CONJUNCTION

GREAT CONJUNCTION:
      A great conjunction in the east south east sky tonight. Perfect visibility here in Winnipeg with Jupiter slightly to the left and above the waxing Moon. Gotta get out there with binoculars, 41 below windchill or not.
Frozen but happy in Winnipeg.

THE CALENDER:

WELCOME TO SUMMER:

Today is the summer solstice, the beginning of summer. Here's an article that tells what it all about.

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Summer solstice

From Wikipedia, the free encyclopedia
This article is about the Earth's axial tilt.
Diagram of the Earth's seasons as seen from the north. Far left: summer solstice for the northern hemisphere. Front right: summer solstice for the southern hemisphere.The summer solstice occurs exactly when the Earth's semi-axis in a given hemisphere is most inclined towards the sun, at its maximum tilt of 23° 26'. Though the summer solstice is an instant in time, the term is also colloquially used like Midsummer to refer to the day on which it occurs. Except in the polar regions (where daylight is continuous for many months), the day on which the summer solstice occurs is the day of the year with the longest period of daylight. The summer solstice occurs in June in the Northern Hemisphere north of the Tropic of Cancer (23°26'N) and in December in the Southern Hemisphere south of the Tropic of Capricorn (23°26'S). The Sun reaches its highest position in the sky on the day of the summer solstice. However, between the Tropic of Cancer and the Tropic of Capricorn, the highest sun position does not occur at the summer solstice, since the sun reaches the zenith here and it does so at different times of the year depending on the latitude of the observer.[1] Depending on the shift of the calendar, the summer solstice occurs some time between December 21 and December 22 each year in the Southern Hemisphere, and between June 20 and June 21 in the Northern Hemisphere.[2]

Worldwide, interpretation of the event has varied among cultures, but most have held a recognition of sign of the fertility, involving holidays, festivals, gatherings, rituals or other celebrations around that time.[3]

The word solstice derives from Latin sol (sun) and sistere (to stand still).

Dates and times The following lists the dates and UTC times of the summer solstice for the early portion of the 21st century.[4]

Year Northern Hemisphere Southern Hemisphere
2000 June 21, 01:48 December 21, 13:37
2001 June 21, 07:38 December 21, 19:21
2002 June 21, 13:24 December 22, 01:14
2003 June 21, 19:10 December 22, 07:04
2004 June 21, 00:57 December 21, 12:42
2005 June 21, 06:46 December 21, 18:35
2006 June 21, 12:26 December 22, 00:22
2007 June 21, 18:06 December 22, 06:08
2008 June 20, 23:59 December 21, 12:04
2009 June 21, 05:46 December 21, 17:47
2010 June 21, 11:28 December 21, 23:38
2011 June 21, 17:16 December 22, 05:30
2012 June 20, 23:09 December 21, 11:12
2013 June 21, 05:04 December 21, 17:11
2014 June 21, 10:51 December 21, 21:23
2015 June 21, 16:38 December 22, 04:48
2016 June 20, 22:34 December 21, 10:44
2017 June 21, 04:24 December 21, 16:28
2018 June 21, 10:07 December 21, 22:23
2019 June 21, 15:54 December 22, 04:19
2020 June 20, 21:44 December 21, 10:02

AMATEUR ASTRONOMY:
TRIPLE PLAY IN THE MORNING SKY:


Assuming you get up before the Sun does, which isn't hard this time of year, there is an interesting sight in the eastern sky. Given good conditions the three planets Mercury, Venus and Saturn will be visible at the same time. Here's the story from that great site Space.com.
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Planet Triple Feature:
Venus, Saturn and Mercury Visible at Dawn This Week
By Geoff Gaherty
Early risers this week will be treated to a spectacular display of planets and bright stars as Venus, Mercury and Saturn take center stage in the predawn sky.

Half an hour before sunrise, three of the brightest planets will stretch across the eastern sky, further enhanced by the presence of two first magnitude stars, blue-white Spica and deep red Antares.

The sky map above shows how Mercury, Venus and Saturn will appear before sunrise in the eastern and southeastern sky.

The first object to attract your attention will be the planet Venus, outshining everything in the sky except the sun and moon. In a small telescope, Venus will appear as a tiny half moon as it approaches its greatest apparent distance from the sun on Saturday, Jan. 8.

Second in brightness will be the elusive planet Mercury, well below and to the left of Venus, close to the horizon. Do not confuse it with the red giant star Antares, almost directly below Venus.

You may need binoculars to spot Mercury in the bright dawn sky. This is not a favorable apparition of Mercury because of the shallow angle that the ecliptic (the path of the sun through the sky) makes with the horizon. Mercury also appears in a telescope as a tiny half moon, with the greatest elongation being on Sunday, Jan. 9.

Finally, above and to the right of Venus rides the planet Saturn, and, just below it, the brightest star in the constellation Virgo: Spica. In a telescope magnifying more than 25 times you should be able to see Saturn's famous rings, although magnification of around 200 times is needed to see the details.

Whenever you view Saturn in a telescope, be on the lookout for its retinue of moons. Even the smallest telescope will show its largest moon Titan, and larger telescopes will show half a dozen more.

