Saturday, September 1, 2012

Starry Sky over Yosemite

A dark sky full of stars has been mystic, appealing  and attractive to me. I can look at the sky for minutes without doing anything or thinking about anything.

During our eight day Sequoia, King Canyon, Yosemite Trip, despite the varying weather at day time, the sky seems to be always clear at night, and it was dark. Thus we had plenty of chances to see a dark sky full of stars. One night at Sequoia, Justin and I looked the starry sky as we walked to hotel room from WiFi area.. The second day at Yosemite, after the hike to the top of Nevada Fall, Justin went to WiFi area, Nicolas was reading in the tent house, Lily and I walked outside to watch the starry sky.

The best star gazing time we had during the trip was on the third day of our visit to Yosemite. That day we participated a night ranger program "starry skies over Yosemite" starting at 9pm. We were lucky to star gazing that night -the sky was darker, the stars were brighter to naked eyes because it was "new Moon" - no Moon in the sky,

As we waited for the ranger to come, the Sun set, stars started to show up in the sky - initially I could only see a handful stars overhead. As it was approaching 9pm, our surrounding was totally dark - I could barely see my own hands, and the sky was full of stars, I could easily see the Milky Way.

The ranger hosting the event lead us to a softball field near Yosemite Fall for star gazing.

Tarps were laid on the ground, and we were asked to lie flat on the tarps and look at the sky.

Lying flat on the tarp totally changed our perspectives: we only saw the sky, no surrounding reference. The sky was full of bright stars. There was this huge group of stars right on top us, seemingly in a light fog - that is our galaxy - the milky way. Away from milky way, the stars were not as densely populated. "how do you feel?" the ranger asked us, "feel really small" - was the most common answer.

Indeed we are small even only compared to the sheer size of our own galaxy: the Milky Way is 100,000–120,000 light-years in diameter, the earth's distance to Sun is only ~ 8 light minutes; our Sun is a like a drop of water in the "ocean" of Milky Way which contains 200 - 400 billion stars

The brightest star in the Sky, Sirius, is more than 8 light years away. The Sirius we saw was what it was more than 8 years ago. As the ranger talked about some very basic constellations, big dipper, little dipper, ...and important stars - such north star - a shooting star swept through the sky - a split of a second, it disappeared. "Wow".  The ranger digressed, asking us the size of a shooting star, someone in the audience answered "size of a grain of sand"!

Since we were at the floor of Yosemite Valley, the surrounding mountains blocked the stars near horizon - such as the bottom of the big dipper. It was nevertheless a beautiful night: dark sky, bright stars.- a night full of wonder of nature.

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