nodejs能够监听80端口吗？

我是一个刚刚接触nodejs的菜鸟，今天在学着写一个程序的时候

var http = require("http");
var url = require("url");
function start(){
	console.log("call the start");
	function onRequest(request,response){
		console.log("call the onRequest function");
		response.writeHead(200,{"Content-type":"text/plain"});
		response.write("aa");
		response.end();
	}
	http.createServer(onRequest).listen(80);
	console.log("Server has started.");
}
exports.start = start;

发现会控制台会报错

call the start
Server has started.

events.js:66
        throw arguments[1]; // Unhandled 'error' event
                       ^
Error: listen EACCES
    at errnoException (net.js:768:11)
    at Server._listen2 (net.js:891:19)
    at listen (net.js:935:10)
    at Server.listen (net.js:984:5)
    at Object.start (/home/xing/ANodeJsWebSite/node/server.js:11:31)
    at Object.<anonymous> (/home/xing/ANodeJsWebSite/node/index.js:2:8)
    at Module._compile (module.js:449:26)
    at Object.Module._extensions..js (module.js:467:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)

而把listen的端口改成8888之后就可以成功运行了。 想请问一下各位大侠，这是为什么