Trail runs cold for hypothetical world

[GoodTaste]

I understand "Trail runs cold for hypothetical world" as Hypothetical world is scarcely supported by evidence" - Am I on the right track? What does "trail runs cold" mean?

If a trail was run by many people, it would be a hot trail. If no one ran on it, it becomes cold. Hence, "Trail runs cold for hypothetical world" would refer to "the hypothesis is less supported by people." I am not very sure.

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No sign of Planet Nine? Trail runs cold for hypothetical world
Analysis of three astronomical surveys provides some of the best evidence yet against the existence of a giant planet at the fringes of the Solar System.

Source: Nature https://www.nature.com/articles/d41586-021-00456-7

 

[tedmc]

The hypothesis is about the existence of a nineth planet. There is not enough evidence to support it but more evidence has been found from astronomical surveys to counter it. Thus the pursuit/trail runs of the hypothesis is said to have turned cold.

 

[emsr2d2]

... the existence of a [STRIKE]nineth[/STRIKE] ninth planet.

emsr2d2

 

[jutfrank]

You're noticing a new idiom here. You might try consulting some dictionaries for some more examples:

In Macmillan, it's listed as: someone’s trail​/​scent has gone cold
In Merriam-Webster, it's listed as: trail goes cold

I believe that there's an extra meaning, in reference to the "icy objects". If that wasn't an intentional association on the writer's part, I'm sure he would be very happy with it nonetheless.