Newsletter October 2011

Education Centre and Observatory We are very grateful for donations which members have already made to enable us to proceed this far with the project.  Much developmental and planning work has been completed and progress leading to construction of the facility continues.  However, there is more to do, and further financial assistance is needed to continue to move forward with the venture.

 

While possible sources for the capital needed for actual construction are being pursued, the money we are seeking now is needed to complete the planning application.  It will also go towards acquiring the fixtures and furnishings needed within the buildings.

 

To this end, we are re-launching the Friend of the Observatory campaign and the pledges associated with it.  Once the Centre has been built, a plaque engraved with the names of all the ‘Friends’ will be placed above the entrance in perpetuity.

 

We welcome any size donation, small or large.  Contributions are welcome in the form of cash, cheque or online transfer, either as one payment, or on a monthly payment basis.

 

Our ABSA bank details are as follows:

Account name – Hermanus Astronomy Centre

Account number – 9230163786

Branch code – 632005

If you make an online donation, please include the word ‘pledge’ and your name, unless you wish to remain anonymous.

 

For further information, please contact John Saunders on 028 314 0543 or at shearwater@hermans.co.za

 

2012 monthly meeting dates The proposed dates for next year are as follows: 26 January, 23 February, 22 March, 26 April, 24 May, 21 June, 19 July, 23 August, 20 September, 18 October, 15 November, and 14 December.  Confirmation and details will follow.

 

WHAT’S UP?

Two features visible this month are a meteor shower and planetary alignment.  Night owls can look for the annual Orionid meteor shower after midnight towards the east from 2 October – 7 November.  The meteors shoot out in all directions from an area located ‘above’ the position of Orion’s head. The shower will peak on 21 October, at around 01.00.   Mercury and Venus are visible for about an hour after sunset this month.  At around 19.00 on 28 October they will be positioned near each other, low in the south-west, just below a 1% moon.

 

LAST MONTH’S ACTIVITIES

Monthly centre meeting Dr Lee-Anne McKinnell, MD of SANSA gave an absorbing presentation on 1 September on the history, and broad range of academic research and commercial work undertaken at the institution based in Hermanus, a location with a necessary magnetically clean environment.  Started in 1932, the HMO became part of The South African National Space Agency (SANSA), a newly created single policy and research organization, in 2011.  ‘Space’ in this context refers to near-Earth space ie. space between the Sun and Earth.

 

The Hermanus location offers a number of positive geographical features including proximity to the South Atlantic anomaly and to Antarctica (where much research is undertaken), limited land mass in the southern hemisphere (which reduces adverse influences on scientific measurements), and its location in Africa facilitates providing assistance to the developing world.

 

Activities undertaken in Hermanus include:

  • space research and magnetic measurements eg. space weather (conditions in the Sun which affect Earth eg. solar cycle), the magnetosphere, the ionosphere, space plasma & waves,
  • technology eg. the only place in SA for calibration of compasses for commercial aircraft and the armed forces,
  • the Space Weather Centre which provides real time data used for research, predictions and public education, and
  • science advancement – the Science Centre, unique in the Cape Town area, provides learning opportunities to learners, educators and the public.   Undergraduate and postgraduate university education is also undertaken in collaboration with universities.

Interest groups Cosmology On 5 and 19 September, 14 and 15 people, respectively, attended Parts 1 and 2 of the 3-part DVD ‘Atom’.

Beginners astronomy On 29 August, 36 people watched the final part of the very popular five-part BBC series ‘Wonders of the solar system’.  Fine weather allowed for star-gazing afterwards.

 

Educational outreach On 1 September, Johan Retief gave a presentation to learners at Bosko Christian School, developing their understanding of the solar system and the dangers of looking directly at the Sun.  Pierre de Villiers’ presentation to 65 Grade 1-8 learners and 7 teachers at Curro Hermanus also covered the solar system, including solar flares, and Johan Retief introduced the MONET project, also providing information on other astronomy opportunities eg. sidewalk astronomy at Gearing’s Point, SANSA presentations.

 

A very successful stargazing evening was held at Camphill on 6 September.  Approximately 40 residents and local and visiting co-workers observed a number of features using telescopes manned by Pierre de Villiers, Derek Duckitt and Johan Retief.

Other activities Sidewalk Astronomy Inclement weather on 2 September prevented viewing, but the large number of people who attended on 3 September illustrate the success of this new venture.

