Is it likely that an aircraft could have been near 10° 08' north at local midnight August 26/27, 2003? Edit: The astronomical data turned out to be different. I'm keeping the constraints below as they where, but those are not relevant to finding the closest person to Mars.
This is part of an effort to determine which human has been closest to Mars. As Apollo astronauts and ISS space station crew are ruled out, this someone must have been on Earth
That's why I'm turning to you. Planes are frequently flying 10km or higher, much higher than any mountain on Earth, and passengers and pilots are therefore higher up than any people on the ground.
There are some rather delicate restrictions:

The aircraft must have been very close to 10° 08' north. There's a quickly growing altitude penalty for being far from this..

The aircraft must have been at this latitude at local solar midnight

The longitude is not overly important. For the western hemisphere, the date is August 26/27, for the Eastern hemisphere, it's August 27/28. Africa can be either, but has a 700m altitude penalty be default.



Is night-time air traffic dense enough for this place to exist?
From initial research, busy airports such as Singapore and Kuala Lumpur are south of this line
Yes, it is very likely that an aircraft would be near that position/time/date as there are many aircraft that fly overnight flights from North American airports to and from South American airports, between Europe and Africa, and also between Asia and Australia.
For example, Air Canada has daily night fights from a Toronto, Canada to Santiago, Chile and both the outbound flight, and return flight, would often pass each other in that very same area and time. I would often operate those flights and we would chat with the crew of the opposite flight to exchange reports on flight conditions.
There are MANY other airlines with similar north-south routes operating overnight flights all over the world.