A DEC 3 Lunar and Two December Solar ISS transits

by John Hlynialuk

The website I use to determine the best viewing locations for ISS transits is
transit-finder.com. It allows you to designate your home latitude and longitude and select a travel radius and range of dates (about a month ahead). I picked 140 km as a travel radius, and it give me the transits that are within a couple of hours driving distance from Owen Sound, ON. There is one lunar transit of the superMoon on Dec 3 and two solar transits in December as well, Dec 8 and Dec 12. Some details for those are provided below.

Dec 3:
lunar transit occurs across the Full Moon but the ISS is not illuminated this time so you have to be watching at the right time (10:11 pm EST ) for the passage of the ISS silhouette, Centreline of the transit is from just S. of Sauble Beach over Allenford and thence SE towards Keady, Markdale, Flesherton and eventually Toronto. (See second map below). This is a short transit of about 1 second silhouetted against the bright super full Moon) with the moon 48° above the western horizon. Time is Dec 3 at 10:11 pm EST. Check www.transit-finder.com for the path in your area if you are outside of Bruce-Grey.

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Dec 8:
solar transit occurs in mid-afternoon at 2:33 pm EST and lasts about 3 seconds as well but the outline of ISS should be visible for the entire time. The Sun is just about in the same position in the sky as the lunar transit two weeks earlier. This time make sure you use solar filters on your telescope. This is the Sun you are looking at! Area of visibility is about the same coincidentally as the lunar transit of Nov 24, but centred over Hope Bay and Cape Croker. Howdenvale is well-placed.

Dec 8 solar

Dec 12:
solar transit occurs with a track of visibility farther south this time and visible Port Elgin to Big Bay. The Sun is a bit higher and the transit is fast -only 1,5 seconds. Be looking at 12:41 pm EST or so. Once again check out transit-finder.com for exact times for your location. Once again, proper solar filters for your telescope are required.

Dec 12 solar PE

Not one, but TWO ISS lunar transits in mid-Nov.

by John Hlynialuk
Lately I have taken to observing ISS transits of the Sun and Moon. These occur much more often than solar transits of planets (which are only possible for Mercury and Venus, both of which I have seen). Of course, no planets can pass in front of the Moon (unless we get a stray asteroid or other object in transit) but the International Space Station does this on a regular basis.

So far I have spotted one lunar and one solar ISS transit (Oct 4 and Oct 9) and have reported on the former event in the
SGN issue for Nov 2017 (pg 5). Click to download a copy.

The website I use to determine the best viewing locations for ISS transits is
www.transit-finder.com. It allows you to designate your home location latitude and longitude and select a travel radius and range of dates (about a month ahead). I picked 140 km as a travel radius, and it gave me 8 transits from Oct 30 to Nov 22, including the two described below.

The morning sky is the place for planet groups right now and will be until the end of 2017. Venus, Jupiter and Mars are located along the ecliptic over a span of about 30° and they are joined by the last crescent Moon in mid-Nov and mid-Dec. Check
COMING EVENTS and SKY SIGHTS on this website for details about some of the more interesting events.

The planets and Moon in the eastern sky before dawn are the backdrop for two interesting lunar transits by ISS that happen on the mornings of Nov 14 and Nov 15. The ISS (with a crew of 6 aboard) will be visible each morning crossing the sky from west to east. On Nov 14, around 5:56 am EST, look northwest and halfway up to the zenith. ISS will be bright that morning reaching -3.8 magnitude, -as bright as Venus! The heavens-above star map for the track of ISS is below:

Nov 14 ISS pass star map

ISS will appear as a very bright moving point of light crossing the sky from NW to SE and towards the crescent Moon above the south-eastern horizon. For most of us in Grey and Bruce, it will just miss the Moon, but if you are on the Cabot Head Rd about 4 km south of the lighthouse, you will see it pass right across the lunar crescent! (See the inset box on map below). The ground track of the ISS shadow is like an eclipse shadow with a specific width and path and is show shaded in blue on the Google map below. The only place it crosses land close to us on Nov 14 is across Cabot Head on the Bruce. The rest of the track is over Georgian Bay although it reaches land again in the Wyevale area and Horseshoe Valley. The location of the only observing spot for Bruce-Grey is shown below:

Nov 14 lunar 558pass

The pass of the ISS downwards across the crescent Moon will take about only 1.8 seconds and it will be illuminated so you will be able to follow it as it approaches the Moon quite easily.