Article in Whale Talk In the September/October issue of Whale Talk, John Saunders wrote ‘About Hermanus Astronomy Centre & some of its activities’, focusing on the MONET project, the naming of Asteroid Hermanus and the planned Astronomy Education Centre and Observatory.

 

THIS MONTH’S ACTIVITIES

Monthly centre meeting  The presenter on 6 October is Dr Debra Shepherd from the University of Cincinnati, currently on secondment from the US National Radio Astronomy Observatory as Commissioning Manager for the South African Karoo Array Telescope (MeerKAT) and SKA project based near Carnarvon.  The title of her presentation is  ‘Astronomy: inspiring the people of South Africa with hope and an understanding of our place in the universe’.  Dr Shepherd will be talking about one of the most important science projects yet undertaken in South Africa.

 

As usual, tea and coffee will be available after the presentation and, weather permitting, an opportunity for star-gazing.  Non-members are welcome for a fee of R20 (R10 for students and children).

 

Interest group meetings  The Cosmology group meets on the first and third Monday of every month. The final part of the three-part DVD ‘Atom’ will be shown on 3 October.  Part 3 ‘The illusion of reality’ considers how studying the atom forced us to rethink the nature of reality.  On 17 October, the first in a series of topics selected by group members from those covered in the ‘Cosmology’ DVD series will be considered.  Discussion will follow re-presentation of one of lectures. The meetings take place SANSA at 7.30 pm.

 

Visitors who attend for one evening are welcome for free, but will need to join the Centre if they wish to attend further meetings.  For further information on these meetings, or any of the group’s activities, please contact Pierre Hugo at pierre@hermanus.co.za

 

The next Beginners astronomy meeting is on 10 October, at SANSA at 7.00 pm.  They will be followed by stargazing from the SANSA car park (weather permitting).

 

An entrance fee of R20 will be charged per person for non-members and R10 for children & students.  To attend, please contact John Saunders at shearwater@hermanus.co.za or on 028 314 0543 to reserve a place.

 

Sidewalk astronomy Star-gazing will take place on Friday 7 October and Saturday 8 October at Gearing Point, from approximately 7 pm, weather permitting.  It is offered free to everyone, members and non-members alike.

 

FUTURE ACTIVITEIS

Trip to Cape Town This trip has been postponed until 2012.

Trip to Carnarvon The visit to see MeerKAT and Kat-7 is scheduled for 11-13 November.  For further information, please contact John Saunders by at shearwater@hermanus.co.za or on 028 314 0543

 

Christmas party The party on Friday 9 December will take place at Molteno’s restaurant in Onrus.  Details will follow.

2011 MONTHLY CENTRE MEETING SCHEDULE

These will take place at 7 pm at SANSA (formerly HMO).

6 October         ‘Astronomy: inspiring the people of South Africa with hope and an understanding of our place in the universe’ by Dr Debra Shepherd, MeerKAT & SKA

3 November      ‘Sir John Herschel’ by Auke Slotegraaf, psychohistorian and amateur astronomer

9 December      Christmas party

OBSERVATORY NEWS

Page 4 of the 29 September issue of Hermanus Times contains details of the application for a lease submitted by the Hermanus Astronomy Centre to Overstrand Municipality for land on Rotary Way on which to build the proposed Astronomy Education Centre and Observatory.  The application is available for review, and any written objections, until 31 October.  Once this part of the process is complete, the application will be considered by the Overstrand Municipality.

 

The Friend of the Observatory pledge campaign has been revived in order to help raise the money needed to complete the planning application and also equip the observatory with necessary fixtures and furnishings (details at the start of this newsletter).  Work is also continuing on possible sources to fund construction of the buildings.

 

ASTRONOMY NEWS FROM STEVE KLEYN

GRAIL and the mystery of the missing moon As early as 8 September, NASA’s GRAIL mission will have blasted off to uncover some of the mysteries beneath the surface of the Moon.  That cratered gray exterior hides some tantalizing things – even, perhaps, a long-lost companion.  If a paper published recently in the journal Nature* is right, two moons once graced our night skies.  The proposition has not been proven, but has drawn widespread attention.

