Volume 14 • Issue 8 October 2015 ISSN 1712-4425 peterboroughastronomy.com twitter.com/PtbAstronomical The Reflector Newsletter of the Peterborough Astronomical Association Measure the ’s size and distance during the next lunar

Image credit: Daniel Munizaga (NOAO South/CTIO EPO), using the Cerro Tololo Inter-American Observatory, of an eight-image sequence of the partial phase of a total .

Ethan Seigel he moon represents per- caused by its geometric configura- of (first accomplished in the haps the first great paradox tion with the Sun and Earth. We 3rd century B.C.E.), now known to of the night sky in all of know that the Sun must be farther be 6,371 km, all it takes is one as- Thuman history. While its angular away (and hence, larger) than the sumption — that the physical size size is easy to measure with the moon from the phenomenon of of Earth’s shadow as it falls on the unaided eye from any location on solar , where the Moon moon is approximately the physi- Earth, ranging from 29.38 arc-min- passes in front of the Sun, blocking cal size of Earth — and we can use utes (0.4897°) to 33.53 arc-minutes its disk as seen from Earth. And we lunar eclipses to measure both (0.5588°) as it orbits our world in know it undergoes lunar eclipses, the size of and the distance to the an ellipse, that doesn’t tell us its where the Sun’s light is blocked Moon! physical size. From its angular size from the Moon by Earth. Simply by knowing Earth’s phys- alone, the moon could just as easily Lunar eclipses provided the first ical size and measuring the ratios be close and small as it could be evidence that Earth was round; the of the angular size of its shadow distant and enormous. shape of the portion of the shadow and the angular size of the Moon, But we know a few other things, that falls on the moon during its we can determine the Moon’s even relying only on naked-eye ob- partial phase is an arc of a circle. In physical size relative to Earth. Dur- servations. We know its phases are fact, once we measured the radius See “Measure the Moon” on page 16 2 • peterboroughastronomy.com President’s Message A Quieter Time for the PAA he paa did not have a lot of out- hands. We saw most of this equipment in reach activity this September. On use at the “Family Wishes Event.” Congratu- September 25th we did go to the lations to all on their new equipment acqui- TPeterborough Museum & Archives for an sitions. evening with the Canadian Family Health As I write this we look forward to a glori- Collective’s “Family Wishes Event.” We had ous total lunar eclipse happening on Sun- a number of telescopes set up with line-ups day, September 27th. I’m sure we’ll see lots at every station as there was a huge crowd of photo coverage of this event. of people. Don’t forget election time is drawing Individually, a number of our members near. Please consider putting your hand up added to or upgraded equipment. This for an executive position. included two iOptron Mini Tower Pro’s, a Mini Tower II and a Cube G. Two more Rodger Forsyth Vixen VMC200L OTA’s have been added PAA President and an Orion 10” Intelliscope has changed

Loony Lunacy uper are over-rated; most of And to end off, in the immortal words of us wouldn’t notice any difference Duran Duran: despite media hype. Now, make the SuperS Moon a total lunar eclipse and the I light my torch and wave it for the pandemonium spreads. While clouds did on Monday, veil the event, some of us were fortuate to And a fire dance through the night. catch a glimpse during the first umbral I stayed the cold day with a lonely phases and the totality. I have to say totality satellite. was darker than I had previously observed Phillip Chee but I wonder if the cloud cover had some Editor, The Reflector effect. Is it crazy to dedicate almost an en- tire issue to lunar subjects? Not as crazy as devoting almost an entire issue to the wordsmithing of one John Crossen. Seri- ously, John writes far and wide on a variety of lunar matter and it is a fitting issue to The Reflector celebrate all things lunar in honour of a wonderful lunar eclipse last . The Reflector is a publication of the Peterborough Astronomi- cal Association (P.A.A.) Founded in 1970, the P.A.A. is your local Rick Stankiewicz has a great summary of group for in Peterborough and the Kawarthas. last weekend’s lunar eclipse with stunning www.peterboroughastronomy.com • [email protected] photo for illustration. Also in the Gallery, Phone: 705.292.0729 Club Mailing Address John Chumak provides an annotated photo Rodger Forsyth, President Peterborough Astronomical Association of the Seven Sisters, a.k.a. M45, the Pleiades 536 Robinson Road RR #1 Star Cluster. Peterborough, ON K9J 6X2 Vol 14 • Issue no. 8 • October 2015 • 3 The Reflector PAA Makes Wishes on a Star Come True

