Posted on by Tammy Plotner

Lingering Lyrids…

Meteor FireBall Break-up Courtesy of John Chumack

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Although we couldn’t remind you just before the date of the Lyrid meteor shower peak, there’s no reason to believe the show is over just yet! If you’re an early riser, this just might be your chance to catch a lingering Lyrid…

Every year the Earth encounters the dusty remnants of the tail of Comet Thatcher (C/1861 G1). It doesn’t occur on a very specific date, but we do know it happens in late April. While the peak time is dawn on April 23, it’s not uncommon to see between 5-20 meteors per hour through the 26th.

Why such a widely varied date and diversified fall rate? The answer is… thanks to Jupiter’s massive gravity, we never know exactly when we might encounter a “clump” of comet debris. The majority of the time, the spawn of Comet Thatcher is no bigger than a grain of sand, traveling through our atmosphere at 49 km/s (110,000 mph). Incredibly enough, these fast moving particles can light up as brightly as 2nd magnitude – easily seen from moderately light polluted skies. Some have even been known to appear as fireballs and leave smoke-like trails that linger in the sky for several minutes!

For the past 2600 years, mankind has been observing the Lyrids – and you can, too. Since their radiant is near the bright star, Vega, your best time to observe is in the hours just before dawn. For many observers, the constellation of Lyra will be high to the east around 4:30 a.m. local time and nearly overhead just before dawn. Even southern hemisphere observers with an unobstructed northern horizon can enjoy the show, too. While there will be some Moon to contend with, placing it behind an obstruction like the corner of a building or a tree will help reduce the glare.

Clouded out or decided to sleep until it was light? Don’t forget your lessons on how to “listen” with your radio! According to NASA, “This year many amateur radio operators tuned into the Lyrids using a technique called radio forward scattering. When fast-moving meteoroids strike Earth’s atmosphere they heat and ionize the air in their path. The luminous ionized trails are not only visually striking — they also reflect radio waves. During a major meteor shower, radio signals from TV stations, RADAR facilities, and AM/FM transmitters are constantly bouncing off short lived meteor trails. For those who know how to listen, it’s easy to hear the echoes.” Don’t remember how to listen? Then take the radio meteor listening tutorial courtesy of the North American Meteor Network.

Will you catch a lingering Lyrid? You never know until you try…

Many thanks to John Chumack of Galactic Images and to NASA for the illustrations.

Posted on by Jon Voisey

Unidentified Triangles

Three dots of light in the sky above Lafayette, Colorodo.
Yes. These 3 dots are really all the "evidence" you get.

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Apparently I have a reputation as a debunker. When I first started writing for Universe Today, Fraser told me to feel free to do articles relating to skepticism. I haven’t much, but I’ve been asked to cast a skeptical eye on the topic of UFOs and aliens, especially given a recent sighting which made it onto Good Morning America.

My general opinion on UFOs is that there’s really just not enough evidence to say whether or not the people making claims about them are right. In fact, there’s so little coherent evidence that it’s more apt to say that they’re “not even wrong“. In such cases, I generally find the topic uninteresting and not worthy of attention. I could address them as an exercise with Occam’s razor, but that’s been done to death. Instead, there needs to be something else that makes the topic worthy of addressing. Coincidentally, this case does.

Typically, there’s two additional reasons I’ll discuss such a topic. The first is if such baseless belief causes demonstrable harm (such as recent doomsday criers convincing people to give up their homes and family to go on a fire and brimstone tour of the US to proclaim The End). With UFO buffs, this isn’t a concern generally.

The other reason I’ll discuss something is if I notice a particular logical fallacy that’s worth exploring in its own right. In watching a few of the videos related to the one shown on Good Morning America, I found another one that I think does a good job of highlighting the willingness to jump to conclusions. In this clip, an awestruck spectator is stunned by the lights because they form “a perfect triangle”. I’m teaching a geometry course this semester and I’ve been dealing a lot with triangles, but I’m not quite sure what he means. By definition, a triangle is simply a polygon with three sides, which meet at three points. Pick 3 points anywhere and you’ll be able to form a triangle by connecting the dots. Thus, all you need to form a “perfect” triangle is 3 points. There’s nothing inspiring about that.

