Which sentence best supports the main idea of the first paragraph? A. Earthquakes in California are so common that many residents barely notice them.
B. Astronomy is a highly accessible hobby that doesn't require a telescope to enjoy.
C. Light pollution interrupts the body's natural rhythms and prevents restful sleep.
D. The best way to really see the sky is to drive a good 15 miles away from the city.

The Dark Skies Movement

At 4:30 AM on January 17, 1994, a major earthquake hit Northridge, California, knocking out power to the city. As people huddled outside their homes, some called their local emergency services because of a strange "brightening" of the sky. They were actually seeing the night sky as it should be—lit by millions of stars that had been obscured by city lights. "Light pollution" in cities has become a growing concern. Scientists say it is hurtful to wildlife; in particular, it disorients nocturnal birds, who use the moon and stars to navigate during their migration. It also adversely affects human health. Finally, lighting cities on a 24/7 schedule costs a bundle of money.
The "Dark Skies" movement is working to change all that by getting city ordinances in place to bring back the night skies. Such laws would mandate that new light fixtures be installed. The new lights would only shine into the area that requires lighting and not up into the atmosphere.
Of course, professional and amateur astronomers have always had an interest in keeping the skies dark so they can study the stars and planets. Today, however, more consumers are getting involved as well because they want to reduce energy usage. The fact is, when lights are not shining up into the atmosphere, a lower wattage bulb can be used for lighting.
Although local government leaders are beginning to pressure lighting manufacturers to produce more dark sky-friendly outdoor lights, many homeowners are still skeptical. They fear that having a lower level of light around their homes will make them more vulnerable to intruders. In reality, burglary and robbery rates in major U. S. cities have declined in recent years. The International Dark Sky Association seeks to reassure people that blocking light from going into the atmosphere doesn't mean blocking out all light. Homeowners are encouraged to purchase energy-saving "motion-sensitive" lighting that goes on if anyone comes on the property. This type of lighting both alerts the residents to potential danger and dramatically saves on electricity bills.