Wadhurst Astronomical Society Newsletter January 2021

Welcome to the New Year and the January edition of the Wadhurst Astronomy Society newsletter. How many Zoom meetings before we can meet again in person? But first we look at last month’s meeting; our Christmas Zoom meeting. We learnt about the observatory at Greenwich, how it came into being, of its importance to navigation and then we learnt about the Astronomers Royal.

John Wayte presided over another of his popular Christmas Quizzes, which was great fun and included some questions to amuse and challenge our knowledge of astronomy.

Towards the end of the newsletter, Brian Mills provides his detailed Sky Notes for January, and finally there is a bit of sad news about the loss of a distinguished observatory.

THE DECEMBER ZOOM MEETING

Phil Berry opened the December Zoom meeting and after outlining the evening’s programme he introduced our own Chairman, Brian Mills to give the Christmas talk but before Brian began, he said it had been decided by the Committee that owing to the pandemic, the Society had been unable to hold any actual meetings at Uplands Community College since March and therefore anyone who paid their subscription any time during 2020 will automatically remain a paid up member of the Society for the year 2021.

Greenwich and the Astronomers Royal Brian Mills FRAS

At the start of his talk, Brian posed the question, why was the observatory built. In the 17th century Britain, as an island nation was dependent for trade and contact with its colonial outposts solely by sea. We were reminded of the many disasters that occurred at sea with the loss of ships, their crews and their cargo because in those day, maps were not very accurate and sea captains had no real way of knowing exactly where on these maps they were. So, it was necessary to acquire a way of knowing their positions much more accurately.

It had been suggested that the position of the Moon as it moved in front of the background fixed stars could be one method of finding longitude at sea. The essential thing was that the position of the Moon and stars would need to be known much more precisely. With this in mind an approach was made to King Charles the Second and work was begun to build the observatory at Greenwich overlooking the Queen’s House and the Thames.

The location for the new observatory was on the site of the old Duke of Humphrey’s Tower which had become a ruin. The observatory was built by Christopher Wren and finished in 1675.

The new observatory at Greenwich to the left, overlooking the Queen’s House and the River Thames

Image: Engraving by S Wellcome/Creative Common licence 1

Brian said that the Royal Society were already planning an observatory at Chelsea with as observer, so it followed that Charles II appointed Flamsteed as the observer at the new Greenwich observatory.

Originally, the building was intended for navigation purposes and not as an observatory and since the original foundations were used, it faced onto the Queen’s House, which meant that it was not in line with the meridian but was 13o off to one side.

Early observing was done from the flat roof of the new building using a 16-foot-long telescope which was later replaced with a 27- foot telescope. A 60-foot telescope was also used in the grounds of the observatory.

Flamsteed did the observing himself and with help, built the instruments he used, although at the time he wasn’t called but Astronomical Observator. We were told that that title wasn’t assumed until Neville Maskelyne adopted the title himself in 1765.

The Astronomer Royal was responsible for everything including his budget until 1965 when the Science and Research Council was formed and took over responsibility for the Royal Greenwich Observatory, the Royal Observatory in Edinburgh, the Appleton Laboratory and the Rutherford High Energy Laboratory.

Brian said that in 1971, Richard Wooley was still in the post of Astronomer Royal but it was announced that when he retired, the new director would not necessarily be the Astronomer Royal and Margaret Burbage became Director of the Royal Greenwich Observatory, with becoming Astronomer Royal, a title that became a purely honorary one.

The Astronomer Royal has always been a member of the Royal Household, answerable to the Lord Chamberlain and must be available to the Monarch to answer questions on astronomy and science, all for a stipend of just £100 a year.

The first person to take on the role of Astronomer Royal was John Flamsteed from 1675. His assistant built the mural arc with which he and Flamsteed made 28,000 observations of star positions.

At the time, Isaac Newton was perfecting his calculations on the motion of the Moon and needed precise data which Flamsteed already had and was continuing to obtain. But Flamsteed regarded the data as his personal property and there was conflict between the two with the result that they became hostile to each other.

Somehow the Royal Society managed to get hold of a copy of Flamsteed’s work and 400 copies appeared in 1712 against Flamsteed’s wishes. He manages to get hold of 300 of them and burnt them in Greenwich Park.