To give the guy as much credit as possible, I’ll assume that the guy meant “equilateral” which would mean that each side is perfectly equal. This would be slightly more interesting. It would mean they were each affixed to a larger body to keep them at just the right distance, or, they were each manipulated independently to remain in the right formation. Still, neither of these tasks is especially impressive (I’m more impressed by the Blue Angels keeping formation at supersonic speeds), but before we need to consider that, we should be asking an even more fundamental question: Is the triangle actually equilateral?

Quickly taking a screen cap and importing it into a drawing program in which I can trace on some lines shows immediately that it doesn’t look at all equilateral. But there’s a good reason for that: We’re seeing it at an inclination and objects will look very different depending on your particular point of view . What we’re really seeing is a two-dimensional projection of a shape in three-dimensions. The closer to the plane of the triangle you put your eye, the flatter it looks. Rotate it and the third point will seem to shift relative to the other two. In other words, we could very easily have an equilateral triangle projected in such a way that it looked just like the one the spectators saw. But at the exact same time, any triangle, equilateral or not, could be viewed in such a way to replicate that projected shape.

Why then, did this fellow claim it was a “perfect triangle”? Simple: He had prior expectations. He couldn’t know, but mentally, he could envision it being “perfect” and his mind seized on that solution, ignoring all others and manufacturing details that didn’t necessarily follow from the observations. Sound familiar?

Ultimately, we can’t say what these lights were (although I find the road flares on balloons explanation to be simple and fit perfectly with all observations thus passing the test of parsimony). And I think that’s the important note: We don’t know. But let’s at least be knowledgeable and honest enough to admit what we don’t.

Posted on by VirtualAstro

Fancy doing a Messier Marathon this Weekend?

The Messier Catalog
The Messier Catalog Credit: SEDS

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If you are new to astronomy, you may ask “what is a Messier Marathon and how do I do one?”

Basically a Messier Marathon is an all night (Dusk til Dawn) observing session held around mid March/ early April every year, where an observer attempts to see all, or as many of the 110 Messier objects as listed by Charles Messier.

The Messier list includes: Nebulae, Galaxies, Star clusters, Supernovae and many other deep sky objects. All of the objects in the Messier list are observable with small amateur telescopes and many of the objects are observable with binoculars.

The reason why Messier marathons take place from mid March to early April is because this is when all of the objects are visible in one evening. Other times of the year aren’t suitable as some of the objects will be in daylight or below the horizon etc.

You don’t have to be an astronomy ace or a seasoned astronomer to do a Messier marathon, but you will need a good telescope to see all of the objects. You don’t even need to do a full Messier marathon as many people do half marathons and depending on your location, or when you observe, you may not be able to see all 110 objects as there is a very tight window of opportunity and higher latitude observers do lose a couple of objects below the horizon.

Timing is key to enable you to see as many of 110 messier objects as possible. Many astronomers put tables and even star charts on the internet to help observers see as many objects as possible.

Observing starts at dusk and ends after dawn and on average each object gets about 5 minutes of observing time before you have to move onto the next one. There can be a short respite half way through the observing session for food and rest, but this depends on the order and success of the objects you are viewing?

Before starting your night of viewing Charles Messier’s wonders, make sure you have all your equipment ready, are dressed warm as it will get cold, have all your charts and viewing tables ready. It also helps to have a hot drink and something nice to eat.

The best dates this year for doing a Messier Marathon have passed and the sky was drenched with the glow of the full moon, but we still have early April. Good luck.

Charles Messier (26 June 1730 – 12 April 1817) was a French astronomer most notable for publishing an astronomical catalogue consisting of deep sky objects such as nebulae and star clusters that came to be known as the 110 “Messier objects”. The purpose of the catalogue was to help astronomical observers, in particular comet hunters such as himself, distinguish between permanent and transient objects in the sky.

Posted on by VirtualAstro

Why are Dobsonian Telescopes a Favorite Among Amateur Astronomers?

Dobsonian Telescope
The Meade 16" LightBridge

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Welcome to the scary and expensive world of buying your first, or replacing your old telescope!

