Torbay Astronomical Society: Astronomy v astrology

Torbay Weekly

Stargazing with John Stapleton from Torbay Astronomical Society:

In these articles I have often referred to 'background constellations'.

This is to imply that the planets move in front of the star patterns and not through them.

The classic phrase used in the pseudo-science of astrology is that a planet is 'in' a certain constellation and is, therefore, able to affect the behaviour of a person born under the sign of that particular constellation. This is utter poppycock!

The planets all orbit our Sun at distances ranging to about 3,200 million miles and our Sun’s gravitational influence reaches to about six million, million miles - one light year.

The absolute nearest other star is over five times more distant than this at about 30 trillion miles - 4.2 light years.

However, as the planets all orbit in roughly the same plane around the Sun, they are seen against the background of constellations that also lie in this same plane.

This is what is known as the zodiac.

However, there are five or six other constellations which also partly lie within this plane and against which the planets can sometimes be seen - Orion and Ophiuchus being the most well-known.

So sometimes the planets are not seen against any zodiacal constellation although astrologers will say that they are.

Furthermore, the constellations of the zodiac are all different sizes in the sky and the planets do not spend equal amounts of time in each of them.

So, to say that a particular constellation 'rules' a particular month is preposterous.

Not all of the stars in a constellation are the same distance away, the patterns we recognise are purely line of sight effects.

For example, the brightest star in the constellation of Virgo - Spica - is 2,200 times brighter than our Sun and lies 250 light years distant while the third brightest star in this constellation - Porrima - lies only 38 light years away.

The distances between the planets and these stars, and the distances between stars within a similar line of sight from our point of view are absolutely vast.

Therefore, they cannot possibly have any influence on each other let alone on humans who are randomly born while different constellations cross the meridian - lie due south at midnight.

Many years ago Patrick Moore did a radio broadcast on the event of a great conjunction of planets - several planets all appeared in the same part of the sky - where he suggested that the combined gravitational pull of these planets might have a miniscule effect on the weight of people on the Earth for a brief period.

The BBC received thousands of phone calls saying that, at the exact predicted time people stood on their bathroom scales and noticed a significant drop in their weight.

The BBC also had a control group, who had not listened to the broadcast, that noticed no change.

The date of this broadcast? April 1!

This proved that the power of suggestion was far greater than any influence the planets might have.

Astrologers also used to draw up their charts using only seven 'planets' - including the Sun and the Moon, which are not planets at all - and then, when Uranus and Neptune and eventually Pluto were discovered, they added these into their charts, now with 11 'planets' - they still count the Sun and the Moon - without so much as a blink of an eye.

When Pluto was demoted to the status of a dwarf planet, some astrologers stopped including Pluto in their charts, but others did not.

However I am yet to hear of any astrologer who still uses Pluto, including the other dwarf planets that have been found since, in their charts.

Finally, some, but not all, astrologers allow for a phenomenon known as 'the precession of the equinoxes'.

This is caused by a wobble of the Earth’s axis resulting in a gradual change in the orientation of the axis, relative to the stars.

The observable results are that the North Polar Axis, which currently points towards Polaris - Pole Star - will over 25,700 years describe a circle so that other stars will become aligned with the pole until it returns to Polaris once again, and that the zodiacal constellation that crosses the meridian - due South at midnight - at any given time will be one further on than as now.

In fact, this has already happened so that, without correction, if you believe you were born under the sign of Taurus, for instance, within the last 50 years, you were actually born when Gemini was crossing the meridian.

This gives rise to some astrologers giving charts for ascendant and rising signs.

When I challenged a nationally syndicated astrologer about this, she told me: “We work on a virtual, idealised sky. It has nothing to do with stars in space.”

So they just make it up, then?

The James Webb Space telescope has successfully entered its orbit and has been testing its main mirror.

This mirror is actually made up of 18 separate hexagonal segments.

Each segment has been positioned and tilted to capture an image of a bright isolated star known as HD84406.

Each 'segment image' is unique in the way that it distorts the out-of-focus image, allowing NASA scientists to begin to 'stitch' the 'segment images' together to form a single image.

When this is done, the 18 mirrors will be able to be aligned so that they produce a single coherent image and the telescope will be ready to begin observing its first target.

The Star Chart

The sky will look like the chart on March 7 at 9pm and again on March 21 at 8pm. And four minutes earlier on each successive night e.g. 8.56 on March 8.

To use the chart, hold it above your head while facing south so that you can look directly from the chart to the sky.


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

Sun: Throughout this month there are just under 11 hours of daylight. The Spring or Vernal Equinox (the day when night and day are of equal length) occurs on March 20.

Mercury: Mercury is no longer visible as it rises only half an hour before the Sun and is very low in the sky in a South-Easterly direction.

Venus: Venus is also a morning object rising about 2 hours before the Sun throughout the month. Through a telescope Venus shows phases like the Moon. At the moment the phase is getting larger (about the same as a half-moon)) and so Venus is becoming even brighter. Easily the brightest object in the sky after the Sun and the Moon.

Mars: Mars is now poorly placed for observation.

Jupiter: Jupiter now lies in conjunction (in the same direction) with the Sun and is not visible until it reappears in the morning sky, at the end of the month. The giant planet will then rise just 20 minutes before the Sun.

Saturn: Saturn is now visible in the morning sky, low in the South-East before sunrise. It is rather faint but will become easier to see as it begins to rise earlier and earlier before the Sun.

Uranus and Neptune: is seen against the background stars of Aries and close to the Pleiades star cluster.  At magnitude 5.8 it is visible in binoculars.  Look for a tiny greenish disc compared to the pinpoints which are the stars.  Uranus now sets at about 23:00 so the observing opportunities are closing.  Neptune is in conjunction with Sun and is not visible this month.

Meteor shower: There are no regular meteor showers this month. However stray or sporadic meteors can still be seen at any time. Some of these can be very bright.

Comet: Comet 19P/Borrelly will be well placed this month moving through the background constellations of Ares and Perseus.  However it is a faint, telescopic object.  On 15th it will be quite close to the Pleiades star cluster in Taurus and would make a good photo opportunity with a DSLR camera.

The New Moon occurs today, March 3, with First Quarter on March 10, Full Moon then follows on March 18 and Last Quarter on March 25.

Data supplied by Simon Harding, Observations Secretary Torbay Astronomical Society

Diary Dates

The next meetings of the Torbay Astronomical Society, complying with the current Covid regulations, will be held at Torquay Boys' Grammar School this evening, March 3.

Members will be delighted to provide views of the objects discussed in this article.

In the event of bad weather, short talks and videos will be presented alongside informal discussion and an opportunity to get to know the society.

On March 24, Gary Poyner of the Heart of England AS will give a talk entitled An Introduction to Variable Star Observing. Mr Poyner is a past director of the BAA Variable Star Section.

Talks will also be available online via Zoom. For details, email the secretary on Visitors and prospective members especially welcome.