John Flamsteed suffered from ill health towards the end of his life and died in 1719 at the age of 73. His widow and assistants completed his “Historia Coelestis” Britannic in 1725 and his “Atlas Coelestis” in 1729. We were told that his widow removed all the equipment from the observatory as directed in Flamsteed’s will.

John Flamsteed, the first Astronomer Royal , the Second Astronomer Royal Image: Portrait by Godfrey Kneller/ Wellcome Library Image: Portrait by R Philips

Brian said that by comparison, the second Astronomer Royal, Edmond Halley, was by all accounts a far more agreeable man.

2 Halley was born in Hackney to a rich family in 1656. He went to Queen’s College in Oxford where he met Flamsteed but left his studies at Oxford to travel to St Helena and record the southern stars to complement Flamsteed’s work. Although he only managed to record 341 star positions, the results were published in 1678 in his “Catalogue of the Southern Stars”.

When trying to explain Kepler’s three laws of planetary motion from his observations, Halley couldn’t manage ellipses so contacted Isaac Newton who said he had already worked it out and eventually Halley paid for Newton’s work on the results to be printed as Newton’s “Principia”.

In 1703 Halley became professor of Geometry at Oxford despite Flamsteed’s objections.

We were then told that Halley eventually took on the role of Astronomer Royal at Greenwich Observatory in 1720, having to replace the equipment removed by Flamsteed’s widow. One of his tasks was to follow and measure the precise position of the Moon over one entire Saros cycle which Brian described as the time between the Earth, Moon and Sun being in line and returning to almost exactly the same geometric positions, taking 18 years, 11 days and 8 hours. The purpose was to allow more accurate lunar tables to be calculated and so more accurate longitude measurements to be recorded.

Halley was quite elderly when he took over the post and died from a stroke, dying five years later in 1742 aged 85. But he was able to predict that the comet of 1682 would reappear in 1758 and finally the comet would be named after him.

The next Astronomer Royal was , also educated at Oxford. Whilst at Oxford he became professor of astronomy and discovered the Aberration of Light which produces an apparent motion a celestial object to be displaced towards the direction of the observer’s motion. Brian said that from this it showed finally that the Earth was not at the centre of the Universe and that the Earth was in fact orbiting the Sun.

Bradley was Astronomer Royal from 1742 to 1762 and during his time managed to improve on previous levels of accuracy of observations and also showed the nutation of the Earth. Precession taking 26,000 years was already known but these small fluctuations, taking just 8.6 years, became apparent because of Bradley’s accuracy in observations. Brian said this nutation is caused by the gravitational effects of the Sun and Moon through the Earth’s equatorial bulge.

Nathaniel Bliss became the next Astronomer Royal in 1762 and remained in office until only 1764 but we were told he contributed very little to astronomy.

Brian then briefly covered the following Astronomer Royals beginning with in the role from 1765 until 1811. During his tenure he was a great critic of John Harrison who made more and more accurate clocks to be carried on board ships to improve the measure of longitude of the vessels as they travelled at sea. Maskelyne’s concern was in how the Board of Longitude was spending public money.

Maskelyne attempted to measure the mass of the Earth by using an almost conical shaped mountain in Scotland and multiplied it up to try and calculate the density of the Earth.

The next Astronomer Royal was from 1811 until 1835. It was Pond that was responsible for the installation of the Time Ball on the observatory roof in 1883, so that when it was released and fell at one-clock, ships in the Pool of London could see it and set their clocks.

Brian related the story we heard during a Society visit to the observatory, that during restoration of the building the ball was taken down and the builders thought it was going in a skip and kicked it around the yard as a football, hence the battered shape we see today.

The Greenwich Observatory Time Ball as it appears today

Image: Geoff Rathbone

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George Airy followed between 1835 and 1881 and in 1851 established Greenwich as the Prime Meridian.

William Christie was Astronomer Royal from 1881 until 1910

He was followed by Frank Dyson, 1910 until 1933 who was responsible for introducing the time-signal pips broadcast from Greenwich. He also helped prove Einstein’s theory of Relativity along with Eddington.

