Our tiny corner of the Universe – the Solar System – is home to one star, nine planets, and dozens of planetary satellites. It also contains untold billions of asteroids and comets – the left-over debris from the cosmic construction site that created the planets and their moons. Rosetta's task is to study three of these primitive building blocks at close quarters so that scientists may gain new insights into the events that took place 4.6 billion years ago, during the birth of the Earth and its planetary neighbours.

Since ESA's Rosetta spacecraft arrived at Comet 67P/Churyumov-Gerasimenko on 6 August, the race has been on to find a suitable location for the lander Philae. Five candidate locations were announced on 25 August for further investigation, in order to determine possible orbital and operational strategies for Rosetta to despatch the lander to each of them. By 14 September, the five candidate sites will have been assessed and ranked, leading to the selection of a primary landing site and a backup. The final two sites, along with their operational challenges and scientific expectations, will be presented during the briefing on 15 September.Watch live as the target for Rosetta's lander is announced at ESA Headquarters on 15 September, streaming starts at 0900 GMT / 1100 CEST.

As Rosetta began homing in on Comet 67P/Churyumov–Gerasimenko in the weeks leading up to its arrival in August 2014, it became very clear that this was no ordinary comet. But its striking shape was only just the beginning of the comet’s surprises. After more than two years spent living with the comet, Rosetta scientists reflect on some of the mission’s unexpected discoveries, the mysteries solved and the new questions raised.

Why is the mission ending?The decision to end the mission on 30 September ultimately comes as a result of the spacecraft’s ever-increasing distance from the Sun. Comet 67P/C-G, and therefore Rosetta, is currently heading out towards the orbit of Jupiter, resulting in significantly reduced solar power with which to operate the craft and its instruments. In addition, by early October, the teams would be faced with a month-long solar conjunction – when the Sun lies between the Earth and Rosetta and the comet. This would result in significantly reduced communication capabilities (including downlinking science data) for around a month. Combined with an ageing spacecraft and payload that have endured the harsh environment of space for over 12 years – not least two years close to a dusty comet – this means that Rosetta is reaching the end of its natural life and so 30 September was considered the optimum date to conclude the mission.

Rosetta and Philae at comet

Why is Mars red?

Rosetta and beyond: Patrick Martin

Rosetta and beyond: Claire Vallat

Rosetta's first fly-byof Earth on 4 March 2005.

Achievements during 2010