Thursday, 14 September 2017

Lecture, 4Ms, Hayden on TV, Cassini end, Portballintrae event, ISS, No DE? DIAS,

Hi all,
(I'm back after an amazing and successful eclipse trip/holiday in the USA. There will be an illustrated talk by Dr Andy McCrea and myself on this event later in the year.)
1. NEXT IAA LECTURE: "Ancient Stones and Comets: Developing the Giant-Comet Hypothesis" Wed 20 September.  This will be given by Prof Mark Bailey, Emeritus Director of Armagh Observatory:
   This is the opening lecture of the new IAA season, and we are delighted to welcome back Prof Mark Bailey to talk on a fascinating topic, on which he is an acknowledged expert.
Synopsis; A bright comet can become the most prominent object in the sky other than the Sun and Moon and a source of wonderment and awe for those lucky enough to see one.
   This talk begins with an introduction to comets, their origin and proximate source in the Oort cloud; and then discusses evidence for exceptionally large, so-called "giant" comets with diameters 50km to 100km or more.  Such an object can be expected to arrive in the inner solar system at intervals of the order of 50 to 100 thousand years, and debris from their evolution may produce a very much more "active" sky than that experienced today. 
    Evidence for the arrival of the most recent giant comet some 10 to 20 thousand years ago suggests a possible explanation for mankind's early interest in the sky, a powerful motivation for the erection of monuments with astronomical associations, and the origin of religion.
Wed 20 September 7.30 p.m., Bell Lecture Theatre, Physics Building, QUB. Free admission.  Free parking on QUB campus after 5.30 p.m.
2. Mercury, Mars, Moon and Morning Star 
Mercury, the innermost planet, and the most difficult of the 5 'classical' planets to spot, is currently well-placed in the dawn sky. It has Mars, the Moon, and the Morning Star (Venus) for company over the next week or so, making it easy to locate! The following details rely to mornings, looking East, about 1 hour to 45 minutes before sunrise.

   On Sep 16, Mercury will lie just 28' above right of much fainter Mars (mag 1.8); next morning it will be only 22' below and right of the red planet. 

    On Sep 18, the waning crescent Moon will lie 3º below Venus, and very close to Spica. It will be about 8º above much fainter Mars (mag 1.8). That morning at about 06.30 there will be a 5-object line up: Mercury, Mars, Moon, Spica, and Venus.

   On Sep 19 the waning crescent Moon will lie 3º below Mercury, giving a nice line-up of Moon, Mercury, Mars and Venus. You can get sky charts on

3. Hayden Geraghty on UTV Life this Friday, The amazing Hayden, by far our youngest IAA member, and both a media star and a hit with various astronauts, will be on UTV at 8.0 p.m. on Friday 15 sep, with Pamela Ballantine., Also joining them will be space fanatic  Dr Niamh Shaw
4. Goodbye, Cassini: The Final Countdown:

September 14 (21:45 UT) Cassini turns its antenna to point at Earth, begins a communications link that will continue until end of mission, and sends back its final images and other data collected along the way.

September 15 (8:37 UT) The "final plunge" begins. The spacecraft starts a 5-minute roll to position its instruments for optimal sampling of the atmosphere, transmitting data in near real time from now to end of mission.

September 15 (11:53 UT) Cassini enters Saturn's atmosphere. It's expected to lose radio contact with Earth within about one to two minutes after beginning its descent into Saturn's upper atmosphere. Its thrusters fire at 10 percent of their capacity to maintain directional stability, enabling the spacecraft's high-gain antenna to remain pointed at Earth and allowing continued transmission of data as long as possible.

September 15 (11:54 UT) Cassini's thrusters are at 100 percent of capacity. Atmospheric forces overwhelm the thrusters' capacity to maintain control of the spacecraft's orientation, and the high-gain antenna loses its lock on Earth. At this moment, expected to occur about 940 miles (1,510 kilometers) above Saturn's cloud tops, communication from the spacecraft will cease, and Cassini's mission of exploration will have concluded. The spacecraft will break up like a meteor moments later.

During its dive into the atmosphere, the spacecraft's speed will be approximately 70,000 miles (113,000 km) per hour. The final plunge will take place on the day side of Saturn, near local noon, with the spacecraft entering the atmosphere around 10 degrees north latitude.