The tenth Astronomer Royal was Sir from 1933 until 1955 and was responsible for obtaining funds to move the Observatory to Herstmonceux.

Sir Richard Wooley followed in 1956 and remained Astronomer Royal until 1971. We were told that from then on, the role of Astronomer Royal was separated from Director of the Royal Observatory.

Then came Sir Martin Ryle from 1972 to 1982. Ryle was also the first professor of Radio Astronomy at Cambridge.

Sir Francis Smith was Astronomer from 1982 to 1990, Professor Arnold Wolfendale, 1990 until 1995 and from 1995 and continues in the role today.

Once again, John Wayte has devised another of his ever-popular Christmas Quizzes. As he said, a Zoom-presented quiz is intended for one’s own amusement and the prize can only be virtual kudos.

There are 15 questions covering a wide variety of astronomy-related subjects and of varying obscurity.

The answers are at the end of the newsletter.

Question 1

How many Earth-volumes can be fitted into the Sun?

Question 2

The Andromeda Galaxy is going to crash into the Milky Way. When?

Question 3

If a person weighs 75 kg on Earth but what would they weigh on the surface of Mars?

Question 4

We all know who spoke the words “One small step…….” But who was the last man to walk on the Moon?

Question 5

While we are on the subject of the Moon, can you say what the name of the programme for landing on the Moon scheduled for the mid 2020s is?

Question 6

Where are the Planetoids usually located? Between which of the following? A. Mars and Jupiter B. Saturn and Jupiter C. Mercury and Venus D. Earth and Mars

Question 7

Which of the planets have rings around them? Please name them.

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Question 8

Which planets in the solar system do not have moons?

Question 9

We’ve just had a Blue Moon. The definition of a Blue Moon is that there are two full moons in a month. But what is the date of the next one?

Question 10

Which year will Halley’s Comet next be visible from Earth?

Question 11

What is the approximate diameter of the Milky Way?

A. 1,000 light years B. 10,000 light years C. 100,000 light years D. 1,000,000 light years

Question 12

A femtosecond was the shortest measurable time period in the 1990s, but now a shorter measurable time period has been developed. What is its name?

Question 13

And as the second part of the previous question, how is it measured roughly?

Question 14

There is a spacecraft cemetery in the Pacific Ocean. What is the area known as? A. Point Nowhere B. Point Nemo C. Exit Point D. Space Point

Question 15

Which of these if NOT a theory about how the Universe will end? A. The Big Crunch B. The Big Freeze C. The Big Dipper D. The Big Rip

THE SKY NOTES FOR JANUARY

Planets

Mercury was at superior conjunction on December 20th after which it moved to the east of the Sun to begin an evening apparition. It will move gradually out of the solar glare until, on January 24th it will reach a greatest eastern elongation of 19°. With the Sun 6° below the horizon at around 17:13 Mercury will be 9° above south-western horizon shining at magnitude −0.6. This will be one of the best evening apparitions of the smallest planet during 2021. The other will be in mid-May which will be slightly better in terms of its height above the horizon. Following elongation, the planet then begins to move back towards the Sun quickly losing both magnitude and altitude as it approaches inferior conjunction (between the Earth and Sun) in early February. Fig 1 gives the position of Mercury (altitude +9°) on the day of elongation with the Sun 6° below the horizon.

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Venus is still a morning object but is now becoming more difficult to locate in the twilight although, at magnitude −3.9, its brightness will be a considerable asset. At the beginning of the month, it is 10° in altitude at sunrise but by the end this has fallen to just 4°.

Fig 2 shows the position of Venus relative to the horizon every ten days throughout the month. As you can see, it is making its way back towards the Sun in preparation for superior conjunction in late March. This is the time when the Sun, Earth and Venus are all aligned with Venus and Earth on opposite sides of the Sun. As Venus moves closer to our parent star the phase that it exhibits to us becomes more and more full increasing from 94% to 97% during January. Of course, when it is “full” it is on the other side of the Sun and invisible to us.

Earth reaches perihelion (our closest to the Sun) on January 2nd at 13:51 when the two bodies will be precisely 147,093,163 km apart.