AMATEUR ASTRONOMY:

LUNAR ECLIPSE NOT VISIBLE IN MANITOBA:

As with so many other astronomical events the first total lunar eclipse to coincide with the winter solstice since 1638 isn't visible tonight in Winnipeg as yet more snow drifts gently down to move us to the wettest year in history. Here in the Central Time Zone the umbral phase is due to begin at 12:32 am, and totality at 1:40 am. Totality will last until 2:53 am, making this one of the longer eclipses. There are two lunar eclipses due next year, so better luck next time.

For the curious you can read all about this eclipse in a wikipedia article now on the web. The full eclipse will be basically a North American event this time around with the old world and much of South America missing large parts of the event. For places other than here in the Great Canadian Snowdrift the wikipedia article gives a chart of the phases for various time zones. A good source for viewing conditions in your locale is the Clear Dark Sky website. Much better and more detailed than the average weather report. For those diehards who just have to see something NASA will host a webcam real time version of the eclipse here. Seems like a very poor substitute to me, but to each their own. There will also be a chat room at the NASA site so you can either praise or howl about viewing conditions where you live.

All I can say is better luck next year.

AMATEUR ASTRONOMY:

GEMINID METEOR SHOWER TONIGHT:

Tonight the annual Geminid meteor shower peaks, with the most likely time of maximum intensity being after midnight. The first quarter Moon will set shortly after midnight so there will be little interference from its light. Gemini itself will be rising in the east at about 9pm. Over the past few years the intensity of this shower has been increasing, and it is likely that it will put on a better show than the summer Perseids .

The Geminid shower was first seen only 150 years ago, and it is thought that they are the only meteor shower whose parent body is an asteroid, 3200 Phaethon, rather than a comet. Under good viewing conditions it might be possible to see 120- 160 meteors per minute. For more on this event see this article from wikipedia or, for the more technically minded see the International Meteor Organization Calender. The Astronomy Calender also has a multi-year listing for important sky events. Don't miss the upcoming lunar eclipse on the 21st, the longest night of the year.

AMATEUR ASTRONOMY:

MOON, MARS AND ANTARES AT DUSK:

Early evening tonight 9too late) and tomorrow is a good time to spot an interesting triplet in the dusk sky towards the southwest. on these nights Mars and the Moon pair with the red supergiant Antares shortly after sunset. Antares is the brightest star in the constellation Scorpio and is so large that if it were in our solar system it would extend to somewhere between the orbits of Mars and Jupiter. it is about 600 light years from us, and has the visual luminosity of about 10,000 suns. Despite this its distance means that it is "only" the 16th brightest visual star. catch this triplet tomorrow evening (see diagram). look for Mercury as well.

AMATEUR ASTRONOMY:
JOVIAN SHADOWS:

Coming up in our night sky this weekend which, miraculously enough, is predicted to have clear nights skies.... With only a small low power telescope you'll be able to witness a rather unique event as all four of the Galilean moons of the planet Jupiter casts shadows that will be visible on the planet's surface. Jupiter can be easily spotted in the next few nights as it rises in the southeast and gradually makes its transit across the sky to the southwest as dawn approaches. It is quite bright ( -2.7 magnitude), and is in the constellation of Aquarius near to Pisces.

Tonight is also the peak night of the Taurid meteor shower, in Taurus of course. While not as spectacular as the Leonid meteor shower due to arrive later this month it has the advantage at least in Winnipeg of having good viewing conditions and relatively clement weather conditions.

Here's more on the upcoming "shadow transits" from the Space.com site.
JMJMJMJMJMJM
Jupiter's Moons to Perform Weekend Show for Skywatchers
By Geoff Gaherty

This weekend, a remarkable series of events will take place on Jupiter: The planet's four big moons will cast shadows on the gas giant planet that can be seen from Earth using a small telescope.

The planetary shadow play, which begins Saturday night (Nov. 6) and runs through early Sunday, will be primarily visible from the western coast of the United States. [Illustration: Moon shadows on Jupiter]

The four bright moons of Jupiter are known as the Galilean moons after their discoverer Galileo Galilei. As they revolve around Jupiter, they sometimes pass across the face of the planet as seen from Earth, as well as behind the planet and in its shadow.

How to see Jupiter's moon shadows

First, a word of caution: The overnight between Saturday and Sunday is when we switch back from daylight saving time to standard time, so be careful you get the correct time for your location.

Because the complete sequence of events is only observable from the U.S. West Coast, we will use Pacific Time here to discuss the best viewing times. Observers further east will miss the later events, and should add the appropriate number of hours to the times depending on their location and time zone.

The show begins at 8:53 p.m. PDT (11:53 p.m. EDT) on Saturday (Nov. 6), when Jupiter's largest moon Ganymede begins to cross the planet's face.

Because Ganymede has a relatively dark surface, it appears bright against the limb of Jupiter — but quickly appears to change to a dark gray against the bright central parts of Jupiter's disk. This can be seen with telescopes that have as small as a 5-inch aperture.

At 9:47 p.m. PDT, a second moon — Europa — follows Ganymede across Jupiter's face.

