A lot of astronomy is powered by Python right now, for many good reasons. However, if you're curious about other modern programming languages, Rust might be a great one to read about.
Armin Ronacher just wrote Rust for Python Programmers, which I think might be an interesting read for the astronomy pythonistas here.
At the end, he writes:
Because Rust requires very little runtime support it's very easy to use via ctypes and CFFI with Python. I could very well envision a future where there is a Python package that would allow the distribution of a binary module written in Rust and callable from Python without any extra work from the developer needed.
It'll be interesting to see if, in time, Rust can become an alternative to C and Cython for writing fast science code that can be comfortably called from Python. (Alternatively, Rust might work well for separately building computing infrastructure in the [giant air quotes] Big Data era).
Another language to look at is Julia, but unlike Rust or Go, Julia is aimed specifically at the data science domain.