Why does Meteor use node.js 4.8.2 while the latest version of node.js is 7.7.3?
$ node --version
v7.7.3
$ meteor node --version
v4.8.2
update: According to the PR for Meteor 1.6 , it will pack Node v8.
Because Meteor is a big framework and is hard to keep such a big framework stable and up to date with Node.
As Meteor 1.5 has been just released, it is developed on Node v4.
According to Ben from the MDG, the bundled version of Node for Meteor will be updated to the next LTS (Node v6) on the next Meteor 1.6 release.
The plan for Meteor 1.6 is simple: upgrade Meteor from Node 4 to Node 6, now that Node 4 no longer enjoys long-term support (LTS), and Node 6 is the official stable version. Much of this work has already happened in parallel with Meteor 1.5, so we anticipate a much shorter release cycle for Meteor 1.6. Please see this pull request if you want to get involved, as your help will surely speed that effort along.