Category Archives: Astronomical Event

What is so Super about a Super Moon?

August 10, 2014 just passed. It was the most recent Super moon. The term “Super moon” was coined by astrologers not astronomers and refers to a moon which is both full and also within 4 hours of its closest approach to earth.

The media gleefully report the super moon and show pictures of huge moons (many of which have been photo manipulated).  Here is the straight scoop on the subject. If you’re wondering whether that photo you’ve seen of the “too big to be true moon” has been doctored, we have an article on that.

Extreme SuperMoon [5_059193]

The most “Extreme” Supermoon of the Century occurred in 2012.  Here it was photographed in Yosemite approximately 15 minutes after it reached perigee.

What Makes the Moon Larger or Smaller When Seen from Earth?

Because the orbit of the moon around the earth is not circular, the distance from earth to the moon varies and thus the apparent (angular size) of the moon changes. Every lunar cycle the earth-lunar distance varies between its closest approach called perigee and its farthest distance, called apogee.  How big is the difference? The closest approach is 363,104 km (225,622 miles) and the farthest, 406,696 km (252,088 miles). 

What is the difference in apparent size?  At apogee, the moon is 22,293 km farther away or -5.8% smaller than an average moon.  At perigee the moon is 5.54% larger than the average moon. Comparing apogee and perigee moons, the difference is a maximum angular size difference of about 12%  The average angular size of the moon, by the way, is half of a degree or 30 minutes of arc. That angle is slightly smaller than the size of the nail on your little finger when held at arm’s length. Those of you with significantly mis-sized pinky nails or unusual arm length might want to find another object to measure with at arm’s length.

In short: You’d have to be a very keen observer to notice a 12% difference in size between a super moon and a “wimpy” (apogee) moon.

Because the moon is slowly spiraling away from earth eventually the perigee moon will grow smaller and smaller in apparent size until one day, we will no longer experience total solar eclipses. The perigee moon will be too small to cover the angular disk of the sun which also happens to be almost exactly one half of a degree. From that point on, all solar eclipses will be “annular” like this one in May, 2012. Had the moon been closer to the earth, this may have been a total solar eclipse.

Annular Eclipse Sequence [C_040079+5s]

 

 

How is a Full Moon Determined?

A full moon is defined as the moment in time when the sun, earth and moon are in syzygy. Syzygy is not only an interesting Scrabble(tm) word, but it defines when three bodies are in alignment. When the sun and moon are 180 degrees opposite one another relative to the Earth, we have syzygy which is the instance in which the moon is Full Moon. Many of us think of a “full moon” as that period during the month when the moon appears to be fully lit. That period lasts almost 70 hours, so we understand how reckoning a full moon as a moment in time is a bit confusing.

If you didn’t observe the August moon within 4 hours either side of when it was full, you did not see the super moon.  On the United States West Coast the super moon was not visible. Why? The moon set at 6:10 AM almost 5 hours before the moon was full. Those in Hawaii could just catch the super moon setting.  Those on the East Coast of the US had no chance at all. The whole super moon window occurred during the time the moon was not visible on the East Coast.

The Last (and Next) Visible Super Moons

If you missed the May, 2012 Extreme Super Moon (my term, photo above), you’ve missed the largest possible full moon for more than a century into the future. On May 5, 2012 fullness and perigee occurred within less than two minutes of one another.  But don’t fret.  The difference in size between the extreme super moon an the average super moon is too small to notice unless you measure carefully.  If you paid close attention you probably also noticed that the May 20, 2012 annular solar eclipse followed nearly half a lunar cycle after the May 5, 2012 super moon. That is not a coincidence! The moon was closest to us on May 5th so half of a lunar cycle away it must be farthest from us!

On August 10, 2014, full moon and perigee occurred within about 1 hour of each other. The next super moon is in September 8, 2014. The moon will not be as close to perigee at the moment when it becomes full, but the moment of full moon occurs at 9:38 PM PDT, just as the moon rises. It will be a true super moon!

