August 29, 2017

Into the Wide Blue Yonder

For all the stargazing I've done, I'd never given much thought to the sun—though I had looked through a solar telescope at Carnegie Observatories and had observed a partial solar eclipse from Griffith Park.

But there's a reason why pioneering astronomer George Ellery Hale was so interested in the sun, having founded the solar observatory at Mt. Wilson and built his own solar telescope in his Pasadena backyard.

Because the sun is the biggest star out there that's close enough for us to observe—and what we can see it doing can tell us more about how the solar system behaves, and how the universe is expanding and accelerating, more than any other object in the sky can.

So, while visiting Big Bear back in May, I found myself at the receded shoreline of Big Bear Lake...

... to take a long sought-after peek inside its solar observatory, which usually stands stoically behind a locked gate, accessible only to researchers and not the general public.

Located at the end of a short land jetty on the north shore of the lake, Big Bear Solar Observatory was built in 1969 by Caltech, though it's been managed and operated by the New Jersey Institute of Technology since 1997.

It actually consists of two domes and three buildings...

...the smaller dome housing two telescopes on one mount...

...a hydrogen-alpha (Hα) solar flare patrol telescope and an "earthshine" telescope, both on the same mount.

With the H-alpha telescope, you can view the sun through a narrow slice of the spectrum of light—that is, the light emitted by hydrogen atoms. (And hydrogen is the most abundant element in the sun.) All other light is filtered out—and that's when the sun really "shows its colors" (namely, red instead of white) and really looks like a flaming ball of fire (hence the solar flares).

The earthshine telescope, in overly simplistic terms, observes and measures how much sunlight the earth reflects off its surface and back into space. It studies the path of sunlight without looking directly into the sun.

And since our planet's reflection generally bounces off the moon, this telescope only runs at night. And it's what allows us to see the "dark side of the moon," even when it's waned down to just a crescent.

The second structure isn't a dome at all, but rather a rectangular box that houses the observatory's GONG (Global Oscillation Network Group) telescope—part of Tuscon's National Solar Observatory, which operates a network of six such telescopes located around the globe to study the seismic-like movements that happen inside the sun (a field known as helioseismology).

At the third structure and the second dome, you'll find the largest aperture solar telescope in the world, the NST ("New Solar Telescope").

It's a telescope with a resolution so sharp, it snapped the most detailed image of a sunspot ever back in 2010.

And it's all thanks to a 1.6-meter primary mirror, since looking directly at the beam of light would fry your eyeballs.

This is where scientists can really observe "solar weather"—and all its associated turbulence, including "solar storms"—as well as "space climate."

And it's the weather events that occur at land level—like wind or precipitation—that can mess up the solar observations and create distortion.

Fortunately, its position at 6,750 feet elevation in the San Bernardino Mountains provides mostly clear skies and cool temperatures—and being surrounded by water actually stabilizes many of those atmospheric conditions.

And if the wind does kick up or some heat waves do radiate off the ground, the NST's adaptive optics can generally correct the distortions if they're not too severe.

I asked the researchers what they were looking for—but it turns out that observing the sun isn't exactly a business of proving hypotheses. They're mostly looking to see what they can see, which is predominantly sunspots.

And they're trying not to go blind in the process.

I didn't get the chance to gaze through the earthshine telescope at the solar observatory—but later that night, I did manage to get a good look at it as it loomed large in the sky... weaseling my way into a private sky-observing session at Camp Oakes, a YMCA youth camp near Deadman's Ridge, just east of the Pacific Crest Trail.

With no cell phone signal and not a soul around but the camp director and the telescope operator, the night was ours and ours alone.

And while I would've been satisfied with having chased down our moon, I got the bonus treat of spotting Jupiter shining bright in the sky—alongside two of its own moons.

It was a nice reminder that there are, indeed, not only other planets out there but also other moons—and, beyond those, other galaxies, and maybe even other suns.

We know so little about our own. It's hard to imagine how far outside of this world the limit goes—and whether there's any limit at all.

The ancient astronomers, of course, used their knowledge of the stars for navigation, timekeeping, and, to a certain extent, weather forecasting. And since the beginning of time, those of faith have equated "celestial" with "heavenly," attributing the great vastness above to some guiding spirit.

But I wonder: At what point does our exploration beyond ourselves fall victim to the law of diminishing returns?

What more can we do with what we know?

What are we looking for? And will we know what to do with it if we ever find it?

What good does it do to fully grasp how small we actually are? And what good will it to if we can see our ultimate demise coming in a way that the dinosaurs never could?

Or maybe they did see it coming... and they just couldn't do anything about it.

What would we choose to do... if we could? Would we merely watch it as it's happening?

Related Posts:
Follow The Sun
Intergalactic Reflections at Mount Wilson's 100-Inch Telescope
Counting Stars at Mount Wilson Observatory
Photo Essay: Palomar Mountain & Observatory
Chasing the Moon

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