From the U.S. Department of Interior:
Pan-STARRS comet photographed at the South Rim of the Grand Canyon on March 12th.
It still may be possible to view this comet over the next several days in the northern hemisphere. Use binoculars if you have them.
Start looking 30 minutes after sunset in the direction of sunset. Look low about 10 degrees above the horizon near the top edge of twilight. With your binoculars, you should be able to see the comet head with the tail pointed upward.
Learn more about this comet from NASA.
Photo: Rick Jurgen
If you heard recent news reports about a devastating sinkhole in Florida, you may be wondering how this type of event occurs.
According to the U.S. Geological Survey (USGS), sinkholes are most common in karst terrain, or regions where the rock below the land surface is soluble. When water from rainfall moves down through the soil, the rock begins to dissolve, creating spaces and caverns underground. If the underground spaces get too big, a sudden collapse occurs.
About 20 percent of the United States is susceptible to sinkhole events, but the most damage tends to occur in Florida, Texas, Alabama, Missouri, Kentucky, Tennessee, and Pennsylvania.
Detailed geologic mapping, which defines areas of soluble rock at the surface and subsurface, can help educate land planners and policy makers about sinkhole risk. If you know that you live in an area underlain by soluble rock, check your property for holes in the ground or cracks in your structure’s foundation.
Learn more about the science of sinkholes from the U.S. Geological Survey.
Image description: A Sun Dog in Denali National Park in Alaska.
A Sun Dog is a ring of light that is sometimes visible around the sun when light is refracted through ice crystals.
Photo from the National Park Service
Image description: Today is the 94th anniversary of Grand Canyon National Park. Find out how it was established.
This photo was taken at Shoshone Point on the South Rim of the Grand Canyon.
Photo by Michael Quinn, National Park Service
From the Bureau of Land Management:
Wonderful early-autumn picture of the Centennial mountain range in Montana. The area is a Wilderness Study Area that spans much of this east-west range. The Centennials serve as a connection between Yellowstone and the Northern Rockies for grizzlies and other wildlife to migrate.
Photo credit: Bob Wick, BLM