How is one "proper" while the other is not? The blog URL is literally in the tweet, and it's NASA's official account.
Of course if you're doing citation for your paper the later one would be better but this is "just" posting on HN. I would even go so far as to say I prefer the tweet link so I can easily retweet, and no information is lost.
Of course if you're doing citation for your paper the later one would be better but this is "just" posting on HN. I would even go so far as to say I prefer the tweet link so I can easily retweet, and no information is lost.