Catch One Yourself

We plan to schedule a “Catching the Moon” Webinar well in advance. Stay tuned.  One complication is that the wonderful Photographer’s Ephemeris Tool will cease to work in desktop mode soon. It is being replaced with a browser version. While the tools is excellent, and we highly recommend it (and that you donate if you use it!) TPE still leaves some important bits of the puzzle unresolved – we will fill those in for you and give you a crack at our tool(s).

The moon caught between El Capitan and Half Dome - Actual size, no manipulation

The moon caught between El Capitan and Half Dome, Yosemite National Park – Actual size, no manipulation

Plan C: How To Plan a Time Sequence Shot

If you missed the last total lunar eclipse, don’t worry. You’ll have another chance in October, 2014. For that, I’m grateful since as you can see I had some problems with my apparatus (the CamRanger). The battery failed after the 7th shot of the moon you see below, and then it stopped working again after 3 more shots, and needed to be slayed and restarted just as the moon was transitioning to fully eclipsed.

But this column is not about our troubles, it is about how I planned for the lunar eclipse shot you see below.

Plan C: San Jose City Hall Eclipse Sequence

 

The planning began with a list of possible foreground subjects. The San Jose City Hall Rotunda was “Plan C” and the least well researched of my plans. What were plan A and B? Those were one of my favorite lighthouses and a favorite landmark in San Francisco, California. For each arrangement I had to:

  1. Calculate where to stand to make sure the moon would be in an interesting phase above the object. The plan required solving these problems
    1. Determine how high in the sky the moon would be (to know what viewing angle was best)
    2. Determine which DIRECTION I needed to face to capture the moon.
    3. Determine how “wide” a lens I needed to get the sequence I wanted.
  2. Monitor the weather at each location.

After planning all that was left was to make a last-minute decision where the most likely target would have favorable conditions and make any final on-site adjustments.  I had a Plan D, too… but it was also in San Jose so it would have only been chosen had I found some serious obstacle at the City Hall rotunda.

San Jose City Hall Panorama

Calculating the Angles

Determining the angles needed is pretty simple. I used The Photographer’s Ephemeris including all the nifty tricks we teach in our Catching the Moon Webinar. Below you can see a screen shot from the Photographer’s Ephemeris which shows the moon altitude and direction at the beginning of the eclipse. I also moved the time ahead to show the same for the middle of the eclipse.  The moon’s altitude angle (32 to 41 degrees) gave me an idea how close to be to the rotunda to get the moon overhead.  Lower angles allow me to get farther away which allows me to photograph the moon larger relative to the foreground object. This eclipse, however, and the one in October will have the moon high overhead.

Coming up with a Foreground

There is no good substitute for knowing what interesting foregrounds are possible. And also knowing which direction(s) you should be facing.  I knew that the San Jose City Hall Rotunda was generally easterly because I had watched a sun rise through it. I also knew that the eclipse would be at maximum when the moon was in the southern sky so I knew that the range was SE to S directionally.  You can see a diagram from The Photographer’s Ephemeris below for more complete planning.

Calculating Where to Stand

I had to know approximately how tall the foreground object is. For the San Jose City Hall I flat-out guessed.  I found the overall height of the building through Google, and I guess the Rotunda was 60 to 80 feet tall.   My original calculations had me much closer to the building… it was only when I got on site that I realized that there were adaptations that needed to be made.

Watching the Weather

Remember that the Rotunda was plan C.  I kept a close eye on the weather for each of the planned sites.  My favorite weather app is provided by weather.gov – in particular the hourly graphs. We talked about this tool in detail in a prior column.  Why do I like it so much? Because it gives me numbers instead of “partly cloudy”.  It was pretty obvious that the coastal region for Plan A, and the San Francisco Landmark (plan B) were likely to have bad weather – both fog and clouds. Indeed my friends who headed those directions were frustrated by poor visibility.  We had clouds passing through San Jose, but as the weather predictions had read: it got clearest right near totality, and overall was not a hindrance.

Last Minute Adaptation

When I first got to the site, I realized that the Rotunda was taller than I thought. I set up across the street in order to be able to have the moon over the Rotunda… but there were other problems, too. One of the problems is the floodlight on the top of the building. Another was a street light just to the right of where the red marker is in the graph below. These are problems that would only reveal themselves if you visit at night!

