All posts by Chap Percival

Eclipse Traffic Jam – How Likely A Real Problem?

Eclipse Traffic Jam – How Likely A Real Problem?

The website,, has a interesting post about the likelihood of and issues surrounding travel to and within the August 21, 2017 total solar eclipse path. It is difficult to accurately estimate the number of people who will try to see this event, since no ticket must be purchased. That being said, lots of hotels/motels/campgrounds are already fully booked with more people expressing interest in the eclipse. Read the post here: and if you haven’t started making your plans to see this eclipse, please get started. It will be amazing. – A Great Resource for Your Eclipse Plans

RECREATION.GOV – A GREAT RESOURCE FOR ECLIPSE PLANNING may not be familiar to you, unless you like to camp. But if you want to see the total solar on eclipse August 21, 2017 and have not yet made plans, this site could help. They have published a story here about the eclipse and the resources that they have available to help people who want to go see it. And, let’s be clear; the pace is picking up, interest in the eclipse is rising and it will only go up from here.

This is the logo for NASA’s Eclipse Website. It is clickable.

The Convenient Eclipse

The Convenient Eclipse (at least for Americans)

Every total solar eclipse has a path defined by the full umbra(shadow) of the moon as it moves across the earth. Depending on the variations in the earth-moon distance, the moon-sun distance and the height of the sun above the horizon at each location on the path, the umbra can be as little as zero miles across and, out side of the polar regions, as much as one or two hundred miles across. The duration of totality changes as the shadow moves, reaching a maximum somewhere near the middle of the path. There is one and only one point on the path of an eclipse that is the point of greatest eclipse(GE). Every eclipse has just one.



I have made much of the fact that the August 21, 2017 eclipse is a rare event for America. I have tried to come up with a way to quantify that, to measure it, give it some basis for comparison. This is what I came up with. I live in Sarasota, Florida. The point of GE for the August 21, 2017 eclipse is near Hopkinsville, Kentucky. Using Google Earth, I measured the straight line distance from my home to the GE is about 730 miles. I can, in fact, drive to Hopkinsville along excellent highway in one, long day.


Above is a map showing the paths of the total (in blue) and annular (red) eclipses for the years 2001-2020. For my purposes, ignore the red and focus on the blue lines. Each one has an asterisk (*) which the marks the point of GE for that eclipse. Using the same method to measure the distance from Sarasota to Hopkinsville, I measured the distance from Sarasota to the GE point for every total eclipse back to 1997. Here are the distances.

Year  Distance (in miles)
2016 8,200
2015 4,100
2013 5,000
2012 6,900
2010 4,100
2009 7,800
2008 5,800
2006 6,000
2003 9,300
2002 10,000
2001 6,200
1999 5,600
1998 1,500
1997 6,500

The average of all those is 6,200 miles (10,300 km), nearly 9 times further from Sarasota than Hopkinsville, KY. My point is that, for Americans, the August 21, 2017 total solar eclipse provides a rare opportunity to see, no, experience one of the grandest events in nature. And it is only a day trip distance for 65 million people. I live further than over 100 million people and I am going to see it. You should to. If you haven’t started making plans, now is the time to start.

Ignore The Hype – Please

Ignore The Hype – Please


Here Are The Facts About The November 14, 2016 Supermoon!

“We’re about to see a record-breaking supermoon – the biggest in nearly 70 years.
The closest full moon in the 21st century.” says one site.

Okay. That is a factually correct statement, but it exaggerates the truth to the point where the truth loses its luster. Here are the facts of the situation, plain, simple and unembellished.

  1. The moon’s orbit around the earth is elliptical. By definition, that means the moon is closer the earth than at other times. It is no big deal. The point of closest approach in the orbit is called the apogee.
  2. The earth’s orbit varies slightly over time (years) so that the distance of the moon at apogee is not constant.
  3. Three or four times a year, apogee of the moon occurs very near full moon. When objects are closer to us, appear look larger, so a full moon at apogee looks larger than a full moon at any other point it its orbit around the earth.

Here is a list of the closest full moon apogees for the current decade.

Perigee Moons This Decade

Date                Distance from Earth to Moon (km)
2010 Jan 30    356607
2011 Mar 19    356580
2012 May 06    356954
2013 Jun 23    356991
2014 Aug 10    356898
2015 Sep 28    356878
2016 Nov 14    356523
2018 Jan 02    356604
2019 Feb 19    356846

The one receiving all the hype is in bold face, 2016 Nov 14. Look at the distance during that full moon and compare it to 2011 Mar 19. The difference is 57 kilometers (34 miles). So, yes the November 14, 2016 full moon slightly bigger than others, but only slightly. The difference in brightness between all the full moons in the table could not be perceived by the human eye. The exaggeration/hype of the media sets the viewer up for disappointment.

