In those two cases scientific notation may not be very helpful. But consider that astronomers could very easily be comparing them to many other numbers with a h

In those two cases scientific notation may not be very helpful. But consider that astronomers could very easily be comparing them to many other numbers with a huge range of magnitude, and it makes sense to just use it everywhere. Also scientific notation conveys the real precision where just "1000" could mean "1000 +-1” or "1000 +-1000", which by itself can be even more important than any other reason.