Science Through Shadows: How Astronomical Alignments Reveal the Universe

When one celestial object passes in front of another, it can cast a shadow that spreads across space – and sometimes across Earth. These moments of alignment, called eclipses, occultations and transits, allow scientists to study distant objects in remarkable ways. By observing how light changes when one object briefly blocks another, astronomers can measure sizes and shapes, detect atmospheres, and refine the orbits of asteroids and planets.

The Science Through Shadows project, funded by NASA’s Science Activation program and led by the Fiske Planetarium at the University of Colorado Boulder, explores how these shadow-based events help scientists conduct astronomical research. The project produced a series of short films that explain the science behind eclipses, occultations and solar observations while spotlighting the people who help make these discoveries possible – including students, educators and volunteer citizen scientists.

The videos are designed for use in classrooms, libraries, planetariums and informal learning environments, and are available for free in English and Spanish. Versions are available in 2D formats for streaming and classroom use, as well as fulldome formats for planetariums around the world.

Focus: The annular solar eclipse of October 14, 2023
On October 14, 2023, observers across North America observed an annular solar eclipse, sometimes called a “ring of fire.” During an annular eclipse, the Moon passes directly in front of the Sun but appears slightly smaller in the sky, leaving a bright ring of sunlight visible at its edges.

This video explains how annular eclipses differ from total solar eclipses, explores the science behind these events, and highlights safe viewing practices. It also helps viewers understand what makes eclipse observations both scientifically valuable and deeply memorable experiences.

Focus: The total solar eclipse of April 8, 2024
A total solar eclipse is one of the most dramatic astronomical events visible from Earth. On April 8, 2024, millions of people in North America had the opportunity to see the Moon completely block the Sun, revealing the Sun’s thin outer atmosphere, known as the corona.

This video explores what happens during a total solar eclipse, why traveling in the path of totality offers a radically different experience, and how scientists use eclipses to study the Sun’s atmosphere.

Focus: The science behind eclipses

Why don’t eclipses happen every month? What conditions must occur for the Sun, Earth and Moon to align?

This episode explains the orbital mechanics that produce eclipses and clarifies the differences between solar and lunar eclipses. By addressing common misconceptions, it helps viewers understand the celestial alignments that create these spectacular events.

Focus: The Lucy concealment campaign

When an asteroid passes in front of a distant star, it briefly blocks the star’s light, casting a shadow on Earth. Astronomers call this event an occultation and it can reveal valuable information about the asteroid’s size, shape and environment.

This video follows the Lucy Occultation Project, in which scientists and citizen scientists worked together to observe the Trojan asteroid Polymele ahead of NASA’s Lucy mission flyby. On February 3, 2023, more than 100 telescopes across two continents were deployed to capture the moment Polymelus passes in front of a star. The resulting observations help scientists better understand the asteroid before it encounters the spacecraft.

Focus: NASA’s Parker solar probe

NASA’s Parker Solar Probe is helping scientists explore the Sun closer than ever before. On December 24, 2024, the spacecraft made its closest approach to the Sun, traveling more than 430,000 miles per hour, faster than any man-made object.

This video explores how Parker Solar Probe studies the Sun’s outer atmosphere and helps scientists investigate long-standing questions about the solar corona and solar wind.

Focus: NASA’s PUNCH mission

NASA’s PUNCH (Polarimeter to Unify the Corona and Heliosphere) mission offers a new way to observe how the Sun influences space throughout the inner solar system.

Comprised of four suitcase-sized satellites in low Earth orbit, PUNCH creates three-dimensional global observations of the region between the Sun and Earth. These measurements help scientists better understand how the solar wind forms and evolves, as well as how solar storms move through space.

Focus: Citizen science during recent solar eclipses

Solar eclipses create powerful opportunities for collaborative scientific research. This episode follows two large citizen science projects that took place during recent North American eclipses: the Nationwide Eclipse Ballooning Project, another project funded by NASA Science Activation and led by Montana State University, and Citizen CATE 2024, an observing campaign supported by NASA and the National Science Foundation.

Through balloon launches, telescope observations and hands-on engineering challenges, students, educators and volunteers collected atmospheric and solar data that scientists are now analyzing. The episode shows how curious and passionate people can contribute meaningfully to real scientific discoveries.

2D versions of these videos in English and Spanish can be found on the Fiske Planetarium YouTube channel, and downloadable versions are available through the project’s distribution page. Fulldome masters (1K, 2K and 4K) are also available for free download via the Fiske Productions page, allowing planetariums around the world to share these stories of discovery with their audiences.

Through projects like Science Through Shadows, NASA’s Science Activation program helps connect everyone, everywhere with NASA science content, experts, and engagement opportunities. Whether observing an eclipse, tracking the shadow of an asteroid, or studying data from a spacecraft, these moments of alignment provide powerful opportunities to explore how the universe works and how people everywhere can participate in the process of discovery.

Anyone, anywhere – regardless of country of origin or citizenship status – can collaborate with professional scientists, conduct cutting-edge scientific research, and make real discoveries as a volunteer for NASA citizen science projects. These projects give participants the opportunity to collaborate with professional scientists, conduct cutting-edge research, and make real discoveries related to NASA’s five research divisions: Earth Sciences, Planetary Sciences, Astrophysics, Biological and Physical Sciences, and Heliophysics. Explore available projects and get started: https://science.nasa.gov/citizen-science/