Engineering the World’s Longest Solar Eclipse

How a team of creative Scientists used the Concorde jet to extend the viewing time of a Solar Eclipse

Last week I wasn’t interested in eclipses. It’s something I’ve been tangentially aware of, but I never saw one that made me understand why people get so excited.

Translation: I never saw a solar eclipse at 100% totality, until April 8, 2024.

Admittedly, there has been a lot of “eclipse hype” for those of us who live in the path of totality. It’s been going on for months. It’s on the news, there’s eclipse tourism, and plenty of eclipse merch. I’m also one of those people who sees any hype and goes the other direction. For once, I’m really glad I was dragged into the center of the excitement.

Like the other 30 million Americans who watched the 100% eclipse on Monday, April 8, 2024, I was blown away. I have never seen anything like it. It wasn’t just how dark it got around me (more like dusk really), but how black the Moon was in front of the Sun. It’s beyond description. I’m now a card-carrying member of the eclipse fan club.

Ever since the main-event I’ve been searching for best photos of the 2024 eclipse in my area, learning about the differences in various eclipses, even watching a simulation of the moon shadow from space. But what was the World’s longest Eclipse?

When was the World’s longest Solar Eclipse:

The longest total solar eclipse of the 21st century occurred on July 22, 2009. This eclipse lasted for a maximum of 6 minutes and 39 seconds over the Pacific Ocean, setting a record for the longest duration for a total solar eclipse for this century. Such long durations of totality are rare and are influenced by the Earth’s distance from the sun and the moon’s distance from the Earth, as well as the alignment of the Earth, moon, and sun. The next eclipse that’s set to challenge this duration won’t happen until June 13, 2132. So, the 2009 eclipse holds a special place in the record books for its exceptional length, offering a rare and fascinating spectacle for eclipse chasers and astronomers alike.

How could humans extend the time we get to see a solar eclipse?

Engineering the 74 Minute Solar Eclipse:

Imagine hurtling through the sky at Mach 2 (2,100 mph), chasing the moon’s shadow across continents, all in pursuit of one of the universe’s most awe-inspiring spectacles—a total solar eclipse. This isn’t the plot of a science fiction novel; it’s the remarkable story of a daring mission aboard the iconic Concorde, the only commercial aircraft capable of keeping pace with the speed of the eclipse’s shadow.

In 1973, a visionary team of scientists and aviators, led by French astrophysicist Pier Lena, embarked on an unprecedented journey to witness the longest solar eclipse in human history from a vantage point like no other. Armed with scientific instruments and a meticulously calculated flight path, they transformed Concorde into the fastest moving observatory ever, aiming to unravel the mysteries of the sun’s elusive corona. Join us as we take off on this extraordinary voyage of discovery, where precision flying meets cutting-edge science in a race against the celestial clock.

In the early 1970’s a small group of scientists set out to study the Sun’s corona, a task typically complicated by atmospheric interference from the ground.  They planned to achieve this by harnessing the capabilities of Concorde, the only commercial aircraft fast enough to chase a solar eclipse. In doing so, they could experience a total solar eclipse for 74 minutes—a feat unachievable from a stationary position on Earth. The Concorde’s unparalleled speed and cabin space made it the ideal platform for this pursuit, allowing Lena and his team, along with Concorde test pilot Andre Turcat, to meticulously plan a flight that would intercept the moon’s shadow over Africa and remain within it for an extended period, overcoming significant logistical challenges related to the flight path and operational limits.

The mission required intricate planning to ensure Concorde could enter and stay within the moon’s rapidly moving shadow, with precision timing crucial to maximizing the duration of totality. The aircraft was specially modified for scientific observation, including installing observation windows and modifying its electrical system to support the scientific instruments. The team’s efforts culminated on June 30th, when Concorde, piloting by Turcat, successfully intercepted the eclipse, enabling on-board scientists to conduct unprecedented observations of the Sun’s corona, contributing valuable insights into phenomena such as zodiacal light and the corona’s acoustic waves.

This mission not only achieved a record for the longest experienced eclipse but also demonstrated an exceptional collaboration between science and engineering, offering a unique perspective on a celestial event and advancing our understanding of solar phenomena.