John Crossen he Peterborough Astronomi- Saturn also captured the imaginations of cal Association was delighted to once young and old. The rings presented them- again be invited to show kids and selves beautifully. And as a bonus, everyone Tadults some of the mysteries of outer space. marveled at its moon system. The viewers The near was a hit with everyone were lucky because Saturn will soon be lost as they saw close up the craters and huge in the sunset’s glare. We’ll see it again, but lava flows that make up the face of the it won’t be for another few when it Moon. paa members were busy answering becomes an early morning target. questions about how old the Moon was and where it came from. See “Wishes on a Star” on page 15 4 • peterboroughastronomy.com Pluto The Dwarf Planet with Big Surprises

“The Heart” on Pluto is a relatively flat expanse of ice. It is also called the ombaughT Region after Pluto’s founder, Clyde Tombaugh. Image by NASA New Horizons. Johhn Crossen lot of astronomers thought that ments — one land mass pushing on anoth- when the New Horizons spacecraft er. The weaker of the two either is pushed finally arrived at Pluto we’d find a up to form a mountain chain or down Acold, dead planet. Call it a cosmic grave- where it eventually is reheated and recycled stone marking the outer limits of our solar in to Earth’s molten core. The San Andreas system... Instead we found just the oppo- Fault line is a good example of this. Mean- site. while on the opposite side of the world the At -233 degrees Celsius, Pluto is definitely Himalayan Mountains have been pushed up a cold world. But one look at the moun- thanks to the tectonic plate collision be- tains and vast plains showed that Pluto was tween Tibet and India. But what caused the also one geologically active puppy — far mountains on Pluto? from dead. This wasn’t expected and the At the moment some scientists think that questions as to how and why have already radioactive decay at Pluto’s core may be the sparked some active debate. reason. That’s what causes plate movement Here on Earth mountain ranges have here on Earth, but Pluto is such a small body been caused by tectonic plate move- See “Pluto” on page 15 When it Comes to Moons, Jupiter Outshines Them All

Vol 14 • Issue no. 8 • October 2015 • 5 The Reflector October Means Planets Galore and a Meteor Shower

