Wednesday, March 26, 2008

Making MOST

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As part of our Space Exploration Badge we built a full scale model of a satellite! Here are some pictures of our model.

Canada and Canadians have a history of innovation and success in space exploration. From Alouette 1 to the Canadarm and Canadarm2 used aboard the Space Shuttle and International Space Station. By 2006, Canada had over 33 payloads in orbit. One of these is a tiny observatory called Microvariability & Oscillations of STars (MOST) that is making a big splash in the field of astronomy.

Most is a micro-satellite, about the size of a large suitcase, that was launched by Canada on an Russian rocket in 2003. Launched on a modest (for space exploration) budget, MOST has been called the Humble Space Telescope in reference to its much larger and more expensive predecessor the Hubble.

MOST orbits the earth from pole to pole in perpetual darkness and can keep its cameras focused on stars for almost two months! Because it can pick up small variations in light from the stars it observes, MOST can be used to study planets orbiting other stars and variations in the star's atmosphere (a bit like studying earthquakes). MOST hopes to answer questions about how the Sun may evolve and even how stars contributed to the formation of solar systems.

Expected to operate for about one year, it's still going. In fact, the science team has opened up to the public to propose observing targets through the My Own Space Telescope project!

MOST is unusual for a space telescope in that it uses an unusual lens design. The Fabry microlens array spreads light from target stars over a large number of pixels to achieve high resolutions.

The 433rd has contributed too. Mitchell's dad is part of the operations team, Mang has proposed a couple of targets. Here's a chart showing the parts of the sky MOST can see and some of the official candidate and selected targets.

The chart shows the sky mapped out against the coordinates used by astronomers. The x-axis is the Right Ascension (in hours) and the y-axis is the Declination (in degrees).

There are three zones that are important to MOST. The CVZ (Continuous Viewing Zone) is where MOST can keep itself focused for up to about 60 days at a time! There are two SS (Sun Sensor) zones. Targets within the SS zones represent the extreme range of the telescope and can be focused on for shorter time periods. If you are really interested in a star in the SS zones, one trick is to pick a second star and switch between the two. These are called "switch targets".

These targets are all taken from the official web site for MOST. One thing that may be of interest is that some of the candidate stars were chosen before the operational parameters of MOST were well understood. If you look, you will see candidates well outside the SS zones.

This particular chart shows two stars that I proposed for observation. One is a switch target. Can you figure out what they are? And why I picked them?

Another surprise for me was that I could actually get Excel to produce a chart like this!

More information on MOST can be found at

Do you recognize this badge?

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Last meeting I was looking at our Pack's inventory of badges to see what we were short (and long) on. And I came across this one in our stock.

Now I started in Scouting as a Cub in 1967 and a lot of the badges are familiar. Others are obviously newer. But this one I didn't recognize right out, even though it seemed familiar.

It turns out it's discontinued.

Do you know what it is? Can you guess?

The background may provide a hint.

Wednesday, March 19, 2008

Calculating Easter

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Most people know that Easter moves around a bit. They look it up on the Calendar and leave it at that. But why?

The Short Answer

If you just want a list of Easter's for this century, The Astronomical Society of South Australia has a list here. But you still won't know why.

The Story

It turns out there is quite a story behind this movable holiday. The calculation of Easter has had broad reaching effects that most people are blissfully unaware of.

Good Friday and Easter, are the days Christians recognize the Crucifixion of Jesus Christ and the Resurrection. The Bible tells us that this was a Friday because the Sabbath began that evening. It also tells us that was during Passover because Pilate offers to release Jesus as is the custom during Passover. Easter, also called Pascha, follows on the Sunday. Easter Monday is a remnant of week long celebration and is not just a "bank holiday". There is also some debate if the Last Supper was a Passover meal or not.

At this point you might be tempted to think that Good Friday should be the first Friday in Passover or that it should be on the same day each year. If only it had been that easy.

Now since Passover is based on the Hebrew calendar which is Lunisolar (a hybrid of Lunar and Solar events) the Moon is involved. This is why it moves around on a solar calendar. Anytime you have overlapping calendar systems be prepared for some complication.

Complications did ensue. Some people thought it should be on the same date in the year and others thought Easter should be on a Sunday. This led to disagreements, including the excommunication of the Quartodecimans. And while it seems that folks later made up, this may have been one of several precursors to later disagreements that split the the church.

Easter is defined as the first Sunday after the first fourteenth day of the the Paschal Full Moon that is on or after March 21 and the vernal equinox. However, just to complicate things this full moon doesn't always correspond to a real full moon. Although it should be within a day or two.