 

“It’s an intriguing idea,” says David Smith, GRAIL’s deputy principal investigator at MIT. “And it would be a way to explain one of the great perplexities of the Earth-Moon system – the Moon’s strangely asymmetrical nature.  Its near and far sides are substantially different.”  The Moon’s near side, facing us, is dominated by vast smooth ‘seas’ of ancient hardened lava.  In contrast, the far side is marked by mountainous highlands.  Researchers have long struggled to account for the differences, and the ‘two moon’ theory introduced by Martin Jutzi and Erik Asphaug of the University of California at Santa Cruz is the latest attempt.

 

Scientists agree that when a Mars-sized object crashed into our planet about 4 billion years ago, the resulting debris cloud coalesced to form the Moon.  Jutzi and Asphaug posit that the debris cloud actually formed two moons.  A second, smaller chunk of debris landed in just the right orbit to lead or follow the bigger Moon around Earth.

“Normally, such moons accrete into a single body shortly after formation,” explains Smith. “But the new theory proposes that the second moon ended up at one of the Lagrange points in the Earth-Moon system.”

 

Lagrange points are a bit like gravitational fly traps.  They can hold an object for a long time–but not necessarily forever.  The second moon eventually worked its way out and collided with its bigger sister.  The collision occurred at such a low velocity that the impact did not form a crater.  Instead, the smaller moon ‘went splat,’ forming the contemporary far side highlands.  In short, the lunar highlands are the lost moon’s remains.

 

GRAIL will fly twin spacecraft around the Moon for several months. All the while, a microwave ranging system will precisely measure the distance between the two spacecraft.  By watching that distance expand and contract as the pair fly over the lunar surface, researchers can map the Moon’s underlying gravity field.**   “These measurements will tell us a lot about the distribution of material inside the Moon, and give us pretty definitive information about the differences in the two sides of the Moon’s crust and mantle. If the density of crustal material on the lunar far side differs from that on the near side in a particular way, the finding will lend support to the ‘two moon’ theory.”

 

But this information is just one “piece of the jigsaw puzzle.”  To prove a sister ever existed, other pieces are needed.  NASA’s Lunar Reconnaissance Orbiter has already provided key information on the Moon’s surface topography.  Scientists can also refer to lunar surface chemistry data and look at seismic information from Apollo for clues.

But what’s really needed, says Smith, is a sample return mission to the far side to determine the ages of rocks there.  “The smaller moon, if there was one, was about 1/3 the size of our current Moon.  So upon collision it would have cooled down faster, and the rocks on the far side, where its remains are thought to have spread, would be older than the ones on the near side.”

 

In any case, we have something new to think about. Shall we try singing “fly me to the moons” or “shine on harvest moons”?  “Don’t go changing any song lyrics just yet,” says Smith.

Author: Dauna Coulter | Editor: Dr. Tony Phillips | Credit: Science@NASA

Horizons for Pluto NASA’s New Horizons space probe was launched in 2006 and still has 4 years to go before its mission is completed.  It is one of the fastest probes ever launched and is presently doing just under 2 million kms per day. Its destination is the minor planet Pluto which has never before been explored or examined close up. Pluto is a resident of the Kuiper belt, a vast region of icy bodies near the outermost limits of the Solar system.  Classified as a dwarf planet, Pluto nevertheless has a circumference of about 8000 kms around its equator.  Scientists believe that it is probably just one of thousands of similar size bodies in the Kuiper belt

 

To date, the little that is known about Pluto has been limited to images taken by the Hubble space telescope which reveal a newly discovered moon and only smudgy areas that look like a layer of molasses.  New Horizons is equipped with LORRI (Long-Range Reconnaissance Imager), the highest resolution imaging system yet installed on an interplanetary probe.  When about 1600 kms distant from Pluto, LORRI will take first pictures which, at the same distance from Earth would clearly show details such as individual buildings and their shape and size. There is much speculation as to what will be revealed.  The molasses smudges might be primordial organic matter, there might be icy geysers and numerous unknown features and surprises.

 

The 9½ years is the longest flight yet undertaken for a probe to reach its destination, and New Horizons has had to be packed with state of the art equipment and systems, many of which are duplicated in case of failure.  Two computers, two heaters etc. and even the scientific instruments are capable of backing each other up.  With such a long flight New Horizons spends a lot of time in “hibernation” but everything has to wake and work when it reaches Pluto in 2015.

DID YOU KNOW?

Space exploration. Part 5: Second into space: Explorer 1 and Project Vanguard

 

Until the Moon landings, the US was effectively behind in the Space Race, with the Soviets achieving most of the ‘firsts’.  However, the Americans caught up quickly and, in terms of ‘winning’ the race, they achieved this by being first to land a man on the Moon, in 1969.