I am asked all the time “What telescope should I buy” or “What telescope do I need to see X with?” Nine times out of ten, I recommend a Dobsonian Telescope.

So what is a Dobsonian telescope and why are they so good? Read on to find out why.

A Dobsonian is simplicity in itself; a simple set of optics on a simple mount. But don’t be fooled by this simplicity. Dobsonian telescopes are incredibly good and are great for amateurs and professional astronomers alike. They are also very economical compared to other telescopes.

The optical part of the telescope or OTA (Optical Tube Assembly) is the same as a Newtonian reflector telescope. It consists of a primary parabolic mirror and a flat secondary mirror in an open ended tube, with a focuser for an eyepiece set on the side. Light enters the tube, reflects off of the primary mirror at the base and is then focused onto the smaller flat secondary mirror and then finally, into an eyepiece. Simple!

Credit Skywatcher.net

The benefit of this type of optical arrangement is the telescopes light gathering ability. The more light gathered, equals more fainter objects to be seen. A light bucket!

Dobsonian/Newtonian telescopes have a big advantage over telescopes with lenses such as refractors and Cassegrain telescopes, as mirrors are a lot cheaper to make than lenses. Plus they can be a lot bigger!

Both Dobsonian and Newtonian telescopes are measured by the size of the diameter of their primary (big) mirror. Dobsonian sizes range from starter scopes of 6 inches up to 30 inches, but common sizes are 8 to 16 inches in diameter. They can be many times larger and less expensive to produce than scopes with lenses.

The second part of a Dobsonian telescope is the mount. As with the optical part the mount is just as simple, if not more so! A basic manual mount which supports the optical tube and can be manually moved by hand in the Altitude (up/down) and Azimuth (left/right) axis.

The mount is usually made from wood or metal with bearings and support for the two axis of movement. More so lately, some manufacturers have put GoTo systems with motors on some Dobsonian mounts. Personally I think it’s a bit over kill for a Dobsonian, as finding objects manually by star hopping or other manual methods helps you learn the sky better and can be fun.

Dobsonian

Resist the urge to spend lots of money on small computerized scopes that will eventually never get used, as they can be too complicated or you may not see much through them apart from the brightest objects such as the Moon. A Dobsonian is a great all-around telescope, and are available in almost all telescope stores. Some people make their own homemade Dobsonian scopes too!

Due to the nature of the Alt-Az mount, Dobsonians are not suitable for long exposure astro imaging. For that you will need an equatorial mount, which will track the stars equatorially. You may have some success with webcam imaging with some of the GoTo Mounts though.

Skywatcher 10 inch Dobsonian Credit sherwoods-photo.com

Dobsonian telescopes are designed to be simple, easy to use and gather as much light as possible. Because of this robust simplicity, they are very economical and popular with astronomers of all levels of ability. My own and most favourite telescope is my Skywatcher 10-inch Dobsonian and I will probably be using it for many more years to come, as it is difficult to beat!

The name of the Dobsonian telescope comes from its creator John Dobson, who combined the simple design of the Newtonian telescope with the Alt-Azimuth mount. He originally made simple homemade scopes from household materials and ground mirrors out of the glass of old ship portholes.

John Dobson is the grandfather of Sidewalk Astronomy and co-founder of the San Francisco Sidewalk Astronomers.

Credit cruxis.com
Posted on by Tammy Plotner

What A Beautiful Day For A Sunspot

Sunspot 1164 - Credit: John Chumack

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For many of us, this is the first break in the weather we’ve seen for quite some time. Of course, when opportunity knocks, you’ve got to be there to open the door… and today John Chumack took the opportunity to point his Baader solar filter film equipped 10″ SCT and Canon Rebel camera the Sun’s way…

If you’ve had the opportunity to follow solar activity, you’ve seen some major sunspots come and go over the last couple of weeks. Now the next bad boy in line is 1164. Just take a look at its progression in this movie from SDO/HMI. Growing sunspot 1164 has a complex “beta-gamma” magnetic field that harbors energy for M-class solar flares. Not just an off chance, either… but a 35% chance over the next two days. But that’s not all that’s going on!

