Tag Archives: Nasa Climate Day

Total Lunar Eclipse, Mars Just Past Opposition And A Very Early Observing Event At Baltimore Woods on April 15th

Greetings fellow astrophiles!

The next few weeks are busy ones for CNYO and amateur astronomers in general.

April 10th (just this morning)STEM Career Day At National Grid (image below)
April 15th (from midnight to 3:30ish)Total Lunar Eclipse & Mars Just Past Opposition
April 12th and 13thCNYO and New Moon Telescopes (NMT) At NEAF
April 19thMOST Climate Day (And CNYO Lecture)
April 24th – Seasonal Observing At Beaver Lake Nature Center

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A piece of Mars, some meteors, several magnets, terrestrial rocks with larger meanings, four things we didn’t know “when I was their age,” and additional makings of a set of STEM astro demos.

But back to the eclipse and opposition. It is my opinion that lunar eclipses don’t get the respect they deserve. Yes, solar eclipses are much more exciting and it has been well-documented that people have previously responded very strongly (and not always pleasantly) to solar eclipses. The sudden darkening of the sky and noticeable temperature drop can cause all shades of responses (no pun intended) in people. That said, all we really get (besides a view of the solar corona) is an example of what happens when you put a black disc in front of the Sun. Lunar eclipses, on the other hand, tell us a bit about how the Earth itself interacts with the Sun by how this interaction alters our view of the Moon.

Both solar and lunar eclipses tell us something about the Sun/Earth/Moon relationship. Specifically, we learn that the Sun/Earth orbital plane (the oval made as the Earth goes around the Sun each year) and the Earth/Moon orbital plane (our local oval) are not the same – the Earth/Moon plane is tilted slightly off the Sun/Earth plane by 5.2 degrees (small, but just enough). That is, the Moon spends some time above and some times below the Sun/Earth orbital plane, while sitting right in the plane only two times each orbit (where the two planes intersect). How do we know this? Simple. If the Earth/Moon plane were exactly in the Sun/Earth plane, there would be a total solar eclipse and total lunar eclipse every month because there would be a time each month (New Moon) when the Sun, Moon, and Earth made a straight line (Sun-Moon-Earth = solar eclipse) and a time each month (Full Moon) when the Sun, Earth, and Moon made a straight line (Sun-Earth-Moon = lunar eclipse). As the two planes are slightly off, the New Moon is simply “off the radar” of most people because it can’t be seen during the daytime. The Full Moon, on the other hand, is brilliantly bright most of the time because it only infrequently enters the Earth’s shadow.

The image below shows this very nicely (and it’s always better to find and cite a good image than to have to roll your own). Give it a look for 30 seconds to make sure each of the four cases make sense to you.

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The Sun/Earth and Earth/Moon orbital planes. Note the top and bottom orientations that are perfect for eclipses (and the left and right that are not). Image taken from www2.astro.psu.edu (from Chaisson & McMillan Publishing). Click for a larger view.

Total solar and lunar eclipses, then, occur on special, but periodic and predictable, occasions when the Moon finds itself exactly in the Sun/Earth plane. When it’s just ever-so-slightly off this plane AND still between the Sun and Earth (or still falls into the Earth’s shadow in the Sun-Earth-Moon arrangement), we get partial eclipses. Just that simple.

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What to expect on April 15th (the government’s cashing in on its short wavelength tax!). Image from this article at io9.com.

Perhaps the most striking difference between a solar and lunar eclipse is that a solar eclipse obstructs the disc of the Sun, leaving only a view of its wispy exterior (corona), while a lunar eclipse alters the color of the Moon while still allowing us to see it in its entirety. Those watching the lunar eclipse will see the Moon go from its usual bright grey to orange, then a dark red before reversing the color order. The reason for this dark red coloring is the same reason why our sky is blue – the scattering of light in our atmosphere. Recalling our handy scattering relationship – that scattering (I) is proportional to 1 / wavelength4, we see that shorter wavelengths scatter more than longer wavelengths (because the wavelengths are in the bottom of the proportion, so larger numbers decrease the value of “I”). The image below was taken from one of the great non-wikipedia physics sites (well worth several afternoons to explore), hyperphysics.phy-astr.gsu.edu.

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The scattering relationship. See hyperphysics.phy-astr.gsu.edu/…/blusky.html for much, much more.

We see that shorter wavelength light gets “bounced around” more, while longer wavelength light passes for longer distances unimpeded by interactions with molecules and larger particles (like soot after big volcanic eruptions) in our atmosphere. Light going straight from the Sun hits our atmosphere and gets increasingly scattered as wavelength gets shorter – blue scatters more than red, so we see the blue strongly when we look up during the day. With the blue light strongly scattered, those people on the edges of where the Sun’s light falls – those just starting or ending their days – see more red light because that wavelength wasn’t as strongly scattered – effectively those at sunrise and sunset get the filtered-out leftovers of the light that those at high noon see as blue. The “lit” side of the world experiences a range of different colors depending on where they are during the day, but all are being illuminated by waves of light from the Sun that left at the same exact time (plus or minus a nanosecond or two).

