Last night a 900 foot wide asteroid made the latest in a series of close approaches towards Earth.
There is a chance it could collide with the Earth in 2036, the biggest threat would be if it fell on land mass.
Speaking to ITV Daybreak, Dr Maggie Aderin-Pocock said if it hits a city it would cause devastation.
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A noisy, lively few hours ahead
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Breezy with bright skies limited by cloud