According to Spaceweather.com “A solar wind stream hit Earth’s magnetic field during the early hours of March 1st. The impact sparked a geomagnetic storm that was, at first, minor, but the storm has been intensifying throughout the day. Spotters are now reporting auroras over Northern Ireland, Latvia, Norway, and Sweden. If trends continue, the display could spread to the high latitudes of North America after nightfall. ”

So how do you see aurora? Like John, you’ve got to be there when opportunity knocks! Be outside around nightfall and keep watch loosely to the north. Aurora can appear like distant search lights, reddish clouds or even ghostly green patches of mist. They appear and disappear… Somtimes you can see stars through them and sometimes the aurora is bright enough to block the starlight. Depending on where the auroral oval is at, you can see them to the north, north-east or north-west. There have even been times when the oval has shifted enough that they appear to the south!

Answer the door… it just might be for you!

Posted on by Tammy Plotner

Moon And Venus Steal The Morning Scene…

Venus and Waning Crescent Moon by John Chumack

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If you’re an early riser, then perhaps you’ve noticed Kepler’s Laws in action? No, it’s not a new Bruce Willis movie, just the inevitable pairing of the waning crescent Moon and shining Venus. As you can see from this great photo taken last month by John Chumack, it happens as regular as clockwork… and it’s about to happen again. But what is it about such pairings that command our attention? Step inside and find out!

According to the Sky & Telescope press release, the brightest planet and the eerie waning crescent Moon will create an arresting sky scene low in the southeast in the early dawn of Monday, February 28th, and Tuesday, March 1st. “These are the two brightest astronomical objects in the sky after the Sun,” says Alan MacRobert, a senior editor of Sky & Telescope magazine. “They’ll certainly catch your eye, if you look low in the southeast about 60 to 40 minutes before sunrise — weather permitting.”

Venus will be shining to the Moon’s lower left on the morning of Monday Feb. 28th. The next morning Venus will be to the Moon’s right or upper right. Although they look close together, they’re not. Venus is currently 400 times farther away than the Moon. It’s at a distance of 8.8 light-minutes (the distance light takes to travel that far), compared to the Moon’s distance of 1.3 light-seconds. In miles, that’s 99 million miles for Venus and just 249,000 miles for the Moon. (In fact, you may have driven cars enough miles to get to the Moon.) And despite appearances, Venus is 3½ times wider than the Moon’s diameter.

Locator Chart Courtesy of Sky & Telescope Magazine

“Why do people care about this?” asks MacRobert. “Because some people know we need to look up beyond our own little world — and recognize where we are as part of nature, part of the universe. So many of us live our busy little ant-hill lives without ever noticing the gigantic universe beyond the anthill. A lot of people don’t even know you can see alien planets from your driveway while you’re unlocking the car to go to work.”

But just what is it about such a celestial scene that draws our eye like no other? When it comes to our eyes, almost every photoreceptor has one ganglion cell receiving data in the fovea. That means there’s almost no data loss and the absence of blood vessels in the area means almost no loss of light either. There is direct passage to our receptors – an amazing 50% of the visual cortex in the brain! Since the fovea doesn’t have rods, it isn’t sensitive to dim lights. That’s another reason why the conjunctions are more attractive than the surrounding starfields. Astronomers know a lot about the fovea for a good reason: it’s is why we learn to use averted vision. We avoid the fovea when observing very dim objects in the eyepiece.

“Your eye is like a digital camera,” explains Dr. Stuart Hiroyasu, O.D., of Bishop, California. “There’s a lens in front to focus the light, and a photo-array behind the lens to capture the image. The photo-array in your eye is called the retina. It’s made of rods and cones, the fleshy organic equivalent of electronic pixels.” Near the center of the retina lies the fovea, a patch of tissue 1.5 millimeters wide where cones are extra-densely packed. “Whatever you see with the fovea, you see in high-definition,” he says. The fovea is critical to reading, driving and even watching television. The fovea has the brain’s attention. The field of view of the fovea is only about five degrees wide.” When Venus and the crescent Moon are close to that narrow angle, it signals to the brain, “this is worth watching!”

