When a planetary system forms, the chances that a planet capable of supporting life will be formed are high. ███ ███████ ████ █ █████ ██████ ███ ████ ██ ███████ ██ ██████ ████ ██ ███████ ████████ ███ ████ ███████ ███████ ███ ███████ █████ █████████████ ██████ ████ █████████ █████ ████ █████ ██████████ ██████ ██ █████ ███████ ███████████ ████ █████ █████ ████ ██████ ██ ██████ █████ █████████ ███████ ███ ████████ ██ ███████ ███ █████ ████████ ███ ███████ ████ ███████████ ████ ████ ██████ ██ █ ██████ ████ ██████████ ████
The author concludes that the chances that intelligent life will emerge on a given planet are low. This is because planetary systems generally lack large planets, which protected Earth from large comets before life on Earth eventually arose.
The author assumes that other planets, like Earth, need to be protected from large comets by large planets in order for life to emerge. To evaluate this argument, it would be good to have information that would show whether this assumption is valid or not.
Knowing which one of the █████████ █████ ██ ████ ██████ ██ ██████████ ███ █████████
whether all planetary ███████ ███ ██████ ████ ███████ ███████ ██ ██████
We’re not interested in the amount of matter in a given planetary system. We want to know more about the danger of large comets striking planets capable of supporting life, and whether large planets are necessary to deflect such comets.
whether intelligent species █████ ██ ██████ ██ ███████ ██ █ █████ ██████ █████ ██████
We're not interested in what happens after intelligent life emerges. We're interested in the conditions that allow it to emerge in the first place.
whether large comets █████ ██ █████████ ██ ████ ███ █████ ██████ ██████ ████ ██ ███
Even if one large planet would suffice, the author claims most planetary systems are unlikely to have any large planets at all. This information wouldn't help us evaluate the author’s argument.
how high the ███████ ███ ████ █████████ ███████ ████ ███████ ████ █████ ██████
This would help us evaluate the author's argument. If virtually every planetary system contained many large comets, the author’s argument would be strengthened: without large planets to deflect those comets from planets that could support life, the chances of life emerging are low. If most planetary systems had no large comets, on the other hand, then there would be no need for large planets to protect smaller planets capable of producing intelligent life.
how likely it ██ ████ █████████ ███████ ██████████ █████ ███████ ████ ████ ███████ ███████ ███ ████ ██ █████
The author never claims Earth is the only size of planet that can produce intelligent life. What we're interested in is the claim that since most planetary systems are unlikely to have large planets, intelligent life is unlikely to emerge in those systems.