To see the last images look at, and check and follow it to the end at and

More at
5. Galaxies to Girona Gold.  Portballintrae Community Development Group, Portballintrae Village Hall, Portballintrae, Saturday 30th September 2017 11am – 4pm. Light Lunch included.
Come and hear the latest thinking on a wide range of issues affecting Life on Earth. You will be hearing from experts on – The Cosmos, our Planet, the Oceans, Biodiversity, Archaeology, Wildlife, Butterfly Conservation, Geology. Irish Astronomical Association – Geology - Marine Archaeology
Biodiversity - Meteorology – Butterfly Conservation,
 Irish Whales and Dolphin Group with Ulster Wildlife Living Seas.
Admission £7.50 for adults & £3.50 per child. Tickets purchased through email button on Facebook, Contact Lorna on 07486290430 or email:
6. ISS  in morning skies until 19 Sep. It will then reappear for a series of evening passes on 26 Sep. Details on the excellent free site
8. DIAS Lecture, 19 Oct:  "Brave new worlds: the planets in our galaxy" by Professor Giovanna Tinetti, University College London.
The DIAS School of Cosmic Physics Statutory Public Lecture 2017 takes place on Thursday 19th October at 6:30pm in UCD. (Theatre C (O'Connor Theatre - Room H2.22), Science Hub, University College Dublin.  Admission is free but advance booking is required on eventbrite here. 
9. Saturn: Soon disappearing from our view until next spring, but what a finale! Our celestial showpiece, and undoubtedly the most beautiful sight in our solar system, if not the entire sky, was directly opposite the Sun in the sky, and so visible all night, on 15 June. It's now past its closest to Earth, so it's still a good time to observe it. BUT - it's also almost as far South in the sky as it can be, so it's poorly placed for observing from our latitudes. Not only is it always quite low down in the sky, with atmospheric absorption and poor seeing, it's above the horizon only for a fairly short time (pace the comment above - think about it; this is when the nights are shortest!). Nevertheless, it's always worth a look just to see those glorious rings! See item 4 above.
10.  Mayo Dark Sky Festival 27-29 October. A great line-up of speakers again this year

Booking now open at


11. Backyard Worlds: Planet Nine. Backyard Worlds is hoping to discover a large planet at the fringes of our solar system — a world astronomers call Planet Nine. But Backyard Worlds need your help! Finding such dim objects requires combing through images by eye, to distinguish moving celestial bodies from ghosts and other artifacts. So come and join the search — there are many images to look through. In the end you might discover a rogue world that's even nearer to the Sun than Proxima Centauri! Discover more about the project and how to contribute here: 



Astronomy Museums, Visitor Centres, & Public Observatories Workshop, 27-29 September 2017, Leiden, the Netherlands. See:  
World Space Week 2017: 4–10 October 2017, Location: All around the world. More Information: 
International Observe the Moon Night: 28 October 2017, Location: All around the world, More Information:

36th International Meteor Conference, in Petnica, Serbia, from September 21 to 24, 2017. For details contact the Local Organizing Committee at 

 International Observe the Moon Night, 28 October 2017. More Information: 


13. Interesting Weblinks: (Disclaimer - Use of material herein from various sources does not imply approval or otherwise of the opinions, political or otherwise, of those sources).  NB: If the title in the weblink does not indicate the subject matter, I give a brief simple intro before the link. I may also comment about the link afterwards.
Astrophysics The telescopes comprise just the VLT - Very Large Telescope. The VLTI is the VLT Interferometer - the instrument and technique used to combine the images from the telescopes via computer to give the resolution of a telescope equivalent to their separation.
UV light from superluminous supernovae reveals explosion mechanism 
New Physics to explain cosmological mysteries 
New study to check if laws of physics are the same throughout the universe 
Earth & Moon  
QUB astronomers find exoplanets which could spot Earth 
Solar System:
SPACE: I wonder how they will reduce the atmospheric pressure to less than 1% of that on Earth, get temperatures down to below minus 100 degrees C, and bombard the surface with high-energy solar and even higher-energy cosmic radiation? Should be fun!


15. JOINING the IRISH ASTRONOMICAL ASSOCIATION: This link downloads a Word document to join the IAA.
If you are a UK taxpayer, please tick the 'gift-aid' box, as that enables us to reclaim the standard rate of tax on your subscription, at no cost to you. You can also make a donation via Paypal if you wish: just click on the 'Donate' button. See also


Clear skies,

Terry Moseley

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