And then there are all of those flag posts.  My original guess at the Rotunda Height would have allowed me to stand between the fountain (brown area) and the building… but that clearly didn’t work as the rotunda was too high.  Setting up across the street (and very low) also had its challenges… namely buses and cars that came regularly.  I also realized that I had miscalculated the eclipse time by an hour (forgot it was now daylight savings time).  The miscalculation turned out to be a good thing as it left plenty of time to move around.  It would seem the ideal spot was in the MIDDLE of Santa Clara Street, but that wouldn’t have worked, of course.  Eventually I picked the spot with the red marker as a compromise between altitude of the moon above the structure, removing the glare from the tower lights, the wash-out of the street light, and the many flag poles in the way.

Planning Moonrise

If only my CamRanger had cooperated, I’d have had a continuous sequence of shots of the moon passing over the Rotunda.  There is always October… and maybe Plan A will work for that!

Of course that’s not ALL that was required to get the shot. I also had to composite each of the moon shots into their proper locations. I did that by first taking a panorama of the area, then making sure that when the exposures began I had a piece of the rotunda in each shot so I could properly align the moon over its actual location.  The creation of the image used the Easy HDR method we have previously described.

Catching the Moon Simplified

Freedom Gazes at the Moon [5_055475-7deB]

Freedom – the statue at the summit of the Nation’s Capitol – Gazes at the rising Moon

One of our popular webinars is Night Photography 111: “Catching the Moon (and the sun)”. The next webinar is April 2, 2014, by the way. Long before the many tools that now exist to help solve for moon+landmark alignments I began working on a tool I call the MoonChase Tool. As snazzy tools came into being like Stephen Trainor’s Photographer’s Ephemeris, SunMoonCalc, MoonSeeker, and many more, I neglected the MoonChase Tool and focused more attention on the Advanced Stacker PLUS. In fact, after Google discontinued the V2 map interface upon which MoonChase was built the tool languished for about a year and a half. I also stopped teaching how to use it in the NP111 Webinars. But, I kept finding that all existing tools just didn’t do what I needed, so I resurrected the MoonChase tool. I ported it to the newest Google Maps API (V3), and I then added some of the features I had on my wish list.  I’m really proud of what the tool can do now. And I have some fiendishly clever plans for the future of the tool, time permitting, of course. Operationally the MoonChase Tool is simple. The hardest part is coming up with the location where you want to stand and the landmark you want to face. If you know that there is a sightline to a landmark in the distance you can fire up MoonChaseTool and in 3 steps know when to go to get the moon or sun behind your landmark!  That’s right. You paste, paste, click and click. Or drag, drag and click. We cover how to cook up good locations in the Webinar. How do you get your hands on this tool? We’ll tell you! If you’ve attended a NP111 webinar with us, or purchased the video and notes you already HAVE access through the “private page” (you did save the password, right?).  You’ll find the link to the MoonChase Tool on the private page.  Or sign up for our webinar which includes the notes and video AND access to the MoonChase Tool – and you don’t have to wait for the webinar, we send you all the links when you sign up (see below). The tool isn’t especially pretty, we admit that.  But it is pretty EASY to use and it works even from your iPad or tablet as long as you have internet access.

3 Steps to Moon (or sun) catching

3 Steps to Moon (or sun) catching. And there is more: you can check the view with Google Street View, and even check the weather with the weather button.

After clicking “Moon” you get the report thanks to Jeff Conrad’s SunMoonCalc tool. Be careful to be sure it selects the time correctly. Below it’s off by an hour due to Daylight savings time.

LickFromSJC

Moonrise over Lick Observatory from near SJC Airport… all opportunities from this location for the next 4 years!

 

What Problems Does the MoonChase Tool Solve?