Let’s pretend we’re a photoreceptor. If a light were to strike us, we’d be “on” – recording away. If we were a ganglion cell, the light really wouldn’t do much of anything. However, the biological recorder would have responded to a pinpoint of light, a ring of light, or a light with a dark edge to it. Why? Light in general just simply doesn’t excite the ganglion, but it does wake up the neighbor cells (as does hooting and screaming while pointing at the morning sky). A small spot of light makes the ganglion go crazy, but the neighbors don’t pay much attention (unless you’re in your pajamas cleaning the snow off your car). However, a ring of light makes the neighbors go nuts (and their dogs) and the ganglion turns off. It’s all a very complicated response to a simple scene, but still fun to understand why we are compelled to look!

And perhaps howl just once.

Many thanks to John Chumack of Galactic Images and to Sky & Telescope Magazine for the heads up!

Posted on by VirtualAstro

Choosing a New Telescope – GoTo or not GoTo

Guide to Meade Telescopes
MeadeETX125PE

I am often asked by people “I’m a beginner, so what telescope should I buy?” Or more often, what GoTo telescope would I recommend for someone starting out in astronomy?

When venturing out and buying your first telescope, there are a number of factors to consider, but because of glossy advertising and our current digital age, the first telescope that people think of is a GoTo.

Do you really need a GoTo or would a manual telescope suffice? In order to make a good decision on what telescope to buy, you need to decide on what you want to use the telescope for — observing, photography, or both and does it need to be portable or not? This will help you make the best decision for the mount of your telescope.

GoTo telescopes are usually advertised as being fully automatic and once they have set themselves up, or are set up by the user, they can access and track and many thousands of stars or objects with just a simple touch of a button. These features have made GoTo scopes are very desirable with many astrophotographers.

Manual telescopes are not automatic or driven by motors as GoTo scopes are. They are predominantly used for observing (using your eyes instead of a camera) and the scope is moved by hand or by levers by the user to find different objects in the eyepiece. Manual telescopes usually have a finder scope, red dot finder or laser finder to aid in finding objects in the eyepiece. They are unable to track objects, which can make them unsuitable for photography.

GoTo Vs Manual
Compared to GoTo telescopes, manual telescopes are much more economical as you are basically buying a very simple mount and an optical tube assembly (the telescope tube, or OTA). With GoTo you are adding electronics and control mechanisms to drive the scope, which can add heavily to the cost. A small GoTo telescope could cost the same as a lot larger manual Dobsonian telescope.

Good GoTo telescopes make astrophotography very accessible and enjoyable, especially with the addition of cameras and other kits. As opposed to manual scopes, GoTos can be used for long exposure astrophotography. Be aware though, that much astrophotography is done with very expensive imaging equipment, but good results can be achieved with web cams and DSLR cameras.

Manual telescopes are brilliant at helping you discover and learn the sky as you have to actually hunt or star hop for different objects. I once met a person who had been using a GoTo telescope heavily for a year, and at a star party I asked her to show some kids where a well known star was with my laser pointer, she didn’t know because she was used to her GoTo scope taking her to objects.

So which one should you buy?
I would recommend for pure visual observing a manual telescope such as a large Dobsonian or Newtonian telescope. The human eye needs as much light to enter it as possible to see things in the dark, so a big aperture or mirror means greater light gathering and more light entering your eye, so you can see more. What you saved by not having GoTo, you can spend on increasing the size of your telescope.

If you want to add photography or imaging capabilities then I would definitely recommend a good quality GoTo scope or mount. You will get a smaller aperture compared to the manual scope for the same money, but the scope will track for astro-imaging and can also be used for visual observing. Be prepared to spend a lot more money, though.

Consider how you want to use your telescope and the size of your budget. Avoid buying low end, cheap, budget, or what is known as “department store” telescopes to avoid disappointment. Save up a little longer and get a good telescope. Visit your local astronomy store or telescope distributor and before you buy ask an astronomer, they will be glad to help.

