What we’re waiting for: The spike in the middle will tell us Rosetta’s awake!  This screenshot from NASA/JPL simulates the ground station spectrum analyser display expected to be seen later today (for real!) when Rosetta sends its radio shout 807 million km across our Solar System to Earth.

What we're waiting for: The spike in the middle will tell us Rosetta's awake. Credit: NASA

What we’re waiting for: The spike in the middle will tell us Rosetta’s awake. Credit: NASA

And for keen radio engineers out there, this is how the plot will look once Rosetta starts sending telemetry (data), expected about 2 hours after receipt of signal (AOS).