A total solar eclipse happens when the disk of the moon appears to completely cover the disk
of the sun in the sky as it passes between earth and the sun and can only happen during a new
moon. The last time a total solar eclipse was seen from anywhere in the continental United States
(CONUS), however, was 1979.
Daylight turns into twilight and the temperature drops rapidly revealing large delicate
streamers of light (the solar corona) streaking out from the silhouette of the moon.
A total solar eclipse is a natural phenomenon, nevertheless, in some ancient and modern cultures,
solar eclipses have been attributed to supernatural causes or regarded as bad omens.
A total solar eclipse can be frightening to people who are unaware of its astronomical explanation,
as the Sun seems to disappear during the day and the sky darkens in a matter of minutes.
The approach the moon's inner shadow projecting on the atmosphere can look like an approaching
storm, and an eerie orange twilight color rings the horizon during the total phase.
If the Moon were in a perfectly circular orbit, a little closer to the Earth, and in the same orbital plane, there would be total solar eclipses every month. However, the Moon's orbit is
inclined (tilted) at more than 5 degrees to the Earth's orbit around the Sun, so its shadow at
new moon usually misses Earth. The orbital planes cross each other at a line of nodes resulting
in at least two, and up to five, solar eclipses occurring each year; no more than two of which
can be total eclipses. However, total solar eclipses are rare at any particular location because
totality exists only along a narrow path on the Earth's surface traced by the Moon's inner
shadow or umbra.
Since looking directly at the Sun can lead to permanent eye damage or blindness, special eye
protection or indirect viewing techniques are used when viewing a solar eclipse. It is technically
safe to view only the total phase of a total solar eclipse with the unaided eye and without
protection; however, this is a dangerous practice, as most people are not trained to recognize
the phases of an eclipse. The partial phase can span 2-3 hours while the total phase can only
last up to 7.5 minutes for any one location. In order to see the most impressive experience, the location for which you choose to view the eclipse should be clear and sunny. NOAA's cloudiness map may improve your experience!
Totality for the August 21, 2017 eclipse can be seen within about a 70 mile wide path from
portions of the following U.S. States: Oregon, Idaho, Wyoming, Nebraska, Missouri, Kansas,
Illinois, Kentucky, Tennessee, North Carolina, Georgia, and South Carolina. Maximum duration
for this total eclipse is 2 minutes 40 seconds. The partial phases last almost 3 hours.
This dataset shows the motion of the Moon's shadow on the Earth depicting the relative darkness
of the inner shadow, called the umbra where the eclipse is total, and the outer penumbra where
the eclipse is partial. A transparent overlay delineates more specifically where the umbra
(inner black dot) and the penumbra (large gray circle) are located. Other overlays show some
of the cities in the path of totality and a diagram showing the alignment of Sun, Moon, and Earth.
C1 Patterns. Children recognize that patterns in the natural and human designed world can be observed, used to describe phenomena, and used as evidence
C4 Systems and System Models. Students understand objects and organisms can be described in terms of their parts; and systems in the natural and designed world have parts that work together.
C5 Energy and Matter. Students observe objects may break into smaller pieces, be put together into larger pieces, or change shapes.
C7 Stability and Change. Students observe some things stay the same while other things change, and things may change slowly or rapidly.
C1 Patterns. Students identify similarities and differences in order to sort and classify natural objects and designed products. They identify patterns related to time, including simple rates of change and cycles, and to use these patterns to make predictions.
C4 Systems and System Models. Students understand that a system is a group of related parts that make up a whole and can carry out functions its individual parts cannot. They can also describe a system in terms of its components and their interactions.
C5 Energy and Matter. Students learn matter is made of particles and energy can be transferred in various ways and between objects. Students observe the conservation of matter by tracking matter flows and cycles before and after processes and recognizing the total weight of substances does not change.
C7 Stability and Change. Students measure change in terms of differences over time, and observe that change may occur at different rates. Students learn some systems appear stable, but over long periods of time they will eventually change.
C1 Patterns. Students recognize that macroscopic patterns are related to the nature of microscopic and atomic-level structure. They identify patterns in rates of change and other numerical relationships that provide information about natural and human designed systems. They use patterns to identify cause and effect relationships, and use graphs and charts to identify patterns in data.
C4 Systems and System Models. Students can understand that systems may interact with other systems; they may have sub-systems and be a part of larger complex systems. They can use models to represent systems and their interactions—such as inputs, processes and outputs—and energy, matter, and information flows within systems. They can also learn that models are limited in that they only represent certain aspects of the system under study.
