The probe should hit Dimorphos at 22,000 kilometers per hour. Its purpose is not to blow up the entire moon, but to push it out of orbit. This is expected to happen on Monday at around 1.15pm (Netherlands time).
The impact is likely to change the moon’s orbital period, which is usually 11 hours and 45 minutes, by 10 minutes. In cosmological terms, this is only a small push. But a slight change in course could cause a future asteroid to pass Earth on a collision course.