Spacecraft begins seven-year mission to asteroid … to collect a bag of dust

A rocket on an ambitious mission to collect dust from an asteroid and return it to Earth for scientific analysis has blasted off from Cape Canaveral in Florida. Nasa’s Osiris-REx spacecraft was beginning a 23-month journey to reach Bennu, a 500m-wide asteroid which scientists believe contains perfectly preserved material from 4.5bn years ago when the solar system was formed. The spacecraft will spend two years scanning the surface of the asteroid gathering data. Then, in July 2020, it will descend at a speed of less than 10cm a second towards the surface where it will land briefly to collect dust and rock from the surface.

We are going to asteroid Bennu because it’s a time capsule from the earlier stages of solar system formation, back when our planetary system was spread across as dust grains in a swirling cloud around our growing proto star.

Prof Dante Lauretta, the mission’s principle investigator

Nasa scientists are hoping the nearly $1bn mission will help them unravel how life began on Earth, how the solar system formed and how to protect our planet from stray asteroids such as Bennu. They believe it contains carbon forming molecules which may be the key to life but have long since been erased from Earth. NASA also wants to understand the effects of the sun’s heat on the asteroid’s orbit. In 2035, Bennu is due to pass the Earth closer than the moon. But the combination of the heat effect and the Earth’s gravitational pull means there is a one in 2,700 chance that it will smash into the planet 150 or so years later, creating a crater 5km wide and 500m deep.

Those carbon-forming molecules are really important ingredients for what many scientists believe could be the building blocks, the origins for life on our planet and perhaps other worlds.

Dr Jim Garvin, chief scientist at the NASA Goddard Space Flight Centre

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