On 10/5/2021 11:10 PM, Andrew McDowell wrote:
> On Tuesday, October 5, 2021 at 11:54:20 PM UTC+1, Lynn McGuire wrote:
>> "'Planetary defense!' NASA will launch November mission to deflect
>> 'devastating' asteroid from hitting Earth by NUDGING it with a
>> spacecraft, agency says"
>> * NASA's mission to deflect an asteroid using a spacecraft is targeting
>> a late November launch
>> * The DART spacecraft will head towards the Didymos binary on November
>> 24 aboard a SpaceX Falcon 9 rocket
>> * It will smash into Didymoon at roughly 13,500mph on October 2, 2022
>> * Didymoon came close to Earth in 2003, coming within 3.7 million miles
>> * According to NASA, over 25,000 near-Earth objects have been discovered
>> I am sure that nothing will go wrong.
> There is a NASA podcast on this and a summary at https://www.nasa.gov/planetarydefense/dart
- they have chosen an asteroid with a smaller body orbiting it, and will crash into the smaller body, because the effect of crashing into it would otherwise be unobservable - in this setup it affects the orbit of the smaller body round the larger, making very little difference in the trajectory of either asteroid round the sun. It doesn't sound like there is much of a risk of knocking either into the earth - cut and pasted:
> The DART spacecraft will achieve the kinetic impact deflection by deliberately crashing itself into the moonlet at a speed of approximately 6.6 km/s, with the aid of an onboard camera (named DRACO) and sophisticated autonomous navigation software. The collision will change the speed of the moonlet in its orbit around the main body by a fraction of one percent, but this will change the orbital period of the moonlet by several minutes - enough to be observed and measured using telescopes on Earth.
Well, I hope that no one is living on that asteroid. Robert Heinlein's
documentary on asteroid living, "The Rolling Stones", says you need to
check things out thoroughly first.