Veritasium Chases a Solar Eclipse from Spain to Space with NASA Balloons

In this video, Veritasium travels to Burgos, Spain, with NASA and science teams to film a total solar eclipse from the center of the Moon's shadow. The episode delves into why eclipses favor the Northern Hemisphere, how eclipse seasons work, and the mysterious shadow bands observed on the ground. Along the way, balloons are launched to the edge of space to capture data and images, and hands-on demonstrations reveal how eclipses create crescent shadows and why the corona appears during totality. The piece blends live chasing, balloon science, and historical anecdotes to illuminate the science behind solar eclipses and the methods researchers use to study them.

Introduction and Mission Overview

Veritasium, Henry, and Amelia join NASA and a coalition of science groups to observe Spain's first total solar eclipse in over a century. The team aims to place the Moon’s shadow at the center of totality and to use a fleet of weather balloons and a high altitude bomber mission to capture data and high resolution imagery of the event. This overview sets the stage for a wide ranging exploration of solar eclipse science, from celestial mechanics to atmospheric optics.

Patterns of Eclipses Across Hemispheres

The video explains a long standing pattern: when you map total solar eclipses from 2000 BCE to 3000 CE, the Northern Hemisphere experiences more total eclipses than the Southern Hemisphere. The reasons lie in orbital geometry and the tilt of the Earth. The Moon's elliptical orbit causes its apparent size to vary by up to 30 percent, while the Sun’s apparent size also changes with Earth's orbital position, making total eclipses more likely in certain seasons. Over millennia this pattern will reverse as the Earth’s axial precession and orbital dynamics slowly shift the balance, predicting a future dominance of Southern Hemisphere eclipses.

Eclipse Seasons and Frequency

The discussion then dives into eclipse seasons, a roughly 34 day window when eclipse options become possible due to the alignment of the Moon’s nodes with the Earth and Sun. Since new moons occur every 29.5 days, you are guaranteed at least one eclipse within each season, with the number of eclipses per year varying between two and as many as five when counting partials and reentrant seasons. The video emphasizes that while two eclipses per year may seem common, the total and annular types depend on the Moon’s distance and the Sun’s apparent size at the time of new moon.

Balloon and Space-Based Observations

To maximize data collection, NASA and Borealis field teams launched weather and launcher balloons from multiple sites, including Spain and Reykjavik, Iceland. A separate mission uses a 70 year old bomber aircraft to chase totality, delivering stable, multi instrument observations of the Sun’s outer regions. The footage contrasts the stability of a jet with a weather balloon, highlighting how higher altitude observations permit more sensitive solar measurements and better corona imaging.

Historical Context: Helium and Coronium

The transcript recounts the 1868 eclipse, when Jules Janssen and Norman Lockyer used slit spectrometry to identify a new element later named helium, discovered in the solar spectrum’s chromosphere. What was once called coronium turned out to be highly ionized iron. This historical vignette illustrates how eclipses have historically guided major discoveries and underscores the enduring value of eclipse research.

Shadows, Shadows, and Cardboard Experiments

A central part of the video is a hands on demonstration with cardboard cutouts that produce projected shapes of triangles, crescents, and other figures. As the cardboard is moved away from the ground, the projected image morphs from a triangle to a circle, revealing how light travels in straight lines and how the focal point and geometry invert the ground projection relative to the sky. The crescents observed on the ground point in the opposite direction from the crescents seen in the sky, which in the analogy resembles a pinhole camera effect. The segment also depicts how viewing shadows at 90 degrees can create a sharp versus blurry appearance, a key to understanding eclipse shadow dynamics.

The Shadow Bands Mystery

Leading scientists propose that shadow bands arise from the atmosphere’s stratified layers with varying temperatures and densities, which refract sunlight into fine beams and create a shimmering banding effect in the final seconds of sunlight. An early 1905 hydrogen balloon experiment near Bergamo offers historical context for attempts to observe these bands from altitude, revealing how observers can experience the bands across different surfaces rather than just on a white sheet. The video notes that while the precise origin of shadow bands remains an active area of study, interference from lunar topography and multiple light sources also contributes to secondary effects during totality.

What You See At Totality

As totality nears, observers witness a dramatic transition: the Sun's corona becomes visible, the atmosphere sharpens shadows in certain directions, and the sky shifts in color. The team describes why time lapse footage often shows the Sun turning white rather than bright white, with filters and exposure settings playing a large role. They also discuss the common red or orange filter used for safety, and how totality reveals the corona’s brilliance that is otherwise overwhelmed by the Sun's glare during partial phases.

Takeaways and Human Experience

The footage captures the exhilaration and awe of witnessing a total solar eclipse, including the drive to chase a perfect path of totality, the 360 degree sunset phenomena, and the emotional resonance of viewing a rare celestial event in person. The video concludes with reflections on the scientific value of eclipse research, the collaboration between researchers and video makers, and the ongoing mysteries such as shadow bands that continue to inspire exploration and curiosity.