A repeat of this happens again the next morning on Nov 15 at 5:08 am EST. This time a wider audience can get a view, and anyone from Miller Lake to Cape Croker will see it even though the lead up will be much shorter. This time ISS comes out of shadow just before it encounters the Moon, so look at the crescent at the appropriate time and the space station will appear right above it and slowly drop down to cross the Moon’s thin face. Those of you living in Lion’s Head can see it from home if you have a low enough eastern horizon where the Moon can be seen above the trees. (I suggest the Isthmus Bay Road which is where I will be set up if the weather allows).

Nov 15 ISS pass star map

Nov 15 wider view

The two maps from transit-finder.com show the entire track across the Bruce (above) and a close up of the the track across Lion’s Head (below). Isthmus Bay Rd about 2 to 3 km from “city centre” is a good location to view since it has a nice clear horizon to the east where the crescent Moon will be rising. This pass lasts about 4.5 seconds which is close to the maximum that can occur. Lots of time to get a good look at the ISS! I suggest you fill the FoV of your scope with Moon and watch the action! And if you get some images please let us all have a look by posting them here. I guarantee HOME page coverage.

Nov 15 lunar pas 508

Cassini Death Plunge

Goodbye Cassini and WELL DONE!
by John Hlynialuk

Intentionally crashing a 5600 kg spacecraft into a planet does not sound like a good thing, but controllers at the NASA Jet Propulsion Lab in Pasadena, California will do just that to end a multi-billion (that “b” is not a typo) dollar mission that has been studying Saturn for the last 13 years. It happens on Sep 15 and it is, in fact, the smart thing to do. One of the discoveries made by Cassini, the vehicle in question (think fully-loaded, over-sized SUV), is that one of the moons of Saturn probably has an ocean under its ice layer that could harbour some form of life. If the spacecraft contaminated that moon with earthly bacteria (spacecraft are routinely sterilized but you can’t keep a hardy bug down), it would not be a good thing. It is much wiser to vapourize the vehicle intentionally in Saturn’s atmosphere where the incineration would reduce everything to sterile atoms.

PIA21438 2

But even to the very end Cassini’s instruments will be wringing out information about Saturn.

To quote Linda Spilker, Cassini project scientist from NASA’s Jet Propulsion Laboratory:

The Cassini mission has been packed full of scientific firsts, and our unique planetary revelations will continue to the very end of the mission as Cassini becomes Saturn’s first planetary probe, sampling Saturn’s atmosphere up until the last second. We’ll be sending data in near real time as we rush headlong into the atmosphere – it’s truly a first-of-its-kind event at Saturn.

The data about the composition of Saturn’s atmosphere will be added to the wealth of other data and terabytes of images sent back by the spacecraft over the last 13 years. The discoveries have increased our knowledge about the planet immensely; where we had a single chapter in astronomy texts on Saturn, now there are literally dozens of volumes of information about the planet. As of December 2016, there were 3700 papers published in scientific journals using the data from this mission and it is not over just yet.

Cassini has clearly transformed our knowledge of the planet. Starting with the beautiful feature visible in telescopes from Earth, Saturn’s rings, Cassini found a highly dynamic system of particles constantly changing over time. Another surprise were the small moons embedded in the rings; these carve out gaps leaving behind beautiful sinuous patterns in their wakes. The dynamics of the rings of Saturn have revealed secrets about how planets form around stars and give insights into how our own planet may have coalesced from the dust circling our Sun in our early solar system.


As some discoveries have solved mysteries about Saturn, other mysteries have arisen as scientists scramble to analyze the data coming in. This includes giant hurricanes at Saturn’s poles, one with bizarre hexagonal sides unlike anything ever seen. How can this pattern be maintained over time? The number of scientific papers will continue to grow as planetary meteorologists propose theories to explain this unusual structure and other weather patterns in Saturn’s immense atmosphere.

