Rail passengers using high-speed domestic trains from Kent to London can see a giant new art work at St Pancras International.

Cloud:Meteoros is an enormous piece of public art which is unveiled today. (18) It is designed by celebrated sculptor and British-born artist Lucy Orta and her husband Jorge, and will be suspended above the vast Grand Terrace. It joins two iconic statues in the station - The Lovers and John Betjeman. It is 15m wide, 3m high and 3m deep and fills the space taken up last year with the five Olympic rings.

Inspired by the history and grandeur of the station, the Ortas have designed Cloud: Meteoros to unite people inside the station with the world outside. The cloud will hover above the buzz of visitors to St Pancras with figures gently resting on top who echo the passengers waiting on the platforms below.

The artists visualised a Greek Agora – a meeting place – when they conceived the concept of the figures gathering together on the cloud.

The work was commissioned by HS1 Ltd, owner of St Pancras International and the railway between London, Ebbsfleet, Ashford and the Channel Tunnel. Nicola Shaw, chief executive, said: “The team at HS1 is delighted with the Ortas’ response to the brief and we hope that the visitors to the station and to London will find time to look up and enjoy the work.”

Broadcaster Evan Davis was one of the judges who chose the piece. “St Pancras is an intimidating space to fill so it has been fascinating to see how the shortlisted artists responded to the challenge in divergent and imaginative ways.

“Lucy and Jorge Orta’s work stood out for its ambition and for its ability to stand out against the architecture. Passengers may feel they’ve seen enough cloud this year, but I hope these ones will inspire them and get everyone looking upwards as they use the station.”

The work will be displayed until the autumn, with further pieces promised in 2014 and 2015.