Because it’s a busy week and the author is feeling lazy, he refers you to the top image of the three-panel image below, showing how the scattering of sunlight in our atmosphere occurs sooner after entry (on average) for blue, a bit later (on average) for green, then a bit later (on average) for yellow, then out to red, some of which is and isn’t scattered (on average).

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The scattering of light by Earth’s atmosphere (shorter wavelengths scatter sooner). The other two images are placed into context by your reading about extrasolar planetary atmosphere studies. See www.universetoday.com/…-in-blue-light/ for that info.

And so, we know that blue is scattered strongly and red is not. This red light then races to the edges of our illuminated globe and the red light not scattered directly down to Earth or scattered in the opposite direction (out into space right above you) races past Earth at various altered (scattered) angles. During the most complete part of the lunar eclipse, the red color you see is, in fact, the red light that is passing through the edges of our atmosphere at those places experiencing sunrise and sunset (the sunlight performing a “grazing blow” of our atmosphere). As you might guess, if Earth were to lose its atmosphere (but don’t give any of your industrious friends any ideas), our lunar eclipses would appear quite different. Instead of a dark red Moon, we’d simply see a black disc where no stars shone (like placing a quarter at arms length and obscuring anything behind it).

This lunar eclipse just happens to coincide with another special event in our Solar System that just passed on April 8th – Mars at Opposition. Earth-centric oppositions occur when the Sun and a planet (from Mars out to Neptune, then dwarf planets, comets and asteroids also fit the description) are on opposite sides of the sky to one another (this cannot happen for Venus and Mercury to an observer standing on Earth – this also means that Earth is never “at opposition” for Mars). This necessarily means that, when this occurs, the Earth and that other object are as close as they will get for that Earth year. Because our orbits are not circular around the Sun, our distances at opposition do vary. The slightly outdated image below shows this difference of opposition distances for Mars from 1995 to 2001. August of 2003 was our closest approach (34 million miles) to Mars in roughly 60,000 years, making for some impressive views through even medium-sized scopes.

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Mars distances at four oppositions. Image taken from the Hubble Space Telescope website. Click for a larger view.

What does this opposition mean for us? For those attending Baltimore Woods for Bob Piekiel’s special Lunar Eclipse observing session on the (really early) morning of April 15th (that is, we’ll be set up from 11:00 p.m. on the 14th and hanging out until it’s over), this means that Mars will be just a few days past its closest approach to Earth, making for especially good views through the scopes in attendance. Add Jupiter and Saturn over the course of the lunar eclipse, and we’ve a small feast of planetary observation for the evening. We hope you can join us!

CNYO Observing Log: International Sidewalk Astronomy Night, 7 March 2014

Greetings fellow astrophiles!

CNYO members Larry Slosberg and Michelle Marzynski, John Giroux, and I used the available clear skies of Friday, March 7th (and forecasts of far worse conditions on the official night of March 8th) to host the CNY branch of the International Sidewalk Astronomy Night (ISAN 7). ISAN 7 was made more significant to the amateur astronomy community with the passing of John Dobson on January 15th of this year (instead of reproducing more content about John Dobson in this post, I will instead refer you to the official announcement of our ISAN session. Needless to say, he left quite a legacy).

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Our session was held at our favorite downtown location – along the length of the Creekwalk between the MOST/Soundgarden and the Syracuse University Architecture School/Warehouse, on the same block as Walt the Loch West Monster. The location is definitely bright, but this limitation to observing can be overcome with the judicious selection of Messier Objects and planets (no galaxies!). The last two astronomy events held at this same location – the 2012 Transit of Venus and 2013’s NASA/MOST Climate Day, featured an easier target (the Sun), but also gave us plenty of on-the-ground time to find the Creekwalk a great spot to have both reasonable parking and a regular stream of passers-by to coax into looking into strange telescopes.

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“And so,” you might ask, “how long was your observing list for the evening? And what’s the point of observing from such a bright location?” I’ve run into such questions a few times in my own travels, and I assume that some other outreach-centric amateur astronomers have been asked the same questions. The answer for ISAN 7 over a +2 hour session was the Moon, Jupiter, the Pleiades (M45), and the Orion Nebula (M42). That’s it. Didn’t try for anything else, didn’t want to.

And, importantly, those four were plenty.

At the heart of sidewalk astronomy is getting people who’ve never looked through a scope before to take in a detailed batch of photons a few seconds (the Moon), several minutes (Jupiter), or even several light years (M42, M45) older than the ones they’re usually exposed to. As some people are hesitant to even get their eye near the eyepiece, the very best way to run a sidewalk astronomy session (or any public viewing session) is to put the easiest, most obvious, and brightest nighttime objects into the field of view to draw the observer in. Any fuzzy object, 16th magnitude asteroid, or even Uranus and Neptune are the last things a trained observer should try to expose a new observer to (IMHO) given that the passers-by at a sidewalk astronomy event will only stick around (as we discovered) for about 4 minutes (a few definitely stuck around longer, while a few others we surgical about their inspection of the Moon and Jupiter before continuing on. I think they half-expected us to “pass the hat”).

