There are also many new devices for detecting extrasolar planets.

In 2006, LBT , The Large Binocular Telescope, started looking for Jupiters. The dual mirrors of LBT, peering into space side by side, will phase starlight. This is called ‘Nulling Interferometry’.

This process relies on the fact that light waves have crests and troughs, just like waves of water. By precisely aligning the light waves gathered by two mirrors from a particular point in the sky, astronomers can overlap the wave crests from one mirror with the troughs from the other so that the light simply cancels itself out ( noise-cancelling headphones use the same principle to deaden sound waves; with light, the result is a patch of darkness ).

This procedure can blot out the light of a star so that a giant planet, hundreds of thousands of times fainter, can be directly seen, as opposed to being detected by star wobbles or dimmed starlight.

To be visible to an Earthbound telescope, an alien Jupiter would have to be several times bigger or much younger. ( Still warm from its violent birth, a younger Jupiter would glow in infrared light ). Devices like LBT, operating in orbit, are able to see much more without the interference of the Earth’s atmosphere.

That sensitivity is important in finding another planet of this Earth’s proportions, as, in relation to the extrasolar planets so far found, it would exert only a feeble tug on its star.