Cassini also studied the dozens of moons circling Saturn and discoveries of wonderful things have involved them as well. Plumes of water vapour stream up from Saturn’s moon Enceladus, indicating a sub-surface ocean that is a possible abode for living organisms perhaps like those near Earth’s own deep ocean vents, the “black smokers”. The Cassini mission to Saturn also involved a smaller spacecraft called Huygens, which piggy-backed on Cassini from Earth and was released to parachute into the atmosphere of Titan, Saturn’s most enigmatic moon. There it found hydrocarbon lakes and rivers containing organic compounds, -a world where the chemistry may resemble our early Earth giving us a possible look back at our own evolution.

I highly recommend a look at the NASA Cassini website for more about the spacecraft and its discoveries, including some of the most spectacular images of Saturn, its rings and moons that I have ever seen. The link is provided here: https://saturn.jpl.nasa.gov

Goodbye Cassini, you have served us well!


by John Hlynialuk
As a satellite in our solar system, Earth’s Moon is actually one of the larger ones, ranking 5th biggest in diameter. Only three moons of Jupiter and one of Saturn, appropriately called Titan, are larger. Ganymede, circling Jupiter, holds the number one spot at 5262 km across, half again as big as our Moon which is 3475 km in diameter. Six of the several hundred planetary satellites in our solar system are actually bigger than the former planet, Pluto, now a “dwarf planet”, which I think puts it in its proper place.

The four large moons of Jupiter are interesting to watch in a telescope as they circle the giant planet especially when one (or more) cast shadows onto Jupiter’s disk. Through our telescopes, we can actually see the shadows produced by these moons during their eclipses and can follow the dark blots as they pass across the face of the planet.

Our own Moon also casts a shadow, and being on the surface of the Earth, we have the opportunity to put ourselves inside the shadow where it appears. All this comes together during a total solar eclipse.

The solar eclipse on Aug 21 is the most spectacular astronomical event of the year and will probably be seen by millions of people. For about an hour and a half, the Moon’s 110 km wide shadow will travel diagonally across the USA from Oregon to South Carolina. Two dozen BAS members will be watching near Grand Island, Nebraska where we reserved campsites a year and a half ago. Many more casual observers in the 11 states the path crosses will likely clog up the highways to the shadow path on that date, -one estimate predicts up to 7 million people may try to get to the narrow track at eclipse time.

The Moon may be large, but it’s shadow dwindles to a tiny dot by the time it reaches the Earth and only in that very narrow path, can one say that they have “caught” the Moon’s shadow. (it’s more like letting it pass over you for the few minutes of totality). I “caught” my first Moon shadow in the clear, cold sky above Gimli, Manitoba on Feb 26, 1979, over 38 years ago, and I still get goose-bumps on the back of my neck when I think about it. The shadow could be seen moving our way and then it swept over the group creating a 360* sunset. I could not help but shiver, not from the Manitoba cold but from the experience itself. And up in the sky an incredible sight! The corona, the outer atmosphere of the Sun appeared, wispy streamers like white, irregular flower petals, surrounding a black hole, the silhouette of the Moon. More shivers!

In the Bruce-Grey area on Monday, Aug 21, only a partial eclipse will be seen since the Moon misses crossing the centre point of the Sun. The maximum is at 2:30 pm DST, when 70% of the Sun will be covered.
The partially eclipsed Sun will NOT BE SAFE TO VIEW without solar eclipse glasses like those available from FotoArt or from suppliers like Rainbow Symphony or American Paper Optics online. SkyNews magazine July/Aug issue came with a pair as an insert and it may still be available at local outlets. Also a #14 (not #12) arc welders filter will provide safe viewing. Please note, none of these filters are to be used with binoculars or telescopes, they are for naked eye viewing and only for short intervals. Please be careful with your eyesight!
First contact last contact

From Owen Sound, some part of the Moon’s silhouette will be visible on the Sun from 1:08 pm DST to 3:45 pm DST. If you are further north or south, times may vary by several minutes, -first contact occurs later if you are north of Owen Sound’s latitude and earlier if you are south.


So if you are stuck on this local part of Earth on Monday Aug 21, at least have a quick look at the Sun with solar eclipse glasses around 2:30 pm or so. And on Sep 6 at 7 pm, you are welcome to join BAS at the Fox Observatory as we recap the event from the path of totality.
Here’s hoping for cloud-free skies (all over North America) on Aug 21!