John Crossen ctober is a planet hunter’s paradise. Jupiter, Venus and Mars rise about an hour before the OSun’s glow erases the night from the sky. Throughout the month the trio is getting closer and closer together. On October 28th the threesome form a tight triangle in the hind legs of the constellation Leo. Venus will be the brightest of the three followed by Jupiter and tiny Mars. It will make a great photo-op for the camera bri- gade. But the three-planet conjunction isn’t the only planetary attraction. In the southwestern sky is Saturn. The The constellation Orion is portrayed as a fierce hunter. ringed beauty will be available at dusk, a However, despite his weapons and nasty spirit, he fell prey to a tiny scorpion. Orion was also reported in much more reasonable hour. Look for it ancient myth to be a womanizer who is chasing the near the bright star Antares in the constel- Messier Object known as the Seven Sisters of the Pleia- lation Scorpius. You can spot Saturn naked des across the sky. eye, but to see the rings you’ll need a tele- the wee hours of October 21 – 22. Emanat- scope operating at 30 times magnification. ing from the constellation Orion they will Right behind Saturn lurks Pluto in Sag- put on a fine show (15/hr) for the following ittarius. It’s a telescopic sight only and four hours, until sunrise brightens the sky. you’ll need a big scope, too. Being a 14th The Orionids are the left-over bits from 1P magnitude target, you’ll need eight-inches Comet Halley. (200mm) of aperture at the minimum and When comets near the Sun they melt you must have a very dark sky. To find Pluto (sublimate) and leave small rocky bits I suggest Googling up www.space.com to check behind. If they cross Earth’s orbital path out their map. around the Sun, we collide with their Uranus will be precisely opposite the leave-behinds and enjoy a meteor shower. Sun on the night of October 11-12. It’s an The meteors are usually about the size of a event known as opposition. As the Sun sets, peanut and burn up harmlessly in Earth’s Uranus will rise. By around 10:00 it should atmosphere. Larger hunks, say the size of a be out of the atmospheric soup near the ho- baseball, are vastly brighter and are known rizon. It will be visible, but you’ll need super as fireballs. They often light up the ground acute vision and a very dark sky. Shining at and leave a smoking trail in the night sky. magnitude 5.7, it is near the limit of vis- To watch a meteor shower takes nothing ibility for most of us. A pair of binoculars more than your eyes. Telescopes and binoc- will reveal the distant blue-green dot more ulars narrow your field of view to the point easily. It is currently in the constellation they are useless. So settle back in a comfort- Southern Pisces, also known as the South- able chair with a view to the east and watch ern Fish. the show as Orion rises. Those with a yen for meteor showers will Those are the celestial highlights for Oc- be treated to the Orionid Meteor Shower in tober. Clear skies to everyone. 6 • peterboroughastronomy.com There are Astronomical Falsehoods in the Hood

Saturn’s rings may look solid through a telescope on Earth, but they’re really trillions of ice chunks orbiting the planet.

John Crossen et’s jump out to the asteroid it engulfs all the planets out to Jupiter. At belt. Anyone who has watched a 1950s that point it will simply dissipate and leave sci-fi flick might get the idea that the behind a glowing nebula to mark our solar asteroidL belt is thick with rocky hazards. system’s grave. It’s coming in about 3 billion But that’s just for looks. Asteroids average . Reserve your seats now. around 600,000 km apart — more than the If you think the Sun would look like just distance to the Moon! another star from Pluto you need to get out Will planetary alignments tear Earth more often — way out. The average day on apart? Will the oceans rise, rav- Pluto is almost as bright as Earth at twi- age continents and humanity be destroyed? light. So despite the fact that it takes nearly No. The Earth as we know it is at least 3 5.5 hours for sunlight to reach the puppy billion years old. In that time the planets planet, it does light the place up — at least a have lined up in all kinds of configura- little. tions — and Earth is still puttering along. Astronomers call Jupiter and Saturn “gas At the distance the planets are from Earth, giants.” But it’s not because they’re gas their gravitational affect is close to zot. straight through. They’re referring to the Even if all the planets lined up and exerted incredibly thick outer atmosphere of cloud maximum gravitational pull on Earth it cover. Deep beneath their outer layer Jupi- would be about the same as the Moon’s tidal ter and Saturn have solid cores. The same force. also goes for Uranus and Neptune. This The Sun will bring life on Earth to an duo is frequently referred to as “ice giants.” end. But it won’t be with a supernova mega- But that’s also misleading. Again they have bang. Instead the Sun will expand until See “Saturn” on page 15 Vol 14 • Issue no. 8 • October 2015 • 7 The Reflector Records In Space