Because Europa's surface is icy, it reflects a much more light than Ganymede, and closely matches Jupiter's cloud belts behind it. As a result, it vanishes in all but the largest telescopes, perfectly camouflaged.

At 10:24 p.m. PDT, yet another moon — the volcanic Io — begins to disappear behind the opposite side of Jupiter.

At 11:52 p.m. PDT, Europa's shadow starts to take a notch out of the western limb of Jupiter. This can be seen with telescopes that have as small as a 3-inch aperture. Two minutes later, Ganymede moves off the disk of Jupiter and is once again a bright spot in the sky.

But wait, there's more — the Jupiter moon show isn't over just yet. Here's a rundown of the movements of Jupiter's moons to watch for on Sunday:

At 12:31 a.m. PDT, Europa leaves the disk of Jupiter.
At 1:12 a.m. PDT, a second shadow, that of Europa, puts the bite on the west limb of Jupiter. We now have two shadows creeping across the face of Jupiter, while the moons casting them are off to the right, a wonderfully three-dimensional effect.
At 1:41 a.m. PDT, Io emerges from Jupiter's shadow, ending its eclipse.
At 2:00 a.m. PDT, Daylight saving time officially comes to an end, and you should move your clock back to 1 a.m.
Now, at 1:34 a.m., Pacific Standard Time, Europa's shadow moves off Jupiter's disk. Finally, at 3:08 a.m. PST, Ganymede's shadow also moves off the disk.
You may be puzzled by the fact that Ganymede leads Europa across Jupiter's disk, but Europa's shadow precedes Ganymede's all the way across.

That's because Europa orbits much closer to Jupiter than Ganymede, so that the angular distance between Ganymede and its shadow is much greater than the angular distance between Europa and its shadow.

Gallery: Photos of Jupiter and its Moons

AMATEUR ASTRONOMY:

STRANGERS IN THE NIGHT:

Well Molly has been back from vacation for a few days and is hard at it again. I'm almost over the agitating experience of coming back and having to make close to 70 phone calls. Let alone the usual set of mechanical disasters. It also means I'm back to my usual late nights. Good thing this evening as I was doing this, that and the other thing in the yard and at the car, and I had a chance to catch the pairing of the almost full Moon and the planet Jupiter when they were by my own crude estimate only 2 1/2 to 3 degrees apart. Quite striking.

As the diagram shows they will gradually separate over the next few days, but they still make a great sight. Jupiter is almost at the closest approach to Earth (it happened on September 20 last month) that it will have until 2022. The pairing with an almost full Moon (Hunters' Moon this Friday, October 22) makes for particularly good viewing. The best time today was in the early evening. By midnight clouds were already starting to obscure these strangers passing in the night.

The annual Orionid meteor shower is also due this week. The projected peak will be just before dawn on Thursday 21, but the almost full Moon will obscure all but the brightest meteors. The Orionids result when the Earth crosses through the debris of Halley's Comet.

This will probably be a disappointment, but do catch the couple now in the sky.

AMATEUR ASTRONOMY:

PERSEIDS TONIGHT:

Tonight will be the best time for viewing the annual Perseid meteor shower (see diagram above). The peak will arrive at approximately 1:00 Universal Time. That is at about 7 PM CDT here in Winnipeg. To work out what that is in your own time zone see the Time and Date website. That also also gives useful information about such things as sunset and moonset. Tonight the very thin waxing crescent Moon will set early and provide little interference with meteor viewing.

The weather report from the Weather Network predicts overcast skies tonight here in Winnipeg. There is, however, a much better sight for forecasts of sky conditions. The Clear Dark Sky site also gives viewing conditions for the entire North American continent if you plug your location in. It lists not just cloud cover but other conditions that affect visibility. According to that sight there will be a window of opportunity here in Winnipeg for viewing between 9PM and midnight. That is exactly what it looks like to me observing the sky shortly before sunset. The best time for viewing meteor showers is usually after midnight, but you take what you can get. If tonight fails for you don't panic. While predictions for the Perseids this year say anywhere from 50 to 80 meteors per hour you will be able to see a diminishing number in the next few nights.

Molly has blogged extensively about the Perseids in previous years. For 2009 see here. In 2008 there was this, this and this. For 2007 see this and this. So, for all sorts of fun facts about this event and meteor showers in general consult these previous posts.

Here are a few other fun sites where you can read about the Perseids.

Shadow and Substance (an animation of the shower)

Cosmic Log

Sky and Telescope

Happy viewing.

AMATEUR ASTRONOMY:

ASTEROID DEFENSE:

Some, who have not been fans of this blog for years, may find it strange that I would post what follows below. It is not strange in the world of Molly's Blog. I am an amateur astronomer, and I very much support the space programs of various countries. I watch the progression of the constellations and the planets across the skies, and I am thrilled to see them. What follows is one of the reasons. Whatever one's ideological beliefs they would indeed be destroyed by a planetary catastrophe. Such catastrophes have happened in the the past, and they will happen in the future unless we are able to prevent them. This is an inevitable truth. The following, from the Planetary Society, gives their idea of "planetary defense".

