The phrase "astonishingly powerful" is correct and usable in written English.
It can be used to describe something that has an impressive or surprising level of strength or effectiveness.
Example: "The new software is astonishingly powerful, capable of processing data at unprecedented speeds."
Alternatives: "incredibly strong" or "remarkably potent."
The Pi is a very small, very cheap computer that is astonishingly powerful.
Television remains an astonishingly powerful medium – nothing comes close to its ability to communicate and sell things.
Toward the end of this astonishingly powerful novel Hattie attends a church service in which the pastor delivers a sermon on the Book of Job.
I then followed his forums and blogging on Safari Talk, and that's where I stumbled on the astonishingly powerful elephant portraits, and conservation work, of Nick Brandt.
But for a 1.0 app, created in the space of only a few months, Google Maps for iPhone is an astonishingly powerful, accurate, beautiful tool.
It's an open, accessible, involving tradition that now feeds into many of our programmes - from Norma Percy's The Death Of Yugoslavia to Peter Taylor's astonishingly powerful and redemptive Loyalists.
A tower-mounted news camera in Tuscaloosa captured images of an astonishingly thick, powerful tornado flinging debris as it leveled neighborhoods.
He found an astonishingly potent anti-HIV activity.
She introduces us to Bonajuto; the almost hidden store offers the finest Modican chocolate: curiously granular, fat-free, made to the original Aztec recipe and flavoured with vanilla, cinnamon or chilli – astonishingly pure and powerful.
And while there is no straightforward answer to why writers drink, Laing explores the causes in admirable detail and astonishingly good prose – incisive, powerful, illuminating – that rivals the output of the authors she is writing about.
Within this astonishingly complex human development process, God has provided a remarkably powerful instrument by which humans can exercise some control over their own formation.