I would say that all full moons are worth looking at. So go out, weather permitting, and enjoy the full moon November 14. I know I will.

One Year To Go

OneYearTOGOv2This weekend marks one year until the total solar eclipse of August 21, 2017. Me and my minion friends can hardly wait. The anticipation is starting to build. I have traveled to see five of these on 4 continents and they are truly amazing! This is no hype. It is not just something to see, but something to experience. Most Americans have not seen one of these since the last one anywhere in the 48 states was 1979 and the last one east of the Mississippi was 1970. As another example, the last one in Missouri was 1834!

People make plans a year in advance for things like reunions, cruises, and the like. It is not too early to start making yours. I will be viewing this eclipse from Cookeville, Tennessee. Come join me there or chose your own place. But whatever you do, start making those plans NOW! Please check out the rest of my site to make sure you are prepared to experience this once in a lifetime event.

CREDIT: I got the idea for using this image from Dr. Kate Russo.

And So It Begins – Day 0

Tomorrow morning, Saturday, May 28, 2016, my wife and I begin the most ambitious project we have every undertaken: a 9 week, 8,000 mile road trip across the USA. The primary purpose of this trip is to promote and educate people about the total solar eclipse coming to the USA August 21, 2017.

We begin by taking a week to drive to the Grand Canyon to participate in their annual Star Party. I, along with many other astronomy enthusiasts, volunteer our telescopes for the visiting public to look through. We did this last year and every night for a week there were at least 40 telescopes set up in the Visitor Center parking lot and a 1,000+ visitors looked through the scopes, many for the first time in their life.

We will then slowly work our way to northern California then Oregon, where we will begin our return leg, traveling the entire 2500 mile long path of the total solar eclipse back to South Carolina, then finally home.

The camper is prepped and we are packed to the gills. Please follow along as I document this adventure: the good and perhaps, the bad and the ugly.

IMG_3747crop (Medium)

And if you see us along the way, honk, wave, or stop and say hello. (We will be driving more slowly than most folks, so if you are on our road, this will likely be your view of us.)


What is a Blue Moon (Kudos to the Weather Channel)?

In most years there are 12 full moons, one per month. However, since the length of time between full moons is about 29.5 days (shorter than the average month), some years have 13 full moons. In fact, in every 19 years there are 7 years that have 13 full moons. That extra moon is called a “blue” moon. The rarity of that extra moon in a year has given rise to the colloquial meaning, as in “once in a blue moon.”

Today we don’t pay too much attention to the phases of the moon, but in the 19th century, it was something most everyone was aware of. In fact, every full moon had a name like harvest moon, hunter’s moon, etc. The Maine Farmer’s Almanac (one of many almanacs published back then) called the 13th (extra) full moon a blue moon. By looking at 100 years of that publication, we have determined that they meant to go by seasons. Most seasons have 3 full moons. But when a season had 4, the 3rd full moon in that season was called a blue moon. It is not the second full moon in a month. That explanation was caused by a 1947 article in Sky & Telescope magazine. It has since been retracted.

This report by the Weather Channel gets it right. And Mars will be worth looking at as well. Nice job.


Weather Channel- Blue Moon and Red Planet


Astronomy Day

Today, May 14, 2016 is Astronomy Day. This is celebrated twice each year, once in the fall and once in the spring. Many astronomy clubs hold events to help people engage with the sky. Check with your local club. The Sarasota/Bradenton Local Group of Deep Sky Observers will set up telescopes at Riverview High School in Sarasota from 8:00-10:00 PM.1-gc
Telescopes set up at the Grand Canyon National Park. Micheal Quinn/National Park Services

Transit of Mercury

Today the planet Mercury, smallest of the planets, passes exactly between the Sun and the Earth. We don’t call it an eclipse because the sun is not completely covered by Mercury. In fact, Mercury looks like a small dot on the sun. There are sunspots also on the sun and they look fainter and not as sharp and round as Mercury. This image was taken at 10:18 EDT and shows a nice grouping of Mercury and sunspots on the sun. 1018EDTannotated2

Here are the final minutes of today’s transit as Mercury approaches the limb (edge) of the sun and slides off. The wind had picked up so images are a little blurry.

Tranist2016exit (Medium)