The title is "How we can mine asteroids for space food" not "We can mine asteroids for space food." This seems like a pretty major difference to me on a site that suggests against editorializing titles.
That's not OP's fault. In spite of the policy saying you should use original titles, HN automatically strips leading words like "How..." or "Why..." from those titles, because the moderators consider such words clickbaity.
Same with leading numbers, e.g. "10 Ways to Do X" automatically becomes "Ways to Do X".