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Projects
Mirror Bees: Planetary Defense
A New Way to Deflect a Dangerous Asteroid
What do we do if an asteroid is found to be on a collision course with Earth? At this point, the answer is not clear, so The Planetary Society is partnering with researchers to discover ways to protect Earth when we one-day find a dangerous space rock.

We're working with a team at the University of Glasgow in Scotland to study a new technique which uses concentrated light to gently move an asteroid -- a project we call "Mirror Bees."
The researchers at the University of Glasgow, under the leadership of Massimiliano Vasile, became interested in this approach when they set out to compare nine approaches to planetary defense. To their surprise, one of their results was that Mirror Bees would work more quickly and effectively than all but nuclear warheads. (But unlike the use of nuclear explosions, there would be no risk of breaking a huge asteroid into any number of equally deadly smaller asteroids, nor would the procedure face as many political and bureaucratic hurdles.)
So just what are Mirror Bees?
This new technique involves many small spacecraft -- each carrying a mirror -- swarming around a dangerous asteroid. The spacecraft could precisely tilt their mirrors to focus sunlight onto a tiny spot on the asteroid, vaporizing the rock and metal, and creating a jet plume of super-heated gases and debris. Alternatively, the satellites could contain powerful lasers pumped by sunlight, and the lasers could be used to vaporize the rock. The asteroid would become the fuel for its own rocket -- and slowly, the asteroid would move into a new trajectory.

With your help today, The Planetary Society can step in to make a huge difference in this crucial area of space science.

We need advanced and creative thinking to deflect Earth-threatening asteroids and comets. The "Mirror Bees" system is one promising way.
Help make it happen!
Major questions still remain about this technique. For example, will the plume of superheated gasses ejected from an asteroid dissipate, or will it block sunlight to the mirrors?

Would the debris settle on the satellite mirrors?

Can the asteroid's rotation be dealt with effectively?

Will the gas plumes be enough to deflect the asteroid?

The Planetary Society is stepping in to fund a series of laboratory experiments to answer these and other questions. Vasile's group is working with Ian Watson and the laser lab of the University of Glasgow's Mechanical Engineering Department to devise some ingenious small-scale experiments. We'll be funding equipment, supplies, and a graduate student dedicated to working on the experiments.

Only through these types of studies, as well as additional theoretical research, can the details of this technique be worked out and understood. If it pans out, it will be a rapid, effective, and safe option to use against the asteroid that inevitably will come Earth's way.

AMATEUR ASTRONOMY:
THE BLUE MOON THAT ENDS THE DECADE:
Tonight, as the decade ends, we will have the unusual event of a "blue moon" to ring out the old year. The term doesn't actually refer to the moon appearing blue in colour, though this can occur given certain atmospheric conditions. If there is sufficient dust in the air then light of a longer wavelength, ie red, is scattered away from the eyes of the observer, and the light that gets through is shifted to the blue end of the spectrum. this sort of lunar colouration was most prominent after the explosion of Krakatoa in 1883, but it also occurred in the 1950s after large forest fires in Canada and Sweden. It was also reported after the eruption of Mount Pinatubo in the Philippines in 1991, and there were even reports of "blue suns" in that year (see here). I do not recall it being so, and neither do I recall any change in the colour of the Moon after this year's extensive forest fires in BC. I do recall being able to spot the atmospheric haze after the eruption at Mount St. Helen's in 1980. Does anyone else have any memories or references ?

The origin of the phrase "blue moon" event goes as far back as 1528 when it was used in an anti-clerical English pamphlet entitled "Rede Me and Be Not Wrothe" where the author mocks the clergy saying that, if they declared the moon to be blue then they would expect others to believe it. The use of the term to describe a rare event, as in "once in a blue Moon", dates from 1824 (see here). There is some dispute about the origin of the term in relation to an "extra moon". Some say that the Old Farmer's Almanac began to use the term to refer to an extra full moon in a season in the 1800s, while others claim that the Farmers' Almanac didn't begin using the term this way until the 1930s. In any case the usage of the term as referring to two full moons in a month is of even more recent vintage. It's generally accepted that this way of using the phrase began in 1946 when a writer for Sky and Telescope Magazine misinterpreted the Farmers' Almanac rule of an extra moon in a season as being an extra moon in a month. For more on the history of the term see the Wikipedia article on blue moons.




Today's (tonight's) blue Moon takes place at 19:13 UT. Here in the Central time Zone this translates as 13:13. We obviously can't observe the exact instant of the Moon's fullness here in Manitoba at a little after 1:00 in the afternoon. In Australia and East Asia the event doesn't actually occur until tomorrow, January 1, and it is January rather than December that will have a 'blue Moon' there. The actual "blue Moon" will, however, be the second full Moon of January, not the first. The time of an "exact" full Moon is, of course, an instant rather than a night in duration. If you wish to find the exact time of the full moon and to convert it to your own local time consult the Time and Date.Com site where there is a wealth of other information such as sunrise/sunset and moonrise/moonset data. For those who would like a visual representation of the Moon's phases I could suggest the Moon Phase Calender at the Moon Connection site. A "blue Moon" in the sense of a second full Moon in a month occurs about once every 2.72 years.




There is also a partial eclipse of the Moon visible in Australia, Asia, Europe and Africa tonight, though it is not visible in the western hemisphere. This event has already passed , as maximum totality happened at 19;23 UT.