I hope you enjoy your new telescope for many years to come 🙂

Dobsonian Telescope

Posted on by Mark Thompson

In Case of Jerusalem Video, UFO Could Mean “Unidentified Flashlight Objects”

UFO’s are tricky little blighters. Those three letters have caused so much controversy over the years and I find myself, yet again, discussing one of the most misrepresented acronyms in the entire Universe. UFO stands for ‘Unidentified Flying Object’ and, if you have never seen a helicopter before, then its a UFO, its unidentified and flying! Forgive me then when I saw the news on January 28, 2011 of yet another UFO sighting and cries of alien visitors as if it were obvious. Well stop right there…..
Continue reading “In Case of Jerusalem Video, UFO Could Mean “Unidentified Flashlight Objects””

Posted on by Tammy Plotner

2011 Quadrantid Meteor Shower… Tonight’s the Night!

"Fireball Breakup" by John Chumack

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In just a few hours the peak of the first meteor shower of 2011 will begin – the Quadrantids. Where did these mysterious meteors begin their life and how can you observe one yourself? Then step inside…

Beginning each New Year and lasting for nearly a week, the Quadrantid Meteor Shower sparkles across the night sky for nearly all viewers around the world. Its radiant belongs to an extinct constellation once known as Quadran Muralis, but any meteors will seem to come from the general direction of bright Arcturus and Bootes. This is a very narrow stream, which may have once belonged to a portion of the Aquarids, but recent scientific data points to a what may have been a cosmic collision. According the most recent data, the Quandrantid meteors may have been formed about five centuries ago when a near-Earth asteroid named 2003 EH1 and a comet smashed into one another. Historic records from ancient China put comet C/1490 Y1 in the path of probability.

As Jupiter‘s gravity continues to perturb the stream, another 400 years may mean this shower will become as extinct as the constellation for which it was once known, but we aren’t out of the running just yet. “Peaking in the wee morning hours of Tuesday, Jan. 4, the Quads have a maximum rate of about 100 per hour (varies between 60 and 200),” says Bill Cooke of NASA’s Meteoroid Environment Office. “What makes this year so special is that the Moon is New on the night of the peak, so there will be no interference from moonlight.”

As exciting as it may seem, there are a few problems associated with observing the Quadrantid meteor shower. The first is the weather, because this northern hemisphere show occurs during a notoriously cold season making observations uncomfortable at best. The second is the brevity of the activity itself. Because Earth intersects the debris orbit of 2003 EH1 at a perpendicular angle, we zip right through the trail. That’s why the shower activity is so fast and slightly unpredictable. A third consideration is the high probability of cloud cover – but take heart… NASA has you covered!

“Got clouds? No problem.” says SpaceWeather. “You can stay inside and listen to the Quadrantids. Tune into SpaceWeather Radio for a live audio stream from the Air Force Space Surveillance Radar. When a Quadrantid passes over the facility, you will hear a “ping” caused by the radar’s powerful transmitter echoing from the meteor’s ion trail. During the shower’s peak, the soundtrack is guaranteed to entertain.

So where and when to look? “You can start watching after 2:30am in the North to North East look between the handle of the Big Dipper -Ursa Major and the Constellation of Bootes or the Kite shaped constellation, this is the radiant location as the Meteors will appear to radiate from this general area.” says professional astrophotographer, John Chumack. “Or after 2:30am simply look between the North Star and bright star Arcturus in the East. The Quadrantid Meteors will appear to be coming from this general area of the sky. There is no moon present during this year’s shower, so you can watch all night if you like without moonlight interfering, but the best time will be after 2:30am. As the night goes on the Big Dipper, Bootes and Arcturus climb higher into the sky, so keep watching because the number of meteors usually picks up after 2:30am and gets better through 6:00am. as Earth rotates into the stream. Meteors can appear anywhere in the sky, so look in all directions of the sky as the Quadrantid radiant reaches straight over head. The Quadrantid Meteors are rather fast movers. They enter the atmosphere at about 90,000 to 120,000mph, and can have some impressive long trails.”

Will the Quadrantid Meteor Shower live up to its expectations? No one knows for sure… But we’ll be watching!

Many thanks to John Chumack of Galactic Images for his inspiring photo and to NASA for the locator chart. We thank you so much!