How Soon Is Too Late?
 

How much warning will we need if astronomers find an asteroid on a collision course with earth?

        4 min, 46 sec?... Asteroid 2004MN4 *

                         9½ hours?... Asteroid 2004 XP14

                                      1½ days?... No time for the Oval Office to react

                                                    3 weeks or 11 months?... A scary list of warnings

                                                                   20 years or more?... Asteroid XF17 **

If we are to stand a fair chance of intercepting an incoming asteroid, we need at least a couple of decades' warning.

Back in 1999 Professor Tom Gehrels of Spaceguard was asked if the XF17 scheduled for 2028 could have been stopped were it on an impact path.
"Maybe, with luck," was his reply. That means that even with three decades at their disposal scientists would have been hard
pressed to save our plant from an incoming giant meteor.

.

Apart from the fact that all our asteroid defence systems have yet to leave the drawing board, scientists will need considerable time to reach

 the asteroid. So, it's not just a question of finding near-Earth objects (NEOs), but they must be found decades before they are due. 

The longer we wait, the less time there is going to be "When" it happens. It's a short question with long-term implications, 

as yet unanswered purely because of lack of funding. Governments are doing comparatively little,

and astronomers need support from the private sector ... us. 

Join us—together we can beat the odds.

If we learned anything from the Asian tsunami, 

it must be that authorities who deem 

phenomenal events improbable

can get it wrong!

* Although the MN4 will miss by minutes in 2029, it is doubtful we 
could stop it were it on course.                                                 

** Another confirmed future near miss, this asteroid is still over two 
  decades away; anything sooner is too soon for comfort.