite process will take place. Here the probe will go into “loose” orbits around moons of Jupiter, initially around Ganymede, Jupiter’s largest moon, helping it to brake and slow down enough to reach a stable orbit around its target, Europa.

Once a stable orbit has been reached, Europa Clipper will begin its scientific investigations of the icy moon. It is expected to survive and return information for about three years.

Sky Notes

Please note all times given in this article are in GMT and as the clocks have changed that is the current time.

Sky Schedule

Sun: From the beginning to the end of the month the period of dark sky increases by an hour.  At the beginning of the month the Sun sets before 5pm and by the end of the month by 4:15 pm after which there is the twilight period.  The nights are really drawing in now and there are less than ten hours of daylight, making November a good time to observe fainter deep sky objects such as M42, The Great Orion Nebula, which is actually visible to the naked eye from a dark site.  This cloud of gas is a star forming region in space and can be seen easily in binoculars or a small telescope.  Find the three stars that form the asterism of The Belt of Orion and then drop vertically down from the middle star of these three. You will come to three much fainter stars forming the “sword”.  The bottom one of these should seem rather fuzzy. This is the nebula, a cloud of glowing gas and not a star at all (although it contains newly formed, hot, young stars).  

Mercury and Venus:  Mercury is not visible this month.  However Venus is a brilliant object seen in the South-East just after sunset and setting at around 6pm at the beginning of the month but close to 7pm at the end of November.. 

Mars:  Mars rises about 9pm and is visible against the background stars of Cancer. It brightens a little by the end of the month.

Jupiter:  The largest planet rises around 17:30pm and is visible throughout the month and throughout most of the night. It is seen against the background stars of Taurus.  In the darker skies, the contrast allows the coloured bands and zones on the surface of the planet to be distinguished more easily with small telescopes, as can the Great Red Spot, a colossal hurricane, greater in diameter than the planet Earth. The Galilean moons can be seen with a good pair of binoculars or a small (bird-spotting) telescope.  DSLR images of the planet will also pick up the moons.  These moons orbit Jupiter such that we sometimes see them pass between the Earth and the giant planet along our line of sight.  Watch out for small black dots seen against the surface of Jupiter itself; again more easily seen in the contrast with darker skies. 

Saturn: The ringed planet can be found against the stars of Aquarius, in the South-Eastern sky. The rings are now edge-on to us but can still be seen in a medium-sized telescope. Saturn’s largest moon, Titan, can be seen near the planet with a good pair of binoculars or a small telescope but, whilst the rings are edge-on it is worth looking out for 3 or4 other moons, visible because of the lack of glare from the rings.  

Uranus and Neptune: Uranus is visible all night long throughout November and is seen against the background stars of Taurus r.  It reaches opposition (closes to the Earth and due South) on 17th . Look for a tiny greenish disc compared to the pinpoints which are the stars.  Neptune is seen against the background stars bordering Aquarius and  Pisces (below the asterism known as the Square of Pegasus). At magnitude 7.7 it will require large binoculars or a moderate telescope to find it.  Neptune displays a smaller and truly blue disc compared to that of Uranus although it will appear only as a bluish star to most small instruments 

Meteor Showers:  We are fast approaching the season of meteors.  This month sees not one, not two, but three meteor showers. The last in the month, the Leonids is prone to outbursts called “meteor storms” once every 33 years, as its parent comet returns near the Sun (unfortunately this is not expected until, between 2032- 2035. The second in the month, The Northern Taurids is a shower that generally produces few but bright meteors and extends over a period of about 20 days. The first shower in the month is the most problematic of all.

The Guyfawkid meteor shower has its peak on November 5th and can produce reports of very bright, even exploding meteors.  All joking aside, you would not believe how many spurious reports of unusual shooting stars are made on and around this date. And it is not just meteors.

The British UFO Society still asks its members to be especially aware of sightings of unusual phenomenon on November 5th along with November 17th (maximum of the Leonids) and August 12th (maximum of the Perseids)!

I remember, many years ago, visiting a UFOlogist with a colleague where we were shown a handbook of pictures said to be incontrovertible evidence of UFO’s. Of the ten images in the handbook, my colleague and I were immediately able to explain what eight of them were. One of the others was clearly out of focus (like most images of UFO’s even to this day and with current technology) and it took us less than two days to track down what the tenth image was. This was before the advent of the internet, and if it was so easily achievable by us then why could the UFO researchers not find it? Perhaps they simply did not want to know that there was a sensible explanation. That was certainly the impression my colleague and I got from our visit.

The Taurids occur from 20th and all the way through to 10th December. This shower seems to emanate from a point near the Pleiades.  These meteors are particularly bright and are not affected by strong moonlight.  In fact this shower contains large meteors that can produce fireballs – defined as bright enough to cast shadows. However, the Zenith Hourly Rate is only 12 (the ZHR is always quoted as if the radiant point was overhead, so is often greater than that actually observed when the radiant point is lower in the sky). The Taurids are associated with a comet called Encke, which has one of the shortest orbital periods of any comet; just 3.3 years.  The Leonid shower reaching its maximum on 17th is associated with a comet called Temple-Tuttle which has a 33-year orbit around the Sun.  This is the shower which, once every 33 years, produces a meteor storm with thousands of meteors seen in a night. The last such storm was expected in 1999 but did not occur until 2001, so the next storm is expected sometime between 2032 and 2035.  

Comets:  After the excitement of Comet C2023 A3 which failed to live up to the predictions of the media, mainly because they neglected to take into account that the comet reached its peak brightness and maximum altitude in Northern skies before darkness had actually settled, there are no comets predicted for November. In spite of the difficulties, members of the Torbay Astronomical Society have succeeded in getting images of the comet.

Moon: The New Moon occurs on November 1st with First Quarter on November 9th . Full Moon then follows on 15th and third quarter is on 23rd.