Everything's bigger in Texas, including their Dark Sky park. Big Bend National Park in the southwest of Texas stretches over 300,000 square kilometers for your stargazing pleasure. The dry air and exceptionally flat landscape will allow you to peek at stars barely above the horizon.
Big Bend National Park in Texas. Photography credit: Tyler Nordgren
Plan to stargaze facing south: the flat horizon and low latitude allow you to peak at a few stars in the Southern Cross, while the north has a mountain rudely blocking out part of the sky. Usually, light dims as it gets closer to the horizon and passes through a thicker layer of atmosphere between you and it, but this extinction is reduced in the dry desert air, allowing for excellent near-horizon viewing.
Halfway between El Paso and San Antonio, Big Bend is just far enough away to escape the light pollution of big city lights. As a dedicated dark sky facility, the park has made a concerted effort to shelter any outdoor lights and reduce light pollution. It took some serious retrofitting: the initial survey revealed at least a dozen unshielded dusk-to-dawn lights spilling over 3,000 lumens into the night.
Lighting trespass at Emory peak prior in 2003, and after modifying outdoor fixtures in 2011. Some light trespass is from transient sources (cars). Image credit: NPS/Dark Sky
After retrofits, the total illumination of the brightest location in the entire park, the lodge, totalled 0.037 mLux, with no light trespass beyond the facility. That's a magnitude -2.9 light source, only 50% brighter than Jupiter, and 30% dimmer than Venus.
Moonrise over the northern mountain. Photography credit: NPS/Big Bend National Park
When stargazing at Big Bend, you can give yourself an eye-test by picking out extremely dim magnitude 8 stars with your naked eye. In the spring months, the zodiacal glow can last for hours after twilight, teaching you that night isn't always dark.
Big Bend is a national park, so will cost you $10 a week to visit. The park has on-location camp sites and lodging. Be aware that in the hot summer months, a haze from Mexican industry drifting over the boarder can settle in and reduce visibility.
Learn why dark skies are so important, appreciate Dark Sky week, and consider another Dark Sky park in Utah. Check out more photographs of the stargazing at Big Bend on Tyler Nordgren's website.