Mars begins the month in Pisces but on the 15th, it crosses the border into neighbouring Aries where it remains for the rest of the month. On the 20th it passes 1½° to the north of much fainter Uranus although a first quarter Moon will be nearby to make observation a little more difficult. However, despite its dwindling size, Mars is at a very favourable altitude and crosses the meridian due south on the first of the month 50° above the horizon. By the end of the month this figure has increased to 56° thanks to the planet continuing to move further north in declination. It was in July 2020 that Mars moved north of the celestial equator (and therefore into positive declination) after nine months below it. We were reasonably fortunate that, at the time of opposition last year, the red planet’s declination was positive. When it next reaches opposition, in December 2022, it will be 25° above the celestial equator and will culminate due south with an impressive altitude of 64°. However, as astronomers know, it is very unlikely that all the pieces of a jig- saw will fall into place at just the right moment and the next opposition is a prime example.

6 Although the planet’s declination is good, Mars will be further from the Sun than it has been at any opposition since 2016. At the current time its apparent size is falling quickly and will be just 9″ (nine arc seconds) by the middle of January as the Earth rushes away from it. Its brightness will also drop into positive figures to +0.1. Fig 3 gives the planet’s position every ten days during the month.

Jupiter is still an evening object just visible low down in the south west soon after sunset. On the first of January the planet is 8° high (almost exactly south west) at 16:42 when the Sun will be 6° below the horizon as shown in fig 4. The passage of Jupiter back towards the Sun is rapid, with the result that by the 15th the gas giant is just less than 2° in altitude (when the Sun is −6°). The planet’s magnitude remains high at a striking −1.9, which helps with identification, despite its apparent size falling to 30″ (from 47″ at opposition). However, Jupiter will be in conjunction with the Sun on January 29th and so will be lost to view for a while until it appears to the west of the Sun in the morning skies. It will be late March or early April before Jupiter becomes obvious to the casual viewer and July before it graces the evening skies once more.

Jupiter has, of course, moved on from the “Great Conjunction” with Saturn which took place around December 21st but there is another meeting of planets on January 10th when the two gas giants are joined by Mercury as it passes on its way to elongation.

The three bodies almost form an equilateral triangle with sides of around 2° as shown in fig 5. As you can see from the diagram you will need a good south-westerly horizon because all three planets will be below 5° in altitude by this time. If you do look for this conjunction using optical aid, please make sure the Sun has already set before doing so. 7

Saturn is being left behind by a faster moving Jupiter following their historic conjunction last month. The planet will, by way of its location and lower brightness, be the first of the gas giants to be lost to the solar glare. If you haven’t looked at it already then it is a long way past its best, setting by 17:45 which is just an hour and forty minutes after the Sun. With a magnitude of +0.6 and a disk 34″ across it will very soon be a difficult object to locate although the proximity of Jupiter will help. The ring system will appear to close up during the first half of 2021.

Lunar Occultations In the table below I’ve listed events for stars down to magnitude +7.5 that mostly occur before midnight although there are many others that are either of fainter stars or occur at more unsociable hours. DD = disappearance at the dark limb, RD = reappearance at the dark limb and RB = reappearance at the bright limb. The column headed “mm” (millimetres) shows the minimum aperture telescope required for each event.

Jan. Time Star Mag Phase % illumination mm 15th 16:49 ZC 3227 6.3 DD 7 70 18th 19:42 ZC 60 6.9 DD 30 50 19th 19:29 ZC 178 6.6 DD 40 50 20th 22:46 ZC 298 7.1 DD 50 70 21st 21:59 ZC 404 5.2 DD 59 40 22nd 22:48 SAO 93484 7.0 DD 69 70 23rd 19:33 SAO 93840 7.2 DD 76 90 26th 21:49 ZC 1070 5.2 DD 96 50

Phases of the Moon for January

Last ¼ New First ¼ Full 6th 13th 20th 28th

ISS Below are details for the brighter evening passes of the International Space Station (ISS) this month. The details of other passes, including those visible between midnight and dawn, can be found at www.heavens-above.com. Please remember that the times and directions shown below are for when the ISS is at its maximum elevation, so you should go out and look at least five minutes beforehand.

