Astronomers take clearest ever photo of new planets being born

The clearest ever photo of new planets being formed around a star has been captured by the ALMA telescope in Chile.

Astronomers say the image reveals "extraordinarily fine detail that has never been seen before" and represents an "enormous step forward in the understanding of how protoplanetary discs develop".

The HL-Tauri Sun-like star is located approximately 450 light-years from Earth and is estimated to be around one million years old.

When we first saw this image we were astounded at the spectacular level of detail.

HL Tauri is no more than a million years old, yet already its disc appears to be full of forming planets. This one image alone will revolutionize theories of planet formation.

• Catherine Vlahakis, ALMA Deputy Program Scientist

Such a high-resolution image was only made possible using ALMA's long baseline capabilities, in what is the largest astronomical project in the world, based in Chile's Atacama desert.

Because the planets are formed in a cloud of gas and dust, the ALMA observatory uses antennas up to 15km apart which can pick up signals of much longer wavelengths than the visible light emitted.

The logistics and infrastructure required to place antennas at such distant locations required an unprecedented coordinated effort for the international expert team of engineers and scientists.

• Pierre Cox, ALMA Director

ALMA explains that the planets form within clouds of gas and dust that collapse under gravity. Over time, the surrounding dust particles stick together, growing into sand, pebbles, and larger-size rocks, which eventually settle into a thin disc where asteroids, comets, and planets.

More: This is the brightest dead star ever found