Astronomers have issued the "all-clear" about asteroid 2003 QQ47, suspected by some to be on a possible collision course with the Earth in just 11 years.
By Dr David
BBC News Online science
If it were to have hit, the 1.2 kilometre-wide (0.75 mile) rock would have caused widespread damage and global climate change.
We're all doomed...or are we?
But new data indicates the Earth will be safe on 21 March 2014. In fact, it always was.
Asteroid 2003 QQ47 will be elsewhere in the Solar System, moving on an orbit that will be watched by astronomers just in case it becomes worrisome again, but that is highly unlikely.
The scare started with a press release from the relatively newly established Near Earth Object Information Centre (NEOIC). Funded with UK Government money, it is based at the National Space Centre.
The NEOIC said that an object had just been found that might pose a small risk of colliding with us. It was rated as Torino Scale 1, "deserves
It also said that any threat was likely to evaporate soon.
Many astronomers were unimpressed. They pointed out that Torino Scale 1 objects are found every few weeks.
And since new objects were often given an initial classification of T1, in the absence of information, it would certainly be reduced to T0, "no significance", as more data came in, they explained.
The headlines about Doomsday were predictable; the date of 21 March 2014 became stuck in people's minds, some astronomers moaned about an "own goal", and the media declined to mention the all-clear when it came a day later.
If you think you have heard this type of thing before you are right.
Perennially hazardous asteroids
Asteroid flaps are becoming as regular as the first cuckoo in Spring. We get about one a year.
In 1998, there was 1997 XF11 due to strike in October 2028. It showed,
unsurprisingly, that different groups of astronomers disagreed about the
(low) chances of it striking us. With new observations the risk went away.
There was 1999 AN10. This taught astronomers a lot about how not to release their information about potentially hazardous objects to the public.
So, astronomers revised their rules for releasing information to the public.
The new millennium brought 2000 SG344, a very small object, which might even be a spent rocket upper stage.
At one point, astronomers claimed that it had a 1 in 500 chance of striking the Earth, so media attention was immediate and justified. But within hours new calculations showed no impact was possible, and astronomers looked a little foolish.
The rules were changed, again.
Roll on 2002 and 2002 MN, a small asteroid that whizzed by at about a third of the Earth-Moon distance - quite close really.
Because this happened without astronomers realising it until after the event, some in the media suggested they had egg on their faces in not providing any warning.
The scientists replied, slightly off the point, that it did not matter as
2002 MN did not pose any danger anyway.
And then there was 2002 NT7.
'Most threatening object'
I have regard for 2002 NT7, as far as one can for a rock that could threaten the Earth, as I broke the story and it won me an award.
It had a large diameter and was described by one expert as "the most
threatening object ever found in space". Fortunately, and as predicted in my original report, the threat receded.
Initially, astronomers said nothing about it. They were following their media rules modified after the SG 344 incident. After NT7 those rules were revised once again.
One thing is for certain. There will be another object and another date for Doomsday that will be retracted a day or so later.
And I wonder if we will soon begin to take no notice of false claims. But then what happens when the big one comes?