The multiple references to 14 (quartodecima) arise from the original dating of Easter after the 14th day of Nisan on the Hebrew calendar. Nisan falls in the March-April time frame.

So Easter can fall anytime from March 22nd to April 25th on Christian calendars. And yes, I meant calendars plural. While the west uses the Gregorian calendar, Eastern churches mostly use the Julian calendar. The result is that Eastern churches celebrate Easter from April 4 to May 8 on the Gregorian calendar. Despite this, Easter sometimes falls on the same day as in 2001, 2004, 2007, 2010, and 2011.

The main differences between the two calendars is in the way they handle leap years and leap days. The Julian calendar has too many and consequently that calendar gets ahead of the seasons. Pope Gregory XIII advised by Clavius and Kepler reformed the calendar to bring the Equinox and Easter back in line with the start of spring.

Now before I wander off topic with these last notes, please consider that I am not one to get hung up on literal interpretations of the Bible. As Jesus said, give to Caesar what is his and to God what is God's. I choose to rely on science and faith for the things they each do best. And, I think, mixing them up is unwise.

Of Other Things Easter Related

The Biblical account of the Crucifixion speaks of three hours of darkness, earthquakes, and the Moon turning blood red. Some people believe that the darkness is an eclipse and have used that to try and get an accurate date for this event. However, the facts don't support this. Daytime (Solar) eclipses last only minutes and they happen on the new moon. Lunar eclipses happen on full moons and turn the moon red but they happen at night.

Another problem is that the year and date of Christ's birth aren't really known exactly and may vary from 8 BC to 6 AD. Some people have tried to fit astronomical events to the birth of Christ, but there is simply too much uncertainty. The determination of AD or Anno Domini (the year of our lord and not "after death") was calculated by a monk named Dionysius Exiguus. Prior dates became Before Christ. Ironically, Dionysius didn't set out to determine when Christ was born but was calculating tables of Easter dates.

BC/AD have become widely accepted outside of Christian culture but they are often referred to as BCE and CE (Common Era).

Dates BC/AD cause mathematical problems. Consider, is there a year zero? Since the Romans had no number for zero, the Early Christians wouldn't have had one either. Mind you Dionysius almost coined it! One of the few sciences that actually has to accurately deal with spanning BC/AD is Astronomy. And for ease of calculation, astronomers have their own years which use integer notation. We are living in +2008, 1 BC is 0, and 2 BC is -1.

There is an old myth that you can make an egg stand on end at the moment of the Vernal Equinox. You can. But you can also do it other times as well. A couple of articles and a video were published, here and here.

Exactly how did we get from the Biblical events of Easter to Rabbits and Eggs? Wikipedia has some ideas, here.

And while I remember, folks from Purdy's Chocolates were handing out free samples at the Ontario Science Center during March break. Yum!

  • Astroprof posted a discussion of the Easter Moon and the difficulties of calculating Easter.
  • Additional links about Easter and astronomy can be found over at Cosmos4u at the bottom of the article.
  • The Toronto Star published an account of why Easter is so early. Nice photo of the Cathedral of Strasbourg's astronomical clock too. See here.

Tuesday, March 11, 2008

David Dunlap Observatory Tour and Photos

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On March 4th 2008, the 433rd Cubs, parents, and a few Scouts paid a visit to the David Dunlap Observatory. Unfortunately the weather did not cooperate and we couldn't actually see the stars or do our work for the Globe at Night's light pollution awareness project. We were fortunate to beat a major snowstorm that descended on the city shortly after we left.

We were able to take in a presentation at the administration building that covered many of the requirements of the Astronomers Badge. The tour also counts towards requirement B3 or the Black Star. Our cubs had some good questions and demonstrated their knowledge of astronomy including one or two things that surprised me.

Afterward we were able to visit the observatory dome and see the telescope. The scope is quite massive and the Cubs were impressed that it was so finely balanced that impatient astronomers could move the 25 ton assembly by hand!

We learned a bit of the history of the facility, its use for astrophotography, and a renown Canadian astronomer Helen Sawyer Hogg who conducted research at the DDO for many decades.

We also saw a spectrographic lens and learned a bit about some of the work being done, including a study of rather bizarre systems known as contact binaries. In these systems two rapidly co-orbiting stars are so close they actually touch but do not merge! There are a number of interesting question that aren't known about these including how they came so close.

