Comet chaser makes Earth swing-by

The spacecraft has swung past Earth three times

A European space probe has swung by the Earth to gather energy to chase down and land on a distant comet.

The unmanned Rosetta craft made its closest approach to the planet at 20:57 GMT on Tuesday at a distance of 5,301km above the Pacific Ocean.

The spacecraft was using the Earth's gravity to give it the boost it needs to reach its final destination in 2014.

During the pass, Rosetta attempted to measure light reflected from the Moon and look for shooting stars.

It also observed the magnetosphere - the area of space that is controlled by the Earth's magnetic field.

Rosetta's flight takes it around the Sun four times, Mars once and the Earth three times, before hurtling out towards Jupiter.

The probe must harness the gravitational forces of the planets to build up the speed it needs to chase down and catch the comet.

Warning alert

Tuesday's swing-by was the second close encounter with Earth. It has already had an unexpected effect.

Last week, astronomers issued an alert after an unidentified object was spotted heading towards the Earth. The warning was later retracted when they realised the object was Rosetta.

Rosetta is on a 10-year voyage to the Churyumov-Gerasimenko Comet out near Jupiter. It is due to reach the comet's orbit in 2014 and send a lander to the surface to study its chemistry.