The ultimate eclipse chase: A Concorde raced against the Moon’s shadow

终极日食追逐：协和客机与月球阴影的竞速

A walk down the tarmac at the National Air and Space Museum of France is guaranteed to thrill aviation enthusiasts. Several civilian and military aircraft of the past and the present are showcased in this museum, located at the Paris-Le Bourget airport. One of them is the legendary Concorde F-WTSS 001 prototype, the sight of which should give goosebumps to science enthusiasts as well. That’s because right behind its long nose is a painted map that traces the path of a June 1973 total solar eclipse across Africa.

漫步在法国航空航天博物馆的停机坪上，绝对会让航空爱好者感到兴奋。这座位于巴黎勒布尔歇机场的博物馆展示了过去和现在的多架民用和军用飞机。其中之一就是传奇的协和式飞机 F-WTSS 001 原型机，它的出现也足以让科学爱好者起鸡皮疙瘩。这是因为在它长长的机头后方，绘有一张地图，描绘了 1973 年 6 月横跨非洲的日全食路径。

It’s there on the Concorde 001 prototype because a group of eight scientists set a new world record of observing a total solar eclipse for 74 minutes by flying this aircraft at more than twice the speed of sound. To put this figure into context, the maximum duration of totality on the ground is around 7.5 minutes when an eclipse is observed in the equatorial regions. For the upcoming solar eclipse of August 12, which can be seen from parts of Europe, the maximum duration of totality from the ground will be slightly more than two minutes.

这架协和 001 原型机之所以有此标记，是因为八位科学家曾通过驾驶这架飞机以超过两倍音速的速度飞行，创下了观测日全食 74 分钟的世界纪录。作为对比，在赤道地区观测日食时，地面上的日全食持续时间最长约为 7.5 分钟。而对于即将到来的 8 月 12 日日食（部分欧洲地区可见），地面观测到的日全食最长持续时间仅略多于两分钟。

Repurposing a prototype

原型机的改造

One of the scientists, and the initiator of the record-creating project, was Pierre Léna. A year before June 30, 1973, Léna, who had carried out astronomical observations from high-altitude aircraft, came up with this idea. Since the 1973 eclipse was going to be near the equator, the Moon’s shadow would move at a relatively slower speed, although still more than 2.2 times the speed of sound. There was only one big aircraft that came close to matching this speed: The Concorde.

作为该破纪录项目的发起人之一，皮埃尔·莱纳（Pierre Léna）也是参与的科学家之一。在 1973 年 6 月 30 日之前的一年，曾利用高空飞机进行天文观测的莱纳提出了这个想法。由于 1973 年的日食路径靠近赤道，月球阴影的移动速度相对较慢，尽管仍超过音速的 2.2 倍。当时只有一种大型飞机能接近这个速度：协和式客机。

“In 1970, the Concorde 001 prototype flew supersonic for the first time,” Léna told Ars. “The newspapers were full of these results. By 1972, I thought it was worth trying to approach André Turcat, the chief of test flights at Aerospatiale in Toulouse, and ask him about the possibility of using the 001 prototype to follow the June 1973 eclipse. He was very interested.”

“1970 年，协和 001 原型机首次实现超音速飞行，”莱纳告诉 Ars。“报纸上全是这些报道。到了 1972 年，我觉得值得尝试联系图卢兹法国航天公司（Aerospatiale）的首席试飞员安德烈·图尔卡（André Turcat），询问使用 001 原型机追踪 1973 年 6 月日食的可能性。他非常感兴趣。”

With his plan accepted, Léna began organizing experiments for the historic flight. Flying at nearly 17 km above the Earth’s surface had many benefits. “Flying very high in the stratosphere had several advantages, including no humidity, which meant an excellent infrared transmission of the solar light.”

计划被采纳后，莱纳开始为这次历史性的飞行组织实验。在距离地面近 17 公里的高空飞行有许多好处。“在平流层高空飞行有几个优势，包括没有湿度，这意味着太阳光的红外传输效果极佳。”

“I had planned an experiment to study the particles of dust in the corona in the infrared wavelengths. However, it would have been presumptuous to use this big aircraft only for a single experiment. So the first thing we did, after we got a feeling that the project would go ahead, was to propose to other scientific groups in France, the UK, and the United States a seat on this flight to carry their own observations,” he said.

“我曾计划进行一项实验，研究红外波段下日冕中的尘埃颗粒。然而，如果只用这架大型飞机进行单一实验会显得过于自负。因此，当我们感觉到项目能够顺利进行后，我们做的第一件事就是向法国、英国和美国的其他科研小组发出邀请，让他们参与这次飞行并进行各自的观测，”他说。

Building a team

组建团队

While Léna was from the Paris Observatory, the other scientists came from the French National Centre for Scientific Research; Queen Mary College in London; Kitt Peak Observatory in Arizona; Los Alamos National Laboratory; and the University of Aberdeen. The main goal of this project was to use the long totality to study the solar corona at different wavelengths, as the whole corona is only visible during a total eclipse.

虽然莱纳来自巴黎天文台，但其他科学家分别来自法国国家科学研究中心、伦敦玛丽女王学院、亚利桑那州基特峰国家天文台、洛斯阿拉莫斯国家实验室以及阿伯丁大学。该项目的主要目标是利用漫长的日全食时间，在不同波长下研究日冕，因为只有在日全食期间才能看到完整的日冕。

According to Léna, the experiments included studying the dust in the corona (which was emitting infrared radiation), studying the oscillating hot gas in the corona, and studying the chromosphere. To accommodate these experiments, the Concorde 001 prototype underwent significant modifications, notably the creation of four portholes in the ceiling, with one dedicated window for each experiment. Those portholes are unmissable even today. They can be seen while walking down the aisle of the aircraft.

据莱纳介绍，实验内容包括研究日冕中的尘埃（其会发射红外辐射）、研究日冕中振荡的热气体以及研究色球层。为了配合这些实验，协和 001 原型机进行了重大改装，最显著的是在机顶开设了四个舷窗，每个实验专用一个窗口。即使在今天，这些舷窗依然清晰可见。当你在飞机的过道上行走时，就能看到它们。

With the experiments and the team of scientists chosen, two rehearsal flights were conducted before the actual flight, which took off from Las Palmas in the Canary Islands.

在确定了实验项目和科学家团队后，在正式飞行前进行了两次预演飞行，随后飞机从加那利群岛的拉斯帕尔马斯起飞。