CHRIS HADFIELD ABOARD MIR SPACE STATION. Canadian Astronaut Chris Hadfield plays a collapsible guitar he took on his visit to the Russian Mir Space Station. Image from the Lampton Daily Shield. John Crossen a dog named Laika into space. The dog was very now and then it’s nice to the first-ever live passenger to make it into review who did what first or longest space. The Russian pooch didn’t return, but or highest. It’s a history review for us was part of the first experiment performed spaceE geeks. So here goes with a list of space in space. records set by different countries. We’ll lead On April 12-13, 1961 the Russians did it off with a foursome of Russian firsts. again when Yuri Gagarin, a Russian Soviet In 1957 on October 4 Russia spread panic pilot and cosmonaut, became the first hu- throughout the United States when it suc- man to journey into outer space. His Vostok cessfully launched Sputnik 1, the world’s spacecraft completed one orbit of the Earth. first man-made satellite. It was a case of A month later Alan Shepherd became the one-ups-man-ship that made the u.s. more first American Astronaut to enter outer than a tad uncomfortable. While not fight- space, but it was a second place finish in ing each other, the two countries were well what had become “The Space Race.” defined political adversaries. John Glenn became the first American to On November 3, 1957, the ussr one- orbit the Earth on February 20, 1962. Thirty- upped the Yanks again with the launch six years later, on October 29 of 1998, Glenn of Sputnik-2 carrying a dog onboard. The became the oldest man in space at the age Space Age had barely started and just four of 77. His visit to the iss marked a major later, the Soviets fired the 508.3-ki- triumph for us seniors. logram (1,120.8-pound) spacecraft carrying See “Space Race” on page 13 8 • peterboroughastronomy.com Photo Gallery Total Lunar Eclipse

All leading up to September 27th it was promising to be perfect weather conditions for the total lunar eclipse of the largest (closest) Full Moon of the . At a distance of 356,877 km from Earth, this would be a true “Super Moon”. All Full Moons are big, but this one was just that much bigger and the bonus to this Moon is that a couple hours after it appeared over the horizon it would start to slowly slip into the Earth’s shadow from 9:07 p.m. until 10:11 p.m. when it would be totally “eclipsed”. This was the plan anyway. Mother Nature had other ideas. It was cloudy most of the evening and it even rained where I was south of Peterborough. The night was so mild, even the mosquitoes were out! This was being touted as a “Blood Moon”, but don’t be fooled by all the hype. It was more of a cop- pery colour. The Moon was in total eclipse for about 72 minutes before reversing the process as it slid out of the Earth’s shadow, starting at 11:23 p.m. The show was to have wrapped up by 12:47 a.m. on the 28th. We never got to see all this from around here and I pulled the plug by midnight. It was definitely worth witnessing this unfold in the night sky. This was one of the darkest lunar eclipses I have ever seen, given the Moon did not go through the centre of the umbral shadow. If you missed this event, you will have to wait until January 20th of 2019 to see another eclipse of this kind in North America. Admittedly we have been spoiled over the last two years with three similar eclipses in rapid succession between April of 2014 and now this one. Why or how does the Moon change colour? It is the result of the refraction (bending) of the longer wavelengths of light (reds and oranges) into the darkest part of the Earth’s shadow, called the “um- bra”. Picture the light from all the sunsets and sunrises around the edge of the Earth being reflected off the surface of the Moon and back to Earth, while you watched this eclipse. Nature at its best! The beauty is also that you didn’t need big fancy equipment to see or appreciate this event. Just your bare eyes did the trick. Rick Stankiewicz A Luna-tic All images taken with a Canon 400D camera mounted parafocally on an 8” SCT with iOpteron Mini Tower II mount. Settings were iso 400, ƒ/6.3 (field flattener) and 6 second exposures (average). Vol 14 • Issue no. 8 • October 2015 • 9 The Reflector

The Seven Sisters

Hi Everyone,

Everyone’s favorite cluster!!! M45, The Pleiades, a.k.a. “The Seven Sisters” open star cluster in Taurus. Easily visible to the unaided eye, even from the city, this bright cluster is an amazing view in binoculars or a small wide angle telescope. M45 is one of the nearest galactic open clusters, sitting about 444 light years away, and shining at magnitude 1.6. I did also pick up a faint background edge on spiral galaxy, look to the upper left of Electra to spot it!

M45 is an open star cluster containing middle-aged hot B-type stars located in the constellation of Taurus. It is among the nearest star clusters to Earth and is the cluster most obvious to the naked eye in the night sky. The celestial entity has several meanings in different cultures and traditions.

