That makes the moon informally known as Valetudo an interesting target for further observation, as it gives astronomers an opportunity to potentially watch these potential collisions play out in the coming decades.
Potential collisions pop up dozens of times in an air traffic controller's shift.
One apparently abstract piece is called "Drawing of a Printout of a Superimposition of a Flight of Birds Upon Itself, Inverted To Determine the Range of Potential Collisions".
The device's champions saw it as an environmentally friendly way to ease traffic as well as to increase productivity, but detractors warned of potential collisions and injuries.
Although some organisations collect and analyse data on potential collisions, they are not always precise and there are gaps in their knowledge as the recent collision has shown.
The investigation of that crash took a new and bitter turn today, when Swiss officials acknowledged that an automatic system that alerts air traffic controllers to potential collisions had been shut off for maintenance at the time of the crash.
German crash investigators said that both the DHL Boeing 757 and the Russian Tupolev Tu-154 were equipped with automated collision-avoidance systems that warn pilots about potential collisions and issue instructions for evasion maneuvers.
Mr. Schumer said that despite the busyness of the area's airports, it could be years before the new technology, which alerts air traffic controllers to potential collisions, including those on runways, is installed at all of the airports.
