A comet that hit the headlines when a European probe landed on its surface in November is becoming unexpectedly active, scientists have discovered.
Comet 67P/Churyumov-Gerasimenko (67P) is showing signs of waking up early as it streaks towards the Sun at almost 47,800 mph.
As it approaches the Sun, the rubber duck-shaped lump of ice, dust and rock is expected to heat up and release more gas and water vapour.
Comets are most active when they reach perihelion, the point in their orbit when they are closest to the Sun.
But even at a distance of more than 200 million miles, comet 67P is beginning to stir in dramatic fashion.
Dr Dennis Bodewits, from the University of Maryland, who led one of several teams reporting latest findings from the Rosetta mission in the journal Science, said: "Jets are sprouting up everywhere. We've been surprised to see how active it is."
History was made on November 12 when the probe Philae made a touch-down on the comet's surface, more than 300 million miles from Earth.
The lander ended up resting in the shadow of a nearby cliff or crater wall. After managing to send back a stream of data, it lost battery power.
Scientists hope to revive the probe once the comet gets closer to the Sun. But what effect the comet's increasing activity might have on the fragile craft remains to be seen.