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.
More top news
Some trusts are not charging overseas patients despite them not being entitled to free treatment, a new report has revealed.
The vice presidential candidate was travelling with his wife, daughter and several campaign advisers, but no one was injured.
They deny a 'sweetheart deal' - but a senior source told ITV News the government promised to support such firms in the event of Brexit.