European probe makes historic landing on comet

Scientists have successfully dropped a lander onto the surface of a comet in one of the most astonishingly difficult space missions since humans landed on the moon.

The European Space Agency's Rosetta mission involved a 10-year half billion kilometre journey after a launch in 2004 with the goal of catching up with, orbiting and then softly landing the Philae lander onto Comet 67P/Churyumov-Gerasimenko .

The Lander Control Centre in Cologne, Germany confirmed Philae's soft landing just after 3.30pm Irish time today (wednesday) and began communicating back to Earth via the Rosetta satellite in orbit above the comet.

The overall goal is to have Rosetta and Philae in place to watch the comet begin firing off jets of gas and dust to form a tail as it heats while hurling towards the sun at an incredible 37km a second.

The landing has not all gone ESA’s way however.

Philae must attach itself to the comet using two harpoons to prevent being blown off by surface jets. Early tests showed however that these did not fire into the surface on Philae’s landing, according to a spokesman from the Lander Control Centre.

A small rocket pack on its back also failed to ignite, meant to help press big screws on Philae’s feet into the surface and stop it bouncing during touchdown.

It landed in one piece however and controllers hope they can overcome these problems in the coming days. Importantly, its communications are intact and it can begin sending pictures and data back on the comet and its secrets.

Scientist are hugely interested in comets given they are the unused leftovers when the solar system formed.

Often referred to as “dirty snowballs”, bombarding comets may have delivered millions of square kilometres of water as ice to the earth as it formed billions of years ago. And they are rich in the organic chemicals that could have helped life form on the young planet.

Ireland shared in the success of the Rosetta mission, said Prof Tom Ray of the Dublin Institute for Advanced Studies.

“This is a fantastic achievement by ESA and Ireland, as a member of ESA, can be very proud of what has been done. I am also very excited by the thought that we have now landed on a basic building block of the Solar System and this will help us understand how the Earth and other planets formed nearly 5 billion years ago,” he said.

"The questions Philae will now investigate are profound in that they will help determine the origin or water and organic material in our Solar System and on Earth," said Kevin Nolan, coordinator to Ireland for The Planetary Society. "The answers to come constitute completely new and unprecedented knowledge and will radically alter our understanding of natural origins, both within in our Solar System and potentially universally," he said.