Earth and space sciences

Phenomena Ideas

Here you will find example phenomena for the three NGSS disciplinary core ideas in the earth and space sciences.

ESS1: Earth’s Place in the Universe

What causes the Differences in temperature on Christmas Day in Sydney, Quito, and Denver?

Cities around the world experience variation in weather, intensity of sunlight, and hours of daylight on any given day of the year. In this unit, students will investigate why three cities around the world (one in the northern hemisphere, one in the southern hemisphere, and one equatorial city) experience completely different seasonal conditions on the same date. On December 25th, the northern hemisphere experiences their winter season, marked by colder temperatures and shorter periods of daylight. On the same date, locations in the southern hemisphere are in their summer season, marked by warmer temperatures, more intense sunlight, and longer periods of daylight. However, locations along the equator experience nearly the same temperatures, intensity of sunlight, and hours of daylight on December 25th as they would at any other time of the year.

Recent studies have shown that at the isotopic level, the Earth and Moon are remarkably similar. While they may have relatively different amount of elements such as iron, they share the same isotopic signatures in a number of elements. What does this finding mean in terms of the origins of the two celestial bodies? Scientists have hypothesized a number of possible hypotheses to account for the formation of our moon. Perhaps the Earth captured a wayward planet that became trapped in our gravitational pull. Or maybe the early Earth spun so fast it lost the material that formed into the Moon. Or perhaps the early Earth was struck by another planet, expelling the materials that formed our moon. The answer to this question impacts our understanding of the formation of the entire solar system.

Why are The Earth and Moon "genetically" identical?

ESS2: Earth’s Systems

How can we explain the changes to the normal weather system that resulted in the devastating 2017 hurricane season?

The severity of 2017 hurricanes has been influenced by two main factors: The absence of an El Nino system, which creates a high wind shear and disrupts storms. Wind shear is the difference in wind speed over a distance in the atmosphere (in our case, we are concerned with vertical wind shear). High wind shear disperses the heat and moisture needed for the hurricane to form. Additionally, the difference in wind speed distorts the shape of the storm, making it more difficult for it to condense into a hurricane formation. El Nino weather systems result in increased wind shear, as well as cooler than normal water surface temperatures off the coast of Africa, where most hurricanes form. The cooler water contributes less heat energy, making it difficult for storms to form. Because 2017 did not have the wind shear and water cooling effects of El Nino, more frequent and intense storms were able to form. A second factor contributing to the intensity of the 2017 hurricane season was unusually high temperatures in the Atlantic ocean, which intensify storms by allowing them to absorb more heat energy. Climate change offers an explanation for the rise in temperatures, as oceans act as reservoirs that absorb the increased atmospheric heat, creating warmer water and further fueling the hurricanes.

Spread over 16,000 square miles in eastern Washington are hundreds of monuments to a very different past environment. In an area that gets less than eight inches of rain a year stands an ancient waterfall that was three miles wide and 400 feet high, ten times the size of Niagara Falls. Dry Fall is only one of the hundreds of geologic features that tell of an ancient past of massive erosional forces. These include mounds of gravel as tall as skyscrapers, deep holes in the bedrock that would swallow entire city blocks, rolling hills that look from above like the ripples at the edge of a lake, and countless oddly placed boulders. The first farmers of the area named this the 'scablands'. Today, geologists see these features as an enigma: What could have caused this landscape?

What caused the scablands of eastern washington?

ESS3: Earth and Human Activity

Why are Polar Bears in Peril?

Polar bears require sea ice and glaciers to hunt their prey. Due to rising global temperatures caused largely by human contributions to increased amounts of greenhouse gases in the Earth's atmosphere, the amount of sea ice has decreased significantly. As a consequence of shrinking sea ice habitat, polar bears contact with Arctic coastal communities increases. As the ice recedes and bears can't find food, hungry bears are more likely to come into contact with communities in their search for food. This is dangerous for people and bears. Dangerous interactions with people and loss of normal sources of food from sea ice hunting are among the factors that threaten polar bears.

Conifers in the Western U.S. are dying at high numbers due to infestations of bark beetles. When temperatures are lower and precipitation is higher, the trees and the cold weather limits the number of beetles. With climate change, winters are less severe meaning higher temperatures. More intense droughts are also happening more often. With these changes in climate, beetles are not dying as often, reproducing faster, and trees are less able to defend themselves. In fact, bark beetles populations have exploded to 10x the baseline rate. Since 2000, bark beetles have killed enough trees to cover the entire state of Colorado.

What is causing the decimation of forests in the Western U.S.?