Jan. Time Mag. Alt° Az. Jan. Time Mag. Alt° Az. 19th 18:27:49 -1.6 16° SSE 26th 17:42:36 -3.7 75° SSE 20th 17:40:54 -1.4 11° SE 26th 19:18:09 -2.2 35° WNW 20th 19:15:01 -1.4 20° SW 27th 18:31:23 -3.8 78° N 21st 18:29:10 -2.8 32° SSE 28th 17:43:20 -3.8 83° N 22nd 17:41:21 -2.2 23° SE 28th 19:18:59 -2.3 38° W 22nd 19:16:16 -1.9 30° WSW 29th 18:32:07 -3.9 86° N 23rd 18:29:51 -3.6 59° SSE 30th 17:44:03 -3.8 79° N 24th 17:41:56 -3.1 44° SSE 30th 19:19:54 -2.4 39° WSW 24th 19:17:16 -2.1 34° W 31st 18:32:46 -3.6 68° SSW 25th 18:30:36 -3.9 89° S 8

The Night Sky in January (Written for 22.00hrs GMT mid-month) In the north the brilliant star Vega, the brightest member of the Summer Triangle, is skimming the horizon whilst the faintest partner in that group, Deneb, is still at an altitude of 15°. The tail of the Great Bear points downwards as the constellation begins its annual climb on the eastern side of the meridian. Directly opposite it is the much less conspicuous shape of Cepheus (King Cepheus in mythology), and between the two, the Little Bear hangs by its tail from the Pole Star. Immediately above the celestial pole is the faint constellation of Camelopardalis (the giraffe) which, despite being the eighteenth largest by area in the sky, contains no stars that are brighter than fourth magnitude.

Looking eastwards we see that Leo has fully risen and is due east whilst ahead of it the faint form of Cancer lies mid-way between the lion and the twins of Castor and Pollux. In the centre of Cancer, the open cluster M44 shines with a combined brightness of magnitude +3.1, though this is rather misleading because the 200 or so members are widely spread. In total it is around 1½° across and is one of the nearest open clusters to us. The head of Hydra, the water snake, lies just below Cancer although at this time its tail disappears below the horizon.

Looking south Orion currently straddles the meridian with his retinue scattered around him. South of the hunter is Lepus (the hare) whilst further south still is Columba (the dove) which would be an ideal target for someone on the south coast with a good sea horizon. Now is an excellent time to familiarize yourself with the hunter and the groups around him. The bright star Capella, in Auriga, is just 6° from the zenith whilst around it there are a host of open clusters of which M35 at magnitude 5.1 is the brightest.

Turning to the west we see that the western extensions of Pegasus are on the horizon although Andromeda points towards the zenith and M31 is still some 40° in altitude. At magnitude 3.4 it is certainly a naked eye object although photography really brings out the best in it. It is an excellent target for the DSLR user who takes numerous exposures and then stacks them together. You will easily be able to record two of M31’s satellite galaxies - M32 and M110. Also in Andromeda at magnitude 5.7 is a large open cluster NGC 752 which has around sixty members.

In the same area lies M33, known as the Triangulum or Pinwheel galaxy, which is a spiral that is face on to Earth but more difficult to detect due to its low surface brightness. However, it is also an excellent photographic target.

Meteors The Quadrantids are one of the year’s most active showers with many bright events that leave persistent trains behind them. It is one of a number of showers that have a very narrow peak of maximum activity and this year unfortunately the Quadrantid peak occurs at 11:00 on January 3rd. However, it will be worth watching as soon as the sky is dark on the night of the 3rd/4th although the radiant will initially be low in the north to begin with. The map in fig 6 shows the radiant position (black “R” in a red circle) at 21:00 which is the time that a 76% gibbous Moon rises close by in the east-north-east. From then on only the brightest of events will be visible.