C5 Energy and Matter. Students learn matter is conserved because atoms are conserved in physical and chemical processes. They also learn within a natural or designed system, the transfer of energy drives the motion and/or cycling of matter. Energy may take different forms (e.g. energy in fields, thermal energy, energy of motion). The transfer of energy can be tracked as energy flows through a designed or natural system.
C7 Stability and Change. Students explain stability and change in natural or designed systems by examining changes over time, and considering forces at different scales, including the atomic scale. Students learn changes in one part of a system might cause large changes in another part, systems in dynamic equilibrium are stable due to a balance of feedback mechanisms, and stability might be disturbed by either sudden events or gradual changes that accumulate over time
C1 Patterns. Students observe patterns in systems at different scales and cite patterns as empirical evidence for causality in supporting their explanations of phenomena. They recognize classifications or explanations used at one scale may not be useful or need revision using a different scale; thus requiring improved investigations and experiments. They use mathematical representations to identify certain patterns and analyze patterns of performance in order to re-engineer and improve a designed system.
C4 Systems and System Models. Students can investigate or analyze a system by defining its boundaries and initial conditions, as well as its inputs and outputs. They can use models (e.g., physical, mathematical, computer models) to simulate the flow of energy, matter, and interactions within and between systems at different scales. They can also use models and simulations to predict the behavior of a system, and recognize that these predictions have limited precision and reliability due to the assumptions and approximations inherent in the models. They can also design systems to do specific tasks.
C5 Energy and Matter. Students learn that the total amount of energy and matter in closed systems is conserved. They can describe changes of energy and matter in a system in terms of energy and matter flows into, out of, and within that system. They also learn that energy cannot be created or destroyed. It only moves between one place and another place, between objects and/or fields, or between systems. Energy drives the cycling of matter within and between systems. In nuclear processes, atoms are not conserved, but the total number of protons plus neutrons is conserved.
C7 Stability and Change. Students understand much of science deals with constructing explanations of how things change and how they remain stable. They quantify and model changes in systems over very short or very long periods of time. They see some changes are irreversible, and negative feedback can stabilize a system, while positive feedback can destabilize it. They recognize systems can be designed for greater or lesser stability
ESS1.A The Universe and its Stars. Patterns of movement of the sun, moon, and stars as seen from Earth can be observed, described, and predicted
ESS1.B Earth and the Solar System. Patterns of movement of the sun, moon, and stars as seen from Earth can be observed, described, and predicted
PS4.C Information Technologies and Instrumentation. People use devices to send and receive information.
ESS1.A The Universe and its Stars. Stars range greatly in size and distance from Earth and this can explain their relative brightness.
ESS1.B Earth and the Solar System. The Earth’s orbit and rotation, and the orbit of the moon around the Earth cause observable patterns.
PS2.A Forces and Motion. The effect of unbalanced forces on an object results in a change of motion. Patterns of motion can be used to predict future motion. Some forces act through contact, some forces act even when the objects are not in contact. The gravitational force of Earth acting on an object near Earth’s surface pulls that object toward the planet’s center
PS4.C Information Technologies and Instrumentation. Patterns can encode, send, receive and decode information.
ESS1.A The Universe and its Stars. The universe began with a period of extreme and rapid expansion known as the Big Bang. Earth and its solar system are part of the Milky Way galaxy, which is one of many galaxies in the universe.
ESS1.B Earth and the Solar System. The solar system contains many varied objects held together by gravity. Solar system models explain and predict eclipses, tides, lunar phases, and seasons.
PS2.A Forces and Motion. The role of the mass of an object must be qualitatively accounted for in any change of motion due to the application of a force.
PS4.C Information Technologies and Instrumentation. Waves can be used to transmit digital information. Digitized information is comprised of a pattern of 1s and 0s.
ESS1.A The Universe and its Stars. The sun is just one of more than 200 billion stars in the Milky Way galaxy, and the Milky Way is just one of hundreds of billions of galaxies in the universe. The study of stars’ light spectra and brightness is used to identify compositional elements of stars, their movements, and their distances from Earth.
ESS1.B Earth and the Solar System. Kepler’s laws describe common features of the motions of orbiting objects. Observations from astronomy and space probes provide evidence for explanations of solar system formation. Changes in Earth’s tilt and orbit cause climate changes such as Ice Ages
PS2.A Forces and Motion. Newton’s 2nd law (F=ma) and the conservation of momentum can be used to predict changes in the motion of macroscopic objects.
PS4.C Information Technologies and Instrumentation. Large amounts of information can be stored and shipped around as a result of being digitized.