Naked Eye Astronomy

MIRA: Exploring the Universe
from the Central Coast

The page you are viewing is taken from an exhibit called MIRA: Exploring the Universe from the Central Coast. The exhibit ran from 1 July through 24 September 2000 at the Pacific Grove Museum of Natural History.

For the Central Coast, the full Moon sets into the Pacific Ocean as the Sun rises. If this only happened once a decade, everyone would rise early to watch the Moon slip over the edge of our planet. (Photo courtesy of Bruce Weaver)	Everyday Viewing With giant telescopes scanning the skies from tall mountains, what is there to see for ourselves? The spectacular view of the cosmos is on display for us every night that is not fully clouded, from almost any location on Earth. Just the constantly changing dance of Sun, Moon, and planets against the annual cycle of stars, punctuated by stunning eclipses of the Sun and Moon, is a rich and complex show. The Sun, in its annular path, moves north and then south causing our daily sunbeams and shadows to reveal the seasons. Its motion through the sky unveils familiar constellations as the year progresses.

A common but usually unrecognized sight is Zodiacal Light. Best seen after evening twilight in the spring and before morning twilight in the fall, the tall, triangular white glow is due to the reflection of sunlight off interplanetary dust in our Solar System. It is easily obliterated by light pollution.	Special Events Somewhat rarer is a visit by a comet to the inner Solar System, but the full extent of these great balls of fire and ice are best seen with eyes and binoculars, not giant telescopes. They leave behind trails of debris which are seen annually as meteor showers as the Earth passes through them. Some views, like Zodiacal Light (see photo at left), are frequently available but go unnoticed because of the glare of light pollution or lack of recognition.

Nearly every month brings a meteor shower. This meteor, captured by Robin Casady at the Oliver Observing Station, is a member of the famous Perseid shower. Note the Salinas Valley light pollution.	The Big Picture Of course, the great scale of the Milky Way, our home galaxy, fills the sky; but it, too, needs a site removed from the glare of neighbors' lights. Far from interfering lights, the moonless sky is quite gray rather than dark; our atmosphere is lit by scattered starlight and glows due to the bombardment of the atmosphere by high-speed atomic particles ejected by the Sun. Some of the deepest mysteries of the Universe are seen by the naked-eye. If the Universe is infinite and filled with stars, then everywhere you look should eventually intersect the surface of a star. So why is the night sky dark rather than as bright as the surface of a star? Nobody knows for sure, yet.

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*mira@mira.org* © 2000 MIRA
Last updated February 22, 2001 by et.