9 Advance Warning for 2021

March 22nd - Graze occultation visible from Kent. June 10th - Annular solar eclipse – partial phase visible from the UK (20% from London, 25% from Leeds and 38% from Lerwick). August 12th - Perseid meteor shower maximum – Moon sets at 22:15

Brian Mills FRAS

THE LOSS OF THE ARECIBO RADIO TELESCOPE

In the December newsletter there was a report of serious damage to the huge Arecibo Radio Telescope in Puerto Rico, leading to the decision to dismantle the dish and the 900-ton suspended platform, but as many of you will now know, early on the morning of Tuesday the first of December, the remaining supporting cables for the platform finally gave way and it fell 170 metre (450 feet), smashing through a huge portion of the dish below. A small earthquake was recorded just before the collapse and may have had something to do with the timing.

Some of the support cables date from 1963 and were already showing signs of rust and in some cases some of the strands had already parted. The cables, which supported the large 900-ton structure over the middle were themselves supported by three concrete towers around the dish.

This gives some idea of the size of the suspended structure 170 metres above the surface of the dish. The suspended dome contains the secondary reflector

Image: University of Central Florida

A view of the suspended structure taken from the gantry upper platform

Image: NSF

10 There are several dramatic pictures and videos of the collapse that can be seen by looking for “Arecibo Collapse” on YouTube, including one from a drone being operated at the time when concerns were raised about the top of the eastern cable tower. The cable failure also resulted in the top sections of two of the towers to break away.

Here are two still photos taken at the time of the collapse and showing the resultant damage.

The dark cable at the moment it failed on top of Part of the remains of the gantry lying on the one of the support towers, taken from a drone dish hovering nearby Image: NSF Image: Arecibo Observatory/NSF

Also on YouTube are a number of videos showing earlier visits to the platform and you can see the reason for the enormous weight. There were numerous metal walkways and stairways with access to what was known as the azimuth arm, the inverted Gregorian dome and the Carriage house.

The main mirror, in the form of an inverted spherical dome was built in a natural sinkhole and completed in 1963. The surface was made up of 38,779 perforated aluminium panels, each 1 metre by 2 metres, and supported by a mesh of steel cables. The ground beneath allowed shade-tolerant vegetation to grow.

The telescope was in a Gregorian configuration with the secondary mirror inside the Gregorian dome that also contained a tertiary mirror to focus radiation at a point in space where a set of horn antennae could be positioned to gather received radiation. The dome was on one side of the Azimuth track.

The Gregorian dome could be positioned anywhere up to twenty degrees from the vertical.

On the other side of the azimuth track was the Carriage House with various antennae hung beneath it. Attached to these antennae were highly complex receivers operated in liquid helium to keep electronic noise down to a minimum.

Another unique feature of the telescope was its ability to use radar. The radar equipment being housed within the Gregorian dome.

In addition to the three sets of supporting cables, there were three pairs of cables, one pair from each corner of the platform and tied to concrete slabs beneath the main mirror. With these cables it was possible to adjust the height of the platform to millimetre accuracy.

In 1965, using very narrow radar pulses, the Arecibo telescope was able to determine the rotation of the planet Mercury and also was able to see surface features on Venus.

Following the discovery of Pulsars there were many theories as to what they were but in 1967 Arecibo saw the pulsar at the centre of the Crab Nebula which strengthened the idea that Pulsars are actually rapidly spinning neutron stars.

Following considerable interest in extra-terrestrial life, the most powerful signal ever sent from Earth was transmitted from Arecibo and contained 1,679 bits of information in the form of a string of binary code detailing chemical formulas for components of DNA, a stick figure of a human and a schematic of the solar system. The signal was beamed towards a cluster of about 300,000 stars, roughly 25,000 light-years away.

In the early 1990s Arecibo hinted at the presence of ice at the poles of Mercury, raising the question of whether ice might exist in shadowed craters on the Moon as well.

In 1989 the observatory created a radar image of asteroid 4769 Castalia, revealing the first known double-lobed rock in the solar system.

Fast Radio Bursts (FRBs) are brief, brilliant blasts of radio waves with unknown origins. The first was FRB 121102 spotted by Arecibo in 2012.

Another first for Arecibo was to indirectly sense evidence of ripples in spacetime in 1974, decades before gravitational waves were directly detected in 2015. By tracking the arrival time of radio bursts from pulsar PSR 1913+16 over several years it was found that

11 it was spiralling in towards its companion. As the orbits contract, energy was lost, whipping up gravitational waves. This indirect observation of gravitational waves won the 1993 Nobel Prize in physics.

