Astronomy Haiku

You remember haiku? Three lines, the first line with five syllables, a second line with seven syllables, and a last line with five syllables. It may be poetry, but this is easy poetry to write, a short verse with an elegant cadence.

For an AstroDay activity, Keck held an astronomy haiku project. We have a stack of entries we are just now getting a chance to read. Winners are not yet decided, but I have found a few that are wonderful, and worth giving some recognition to.

I should be clear, these are my favorites! Not necessarily the contest winners.

Orion Nebula
NGC1976 or M42, the Great Orion Nebula

Telescopes are great
They make you see very far
I love telescopes
    -Madison Kobayashi (age 9)

Stars shining brightly
I look to them for comfort
In them I find you
    -Lacey Siweila

Lacey is over 18 and not eligible for a prize in the contest. She knew this and enters a poem anyway. You have to love that!

The Moon is so bright
The stars help light up the night
Let’s lay out tonight
    – Micah Timbresa (age 7)

All poems reproduced with permission.

An Evening with Astronomers

A quandry… Our regular astronomy club meeting was the same night as Keck’s evening with astronomers lecture. These invitation events are presented to donors, featuring a lecture from a professional astronomer beneath the palm trees of the Fairmont Orchid resort. A number of our members go to both events and faced a choice of which event to attend.

A solution was proposed… Cancel the club meeting in Waimea and head for the lecture down at the resort instead. To cap the evening we would bring along a few telescopes to share the sky.

The club setup five telescope ranging from Purrcynth’s 80mm refractor to Cliff’s 24″ Dobsonian. It was an impressive line of telescopes. I setup next to Maureen with her new 10″ SCT, a nice match for the 11″ NexStar I use for public work. Arriving before the guests we had a line of telescopes setup and ready for viewing well before dark. As Venus and Jupiter appeared in the sunset we began providing views to the early arriving guests.

Sharing the SkyMaureen sharing her telescope with guests at Keck's Evening with Astronomers

The lecture was presented by Dr. Chris Martin of Caltech, covering a subject that is often overlooked, the environment between the galaxies, vast expanses of space that are anything but empty. Here can be found enormous reservoirs of gas, accounting for the majority of normal matter in the universe, something astronomers call the intergalactic medium.

I enjoyed the lecture. Having a somewhat more than average astronomy education, I find so many public lectures a bit repetitive, I have heard it before. Not this night! Dr. Martin covered a lot of material I had never previously encountered. How the universe is filled with streamers of moving gas, influenced by the gravity of dark matter the gas streams into the galaxies and clusters of galaxies, allowing the formation of new stars in an extraordinarily dynamic process. It was a view that has altered the way I see the universe.

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Keck in Motion Scene Guide

I have been getting a few questions about the video. To answer a few of them I have compiled a guide to the scenes. Some quick explanations to what you are seeing, information on the camera used as well as the exposure information.

The video is a combination of two techniques. Many scenes were filmed as standard video then accelerated during editing to allow the motion to become clear. Examples of this are scenes of telescopes slewing and the interferometer delay lines moving.

Slower subjects, such as clouds or the stars moving across the sky, were photographed as time lapse. Here a large number of still images were taken. These are then processed and converted to video using Photoshop CS5 before loading into the video editing software, Adobe Premiere Elements. To construct the time lapse sequences sometimes required thousands of separate images, quickly filling memory cards and exhausting batteries. After dark it is long exposure time lapse that is used, with individual exposures often 15 seconds to one minute long.

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Astronomy Basics, So Far…

I have completed the first set of the Astronomy Basics posts I intended to do. I really wanted to get these posted as support material for the astro-events posts.

As I finished these I realize I should probably continue and hit a few more subjects. Look forward to a few more Astronomy Basics posts in the coming months.

Meteor Watching

Watching meteors is one of the simplest forms of astronomical observing. Just about anyone can enjoy meteor watching, from just about anywhere in the world. Enjoying the show takes only a couple things… A dark sky and a comfortable place from which to watch.

Leonids in Orion
A pair of Leonid meteors streak through Orion
Meteors are simply small bits of debris hitting the Earth’s atmosphere at very high speed, typically tens of thousands miles per hour. Our solar system is rich with this debris. Most of these bits are quite small, about the size of mote of dust or a grain of sand. Something the size of a pea would create a spectacular fireball that lights up the whole sky. While they often seem close, they are actually quite high, 60 miles (100km) above the ground when they flare into short lived fireworks.

The mechanism for the show is simple. When something hits the very thin air high in our atmosphere at very high speed it compresses the air in front of it. This compression also heats the air, causing it to glow white hot. Heated enough, the air becomes a plasma, the molecules shredded and electrons freed from the atoms. It is not the meteor itself that you see, but the glowing plasma around it.

