This is the 12028th most frequent Korean word.
놀랄
"놀랄" means "surprising" or "to be surprised" in English.
In this sentence, '놀랄' is used to describe an adjective phrase '놀랄 만한', meaning 'surprising', which qualifies the noun '소식' (news).
그의 놀랄 만한 소식을 들었어요.
I heard his surprising news.
Here, '놀랄' is connected to '정도로' to express the degree of surprise or amazement at the beauty of the scenery.
그 경치가 정말 놀랄 정도로 아름다웠어요.
The scenery was truly beautiful to a shocking degree.
In this case, '놀랄' is used in the expression '놀랄 것 없이,' which negates the surprise, implying calmness or being expected.