For those interested in matters lunar a couple of years ago Molly featured a series of articles that were a "leisurely cruise" through the various most prominent visible features of the Moon. If you're interested just type the item that you might want to read about (such as 'Mare Criseum', sea of Tranquility, etc..) in the search function of this blog and read all about it. See you in the New Year. It's been an interesting year and an interesting decade.

AMATEUR ASTRONOMY:

THE PERSEIDS RETURN:

Tomorrow evening (or for that matter just before dawn today- August 12) will be the optimum time for viewing what is usually the most spectacular meteor shower of the year- the Perseids. The estimated time of the peak (these things are never exact) is at about 15:00 Universal Time tomorrow afternoon. This translates into a Winnipeg time of 10:00 am. Fear not and do not despair. The Perseid meteor shower is actually quite a long drawn out affair,and an excess of meteors may be observed from July 23 to August 22. The Winnipeg branch of the Royal Astronomical Society of Canada actually plans to hold their Perseid viewing gathering next Sunday, August 15, out at Bird's Hill Park, just northeast of the city. The view of meteors is, of course, best seen at a dark location outside of a city, such as Bird's Hill Park. Just as a fyi, however, the Astronomical Society will apparently have their telescopes out, for public education, at the Italian Pavilion down on Wilkes Ave. during this week of Folklorama. Telescopes are of no use for viewing meteors, but those interested can gain an appreciation of the hobby from members who will be present there. The occasion, Italy wise, is the 400th anniversary of Galileo's telescope. Would that we could celebrate a centenary of the end of the Congregation for the Doctrine of the Faith (the Holy Inquisition) who condemned Galileo, but that institution still exists today.

Sunset tomorrow here in Winnipeg is at 8:52 pm, and Moonrise (the Moon interferes with good viewing of meteors) is at 10:52 pm. For those in locations outside of the Central Time Zone please consult the Time and Date website to convert the time of the Perseid peak (and Sunset and Moonrise) to your local time. According to said website the weather conditions here in Winnipeg for tomorrow evening will be "partially cloudy". The Environment Canada site predicts "a few clouds for tomorrow evening. One of the best sites, the Clear Dark Sky site, says that the sky will be basically clear until Midnight, with clouds in the wee hours of Thursday, but clearing about 4:00am. The Clear Dark Sky site is actually one of the best sites to consult because it contains far more parameters than just cloud cover. It is also the site for readers anywhere on the North American continent because it will give viewing conditions for hundreds of sites elsewhere on this continent. So...if you don't live in the centre of the universe known as Winnipeg consult this site to see whether your viewing conditions for the Perseids will be good, bad or indifferent.

By the way, Molly has blogged extensively on the Perseid meteor shower before. If I fail to repost items from previous years (which might happen because of my schedule) try searching "Perseids" on this blog for much more information of this event.

AMATEUR ASTRONOMY:

THE CATALOG OF EXOPLANETS:

Here's an interesting item that Molly just received today in her inbox from the Planetary Society. In the past few years the number of planets found orbiting stars other than our Sun has blossomed into a list of hundreds, and yet more are due to be discovered. If you are interested the Planetary Society has set up a Catalog of Exoplanets to keep track of the discoveries- and also to explain more about the science behind them. Here's the announcement.

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Catalog of Exoplanets:

Ever since the first exoplanet was discovered in the mid-1990s, we’ve had an explosion of discoveries, revealing hundreds of strange worlds orbiting faraway stars. Slowly but surely, as detection techniques improve, scientists are closing in on the exoplanet we are all waiting for: a world like our own, a distant "Earth" orbiting an alien star.

In order to share with you all that has been found to date, The Planetary Society -- with support from our members -- created the Catalog of Exoplanets. Here you will find a regularly updated database of all known exoplanets.

Our catalog is designed with resources for every level of study whether you are a professional, amateur, teacher, student, or simply want to find out what the buzz is about the latest exoplanet discovery.

Find essential information about each exoplanet, such as...

**What is the planet's location and home star?
**What is its mass, and how does it compare to planets in our own solar system?
**How long does it take it to complete each orbit ?
**How was it detected?
**When was it discovered?
**How many other known planets are orbiting its star?

Each planet can be seen in a dynamic animation showing the planet in its orbit around its star as well as the orbits of any other known planets in the system. For example, one animation below shows a sample exoplanet system (GJ 876) and one shows the outer planets in our solar system (Jupiter through Neptune; the inner planets would be too hard to see on the same scale).
Explanation of Animations

And there is more, find out about...

**The different methods used to detect exoplanets.
**Advantages and shortcomings of each detection method.
**Notable exoplanets, those that stand out from the crowd.

The idea for this catalog started when The Planetary Society funded the planet hunting group of Geoff Marcy at UC Berkeley, Paul Butler of the Carnegie Institution, Steven Vogt and Debra Fischer of San Francisco State University to analyze years of data and publish updated parameters such as planetary mass for a whole host of exoplanets. Their results were published by Butler et al. in the Astrophysical Journal, targeted at professional astronomers, and covering a subset of exoplanets. In creating our online catalog, The Planetary Society includes all known exoplanets in a manner intended to be friendly to students and the general public, as well as amateur and professional astronomers.
Enjoy learning about the search for distant worlds!