Hopefully, we will be able to return later this spring to actually look through the eyepiece!

Our thanks to Tuba Koktay, Ian Shelton, and Thomas Karmo at the DDO.

Article on Binocular Astronomy

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A while back I wrote that your first telescope should be a good pair of binoculars. This morning I came across an article on things to look at with those binoculars using Sirius as a reference star. You can find the article at Universe Today. From Sirius you should be able to find two or three Messier Objects even in the city.

Cubs working on their astronomy badge should recall that Sirius is easy to find. It's the very bright star, trailing Orion slightly to the south and east. From Etobicoke we can see down to magnitude 4 on a good night.

And if you want to look at more, there's always the wonders in Orion!

Monday, March 10, 2008

Astronomical distances are .... (well) astronomical

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How can someone begin to describe astronomical distances?

We sometimes use fancy compound terms like outer space, deep space, interstellar space, and intergalactic space.
Image used with permission of Jim Boles.
You can be factual like NASA's page on cosmic distances or Wikipedia's page on astronomical distances.

You can use humour to make your point, like Douglas Adams in the The Hitchhikers Guide to the Galaxy:
Space is big. Really big. You just won't believe how vastly hugely mind-bogglingly big it is.
You can even be darkly poetic, like Michael Moorecock's "Dark Corridor" introduction to Hawkwind's "Space is Deep":
Space is infinite, it is dark
Space is neutral, it is cold
Stars occupy minute areas of space
They are clustered a few billion here
And a few billion there
As if seeking consolation in numbers
But none of these help you visualize how big space is!

Think of the Earth as a shiny blue marble (standard marbles are 1.25 cm or 1/2" in diameter - smaller than the one in the photo). Below are some approximate comparable scale sizes for objects /distances in our solar system:
  • The Moon - 3.5mm or 0.13"
  • Mercury - 5mm or 0.2"
  • Mars - 7mm or 0.37" - a chickpea
  • Venus - another marble (a bit smaller than Earth)
  • Low Earth Orbit Satellites - basically the same size as the marble
  • Uranus -5 cm or 2" - an orange
  • Neptune - another orange (a bit smaller than Uranus)
  • Communications satellites (geosynchronous) - 8.25 cm or 3.25" - a hockey puck
  • Saturn - 12 cm or 4.75" - grapefruit
  • Jupiter - 14 cm or 5.5" - a slightly bigger grapefruit
  • Saturn's visible rings - 26.8 cm or 10.5" - an old LP record
  • The Sun - 1.36 m or 54" - a small weather balloon or large exercise ball
Okay, that was fairly easy. So you might be considering a scale model of the solar system using fruit, vegetables and some odds and ends from a garage sale. Now you need some real estate.

Wait for it! Still using our marble for Earth, the Moon would be 0.75 m or 29" away. Or about an adults' arms length. Below are the approximate distances of things from the Sun using the same scale (I'll give up on Imperial measures here):
  • Mercury - 136 m - a bit larger than a football field
  • Venus - 213 m
  • Earth - 293 m - a bit shorter than the Eiffel Tower
  • Mars - 488 m - a bit shorter than the CN Tower
  • Jupiter - 1.6 km
  • Saturn - 3 km
  • Uranus - 6 km
  • Neptune - 9 km
  • Pluto - 14 km at its' farthest
That is a very long hike from our little blue marble!

Now if you wanted to place these to scale and allow space for the full orbits of all the planets and Pluto (it was demoted to a dwarf planet), the Sun would need to be in Mel Lastman Square in North York at the center of a 28km circle running from Lake Ontario to north of the David Dunlap Observatory in Richmond Hill!
If you're wondering what that looks like, take a look at this map of the Solar System in Toronto.
And it gets worse:
  • Proxima Centauri the nearest star at around 4.2 light years would be 77,000 km away from our marble. On scale, the marble is about 1/5 of the way to the moon!
  • Betelgeuse a red supergiant about 430 light years away would be 7,883,333 km away. On our scale, that's about 1/8 of the way to Mars at it's closest or about 1/20th the distance to our Sun.
  • The Milky way galaxy is about 100,000 light years across. So our marble is now about 1.8 billion km away or outside the orbit of Saturn.
Galaxies are millions of light years apart, the Local Group of galaxies containing our own Milky Way is about 10 million light years across. On the scale of our marble, the local group only gets us about 1/200th the way to the nearest star! The Universe itself is billions of light years across.

I'll stop now before my head hurts trying to visualize all of this in terms of our little blue marble.

