yosemite national park

Perseid Meteor Shower, Milky Way, Half Dome and Yosemite National Park

By Landscape Astrophotography, Meteor Photos, Milky Way Photos

I spent two evenings at Glacier Point during the peak of the 2013 Perseid Meteor Shower, hoping to capture my first photographs of meteors. I have a few landscape astrophotography images that have chance meteors recorded in them, but this was to be my first attempt at photographing meteors as the principal subject. Conditions were nearly ideal. There were virtually no clouds on either night, little wind, and the air was dry and clear, perfect for astrophotography. This image is the result of those efforts, showing the Milky Way galaxy, about 16 meteors, Half Dome and Tenaya Valley and some of the Yosemite High Country in the distance, and the amphitheater at Glacier Point with a few people (and lights) enjoying the evening’s show.

Perseid Meteor Shower and Milky Way, over Half Dome and Yosemite National Park

Perseid Meteor Shower and Milky Way, over Half Dome and Yosemite National Park

As you might imagine, this image is a composite. The Milky Way was aligned above Half Dome in just this way during the mid-evening. Note that the Andromeda Galaxy can be seen as a oval blurry object just above and to the left of Half Dome and to the right of the Milky Way, and the Pleides star cluster is seen at the lower right of the sky, just above the horizon. The individual meteorites, however, came from separate images taken over the course of 12 hours of continuous photography. I selected the best exposed and brightest of the meteorites that I photographed, rotated them about Polaris (the North Star) as necessary to account for the fact that the night sky “rotates” above us all night long, and composited them with the baseline image of Half Dome and the Milky Way. A little green “air glow” is seen near the horizon, and some distant smog or haze is also seen as a brown horizontal layer just above the horizon in the distance.

The Perseid Meteor shower, which is considered to have the brightest meteors of all annual meteor showers, is named for the constellation Perseus from which they appear to emanate. Note that most of the meteors in this image appear to radiate from the lower portion of the Milky Way in this photograph — that’s where the constellation Perseus lies.

Some statistics:

  • Cameras: Canon 5D Mark III, Nikon D800, Nikon D800e
  • Lenses: Nikon 14-24 at 14mm, Nikon 24-70, Canon 16-35 at 16mm
  • Meteor exposure: ISO 6400, f/2.8, 30 seconds
  • Shooting continuous from 9:30pm to 5am the evening of August 10/11, and 11pm to 3:30am the evening of August 11/12
  • Obtained approx 2050 exposures. 93 meteorites were captured. 16 were deemed good enough to contribute to the final image.

Photographing Zodiacal Light over Yosemite National Park

By Landscape Astrophotography

August 11-12 was near peak viewing for the 2013 Perseid meteor shower, and many people including myself were viewing the show from Yosemite’s Glacier Point all evening long. However, because the moon was nearly new and it was late summer, I knew there was an opportunity to see the faint, remarkable Zodiacal Light the following morning. My plan was to let my cameras run all night capturing Perseid meteors until about 90 minutes before sunrise, when I would reset them to photograph the (hoped for) Zodiacal Light. I managed to get a couple nice images of Zodiacal Light, better than my one previous attempt!

Zodiacal Light and planet Jupiter in the northeastern horizon, above Half Dome and the Yosemite high country.

Zodiacal Light and planet Jupiter in the northeastern horizon, above Half Dome and the Yosemite high country.

Zodiacal Light arises from sunlight that reflects off a disk of space dust that orbits our inner solar system. Zodiacal Light is purely a solar system phenomenon (relatively local to our planet) and is not associated with stars that are observed alongside (behind) it. The aforementioned “space dust” is thought to arise primarily from asteroid and meteor collisions (Nesvorny and Jenniskens, 2010), and resides on the plane of the ecliptic. (The plane of the ecliptic is the plane in which planets orbit around our Sun.) While aligned with the plane of the ecliptic, this dust cloud is not thin. Because it extends outward from the sun to the vicinity of Jupiter (with its strong gravitational field), the dust cloud is disturbed in such a way to give it a thickness, explaining the width of the Zodiacal Light that we observe. The Poynting-Robertson effect causes this space dust to slowly spiral inward toward the sun (where it is consumed), so a constant supply of new dust from colliding comets and asteroids is required to maintain the dust cloud. Sunlight reflecting off this dust can be seen in our night sky when there is little or no competing moonlight and/or light pollution from nearby cities. Zodiacal Light appears as a faint pyramid or triangle glowing on the horizon, with the apex of the pyramid tilted in line with the path of the Sun and the plane of the ecliptic. In these photos, planet Jupiter (which lies in the same plane of the ecliptic as our Eath and follows the Sun’s path through the sky) is clearly seen as the brightest object within the triangle of Zodiacal Light. This view is roughly northeast, looking past Half Dome from Glacier Point with the Yosemite High Country in the distance and Little Yosemite Valley at bottom middle.

The faint northern arm of the Milky Way is also discerned in these photos, crossing from upper left to lower right.