The cluster is dominated by hot blue and extremely luminous stars that have formed within the last 100 million years. Dust that forms a faint blue reflection nebulosity around the brightest stars was thought at first to be left over from the formation of the cluster (hence the alternative name Maia Nebula after the star Maia), but is now known to be an unrelated dust cloud in the interstellar medium, through which the stars are currently passing.

New computer simulations have shown that the Pleiades was probably formed from a compact configuration that resembled the Orion Nebula. Astronomers estimate that the cluster will survive for about another 250 million years, after which it will disperse due to gravitational interactions with its galactic neighbourhood.

Greek mythology states that Mighty Atlas (son of a Titan) and his wife, Pleione, had seven incredibly beautiful daughters. Atlas placed his Seven Daughters in the heavens to protect them from mortal men! And to this day Orion the Hunter, who is in love with several of the Sisters, follows them around the sky.

[Taken with a] modified Canon Rebel Xsi DSLR and 5.5-inch diameter Vixen Newtonian reflector scope,iso 1600, for a 76 minute exposure at my observatories in JBSPO in Yellow Springs, Ohio.

Best Regards, John Chumak www.galacticimages.com 10 • peterboroughastronomy.com Meet Astronomy’s Ladies of the Night

Pleiades Star Cluser. Look east and a bit north. The Pleiades will be visible as a faint misty patch. Here we see Comet Lovejoy zipping past the Seven Sisters. Image taken by Alan Dyer.

John Crossen f there’s one night-sky target eyes to adapt to their dark surroundings. that’ll get your attention this autumn What’s the story behind our celestial sis- it’s the Seven Sisters. Also known as the ters? How did they reach their stellar home? PleiadesI (Play-a-dees/Ply-a-dees), the girls are Here’s the mythological lowdown on what an easy naked-eye target. That means you’ll went down. need no special gear to spot them. You will, It seems that the girls were Earth bound however, need a relatively dark sky over- long ago. Unfortunately for them Orion the head. So that leaves downtown Peterbor- Hunter was on the trail of his next meal. ough and most surrounding small towns That’s when he spotted them in a for- out. est clearing. Orion had an eye for beauty If you’re not blessed with a rural location, and a lust for the ladies. Need I say more? get out of town and look eastward about He instantly shifted gears and began his 10:00 p.m. on a clear night. About 45 de- romantic pursuit. The ladies didn’t share grees above the horizon you’ll see our ladies his enthusiasm and took flight. As the chase of the night as a misty patch about the size unfolded the mighty god Zeus looked down. of your thumb nail. If you’re in a good dark Seeing that the sisters were in danger, he sky rural location they’ll pop out quickly to turned them into doves and they flew into your dark-adapted eyes. By the way, dark the sky where they turned into stars. If you adapted eyes can see six times better in the wait until midnight you’ll see the Constella- dark, so wait about 20 minutes for your See “Seven Sisters” on page 13 Vol 14 • Issue no. 8 • October 2015 • 11 The Reflector The Moon Rocks and Rolls

Paritially Eclipsed Moon. September’s Star attraction isn’t a star. It’s our Moon as it slips into Earth’s shadow on the night of September 27/28. Thanks to the fact that it’ll also be a Super Moon, it should cause quite an attraction in the media. No word from the dooms day set on whether the Earth will end, too, Image by Fred Espenak.

