A full moon is always a good reason to go outside and turn your head toward the sky, but those who do so early on January 31 will be treated to the sight of a total lunar eclipse. It’s the only total lunar eclipse visible from North America in 2018, so it’s a great opportunity for students to observe the Moon – and for teachers to make connections to in-class science content.
In the latest Teachable Moment from NASA/JPL Edu, education specialist Lyle Tavernier explains what causes a total lunar eclipse, what it tells us about Earth and how to see one in action on January 31. Teachers and parents can also explore a collection of lessons and activities to get students curious and excited about the Moon.
A new study has found that dust, not spring warmth, controls the pace of spring snowmelt that feeds the headwaters of the Colorado River. Contrary to conventional wisdom, the amount of dust on the mountain snowpack controls how fast the Colorado Basin’s rivers rise in the spring regardless of air temperature, with more dust correlated with faster spring runoff and higher peak flows.
The finding is valuable for western water managers and advances our understanding of how freshwater resources, in the form of snow and ice, will respond to warming temperatures in the future. By improving knowledge of what controls the melting of snow, it improves understanding of the controls on how much solar heat Earth reflects back into space and how much it absorbs — an important factor in studies of weather and climate.
When snow gets covered by a layer of windblown dust or soot, the dark topcoat increases the amount of heat the snow absorbs from sunlight. Tom Painter of NASA’s Jet Propulsion Laboratory in Pasadena, California, has been researching the consequences of dust on snowmelt worldwide. This is the first study to focus on which has a stronger influence on spring runoff: warmer air temperatures or a coating of dust on the snow.
Windblown dust has increased in the U.S. Southwest as a result of changing climate patterns and human land-use decisions. With rainfall decreasing and more disturbances of the land, protective crusts on soil are removed and more bare soil is exposed. Winter and spring winds pick up the dusty soil and drop it on the Colorado Rockies to the northeast. Historical lake sediment analyses show there is currently an annual average of five to seven times more dust falling on the Rocky Mountain snowpack than there was before the mid-1800s.
Painter and colleagues looked at data on air temperature and dust in a mountain basin in southwestern Colorado from 2005 to 2014, and streamflow from three major tributary rivers that carry snowmelt from these mountains to the Colorado River. The Colorado River’s basin spans about 246,000 square miles (637,000 square kilometers) in parts of seven western states.
The researchers found that the effects of dust dominated the pace of the spring runoff even in years with unusually warm spring air temperatures. Conversely, there was almost no statistical correlation between air temperature and the pace of runoff.
“We found that when it’s clean, the rise to the peak streamflow is slower, and generally you get a smaller peak.” Painter said. “When the snowpack is really dusty, water just blasts out of the mountains.” The finding runs contrary to the widely held assumption that spring air temperature determines the likelihood of flooding.
Coauthor McKenzie Skiles, an assistant professor in the University of Utah Department of Geography, said that while the impacts of dust in the air, such as reduced air quality, are well known, the impacts of the dust once it’s been deposited on the land surface are not as well understood. “Given the reliance of the western U.S. on the natural snow reservoir, and the Colorado River in particular, it is critical to evaluate the impact of increasing dust deposition on the mountain snowpack,” she said.
Painter pointed out that the new finding doesn’t mean air temperatures in the region can be ignored in considering streamflows and flooding, especially in the future. “As air temperature continues to climb, it’s going to have more influence,” he said. Temperature controls whether precipitation falls as snow or as rain, for example, so ultimately it controls how much snow there is to melt. But, he said, “temperature is unlikely to control the variability in snowmelt rates. That will still be controlled by how dirty or clean the snowpack is.”
Skiles noted, “Dust on snow does not only impact the mountains that make up the headwaters of Colorado River. Surface darkening has been observed in mountain ranges all over the world, including the Alps and the Himalaya. What we learn about the role of dust deposition for snowmelt timing and intensity here in the western U.S. has global implications for improved snowmelt forecasting and management of snow water resources.”
The study, titled “Variation in rising limb of Colorado River snowmelt runoff hydrograph controlled by dust radiative forcing in snow,” was published today in the journal Geophysical Research Letters. Coauthors are from the University of Utah, Salt Lake City; University of Colorado, Boulder; and University of California, Santa Barbara.
NASA will pay will tribute to the crews of Apollo 1 and space shuttles Challenger and Columbia, as well as other NASA colleagues who lost their lives while furthering the cause of exploration and discovery, during the agency’s annual Day of Remembrance on Thursday, Jan. 25.
NASA acting Administrator Robert Lightfoot, and other agency senior officials, will lead an observance at Arlington National Cemetery in Virginia starting at 10:25 a.m. EST. A wreath-laying ceremony will be held at the Tomb of the Unknown Soldier, followed by observances for the Apollo 1, Challenger and Columbia crews.
Various NASA centers also will hold observances on and leading up to the Day of Remembrance for the public, employees and the families of those lost in service to America’s space program, including Johnson Space Center in Houston and Marshall Space Flight Center, in Huntsville, Alabama.
Some Mars experts are eager and optimistic for a dust storm this year to grow so grand it darkens skies around the entire Red Planet.
This biggest type of phenomenon in the environment of modern Mars could be examined as never before possible, using the combination of spacecraft now at Mars.
A study published this week based on observations by NASA’s Mars Reconnaissance Orbiter (MRO) during the most recent Martian global dust storm — in 2007 — suggests such storms play a role in the ongoing process of gas escaping from the top of Mars’ atmosphere. That process long ago transformed wetter, warmer ancient Mars into today’s arid, frozen planet.
“We found there’s an increase in water vapor in the middle atmosphere in connection with dust storms,” said Nicholas Heavens of Hampton University, Hampton, Virginia, lead author of the report in Nature Astronomy. “Water vapor is carried up with the same air mass rising with the dust.”
A link between the presence of water vapor in Mars’ middle atmosphere — roughly 30 to 60 miles (50 to 100 kilometers) high — and escape of hydrogen from the top of the atmosphere has been detected by NASA’s Hubble Space Telescope and the European Space Agency’s Mars Express orbiter, but mainly in years without the dramatic changes produced in a global dust storm. NASA’s MAVEN mission arrived at Mars in 2014 to study the process of atmosphere escape.
“It would be great to have a global dust storm we could observe with all the assets now at Mars, and that could happen this year,” said David Kass of NASA’s Jet Propulsion Laboratory, Pasadena, California. He is a co-author of the new report and deputy principal investigator for the instrument that is the main source of data for it, MRO’s Mars Climate Sounder.
Sixty years ago next week, the hopes of Cold War America soared into the night sky as a rocket lofted skyward above Cape Canaveral, a soon-to-be-famous barrier island off the Florida coast.
The date was Jan. 31, 1958. NASA had yet to be formed, and the honor of this first flight belonged to the U.S. Army. The rocket’s sole payload was a javelin-shaped satellite built by the Jet Propulsion Laboratory in Pasadena, California. Explorer 1, as it would soon come to be called, was America’s first satellite.