Astronomical distances operate on levels. Just when you think you've gotten used to one of them, you'll see another and be humbled all over again.

Tuesday, March 4, 2008

Polite Comments are Welcome, SPAM is not.

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I encourage comments on this blog. I just ask that if you make them consider that the audience is includes kids. In particular kids of Cub and Scout age (8-13).
All comments are reviewed with this audience in mind. Inappropriate comments and comments containing bad language will be removed (there is no way to edit out bad words). Spammers and very offensive material will be reported and removed. 

Comments posted to recent articles will  appear immeadiately and will be reviewed.  Comments posted to older articles will be held for review.

The following are subject to rejection:
  • Obvious product advertisements (and additionally reported)
  • Offensive languages (and potentially reported)
  • Personal attacks and "flames"
  • Random nonsense (possible testing by spammers)
  • Unsolicited and off topic
  • Unreachable links
If a post is otherwise worthwhile, I may choose to re-post and delete individual bad words.

I will attempt to be reasonable, if there is a discussion about a type of product. Simple and informative posts about something in the same class of product and discussions of pros and cons of these products are expected.

I reserve the right to revise this policy without notice, reinstate comment moderation or take other actions to control spam/offensive material.

And to the spammers who wanted us to know about your alleged anti-virus solution, weight loss product, and enhancements Now you know. BTW, your blogger ID and all your links were reported as abuse.

Monday, March 3, 2008

Scouts in Space (not kidding)

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I came across this article on scouts in space by a leader of 1st Avoca Beach Scouts just north of Sydney in New South Wales Australia!
Of the 294 men and women selected to be astronauts since 1959 to 2005, more than 180 have been Scouts.
and ...
Astonishingly, 11 of the 12 men to have walked on the moon were Scouts.

The first man on the moon, Neil Armstrong, was a Scout and ...

What’s more, Armstrong had carried the World Scout Badge with him on his historic mission.

Update: At least 22 of them were women, here.

Snow Moon Eclipse - simple astrophotography

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The night of the BP banquet also coincided with the Snow Moon and a lunar eclipse. As we were leaving the banquet, the shadow of the Earth had just begun to take a bite out of the moon.

I wanted to try and photograph the eclipse as simply as possible. Using just a camera tripod and digital cameras setup for self-timed exposures to reduce vibration. I was able to catch the Moon framed by Regulus (above) and Saturn (lower left).

The photograph was taken with a Nikon 995 digital camera in manual mode (while Nikon makes wonderful cameras with great optics, I could go off on a nice rant about the user interface). It's the best one of a series taken with maximum aperture, maximum optical zoom, and exposures of between 2 and 8 seconds (I believe this is either a 4 or 8 second exposure). It was also taken from my driveway with all the light pollution of Toronto's west end.

There is a nice composite exposure of the eclipse over here at Visual Astronomy. And another over here at Universe Today.

There was also an article on "What they don't tell you about" lunar eclipses at over here at Breaking News for Sky Afficionados.

Linking with the 9th Benoni Cubs

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The 443rd Cubs wanted to link with a pack from another country. We were fortunate enough to find the 9th Benoni Pack outside Johannesburg South Africa.

Since we wanted to learn about how they were like and unlike us, we decided to have a question exchange. Each pack was asked to put together a list of 5 to 10 questions that they would want to ask the other Pack.

We found out that Cubs are Cubs and despite some differences, including 13,000 km of distance, we were surprisingly alike. Both packs wanted to know about things:
  • each others uniform and scarves
  • meeting places and meeting structure
  • favorite activities and games
  • camps attended in a year and where
  • badges and advancement
  • climate
  • ages of scouting sections
The 9th wanted to know if we had girls in the pack (not this year) and if we played American style football. Our fiercely Canadian Cubs had other sports on their mind.

Scouts Canada seems to differ a bit from South Africa. There seems to be a more granular advancement Cheetah, Leopard, Lion and Leaping Wolf. There is also a badge called the Arrow of Light which Canada doesn't have but South Africa and the United States have. It indicates the Cub is prepared to advance to Scouts.

A reference on South African Cubbing badges can be found here.

Some references on Canadian Cubbing's 70+ stars, badges, and awards can be found here, here, and here.

Akela Joy at the 9th maintains a blog with lots of activities and pictures, here. There are some good activities on it and I encourage you to read it. They recently had a raptor show and South African Eagles are quite impressive looking!

This activity counts towards our centenial crest, here.

BP Banquet 2008

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For some photos of the BP Banquet, see here.