AMATEUR ASTRONOMY:

A GREAT CONJUNCTION-NOV 30 TO DECEMBER 1:

Here's a little break from the usual political subject matter on this blog. Tonight and tomorrow there will be a "grand conjunction" of the Moon, Venus and Jupiter in the southwest sky. If you have been watching in that direction for the past few evenings, as Molly has, you will have seen Venus (lower and brighter) and Jupiter (higher and dimmer) gradually getting closer and closer together. The last time I was able to spot the pair, at about 5:00 on Friday the two planets were about 6 to seven degrees apart. Tonight Venus will overtake Jupiter and appear slightly below and to the east of Jupiter. A very thin crescent Moon will be seen closer to the horizon in the west. Tonight the two planets will be about 2 degrees away from each other, but you will be unable to see them from here in Winnipeg. It seems we almost always have overcast conditions for the best celestial events. The Environment Canada weather site predicts further cloud cover through tomorrow and the day after. A better site for those interested is the Clear Dark Sky site. they predict a period of relatively clearness tomorrow from 3 to 7 pm. This may be a chance to catch the events as the Moon climbs to the west of the planetary pair and Venus likewise moves further from Jupiter. This will actually be the best time to view the event as the three objects will be within a four degree triangle. After December 1 the Moon will be quite obviously to the east of the planets, and Venus will also be further from Jupiter in the same direction. Catch it if you can. The Clear Dark Sky site will give you viewing conditions for your locality if you live in North America.

The photo above, by the way, is from a prairie amateur astronomy site that I recently discovered, the Black Holes and Astro Stuff blog. I recommend it highly. The photo shows the Venus/Jupiter pair, along with the track of the International Space Station that was prominent in the southwest sky the last few days. I'm sure that, weather conditions permitting, that the BHAAS blog will be in the running for the Sky News photo contest this year. Would that I had such photo talent. By the way, here's another item from that blog, a picture of the area where the recent 'Prairie Meteor' was sighted. Pieces of the meteor have apparently been found near Lloydminster, Saskatchewan, but more on that later. See the BHAAS blog on our "Scientific Links' section, with many kudos to a great blogger.

AMATEUR ASTRONOMY:

PRAIRIE METEOR SHOW:

Residents of Alberta and Saskatchewan were treated to a brilliant meteor show around 5:30 local time as a bright fireball was sighted as far apart as Edmonton and Regina. The photos here are from Edmonton. Here's the story from the Regina Leader Post. More to follow tomorrow.

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Meteor lights up Saskatchewan sky:
Kerry Benjoe and Lana Haight,

Saskatchewan News Network

Published: Thursday, November 20, 2008
REGINA -- A flash in the sky has many people in Western Canada asking questions.

According the RCMP in Lloydminster, a meteor fell from the northern skies at around 5:30 p.m. on Thursday. It was visible from Edmonton, east from Lloydminister and into Saskatchewan and as far south as the Regina area.

Some residents in Wilcox can only describe what they saw as 'very pretty.'




George Faris said he was driving home west of Wilcox on Highway 39.

"It was a nice bright green colour. It looked like it was northwest of Wilcox. It was right around 6:25 -- I looked at my watch," said Faris. "It looked like it hit the ground."

He said the sighting was fast and estimated that it lasted between five to seven seconds.

"I thought someone had set off a firework and then I realized, 'No because it was coming out of the sky,' " said Faris.

Angie Roian was cleaning up the table after supper when she saw the tail-end of the meteor.
"I looked out my kitchen window and I saw it coming down. It was the coolest thing," said Roian.

Like Faris, she thought someone had set off a firework but soon realized it wasn't because it was going in the wrong direction.

"It was just like a streak and it looked like there were sparkles in it when it came down," said Roian.

Other areas of the province saw a much brighter version of the meteor.

"It lit up the yard almost like midday, but just for an instant," said Bruce Trapp, who farms near Harris, about 70 kilometres southwest of Saskatoon.

"It was far brighter than any lightning strike I've ever seen."

In some places, the fireball, which streaked across the province and beyond at around 6:30 p.m., appeared white. In other places, it was flash of rainbow colours.

"It seemed like fireworks or a missile coming down. The sky lit up greenish and yellow," said Shawn Mitchler, who was pumping gas at Family Confectionery on Highway 16 at Radisson, about 60 kilometres northwest of Saskatoon.

He estimates the light show lasted five to 10 seconds.

"My heart just started racing because I didn't know what it was."

Mitchler wasn't alone. The RCMP emergency dispatch centre in Regina received 9-1-1 calls from people wondering what was going on.

"We got lots and lots of calls from all over the province -- from one end of the province to the other. Cut Knife to Fort Qu'Appelle," said one dispatcher.
© Canwest News Service 2008

AMATEUR ASTRONOMY:

MOLLY MISSES THE HARVEST MOON:

I had meant to blog on this matter two days ago when, at 4:13 am CDT the full moon called the 'Harvest Moon' reached its peak fullness. Ah, but many things intervened; so here it is now.