There are a number of questions many people ask about meteor observing. You can find many of the answers below. Watching a meteor shower takes no special equipment, expert knowledge or extravagant preparation. This is an activity nearly anyone can enjoy, one of the spectacles of nature available to all.

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Lunar Apogee and Perigee

Does the Moon seem a little larger and brighter than usual? It may not be an illusion, sometimes the Moon really does look a little larger or smaller in the sky.

Like all orbiting objects, the Moon does not orbit in a perfect circle, but rather in an ellipse. This means that as it orbits it is a little further away or a little closer. In the case of the Moon the difference is not much, but you can see it, if you know to look.

Lunar Apogee & Perigee
The apparent size of the moon as seen at perigee versus apogee
When the Moon is furthest from the Earth, a point called apogee, it will be about 405,000km (251,000miles) from the Earth. While at perigee, the Moon will be about 360,000km (223,000miles) from the Earth, as measured from the center of the Earth to the center of the Moon. The change in distance leads to a noticeable difference in the size of the Moon as seen by an observer here on Earth. When at perigee the moon will appear about 12% larger than when seen at apogee.

Lunar Month Animation
Click to view a simulation of a lunar month showing phase, libration (tilt), and the size change as the Moon goes from apogee to perigee. Image credit Tomruen via Wikimedia Commons
The difference is most noticeable at full Moon. If the full Moon occurs near apogee or perigee, an experienced skywatcher can spot the difference. The effect should not be confused with the well known Moon illusion, where the Moon can appear larger near the horizon.

The period of time between full Moons, the synodic month, is about 29.5 days. While lunar perigee occurs every 27.5 days, an anomalistic month. Since these periods are not equal, the cycle drifts in and out of phase. About once a year the cycles coincide and full Moon and apogee or perigee will occur near the same time.

At apogee, the Moon will be appear about 29 arc-minutes in size, a little less than half a degree. At perigee the Moon will be about 33 arc-minutes across, a bit more than half a degree. The numbers may not seem like much, but it is a visible difference. The simulated images shown here will give a better idea of what the numbers represent.

This change in size and distance leads to the moonlight being a bit brighter at perigee than at apogee, about a 30% difference. So if that moonlit night seems brighter than you remember it may actually be the case.

Magnitude

Throughout the astronomical descriptions and event posts here on Darker View I use the term magnitude to describe the brightness of an object in the sky. Magnitude is a simple scale, but somewhat confusing without a quick introduction.

The origins of our current magnitude scale are as old as the science of astronomy itself. One of the first stellar catalogs, the Almagest, was compiled by Claudius Ptolemy in the 2nd century. To denote the brightness of stars the catalog assigned the brightest as being “stars of the first rank”, with a corresponding second rand, third rank, etc. The dimmest of stars, the faintest visible to the unaided eye, were assigned to the sixth rank. This system was used with little alteration for the next two millennium. Subsequent catalogs and observers used their own versions of the scale, perhaps adding a decimal place to denote finer differences in brightness. As there was no instrumental method of measuring the brightness, magnitude estimates varied widely from source to source.

With the dawn of modern photographic methods and later electronic methods, it became possible to systematize the scale. It was desirable to create a scale that approximated the old system and time honored traditions. Thus the current magnitude scale was developed, understanding the origins allows understanding of the modern system.

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Elongations, Conjunctions and Oppositions

As a planet moves across the sky there are particular points in its orbit that describe the motion, part of the jargon of astronomy that can confuse the uninitiated. These terms do not represent anything difficult, you just have to visualize what they mean. Understanding the movements of planets across the sky gives a little insight into our beautiful universe.

Elongation, opposition and conjunctions
Elongation, opposition and conjunctions, the apparent positions of a planet with respect to the Earth
The terms used commonly here on Darker View are ideas that date back to the early beginnings of astronomy. Those ancient astronomers were fascinated by the movements of the bright wandering stars, the planets. They tracked and recorded the motions meticulously and invented the terminology we still use today to describe those motions.

Superior Conjunction, Inferior Conjunction, Opposition and Maximum Elongation tell any experienced skywatcher exactly where a planet is with respect to the Earth, where it is in our sky, and where it will be in the coming weeks or months. It is all part of the intricate patterns of our solar system that allow anyone who learns to become familiar with the night sky.

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Astronomy Basics

-4.9 magnitude? Inferior conjunction? Maximum elongation? 3.4° separation? To explain many of the basic terms I use to describe sky events I really need to post some explanation. Something I can link to in order to explain myself. Using the magic of hypertext as it was originally meant to be used.

I have written a couple more astronomy basics posts to go along with the sky events postings. I have copied over a few more posts from the old DV blog, updating and refreshing them as I did so. Expect to see a series of astronomy basics posts through the month as I get everything setup in the new blog.