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The Moon to a new observer is a jaw-dropper. Assume wow-factor imminent as soon as you see the Moon’s light projected out the eyepiece onto the face of someone slowly making their way to the focuser. Jupiter (and Saturn, for that matter) is also a treat at the right magnification (enough to see surface detail, but not so much that the image becomes dull and unsteady. A Barlow’ed 6 mm is NOT the way to go without a very large aperture and rock-solid mount). The Orion Nebula was our “advanced topics for the persistent observer” object, as it was bright enough to still show some nebulosity and additional detail.

Over the course of about two hours, we put the total count at about 60 (which wasn’t bad, given the temperature and the fact that we were on the far side of the restaurant-heavy part of Armory Square). Larry, John, and I made our way into a few pics (intermixed in this post – we were mostly too busy to stop and take snapshots. Thanks to Brad Loperfido for taking them).

And then there was Pedro Gomes, who single-handedly brought ISAN 7 (and CNYO) to Watertown on March 8th. Some of his image gallery from Facebook is reproduced below and we thank him for sharing his excellent scope run with us!

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Look for future Creekwalk sessions in the near future, including a few solar sessions and the next NASA Climate Day at the MOST.

CNYO Joins Sidewalk Astronomers Around The World In Honor Of John Dobson – Saturday, March 8th (7 to 9 p.m.) Near Armory Square In Downtown Syracuse

Greetings fellow astrophiles,

CNYO is organizing a Syracuse session for the seventh International Sidewalk Astronomy Night (ISAN 7) being held in honor of John Dobson. We’ll have weather and event updates as we approach March 8th (the 7th and the 9th are official weather-alternate dates) and will be setting up next to Walt the Loch West Monster, the same place several hundred Syracusans observed the Transit of Venus in 2012 and a few of us participated in solar observing for the NASA Climate Day in 2013 (map below). Please spread the word and consider stopping by to celebrate John Dobson’s contribution to amateur astronomy. Several Dobsonians built by West Monroe’s own New Moon Telescopes will be on hand to show you their workings and, of course, show you the sights!


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Walt, just above the center green oval between Walton and W. Fayette.

A little background…

The 20th century was, by far, the most important century for amateur astronomy, as it was the first in which telescopes were mass produced for the consumer market (ours wasn’t much of a busy field for all of the rest of human history). The great science aside, it was the major jump in technology for our field that really grew our numbers.

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John Dobson, 1915-2014. Image from latimes.com.

While the list of names responsible for this transition is considerable, a few names are easily recognized as prime movers. John Dobson, who passed away this past January 15th, made one of the great contributions to amateur astronomy by taking the technology back to its foundations, synthesizing a number of great ideas in the amateur building community, throwing in some of his own ingenious ideas, and laying the groundwork for the scope we know today as the Dobsonian.

2014feb18_johndobson_sidewalkastronomersThe “Dob” made it possible for anyone to do large aperture, deep space observing by allowing builders to use very large mirrors in very (well, relatively) portable, reasonably light-weight designs. It is also a much simpler scope for a person to build compared to the many other varieties that used to dominate star parties. As the quality of the scope is limited by the quality of the builder and parts, this also means an expert builder can put together a world-class scope in their own garage that will absolutely compete with the best high-end company-built scopes (a fact that many of us Dob owners are thankful for!).

Better still, John was the world’s leading exponent for sidewalk astronomy, having effectively started the trend as the co-founder of the San Francisco Sidewalk Astronomers. In his honor, CNYO members are joining other astronomy organizations and sidewalk astronomers around the world in the seventh International Sidewalk Astronomy Night (ISAN 7) on March 8th. In our case, we’re fortunate to have a prime piece of the Onondaga Creekwalk just at the edge of Armory Square and will be setting up, as always, next to Walt.

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You know, Walt (twitter). Image from syracusepublicart.wordpress.com

While not the best place in the world to observe, there is plenty to see in the Night Sky even from well-lit Syracuse. Attendees will be treated to views of a first quarter Moon (and if you’ve never looked at the Moon with any kind of magnification, you are in for a real treat), Jupiter (worth the trip out itself!), the Pleiades, the Orion Nebula, possibly the Andromeda Galaxy (at least a small sampling), and a medley of assorted star clusters (which means we’ll find out what we can see when we’re set up). On top of all that, it’ll be a great chance (weather permitting), to hang out with local amateur astronomers and space enthusiasts in an easy-to-get-to location.

For more information about John Dobson, check out his wikipedia page. For more information about ISAN 7, check out one of several sidewalk astronomy sites, including sidewalkastronomers.us and sfsidewalkastronomers.org. And, of course, join our Facebook Group, add our twitter feed, or keep track of cnyo.org for more information as March 8th approaches.