The tool was designed to do the trigonometry for you. Did you know there is trigonometry involved?  Don’t worry, you don’t have to know trigonometry or math.  Nor do you have to know about spherical coordinates, azimuths, altitudes or the three different kinds of twilight.  All you have to know is where you want to stand, and what you want to be in your picture. Drag the markers around on the map and click one of the Solve buttons. OR use the tool in concert with The Photographer’s Ephemeris.

What Do I Need to Know to Do?

It’s very helpful to be able to do the following things: grab GPS coordinates from Google Maps and/or Photographers Ephemeris.  We teach how to grab GPS coordinates in the course. You’ll also want to know how to find heights of your favorite landmarks. Google comes in really handy for finding heights of buildings!  One more thing you’ll want to verify is whether you can See the landmark from the place you want to stand. Again, we describe 4 different ways you can do that in the webinar. The rest is dragging and clicking!

How Long Will it Take?

If you already have the coordinates, it will take perhaps thirty seconds – or not even that long.

I WANT THAT! How Do I Get It?

Easy: Sign up for the webinar and you’ll get immediate access to the private page plus the videos and notes. If you’ve already taken the webinar, go to the private page and you’ll find the link in the Resources section.  Or as a prior purchaser, just sit tight as we’ll be sending the new materials out to all prior purchasers over the next 3 weeks.

Webinar: NP111 Catching the Moon and the Sun
Not Scheduled but usually 7:00 PM PDT (7 MDT / 8 CDT / 9 EDT) for 2 hours
Captured [C_044450-2tc] In this 110 minute Webinar, you will be introduced to several free (and almost free) tools that you can use to plan a moon (or sun) shot - including a tool written by Steven and made available only to attendees. Have you wanted to capture the moon "right where you want it" but weren't sure how? If you know you could resort to photo editing and fake it but you'd rather get the real deal then this class is for you. Steven will demonstrate how to determine when and where to go to capture an image like the Moon over Lick Observatory or the moon at the Transamerica Building or the sun shining through a portal in the Pacific Ocean (below). This is a Webinar so you can conveniently attend from your computer at work or home anywhere in the world. This course includes notes, access to a private page with details - including landmark events Steven has already solved for you, an online viewable recorded webinar with unlimited online viewing that you can watch NOW before the webinar is held. One indispensable tool covered in detail is the Photographer's Ephemeris by Stephen Trainor.

What You'll Learn

Steven will show
  1. How to Plan a moon or solar "contact" shot.
  2. How smartphone based tools may help - or sabotage - your attempts to get an alignment
  3. How to use the moon to illuminate your foreground,
  4. How the presence of the moon affects photos of the night sky,
  5. How to find information about interesting celestial events,
  6. How to find compelling locations for "alignment" images, and
  7. What camera settings you need to get it all exposed just right.
Photon Worshippers **Winner Astronomy Photographer of the Year, 2010 - People and Space **
Remember that this event INCLUDEs online videos, notes, and access to a special tool that Steven uses to solve lunar and solar contact shots.
New Dome [5_009671]

The moon rises behind Lick Observatory on Mount Hamilton, San Jose, California

The Ideal Handheld App For Catching the Sun, Moon and Stars

Here at StarCircleAcademy we’ve been consuming and testing quite a number of photography related apps. So far none have risen to the promise that a handheld app could bring to the table.  Rather than illuminate what is missing from each app, here I describe what I want to DO with my handheld App.

In the Evening [5_057775+92]

  1. First, I need an app with accuracy to within 0.2 degrees! Why? Because the moon and sun are only 0.5 degrees in angular diameter. If I want to catch the moon exactly behind the Pigeon Point Lighthouse less accuracy will result in a “miss”.
    Monumental [C_038216]
  2. I want the app to accurately measure and save all the relevant data so I can reuse it and share it.  At minimum it needs to keep track of: From location, to location, altitude at the to location (degrees above horizontal), and any additional constraints like the fractional number of degrees that each measurement can vary. In some locations like the shore of a lake there is more leeway to move. In other spots, like the balcony of a building there is little leeway to move.  An ideal app would allow me to stand in two or more different spots to define that leeway.Rise and Shine [C_037951+77]If I’m solving for the moon, I’d like it to also remember the moon phase I’m interested in (usually full or slender crescent). The ability to take notes including things like height of the landmark is a big plus.
  3. Ideally I can save an image representing what I want with ALL data on the image so that if all I have is a photo, I can reconstruct the parameters in other tools or other ways.
    For example, SpyGlass shows me my GPS coordinates, the elevation, altitude and azimuth (compass direction) – though as you can see it’s calculation on where to find the moon is off by about 15 degrees (30 moon diameters) due to iPhone 4 compass inaccuracy.

