Astronomy

Our July 2009 Newsletter has got to be a special one, even though in the greater scheme of things you might call it just "one small step for man …". But more of that later, and I make no apologies for this newsletter being rather longer than usual! 

Planets

Whilst Mercury, the nearest planet to the Sun, does rise in the NE before the Sun rises at the beginning of the month, dawn is already lightening the sky and it's doubtful that you would see anything of the planet. As the month progresses, Mercury rises later and will soon rise after Sunrise, so you simply won't be able to see it at all. And here’s the usual solar "health warning": Don't use binoculars or any other optical equipment in an attempt to see Mercury – if you accidentally get the Sun in your field of view, it could cause serious and permanent eye damage.
 
Venus rises in the NE between 01:00 and 02:00 UT (Universal Time – add 1 hour to convert to BST) throughout the month, as does Mars at the beginning of the month, but around about midnight by the end. Both planets will rise further above the horizon and towards the E as the night progresses, until they are washed out by the dawn glare. Venus is still very bright, but dimming marginally as the year progresses.

Jupiter rises in the ESE, about two hours after Sunset, at the beginning of the month, and at just about Sunset at the end. It reaches its highest point in the sky (but only about 20° above the SE horizon at this time of year) just before Sunrise at the beginning of the month, and in the early hours at the end. It is very bright during the entire month, getting ever brighter as it approaches "opposition" (astronomy-speak meaning being in the part of the sky opposite the Sun) at the middle of August. Jupiter's four brightest moons are all on the same side of the planet on the 21st of the month, more or less coinciding with the New Moon and darkest sky in the early hours. Get your binoculars out and see if you can spot them.

The furthest of the naked-eye planets, Saturn, is about 20° above the WSW horizon at Sunset at the beginning of the month, and itself sets at about 23:30 UT, and is about 10° above the W horizon at Sunset at the end of the month and itself sets about 21:30. It's moving towards "conjunction" (i.e. to the other side of the Sun as seen from Earth) in September, and is now about as bright as Mars, so do try to see it as it won't be this well-placed again for the next few months.

Meteors and clouds

There are a number of minor meteor showers ("shooting stars") this month, but none particularly exciting. The alpha-Capricornids are probably the best, starting in mid-July and peaking on 2 August – only about five meteors per hour, but often including slow, bright fireballs! They appear to originate from the constellation Carpricornus, 15° above the S horizon, at midnight and later.

There is an eclipse of the Sun on Wednesday 22 July. The longest time a total eclipse of the Sun can last at one point on the Earth's surface is seven minutes and 31 seconds. The maximum duration of totality for the 22 July eclipse is six minutes and 39 seconds – the longest there will be in the 21st century! The complete path of the eclipse is India, Nepal, Bangladesh, Bhutan, Myanmar and China, then across the Japanese Ryukyu Islands after which somewhere in the Pacific Ocean the longest duration occurs. Sadly we shall see none of it here – not even as a partial eclipse, but I thought it was unusual and interesting enough to warrant a mention in this Newsletter.

Copyright Grant Privett

So if we cant get to see the eclipse (and I think my eclipse-chasing days are over where uncomfortable long-haul flights are involved!) we'll stay at home instead and enjoy the noctilucent ("night-glowing") clouds (NLC), which are at their best this month. This aerial phenomenon is good in June as well though, and I came across this stunning photograph on the Internet recently – Stonehenge and NLC in the same picture! It was taken on 17 June 2009 by Grant Privett, a Herefordshire man who recently moved to Wiltshire, and he has kindly given me permission to use it here. NCL don't appear every night, but if the sky is clear, look just above the N horizon an hour or so after Sunset and later, and look for these beautiful and delicate electric-blue strands of light.

To the Moon

Finally, let's talk about the Moon – there's a lot to say this month. Full Moon occurs on the 7th of the month. Do you remember that the full Moon on 10 January was the closest and brightest full Moon of the year, and was also the third brightest full Moon during the 25 years from 1993 to 2017?  I suggested that you photographed it then, and again at the furthest full moon of the year (July!) with the same camera settings, and you should see the difference in size quite clearly.

The Moon occults (passes in front of) several of the stars of the bright and beautiful star cluster the Pleiades (aka The Seven Sisters), particularly Merope (occultation starts at about 01:20 UT) and Atlas (occultation starts at about 02:20), so worth attempting another photograph or two.

And of course we have to remember the Moon landing on 21 July 1969 – the date on which man first stood on the surface of an astronomical object other than the Earth. So 21 July 2009 is the 40th anniversary of that momentous event.