 

First steps and Explorer 1

 

Explorer 1 rocket

The US satellite programme began in 1954 as the joint Army and Navy Project Orbiter.  However, it was cancelled in 1955 in favour of its competitor Project Vanguard.   Nevertheless, following the launch of Sputnik 1 in October 1957 and explosive failure of the first Vanguard programme launch in December, 1957, Project Orbiter was revived as the still on-going Explorer programme, and its basic rocket design was used for the rocket which launched Explorer 1, the first US artificial Earth satellite, a mission which lasted 111 days.  Built in 84 days and launched in January 1958, it weighed about a fifth of that of Sputnik 1.  Like Sputnik 2, which had also been launched in 1957, Explorer 1 carried scientific instrumentation.  Although Sputnik 2 had, the previous year, detected raised levels of charged particles, it was data from Explorer 1’s cosmic ray detectors which were later recognised as the formal discovery of the Van Allen radiation belt.

 

Taken over by NASA, ‘Explorer’ has continued to be the label used for American robotic spacecraft missions, and the programme has seen the launch of over 80 probes.  As with early Soviet programmes, some early Explorer missions failed, but the vast majority has been successful.  In addition to the Van Allen belt, Explorer satellites have made several important discoveries including Earth’s magnetosphere, the solar wind, properties of micrometeoroids, radiation from the solar system and beyond, solar energetic particles, atmospheric physics, radio and gamma ray astronomy, and geodesy.  Some craft have travelled to other planets while others have monitored the Sun.

 

Project Vanguard

Vanguard 1 explosion

This brief programme ran from late 1956 until late 1959.  Managed by the US Naval Research Laboratory until it was taken over by NASA in 1958, this programme aimed to launch the first artificial satellite into Earth orbit.  However, although its first three sub-orbital test missions had been successful, the first attempt at launching a satellite into Earth orbit, undertaken under pressure from Washington a few months after Sputnik 1 had been launched, failed spectacularly, with a huge explosion seconds after launch.  Photographs of the failure of Vanguard-TV3 were published widely in the press, alongside derogatory reports.  Unlike the Soviets, who carefully managed publicity surrounding their launches, this was a very public US failure, which provided great propaganda for the USSR.

 

Successfully launched in March 1958, Vanguard 1 became the first US satellite to reach ongoing stable Earth orbit, with an estimated life of 240 years. The first ever satellite to be solar powered, it had a 16.5 cm diameter and weighed only 1.47 kg.  Despite its small size, Vanguard 1 has sent back important information including the non-spherical shape of Earth at the poles, and upper atmospheric densities.  Although the mission was officially ended in 1964 when the solar cells eventually died and communications ceased, Vanguard 1 remains aloft and is the oldest manmade satellite still in orbit.

 

Both the other 2 successful Vanguard satellites were launched in 1959.  Like their predecessors, both are still in orbit.  In addition to providing data on atmospheric density, Vanguard 2 was also designed to measure cloud distribution over the daylight portions of its orbit.  It is about 3x the size of Vanguard 1, its instrumentation including two small optical telescopes with which it obtained the cloud data.  The objectives for Vanguard 3 were to measure Earth’s magnetic field, solar X-ray radiation and its effects on the atmosphere, and the near-Earth micro-meteoroidal environment.

 

Overall, although they met all their scientific objectives, only 3 Vanguard satellites were successfully launched out of 11 attempts.   In 1959, Project Vanguard was succeeded by Project Mercury.

 

* Programmes highlighted in bold* are covered in other parts of this series

Sources: http://en.wikipedia.org , www.filer.case.edu/~sjr16/advanced/index.html

COMMITTEE MEMBERS

John Saunders   (Chairman)                                       028 314 0543

Steve Kleyn   (Technical Advisor)                       028 312 2802

Pierre de Villiers   (Treasurer)                            028 313 0109

Irene Saunders   (Secretary)                             028 314 0543

Jenny Morris   (Newsletter editor)                     071 350 5560

Derek Duckitt  (Website editor)                        082 414 4024

Johan Retief  (Monthly sky maps)                         028 315 1132

Peter Harvey (Membership secretary)                028 316 3486

Lynette Geldenhuys (Education co-ordinator)      028 316 2428

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