    SpyGlass copy

    SpyGlass snap. Note that the plotted location of the moon is off due to iPhone compass hardware.

  4. I’d like to be able to pull up my saved locations and re-execute a search to find the next occurrence. For example, a Pigeon Point Lighthouse vista that I really like only occurs a few times a year. It’s not enough to keep track of the one event I photographed or plan to photograph.
    Project Impact [5_057573-615br]
  5. Bonus points if the data is stored in a server somewhere to make it easy to share. Extra bonus points if there is a way to have the server periodically check possible alignments and send me alerts or emails when such alignments are soon to become possible.
  6. For planning shots with the Milky Way or other prominent sky features (like the Andromeda Galaxy and the Great Orion Nebula), the app needs to accurately plot the course of those objects on an Augmented Reality frame. Images of the Milky Way presented must be realistic.  A poorly illustrated Milky Way won’t help me find the galactic center (which is what I most often want) or compare the alignment I want with the foreground I am trying to capture.
    Inflow [C_072091]
  7. For night related photography, the app must also factor in twilight and moonlight. That is, I want to be able point my device at say the Transamerica building and ask the app when (or if) the Andromeda Galaxy will appear above it when there is little or no moonlight.
  8. Make it easy to use, of course.  Most of the apps that embed maps in them are difficult to use on the tiny real estate of an iPhone – and require data connections as well.

Is it unrealistic to think a handheld app could meet these requirements?  I don’t think so. The biggest problem is overcoming the accuracy limitations in the current devices. The iPhone and iPad, for example have quite inaccurate compass readings except in perfect scenarios… but there are some clever ways (I think) to correct for that inaccuracy.  The tilt angle calculations from the on-board accelerometers and gyroscopes seem to be pretty accurate.

What We’ve Tried

  • Inclinometer. Great for measuring angles above the horizon. Even has a voice mode where it says aloud the measurement. Doesn’t do Now includes augmented reality mode so you don’t have to sight along an edge of the device. On an iPad, it seemed to be accurate to about 0.2 degrees!
  • GoSkyMap. Fun interactive sky map. You can change the date / and time and point it “at space” and it will show you great details about what is there. BUT you have to make sure you set the location correctly. Doesn’t have an Augmented Reality mode so you can’t tell how the mountain in the foreground interacts with the Milky Way, for example, but you can ask it where to find constellations and it will indicate which direction you should look.
  • Sky Map. Like GoSkyMap it’s an interactive planetarium.  I prefer to use it without the “point features”. It’s my Planosphere (Sky chart) in hand. Also includes things like Meteor Showers and radiants, a list of “what’s up tonight” showing rise and set times, moon phase, etc.  No Augmented Reality.
  • PhotoPills. Lots of things rolled into one app. Biggest complaints about this app are saving and reusing Plans, usability quirks, a grossly oversized moon or sun icon in the Augmented Reality modes and an inaccurate Milky Way representation. Oh, and I’d really like it if it would measure for me!  The planner would be great if I could have the Augmented Reality compute the Azimuth and Altitude (aka Elevation) for me, especially since it doesn’t seem to have a way to measure like the Inclinometer tool does. I see, for example where someone saved the “Manhattanhenge” event. It would be great if I could load it and click “find next occurrence”. That feature alone might be worth booking a flight to New York!
  • SpyGlass. Clever app with lots of onscreen information in Augmented Reality mode. We especially like the onscreen measurements which are saved when you grab an image.

Do you know of an app that’s highly accurate and will meet our requirements? Let’s hear about it. If it exists on an Android I’ll buy an android!