JWST detects carbon dioxide in alien planet's atmosphere for first time

I understand that they have seen some carbon and some oxygen using spectre. But how they decided that was dioxide?

Not only they can decide presence of carbon dioxide, it is a matter of further analysis to determine the exo-planet’s atmospheric pressure too.

https://wiki.anton-paar.com/us-en/infrared-spectrum-of-carbo...

That's interesting, I would like to know how many molecules of carbon dioxide did scientists observe on the planet.

is this a first for JWST or a first for all exoplanet observations?

Why call it an "alien" planet? There tens of trillions planets with no humans on them, and just one with humans. It's no more alien than any other.

(The answer is clickbait)

Here's the alternative you are suggesting:

> JWST detects carbon dioxide in planet's atmosphere

That's ambiguous. It could be correctly read as "in planet Earth's atmosphere".

There isn't anything deceptive about the word "alien", either. It's an alien planet. It's a place that isn't inhabited by us: the original definition of the word.