Yet another first was the discovery of planets around another star, rocky worlds orbiting the pulsar B1257+12. In 1990, Arecibo was being repaired and so it was stuck staring at one spot on the sky. During its observations, Earth’s rotation swept the pulsar across the telescope’s field of view. Small fluctuations in the arrival time of radio bursts indicated that the star was wobbling as a result of the gravitational tug from unseen planets.

All quite a legacy from a now damaged-beyond-repair huge telescope. RIP Arecibo Radio Observatory.

JANUARY ZOOM MEETING

January 20th 2021 – There will be a short AGM followed by a talk by John Lutkin called “Live Video Astronomy – (If I Knew What I Know Now)”. This will be followed by a “Stellarium Tour” by Brian Mills.

Shortly before each meeting Members will receive an email outlining the upcoming programme together with details of how to join the Zoom Meeting. Please join the meeting with your mic set to mute to begin with.

FUTURE PROGRAMME OF WAS ZOOM MEETINGS

Details of future meetings can also be found on our website at: www.wadhurstastro.co.uk.

February 17th 2021 – We are extremely lucky to welcome back Professor David Rees whose intriguing talk via Zoom is called “Black Holes and Gravity Waves”.

March 17th 2021 – Speaker TBA

April 21st 2021 – Speaker TBA.

ANSWERS TO THE CHRISTMAS QUIZ

Answers to the Christmas Quiz.

Question 1

1,300,000 Earth volumes would be needed. (one point if you are within 10%) The Sun takes up 99.86% of the mass of the solar system.

Question 2 In about 4.5 billion years. This is based on observations gathered by GAIA.

Question 3 28 kg. And just for fun, the same person would weigh just 12.4 kg on the Moon.

Question 4 Eugene Cernan. He followed Harrison and Schmitt in Apollo 17.

Question 5 Artemis Programme. Artemis was the Greek Goddess of hunting, wild nature and chastity. The daughter of Zeus and sister of Apollo. Artemis was regarded as a patron of girls and young women and a protectress during childbirth.

Question 6 A. Mars and Jupiter. Most Planetoids are in the asteroid belt. There are millions of Planetoids in this region, most are very small and their total volume is believed to be less than that of the Moon.

Question 7 The Gas Giants, Jupiter, Saturn Uranus and Neptune.

Question 8 Mercury and Venus

Question 9 August 2023. It will be on the 30th of August. The next time there are two Blue Moons in a year will be in 2037 (January and March)

Question 10 2061. the last time it was visible from Earth was in 1986 and will return in 75 years from that date. 12

Question 11 C. 100,000 light years. The Milky Way is a barred spiral galaxy 100,000 to 120.000 light years in diameter, containing 200 to 400 billion stars.

Question 12 Zeptosecond. A Zeptosecond is a trillionth of a billionth of a second, or a decimal point followed by 20 zeros and a 1 or 10-21 of a second. The shortest time measurement ever made was the time for a photon to cross a molecule of hydrogen, taking 247 zepto- seconds.

Question 13 A zeptosecond is a time-measurement using a special spectroscopy microscope.

Question 14 B. Point Nemo. Point Nemo doesn’t actually exist. It is a position in the Pacific Ocean that is equidistant to 3 different coastlines. It is the most remote place on Earth so that the nearest humans will be astronauts.

Question 15 C. The Big Dipper is not a theory of how the Universe will end.

The successful winner of the quiz was James Smith with 9 correct answers. Congratulations James!

CONTACTS

General email address to contact the Committee [email protected]

Chairman - Brian Mills FRAS 01732 832691

Secretary - Phil Berry 01580 291312

Treasurer - John Lutkin

Newsletter Editor - Geoff Rathbone 01959 524727

Observing Director - Ian McCartney

Librarian - Phil Berry

Catering Manager - Jim Cooper

SAGAS Representative - Eric Gibson

Chris Storey

Wadhurst Astronomical Society website: www.wadhurstastro.co.uk

SAGAS website: www.sagasonline.org.uk

Any material for inclusion in the February 2021 Newsletter should be with the Editor by January 28th 2021

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