Protoplanet Impacting Earth. Summer Stargazing Nightshot. The illustration above shows the Moon be- ing created by an impacting protoplanet 3.5 billion years ago. The Moon’s orbit around Earth is ellipti- cal. So sometimes it is closer to us than at John Crossen other times. The slight difference in dis- tance changes the observer’s view of the ogically you’d think that we can Moon slightly and shows us just a bit more see 50 percent of the Moon’s surface of its surface. The cumulative affect is that and that’s it. But you can throw logic we can see 59% of the Moon’s mug. outL the window. There’s another little- The Moon’s orbit around Earth is ellipti- known factor that lets us see more than half cal not a perfect circle. That means that at of dear old Luna. It’s called “” (not times it is farther from us and at others it to be confused with “Libation”) and it’s the is closer. At its farthest point from Earth reason we can ultimately see 59-percent of it is just a bit over 400,000 km away. At the Moon’s surface. Libration is the term for its closest point it is a bit over 350,000 km the Moon’s tendency to rock just a little to away. If the Moon’s closest approach to the east and to the west and roll a bit north Earth coincides with a full Moon phase we and south. This rock and roll allows us to have what the media have dubbed a “Su- get a peek around the Moons edges to see per Moon” though it only appears about just a little more of its surface. To do so, you 10% larger. Were it not for the hype most have to be an acute observer and follow the people wouldn’t notice any difference in the Moon through its complete cycle from New Moon’s size. Moon back to New Moon. See “Moon” on page 13 12 • peterboroughastronomy.com ESA Pondering Moon’s Back Side

John Crossen the European Space Agency (esa) has a new President, Johan- Dietrich Wörner. At the 31st Na- Ttional Space Symposium, Wörner put forth his vision of a lunar colony on the far side of our celestial dance partner. Neither the Moon colony nor having it on the is a new idea. But they do make sense. Building a radio telescope on the Moon’s far side would help telescope reception greatly because it would be free of the interfering “chatter” it would pick up from Earth-based sources were it on the Earth- facing side. Lunar Fars Sde. Welcome to the far side of the Moon. You’ll notice that it is more crater-pocked than the side So we can score one for the fact that the facing us. Building a Moon colony here might involve Moon doesn’t appear to rotate because it is mining lunar regolith (a sand-like material) that covers gravitationally locked in position by planet the Moon’s surface. It could be used to mould building Earth. On the other hand communications blocks for lunar structures. with Earth would have to be beamed from structures based on the widely-available a satellite orbiting the Moon or an antenna regolith. Then, too, there is the problem of set up on the near side of dear old Luna. financing such a monumental adventure. Those who might think that the far-side Again with each nation contributing of the Moon is always in darkness are them- from its capabilities such as electronics, selves in the dark. At New Moon phase the optics, computers etc, no one country has to far-side of the Moon faces the Sun and is shoulder the load be it finances or research. totally lit. Only when the Moon is in its full National Aeronautics and Space Admin- phase — directly opposite the Sun — is the istration () leader Charles Bolden was far-side in total darkness. All of the phases also at the symposium and on the panel in between allow the far side different levels with Wörner. He expressed interest in the of lighting just as they do the Earth-facing mission saying; “Although Mars is the ulti- lunar side. mate destination for humanity, we mustn’t Wörner sees the lunar colony as a step- forget that there are lots of other places in ping stone from the International Space the solar system. And there are places where Station (iss). The Moon base would be a humans will go and must go.” He continued learning phase for all the countries involved saying; “A lot of our international partners before heading on to the colonization and are interested in the