Pluto may have a polar cap of nitrogen ices. This is the tantalising prospect revealed in the latest images to come down from the New Horizons spacecraft.

After a decade in space and four years in orbit, Nasa's Messenger spacecraft will end its mission on Thursday by crashing into the surface of Mercury.

Blue Origin, the US space company set up by Amazon entrepreneur Jeff Bezos, says it has conducted the first test flight of a new sub-orbital vehicle, reaching an altitude of 93km.

Modifying the DNA of embryos is a "line that should not be crossed" and poses serious safety and ethical issues, a leading figure in US research says.

One in six species on the planet could face extinction due to the effects of climate change if nothing is done to reduce emissions, according to analysis.

After a decade in space and four years in orbit, Nasa's Messenger spacecraft reaches the end of its mission and crashes into the surface of Mercury.