These maria formed when large impacts on the far side of the Moon heated up low lying layers of its crust on the near side. The lunar surface has a terrain that is covered in lunar dust and marked by mountains, impact craters, their ejecta, ray-like streaks and, mostly on the near side of the Moon, by dark maria ("seas"), which are plains of cooled magma. It formed 4.51 billion years ago, not long after Earth's formation, out of the debris from a giant impact between Earth and a hypothesized Mars-sized body called Theia. The body of the Moon is differentiated and terrestrial, with no significant hydrosphere, atmosphere, or magnetic field. Its surface gravity is about one sixth of Earth's, about half of that of Mars, and after Jupiter's moon Io the second highest among all Solar System moons. Within the Solar System it is the most massive and largest satellite in relation to its parent planet, the fifth most massive and largest moon overall, and more massive and larger than all known dwarf planets. It has a mass that is 1.2% of Earth's, and a diameter that is roughly one-quarter of Earth's or with 3,474 km (2,159 mi) about as wide as Australia. The Moon is in geophysical terms a planetary-mass object or satellite planet. Exerting gravitational force on Earth, it and to a lesser extent the Sun are the main drivers of the tides. This results in the lunar month of 29.5 days matching the lunar day. It always faces Earth with its near side, being tidally locked to Earth. It orbits at an average distance of 384 400 km ( 238 900 mi), about 30 times the planet's diameter. In darker areas, use less light to minimize loss of night vision.įor more information on efficient outdoor lighting, visit the NPS Night Skies webpage.The Moon is Earth's only natural satellite.Install motion sensors and timers so that lights are on only when needed.Use outdoor lights only where they are needed.Other principles of night sky friendly lighting include: Fixtures that direct light towards the ground - where it is most needed - protect natural lightscapes and reduce the amount of energy lost upward and to glare. The good news is that unlike many other sources of pollution, light pollution is easily reversible. For instance, a typical unshielded fixture loses half of its light upward in direct waste. But improperly used lighting wastes energy and degrades the night sky. It brings better visibility to roads and security against crime. NPS Photo / Jacob W Frank Good Lighting vs. Although Craters of the Moon still hosts some of the darkest night skies of any national park unit, light pollution from far-off cities such as Idaho Falls and Twin Falls does impact the monument's night sky. These studies provide baseline data on light pollution and have found that it, like other forms of pollution from cities and developed areas, is encroaching on national parks. To better understand the impact of light pollution on this key resource, Craters of the Moon is one of many parks that have participated in a night sky assessment. Light pollution can also affect the natural cycles of plants. Wildlife depend on the cover of darkness to hunt for food and in turn to hide from predators. The 'natural lightscape' provided by dark night skies is important for plants and animals, as well. National parks offer places for people to connect with the natural world, including the night sky. For information on upcoming activities and events, check the park's event calendar. Or simply spend an evening in the campground, leisurely viewing the night sky with a pair of binoculars or even the naked eye. Volunteers from the Pocatello Astronomical Society and others provide telescopes and sky viewing expertise. Tour the heavens above by taking part in a Star Party, held each summer and fall. Enjoying the Night Sky at Craters of the MoonĪs the only national park unit named for a celestial body, it is fitting that there are many ways to enjoy the night sky at Craters of the Moon. In recognition of Craters of the Moon outstanding night skies and staff efforts to preserve and enhance them, the monument was designated an International Dark Sky Park in 2017. Once visible from backyards across the country, light pollution obscures the Milky Way from two out of three Americans today. What has changed in recent decades is the ability of most people to actually see the stars that comprise the night sky. For ages, people around the globe have found the heavens a source of inspiration for stories and art. Since humans first looked skyward, the night sky has remained virtually unchanged. NPS Photo / Kensie Stallings An International Dark Sky Park The night sky is one of the most spectacular sights at Craters of the Moon.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |