A commercial jet or even a fast private one should be able to extend the dark period by heading along with the shadow. The shadow is traveling at what, 1000 mph? If you fly at 600 mph you would a get a longer dark period. I don’t know if the FAA would allow it in the US.
It’s been done many times. It’ll be done tomorrow too.
I’m on my phone so no cites. Try googling [wb-57 eclipse] and see what comes up.
The shadow moves at ~1500 mph vs ~600mph for a fast non-supersonic jet.
So totality from the jet’s POV can be extended ~40% to 6-ish minutes, but not indefinitely to the full duration of 2+ hours.
Apparently, concorde did it in 1973. Extended the totalityness to 74 minutes.
Last week’s Nova about “the great American eclipse” (vs. the one in 2017 that traversed a longer region of the US?) talked about the two NASA jets that tracked the shadow then and will again tomorrow. They work in tandem, one further ahead of the other. So when the shadow outruns the first jet it falls onto the 2nd jet giving a longer total duration in the shadow for corona recording.
Apparently Delta is actually offering two special eclipse viewing flights. Granted, Detroit is a Delta hub so I assume these two flights would have operated anyway, but tomorrow they’re planning to intentionally track the eclipse.
The Moon’s shadow is usually just above Mach II so it’d doable. I reckon with the two jet plan it’s more about how far can one jet fly that fast?
I was watching the NASA coverage yesterday before it arrived where I was, and they had video from a jet racing the eclipse. It extended totality, it did not keep up with it.
Instead of an aircraft, one could be on a spacecraft, since they go much faster. Actually, too fast, sine lower orbits go faster and higher orbits go slower. If you are as high as geosync, you’re eclipse time is exactly the same on the ground. So you have to go even higher than that.
It turns out that for maximum time in the lunar shadow, you need to be on the surface of the moon! Maybe next time…
And then, if you wish to extend it, all you have to do is a little running! (Might be clumsy in a space suit, though.)
The Moon’s circumference is ~6800 miles. It rotates once every ~28 days. If you jog at ~10mph along the equator you can keep up w the sun and remain in perpetual local midnight = perpetual solar eclipse. But there’s an even easier way …
Since there’s no atmosphere there’s no twilight. If you head up near a pole you have 28 days to walk in a circle a few hundred meters around. Easy peasy, even in a space suit dragging your camp along with you.
Let me introduce you to my new business venture, the Lunar Polar Railroad. We’ll build a lunar base on a railbed that encircles the Moon’s south pole, and then just move continuously to keep in whatever degree of shade we want. None of that tedious “dragging your camp along with you” nonsense!
Since the end of the SR-71 program there’s nothing that can sustain Mach 2+ for very long. Like a few minutes tops, then gotta slow to refuel.
All the airplanes able to fly a transcontinental range do so subsonically.
The NASA missions doing real science also needed to carry a bunch of equipment too bulky or draggy for a Mach 2+ fighter to carry.
USAF could have arranged a relay of F-15s and/or F-22s (plus tankers) to chase the eclipse with at least one jet remaining in totality from border to border. And through Mexico and Canada if the host governments were willing.
But the era of those sorts of publicity stunts is long over. Back in the 1960s they did a similar Sun-beating transcon run with a B-58 and separately an SR-71. Both to impress the Soviets and the US taxpayers. Not anymore.
Now that I’m not typing on my phone:
If you’re willing to allow a relay of multiple jets, then you can just leave them on the ground, as long as you have one every ~100 miles.
Indeed you could. And save a lot of hassle. D’oh! I hadn’t thought of that trick!
Switching back to serious, of course the whole reason to mess with airplanes is to get the observing instruments above most of the atmosphere. Which would fail if they were on the ground. Then again, millions of people used their ground based instruments to gather data on Monday. That’s gotta count for something.
I remember that, thanks for finding the cite i was about to look up. 
but just one bad baton exchange (at supersonic speeds) & they’re disqualified
I saw Southwest was offering a one or two as well. I wasn’t interested because if you’re on the right (correct) side of the plane you get a good view but if you’re on the wrong side of the plane you only get a view of the bald spot of the guy in the window seat.
I wouldn’t have taken that flight. I was on a plane that flew over Angel Falls once. My side had a good view, but by the time the plane turned for the other side to get one the cloud and mist obscured the Falls. I assume the airline flights made circles so that everyone could get a view, though.
YouTuber Jeb Brooks was on one of the Southwest flights, but due to Southwest’s non-reserved seating was unable to get a window seat.
