Wednesday, August 8, 2018

It's time to make your plans for the 2018 Perseid Meteor Shower

image: Wikimedia commons (link).

August 11, 12 and 13 are the dates that the annual Perseid meteor shower is expected to peak this year. These nights correspond to the dates of New Moon for the month (on August 11) and a very thin waxing crescent, which has experts predicting that this year's viewing conditions for the Perseid meteor shower could be the best for decades (on either side).

Here is a discussion anticipating this year's Perseid meteor shower from

Here is a similar discussion from Sky & Telescope.

And here's one that appeared in Forbes with a little more discussion about the ominous comment Swift-Tuttle whose trail creates the annual Perseid shower each year when the earth passes through the debris-trail left by that comet's orbit.

Here's a link to a blog post I wrote seven years ago about the Perseid meteor shower, in 2011. And here's another which discusses why meteor showers tend to occur on the same days each year, and whey they have "given names."

Below is an image from Wikimedia commons in which a time-lapse camera captures several streaking Perseids crossing the circular paths of the stars (circular star-paths which are caused by the spinning of our spherical earth on its orbit):

image: Wikimedia commons (link).

As the above-linked articles make clear, observing the Perseids does not really require any special equipment: naked-eye viewing is best. A reclining chair (especially a lawn-chair) can be helpful, although you can also lie rather comfortably on the hood and windshield of your car, if you want (but be careful if you're not used to doing that). 

Although the Perseids are named for the constellation Perseus, indicating the direction from which they appear to originate in the night sky, as this article from Alan MacRobert at Sky & Telescope's weekly "This Week's Sky at a Glance" column explains:
A shower's radiant is the perspective point where the meteors would all appear to come from if you could see them approaching in the far distance. In fact we see them only in the last second or two as they streak into the Earth's upper atmosphere, and this can happen anywhere in your sky.
Perhaps more important than focusing on any single point in the sky is getting yourself to a propitious point on earth's surface from which to best observe the stars . . . and the meteors.

Fortunately, in the modern era, there are a plethora of tools available to help you select a favorable point on the terrain from which to observe the heavens. The familiar Google Maps gives you the ability to turn on the "terrain" mode for viewing, which is invaluable for conducting a little "map recon" of your local area in order to find pieces of terrain which are likely to offer an excellent view of much of the heavens. To use that feature, simply select "terrain" from the "hamburger" menu pulldown, and then begin to use the contour lines to tell you where the high ground and the low ground is likely to be located, and where on the map you might offer good unobstructed views of the night sky.

You can use the map to find high points created by hills, ridge lines, and saddles in the terrain. If you are not that familiar with topo maps and grid lines, the Google Maps give you some assistance by "shading in" the sides of hills and ridges, so that you can tell which is the high ground and which is the low ground (another clue is to look for places with water, such as ponds or streams, which will always be the lowest region, since water seeks the lowest places to pool).

Below, I offer some examples of places that might offer good views of the night sky, based on a "map recon" using Google Maps and the "terrain" view feature. I simply looked at the contour lines and terrain features, and drew in several little arrows pointing to spots that are likely to offer good unobstructed views of the night sky. Note that some of the locations may be unsuitable due to street lamps or other light pollution -- once you have conducted your map recon, it is advisable to go do an actual in-person recon during daylight hours in order to check for any dangerous features (such as sharp cliffs) and to see if there are streetlights in the area that might necessitate going somewhere else.

For purposes of showing the kinds of terrain features to look for, I chose two locations in California's historic gold country: Angel's Camp and Placerville (both places where I believe author Mark Twain  [Samuel Langhorne Clemens, 1835 - 1910] once stayed for extended periods). The first is Angels Camp:

Note that all the points marked with red arrows indicate likely points which would offer good star gazing on dark nights (depending on streetlights or other light pollution). These are all locations with a road running through them. The methodology for this map recon involves looking at the contour lines to find hilltops and ridges with roads that might offer easy access to stargazers. You should be able to apply a similar type of recon to your local area, using Google Maps, so that you can plan in advance of the peak Perseid observation nights of August 11, 12 and 13.

Below is another example, showing Placerville, California and using purple arrows to mark likely spots for star-gazing (and meteor-shower watching), depending on the light pollution:

I hope you will have the opportunity to get outside to look for Perseids during this year's Perseid meteor shower, if at all possible. Once you find an observation point which offers good views of the sky, and which seems to be safe and easy enough to locate after dark, all you have to do is go outside during the peak viewing hours for the meteor shower, and look to the heavens.