Dark Skies -Bright Stars, PLEASE!

By: John Hlynialuk

Amateur stargazers, cottagers and nocturnal animals are really lucky to be living in Bruce and Grey counties. Stargazers have dark skies and bright stars to observe. Cottagers (away from overly-lit urban areas) have dark skies and a beautiful swath of summer Milky Way overhead when the family is out cooking weenies over a campfire. Nocturnal animals that live near or in the Bruce Peninsula Biosphere Reserve have nighttime darkness to which they have adapted over the millennia -no pesky streetlights making them well-lit targets for predators.

The common theme here is, of course, dark skies and a natural environment. Many places like the Bruce Peninsula Fathom Five National Park and the Bluewater Outdoor Education Centre are still mostly pristine environments and from a stargazing perspective, protected from unnecessary nighttime lighting, be it incandescent, florescent, or the most recent abomination, LEDs.

Keeping a dark nighttime environment is crucial for human health. Just google “Dark skies human health” for dozens of medical studies that support this contention. Fortunately, in the Bruce/Grey area of Ontario, nighttime over-illumination is only a problem in a few localities. Furthermore, efforts to preserve the dark nighttime environment locally have borne fruit. There are 17 Dark Sky Preserves in Canada, and four of them are within a 160 km radius of Wiarton. The four include Bruce Peninsula National Park near Tobermory, the Bluewater Outdoor Education Centre near Wiarton, Gordon’s Park on Manitoulin Island, and Torrence Barrens near Gravenhurst. Yes, locally we are optimistic about controlling light pollution, but the planet-wide scene is decidedly much the opposite.

Not to mince words, overall, we are losing the battle to control nighttime illumination. You just have to look at an image of the Earth at night from space to see how bright it is at night. Satellite cameras detect the totally wasted light sent upwards. Much light reflects back down from dust particles and water vapour and brightens the sky generally. The effect is visible even in rural areas as the visibility of faint objects is reduced. Even from 100’s of kilometres away, the light domes over our cities cast an orange glow into the sky. Anywhere near or within a large city, the glare from overhead lights is extreme, allowing only light from the Moon and bright planets to get through. Fainter objects are totally invisible.

[Click on image below to download a copy]

Image from study published in Science Advance magazine.

A study in 2016 authored by Fabio Falchi of the Light Pollution Science and Technology Institute in Italy and Chris Elvidge of the US National Oceanic and Atmospheric Administration (along with other international scientists) has found that in the USA, for ex., 80% of the population cannot see the Milky Way from where they live. The percentage is the same in urban Canadian areas like those along the Windsor to Montreal corridor. The darkest skies on our planet are of course, in areas like the Canada northland and in countries like Madagascar, the Central African Republic and Greenland, where everyone can see the Milky Way by just stepping outside.
[The original paper is available here:
http://advances.sciencemag.org/content/2/6/e1600377 ]

I am lucky to be able to see the Milky Way from my back yard because my house blocks the city lights to the north but there are sickly yellow-orange glows along parts of the southern and eastern horizon. Of course, like other large towns and cities, no Milky Way is visible from downtown Owen Sound. The situation locally has gotten worse in the last few years because the city recently replaced the majority of their streetlights with LEDs. These are certainly more economical and do have proper shielding to prevent upward light spill, but the overall level of lighting has increased approximately 30%, so the total light reflected from the ground upwards (especially in winter) has increased by a large fraction. Many people have commented to me that they find the lights at night overly bright. I agree and have the measurements to prove it.

On Saturday afternoon, May 27, there is an opportunity to visit a Dark Sky Preserve during the Open House at the Bluewater Outdoor Education Centre. The Bluewater Education Foundation and Ducks Unlimited Canada are co-sponsoring this event and it is open to everyone. You are welcome to come to the Outdoor Ed Centre (maps on the BAS website given below) and enjoy the wagon rides, birding, hikes, and fun kid activities like critter-dippin’ and face painting. Events start at 1 pm and will include solar observing with (safely-filtered) telescopes from the Fox Observatory. Everyone is welcome and after the Sun goes down, the observatory will be open for some dark sky viewing. Come and see what a Dark Sky Preserve is all about.

Check www.bluewaterastronomy.com for more information.