[c#] Await operator can only be used within an Async method

I'm trying to make a simple program to test the new .NET async functionality within Visual Studio 2012. I generally use BackgroundWorkers to run time-consuming code asynchronously, but sometimes it seems like a hassle for a relatively simple (but expensive) operation. The new async modifier looks like it would be great to use, but unfortunately I just can't seem to get a simple test going.

Here's my code, in a C# console application:

static void Main(string[] args)
{
    string MarsResponse = await QueryRover();
    Console.WriteLine("Waiting for response from Mars...");
    Console.WriteLine(MarsResponse);
    Console.Read();
}

public static async Task<string> QueryRover()
{
    await Task.Delay(5000);
    return "Doin' good!";
}

I checked out some examples on MSDN and it looks to me like this code should be working, but instead I'm getting a build error on the line containing "await QueryRover();" Am I going crazy or is something fishy happening?