This July, Christian Marois, a young astrophysicist with Canada's National Research Council, was on a plane over the Pacific poring over telescopic images of the star HR 8799 – an unremarkable pinprick in the Pegasus constellation – when things suddenly fell into focus.

And for the first time in the history of creation, a creature on a planet in our solar system was looking at an image of planets orbiting in another. The discovery was released yesterday in the journal Science.

Circling HR 8799, 128 light-years (that's 128 x 9.5 trillion kilometres) from Earth, the planetary trio is between seven and 10 times the mass of Jupiter.

Getting the images was no easy task. "We had to look at a lot of stars in order to be able to see these," says Marois, whose planetary quest began eight years ago.