Those of us old enough to have been around at the time will never forget that day, but it all really started several days earlier. The Apollo 11 Saturn V launch vehicle lifted off from Pad 39A at the Kennedy Space Centre at 13:32 UT on Wednesday 16 July 1969. It took 12 minutes to reach Earth orbit. Then after one-and-half Earth orbits, the Saturn V’s third stage engine increased Apollo's speed enough to escape the Earth's gravity and start the real journey towards the Moon.

I was working for the GKN Research Centre, Wolverhampton at the time, but was seconded for a project at Shotton Brothers Ltd., a subsidiary of GKN in Halesowen, on the day of the launch. Some of us were able to listen to the Launch Control commentary live on portable radios – I don't recall much work being done that afternoon!

The Lunar Lander, call sign "Eagle", landed on the Moon at 20:17 UT on Sunday 20 July with about 25 seconds of descent braking fuel left. They had expected about 90 seconds, but the terrain was much more inhospitable than had been anticipated, and Neil Armstrong had to take over from the automatic systems, find a suitable spot, then bring the craft down manually.

Buzz Aldrin on the moon

The first words spoken from the surface of the Moon were not Armstrong’s "one small step for man" speech, but Buzz Aldrin's technical announcement as he called out navigation data to Armstrong "Contact light! Okay, engine stop."  (It always sounds like "Contact lights" to me, but the official version is in the singular.)

It was a beautiful summer evening here on Earth – well, certainly in Kidderminster – and realising that the Moon would set locally in a couple of hours time and that in less than 24 hours the astronauts would have left the Moon, I rushed into my garden to see the Moon, about 16° above the SW horizon, with the first two Moon-landing Earthmen on it! Nerd or what?

Some technical housekeeping was then required, after which the flight plan called for a sleep period for the astronauts, but understandably they wanted to get on with the Moonwalk. Armstrong descended onto the Moon’s surface at 02:56 UT on Monday 21 July 1969. (It's ironic that, because of world-wide civil time-zones, the Moonwalk occurred on 20 July in the USA whereas the officially recognised date the world over is 21 July!)

On the way down the ladder, Armstrong activated the black-and-white TV camera attached to the Lander, and although it was amazing to see live television from the surface of the Moon, the picture quality was disappointing. This was because NASA was using a slow-scan system which sent ten frames per second with a resolution of 320 lines and which was incompatible with public TV systems around the world. So they transmitted the image simply by viewing it with a conventional TV camera, this technically crude method causing significant loss in picture quality.

Armstrong then spoke his famous first words from the surface of the Moon: "That’s one small step for man, one giant leap for mankind", and shortly afterwards, Aldrin joined Armstrong on the Moon's surface. They spent the remainder of the 2˝ hour Moonwalk undertaking a variety of tasks: photographing the Lander so that NASA engineers would be able to see its condition; testing methods of moving around, including hopping; collecting over 20 kg (47 lbs) of moonrock; and setting up lunar monitoring equipment, including a passive seismograph and a laser ranging reflector.

After less than 24 hours on the Moon's surface, the Eagle took off again, rendezvousing with the Lunar orbiter, and making a thankfully uneventful return to the Earth. Apollo 11 had successfully met John F Kennedy's belief that " … this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to the Earth … " with just over five months to spare! Phew!

Despite all the technology that originated from the Apollo project (and, no, I don't mean non-stick frying pans – how about the microprocessor that has had the most profound influence on the lives of all of us?) some people still ask what use it was. To quote a story told by the late American astronomer Carl Sagan in his book "Broca's Brain": "… British physicist Michael Faraday was visited by his monarch, Queen Victoria. Among Faraday's many celebrated discoveries … were more arcane findings in electricity and magnetism, then little more than laboratory curiosities. The Queen asked Faraday of what use such studies were, to which he is said to have replied, 'Madam, of what use is a baby?'"

Open day

Finally, the Carolian Astronomy Society and King Charles I School and Specialist Science College, Kidderminster are jointly commemorating the International Year of Astronomy and the 40th Anniversary of the first manned Moon landing, with an astronomy Open Day at the School on Comberton Road, Kidderminster DY10 1XA, on Saturday 11 July. The attractions will include, amongst others, a planetarium, an astronomy "project" area aimed at teenagers and younger children, an opportunity to safely look for Sunspots (weather permitting) using the school's Solarscopes, trade stands, and, in a lighter vein, Lego "Star Wars" sculptures, including a 2ft by 3ft Millennium Falcon. There will also be a series of general astronomy talks of interest to the general public during the day, including, amongst others, "Choosing and using an astronomical telescope", "Images of the Universe", "Dark Skies", "How we got to the Moon" and again in a lighter vein "The work of Ralph MacQuarrie" (conceptual designer and futurist responsible for the "look" of the original "Star Wars" trilogy).

Admission is free, and the programme of events will be added to by the day. So keep an eye on our website for up-to-date additions.

 Hopefully see you there on the day!

Watch the Skies! Martin Humphries.