The Harvest Moon is defined as the full moon closest to the autumnal equinox which we come next Monday, September 22 this year. The Harvest Moon may come either before or after the equinox, and about once every four years it occurs in October rather than September. This often leads to confusion with the following 'Hunters' Moon', and the two actually share a similarity.

The reason the Harvest Moon is so called is that, while the Moon usually rises about 50 minutes later each night at the time of the equinox this day to day duration is shortened. For instance this year, as per the Time and Date website, moonrise was at 7:30 pm on September 15th, the day of the Harvest Moon, while today, on the 17th, it is 8:05 pm here in Winnipeg, Manitoba. In other words only a 15 minute difference from day to day (the difference is longer the further south you go). This means that there is a lesser period of absolute darkness between sunset and moonrise at this time of year and that harvest activities could be resumed by moonlight well into the night after the Sun had set.

The Harvest Moon also has a few other tradition names, including the 'Wine Moon' , the 'Singing Moon' and the 'Elk Call Moon'. In any case the Harvest Moon is reputed to confer the blessing of the Norse trickster god Loki for a plentiful harvest. So, no tricks now, have a happy Fall, and more on the upcoming autumnal equinox soon.

AMATEUR ASTRONOMY:

TRIPLE CONJUNCTION THIS EVENING:

Yesterday the planet Mercury reached its greatest elongation , 27 degrees,(its highest above the horizon), but today it is still quite visible in the evening twilight. During the past week Mercury has formed a triangle in the evening sky with the planets Venus and Mars, and tonight Venus and mars make their closest approach, being only 18 arc-minutes from each other. Venus, shining at a magnitude of -3.9, will be the brightest of the trio, Mercury will have a magnitude of -0.2 and Mars, the dimmest of the pair, will shine at about 1.7. The diagram to the left shows how the planets will be on a line of sight this evening.

Mars will be located just slightly left of and below Venus, and Mercury will be below the air and to the left. The bright star Spica will also be visible further to the left. You will need binoculars or a moderate power telescope to view the trio because of the closeness of Mars and Venus and because of the interference of twilight. People living further south than Canada will have a better chance of viewing as the planets will appear higher above the horizon to them. Conditions are likely to be overcast here in Winnipeg, but people elsewhere may have better luck.

Good viewing.

AMATEUR ASTRONOMY:

THE PERSEIDS ARE HERE TONIGHT- BUT WE SURE WON'T SEE THEM IN WINNIPEG:

Yes, the Perseid meteor shower will be peaking later this evening in the early hours before dawn tomorrow, but we sure won't be able to see them here in Winnipeg. Speaking of showers it's been raining cats and dogs since last night, and the weather reports (both Environment Canada and the Clear Dark Sky organization) say that this will persist until shortly before dawn on Wednesday morning. Maybe you'll still be able to catch a few meteors on that day, but at least for Winnipeg this years Perseids will be a "wash-out". The viewing conditions including cloud cover, transparency, visibility, etc. can be seen for Winnipeg by clicking the strange looking long rectangle divided into boxes at the bottom of our links section.

For people living elsewhere on the North American continent, however, conditions may be far better especially if you live on the west coast where the peak occurs when it is still dark. The Clear Dark Sky link reports conditions for 3,497 different locations in North America, from Mexico and the Bahamas in the south to Alaska, Yukon, NWT and Nunavut in the north. It's a great site and Molly encourages visitors to it. So, may you have better luck than we do here in Winnipeg.

AMATEUR ASTRONOMY:

THE PERSEIDS ARE HERE-TONIGHT!:

Well, not exactly, more like the wee hours of tomorrow, August 12. But still "this night" has some meaning. Here are a few relevant times of other events that may affect your viewing from the Time and Date website. These times are for here in Winnipeg in the Central Time Zone. If you live elsewhere consult the above website for your local times.

Sunset today, August 11........................8:53 PM

Sunrise tomorrow, August 12...............6:15 AM

Moonrise tonight, August 11.................6:12 PM

Moonset tomorrow, August 12.............1:19 PM

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As previously mentioned on this blog the peak of the Perseids will fall between 11:30 and 14:00 UT. This translates as 6:30 am and 9:00 am here in Winnipeg so observers in this province will miss the peak of the shower. Viewing in the early pre-dawn hours, however, may still be rewarding. The further west you go the better the timing, and people on the west coast should have a good show.

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THE RADIANT

The diagram above shows the "radiant" for the Perseid meteor shower. The radiant in a meteor shower is the place in the sky where the meteors appear to be coming from if you trace back their paths. As you can see above the radiant of the "Perseids" is actually between Perseus and the constellation Cassiopeia. Still somewhat closer to Perseus however. See if you can determine the radiants of the meteors you see tonight.

AMATEUR ASTRONOMY:

THE PERSEIDS ARE COMING- WHAT IS A METEOR SHOWER ?:

As mentioned previously the Perseid meteor shower will peak this coming Tuesday, August 12th between 11:30 to 14:00 hours UT. That would be 6:30 to 9:00 here in the central time zone in Winnipeg. To get an idea of the time in your locality see the Time And Date website. This website also gives the times of Moonset and Moonrise, important this year as the light from a waxing gibbous Moon will reduce meteor viewing considerably. The good news is that the Moon will be setting shortly after midnight. The bad news for European and eastern North American viewers is the time of peak. In Europe this will occur during daylight hours, and even in North America the Sun will be rising during at least part of the peak. Still, any meteors seen in the early predawn hours may turn out to be spectacular "Earth grazers".

