JavaScript does not recognize the ** exponential operator

[JB-Walker]

MDN Web Docs - JavaScript - Arithmetic operators

When this simple test function was executed in the 'Write Number in Expanded Form' kata the exponential operator was not recognized and it resulted in a syntax error:

function expandedForm(num) {
return (2 ** 3);
}

STDERR:
[eval]:8
return (2 ** 3);
.....................^ {note: dots added to correctly position caret}
SyntaxError: Unexpected token *
at createScript (vm.js:56:10)
at Object.runInThisContext (vm.js:97:10)
at Object. ([eval]-wrapper:6:22)
at
at evalScript (bootstrap_node.js:353:27)
at run (bootstrap_node.js:122:11)
at run (bootstrap_node.js:389:7)
at startup (bootstrap_node.js:121:9)
at bootstrap_node.js:504:3

[kazk]

Node 6.x doesn't support exponentiation operator. See node.green ES2016-features.

Select "Node v6.11.0/Babel" or "Node v8.1.3" to use it.