Moon.” exploration of Mars. Currently nasa is interested in establish- Key points he mentioned were learning ing an infrastructure orbiting the Moon how to better reuse supplies rather than that will assist other countries and com- relying on shipping new supplies. It works mercial enterprises in landing on the lunar for the iss, but Mars would be a long haul surface. The time from 2020 to 2030 will and a long wait. Also of importance would be spent on this program and he is inviting be making use of available on-site materi- other nations to participate. als. On the Moon that could mean building Vol 14 • Issue no. 8 • October 2015 • 13 The Reflector continued from previous page 10 affect our and the gravitational stabil- Seven Sisters ity of our planet. The difference between high and low tides will be much less. So our tion Orion rising just behind them — still in friends in the tourist business at the Bay hot pursuit. of Fundy had better make money while the There are probably as many renditions tides are still high and low. of the aforementioned story as there are Since the Moon was created by an im- cultures on the globe. They are visible from pacting protoplanet now referred to as the North Pole to the tip of South Africa. Theia, over 3.5 billion years ago it has Once you have them in sight, you may wish slowly moved away from Earth. Early on to switch to a pair of 10 × 50 binoculars. The the Moon and Earth were separated by ladies are dazzling at just 10 power and just 200,000 km. Now we average about binoculars with a 50 mm front lens have 375,000 km separation. What the future plenty of light gathering ability for doing brings as the Moon continues to expand its astronomy. orbit could mean a bad sol for Mars. The Seven Sisters are only about 1 mil- lion years old. In cosmic terms that’s pretty young. The star cluster is about 425 light continued from previous page 7 years from Earth. That makes our ladies the Space Race closest star cluster to dear old terra firma. By the way, a light year is the distance a The first woman in space was Valen- beam of light would travel in one year. That tina Tereshkova. On February 16, 1962 her works out to 10 trillion kilometres per light Vostok 6 rocket left Earth and she suc- year. cessfully completed 48 orbits of the home The Seven Sisters was first catalogued by planet. Due to regulations Valentina was Charles Messier. It is the 45th item on his made a honourary member of the Soviet list of deep sky objects and is often referred Air force before she could become a Cos- to as Messier 45 or just M45. So get out and monaut. 1n 2013 she volunteered to join the look up. One of astronomy’s most beautiful one-way Mars mission to establish a colony sights is waiting for you. on Mars. She was the first and only female in the male-dominated Russian space pro- gramme. Let’s jump ahead to July 20, 1969. That’s continued from previous page 11 when Apollo 11 set down on the Moon. The Moon u.s. had won the space race by landing the The Moon also helps stabilize the Earth first humans on the Moon. The late Neil as it rotates. Without the Moon’s gentle Armstrong was the first to set foot on dear gravitational pull on Earth, our home planet old Luna and Buzz Aldrin was right behind. would wobble like a top spinning down. As Astronaut Michael Collins remained aboard a result we’d have dramatic weather swings. the orbiting command module and would Given that life needs millions of years to eventually rendezvous with the moon-walk- take hold and adapt to a climate, those dras- ers for the return to Earth. tic swings would make it impossible for life The first joint U.S.-Soviet space mission on Earth to begin. came about in 1975. It was an open showing Unfortunately, the Moon is slowly pulling of the new detent between the U.S. and So- away from Earth. It’s not much, just 3.8 cm viet Union. Dubbed the Apollo-Mir mission per year. But it adds up with the time. Since it was the culmination of a team design for first taking laser measurements in 2007, the docking mechanisms that would allow the Moon has drifted 30mm or 1.3 inches the last Apollo spacecraft to dock with the further away every year. Over time that will Mir Space Station. 14 • peterboroughastronomy.com