METEOR SHOWER...WHAZZAT ?:
A "meteor shower", also known as a "meteor storm" or a "meteor outburst" is when there is an unusually high number of meteors in the sky and when these events can be traced back via an imaginary line to a point of common origin in the sky called the radiant.

Meteors happen when the Earth encounters bits of cosmic debris in its orbit around the Sun. Like litter in a campground such debris is ubiquitous in space, and there is always a background of sporadic meteors that occur randomly. Some neighbourhoods, however, are filthier than others. Throughout the year the Earth periodically passes through particularly concentrated trails of material. These have usually been traced to the residue of passing comets, and their position in the orbital plane means that they regularly appear in the same place in the sky at the same time of year.

When the cosmic debris is just hanging around orbiting the Sun (maybe playing cards, smoking cigarettes and, like a Spanish policeman, doing as little as is possible) it is known as a meteoroid . It is only when the Earth catches up to this non-event that things begin to get interesting. As the Earth and the space particle collide the debris becomes a visible meteor . These pass into the Earth's atmosphere at anywhere from 14 to 71 kilometers per second. Most meteors become visible at about 60 kilometers up. They are heated to over 1,700 degrees centigrade, begin to glow from the heat and are usually consumed by the heat as they enter the inner atmosphere. This heating is not caused by "friction" but rather by something called "ram pressure". As the meteor plunges into the atmosphere it compresses the air in front of it, thus heating it up. The heat of this compressed air simple diffuses to the meteor itself. In other words the heat comes from a push rather than a rub.

Should the meteor actually make it through the atmosphere and strike the Earth it is called a meteorite. There are two basic kinds of meteorites. Iron meteorites are made up of about 91% iron. Stony meteorites contain a higher proportion of other elements such as magnesium and especially silicon and oxygen in the form of silicon dioxide- good old sand.

(Hey, Molly could make a song out of this...
"Let's build sand castles in the sky
Let them loose to see if they can fly")

Some meteors explode before they evaporate or strike the Earth. The result is commonly called a fireball, and its sound can be heard dozens of miles away. Iron meteors are more stable than rocky ones. Slow meteors are less likely to explode than fast ones. Meteors arriving at an acute angle to the Earth are subjected to less stress than those that come in at an oblique angle. Yet...even a slow travelling iron meteor that falls from near the zenith has a chance of exploding and creating a fireball.



There is reportedly another sound produced by meteors that is poorly understood. These events are referred to as electrophonic meteors which seem to produce a sound even though it is physically impossible for any sound to travel from the height of the meteor. See 'Electrophonic Meteors' and 'Listening to the Leonids'. The theory is that this sound, variously described as "sizzling" or a "snap,crackle,pop" is produced when electromagnetic radiation in the VLF range is converted into sound energy near the ground.



When a meteor strikes the ground it produces a crater anywhere from 12 to 20 times its own size. Smaller impacts produce simple bowls. When larger objects strike terrestrial rebound creates a central peak along with a rim that is often "terraced" as the ground subsides after the initial impact. The largest impacts of all create multiple inner peaks due to the creation of several rebounds.



The largest impact in recorded history occurred on June 30th, 1908 when an object struck in Siberia. This has become known as the Tunguska event. This object flattened more than 800 square miles of trees. The cause of this explosion has been disputed, but the present consensus is that it was an exploding meteor. An Italian research team has recently obtained results that are suggestive of a remnant of part of this meteorite at the bottom of Lake Cheko about 5 miles northwest of the epicentre of Tunguska. See http://www.blackwellpublishing.com/journal.asp?ref=0954-4879&site=1 for the article 'A Possible Impact Crater for the 1908 Tunguska Event'.



Every year many meteorite strikes are reported across the planet. The first structure to be proven as being due to a meteorite impact is the Meteor Crater of Arizona. This crater is 600 feet deep, about a mile across, and its rim rises 150 feet above the surrounding ground. The meteorite that produced this crater impacted sometime between 20,000 and 50,000 years ago. The largest meteorite ever recovered in the USA hit ground in southern Nebraska in 1848. Observers reported that the fireball, which occurred in the afternoon, was "brighter than the Sun" This item, weighing 2,360 pounds was found buried 10 feet deep in a wheat field. Of course the Russians always did it first and better, as anyone who has listened to Chekov in old Star Trek shows can tell you. In 1947 the Russian Sikhote-Alin meteorite created more than 100 small craters some 20 meters across. Eat them apples American imperialists.



There is even a recent controversial theory that the die-off of mega fauna in North America at the end of the last ice age was not due to over hunting by recently arrived paleo-indians-the accepted theory- but rather due to localized climatic change because of an impact event. Maybe yes, maybe no.



For those interested in learning more about meteors in general look to the following sites:
The International Meteor Organization
The American Meteor Society
Meteor Showers Online