Astronomy Question:

No one can say no in answer to this, because we do not know what else is out there.

However, it seems likely that due to its chemical properties that life elsewhere would need to be based on carbon if it was of any size, although we cannot say for sure.

There are not that many elements that seem to have the flexibility that carbon does, the stability and abundance... however it is possible that something like silicon could perhaps be a candidate for life forms elsewhere; for very simple life forms there might be a larger range of candidate elements.