The Sky this Month

Mercury is well placed in the early morning sky from the 7th to the 31st. Greatest elongation west (18°) on the 16th. Inferior conjunction on the 30th. Venus reaches greatest elongation west (46°) on the 26th. In conjunction with Jupiter on the 26th. Mars is low in the eastern dawn sky in Leo for the month. In conjunction with Jupiter on the 17th. Jupiter low in the morning sky in Leo. In conjunction with Mars on the 17th and Venus on the 26th. Saturn is low in the southwest twi- light evening sky. Moves from Libra to Scorpius on the 16th. Orionid Meteor Shower peaks at 7 PM on the 21st. Zodiacal Light from the 11th for the next two weeks in the east before morning twilight.

Moon Phases Last Quarter 5:06 PM October 4 New Moon 8:06 PM October 12 First Quarter 4:31 PM October 20 Full Moon 8:05 AM October 27 Vol 14 • Issue no. 8 • October 2015 • 15 The Reflector continued from page 3 continued from page 4 Wishes on a Star Pluto The paa was out in force with a couple that any heat from decay should have dis- of new faces hovering over the eyepiece. sipated into space millions of years ago. Bridget Gallagher got her new scope up and Or could Pluto be some kind of anomaly? running. It was her first outing with the It’s a riddle waiting to be solved and there’s group and she soon had a long line of eager still evidence coming in from the New Hori- stargazers at her scope. zons spacecraft. I left before the event was over, but I’d Scientists were also expecting to find a guess the turnout was at least 150, and bland little ice ball with a uniform surface. that’s just for the stargazing session which Instead they found a multi-coloured world concluded the evening’s entertainment. It with huge flat plains, mountains of ice and was a great outing with 10 paa scopes on red dust-like particles that not only covered hand. large portions of Pluto’s surface, but those We would like to give special thanks to of its largest moon, Charon. the weather folks who arranged a warm, Currently it is thought that the red clear night for us. If you have a scope and particles were formed by a chemical reac- haven’t been out with the observing group tion between the methane and nitrogen in you’re missing out on a lot of fun. You don’t Pluto’s atmosphere. When exposed to the have to know a lot, just show up and we’ll infrared light wave lengths of sunlight these show you the wonders of the universe. two chemicals react. The end result is a red dust called folin. Speculation is that much continued from page 6 of Pluto’s surface is covered in a thin coat- Saturn ing or folin. But the folin isn’t just on Pluto. Pluto’s atmosphere has been escaping to a thick layer of clouds, but dig inside and the polar region of Charon. Because the two that’s where the ice is. Its gas that’s so cold bodies share the same centre of gravity as it has frozen. And again both have rocky they orbit each other, the folin has drifted cores. from Pluto to Charon where it has con- Ever hear someone say you can tell the densed over million of years to form a thin difference between a star and a planet be- layer on Charon’s northern polar region. cause stars twinkle. That’s not always true. An even bigger surprise was what scien- On a night when the Earth’s upper atmo- tists didn’t find — fields of crater upon cra- sphere is very active even planets appear ter overlapping each other. Instead much to twinkle. It’s the movement of our atmo- of Pluto’s surface is smooth and crater-free. sphere that bounces the starlight around This doesn’t mean that Pluto escaped be- and makes stars appear to twinkle. Ditto ing hit by meteors. Instead it suggests that goes for the planets. So make sure when Pluto has been actively resurfacing itself. you wish upon a star it’s not a planet. How and why are still up for grabs. 16 • peterboroughastronomy.com continued from page 1 Measure the Moon ing a lunar eclipse, Earth’s shadow is about 3.5 times larger than the Moon, with some Articles slight variations dependent on the Moon’s Submissions for The Reflector must be received by the date listed below. E-mail submissions point in its orbit. Simply divide Earth’s ra- are preferred (Microsoft Word, OpenDoc, ASCII dius by your measurement to figure out the and most common graphic formats are accept- Moon’s radius! able). If your article contains photso or graphics, Even with this primitive method, it’s please provide a separate file for each. Typed or straightforward to get a measurement for hand-written submissions are acceptable pro- vided they are legible (and not too long.) Copy- the moon’s radius that’s accurate to within righted materials will not be published without 15% of the actual value: 1,738 km. Now that written permission from the copyright holder. you’ve determined its physical size and its Submissions may be edited for grammar, brev- angular size, geometry alone enables you ity, or clarity. Submissions will be published at to determine how far away it is from Earth. the editor’s sole discretion. Depending on the volume of submissions, some articles may be A lunar eclipse is coming up on September published at a later date. Please submit any ar- 28th, and this supermoon eclipse will last ticles, thoughts, or ideas to: for hours. Use the partial phases to measure [email protected] the size of and distance to the Moon, and Next submission deadline: see how close you can get! October 27 2015

Meetings The Peterborough Astronomical Association meets every first Friday of each month, except July and August, at the Peter- borough Zoo Guest Services and Rotary Educa- tion Centre (inside the main entrance at the north end of the Zoo) at 7 p.m. P.A.A. general annoucements will begin each meeting with the guest speaker starting at 7:30 p.m.