in den Sternen stehen

Etymology
lit. 'to be written in the stars'.

Verb

 * 1) to be in the stars, in store, preordained; to happen in the future
 * 2) to be uncertain, unpredictable
 * 1) to be uncertain, unpredictable

Usage notes

 * The second sense is by far the commoner of the two.
 * Only the auxiliary is used in northern and central Germany. In southern Germany, Austria, and Switzerland,  is common in the vernacular and also, alternatively, in standard usage.