Asteroid TC4 Earth capture

[Owmuchonomy]

Based on the recent 'graze' of TC4 is there anybody that can answer if it would be possible for Earth to capture such an object.  I did do a course whereby we calculated this for Sun grazing comets but I have forgotten how to do it. Is it a matter of distance from Earth and the kinetic energy of the asteroid? Escape velocity? I would be very interested in seeing the working. How close would such an object need to graze us?

[Starlight 1]

I was reading a report last night, it said its about the size of a house and the next 2 dates as to coming around again, the next date will pass Earth but the last date will not. Going to saying it be like the last one was it in 2013.

[furrysocks2]

https://en.wikipedia.org/wiki/Asteroid_capture

Interesting to see this worked through with specific distance and mass. And how it differs for Jupiter which has clearly saved us from a few in the past!

[furrysocks2]

Starting to pick at this over a coffee... found two graphics to start with:

Source: http://www.telegraph.co.uk/news/0/asteroid-2012-tc4-pass-damn-close-earth-tomorrow-give-rare-chance/

Each time it has come round, the orbit changes due to the graze with earth, but it's still orbiting the sun, not us.

 

From the same article:

Quote

 4.5 miles a second... 27,000 miles 

 

From https://en.wikipedia.org/wiki/Escape_velocity:

Quote

On the surface of the Earth, the escape velocity is about 11.2 km/s ... at 9,000 km altitude in "space", it is slightly less than 7.1 km/s.

4.5 miles/second happens to be very close to 7.1 km/s, so if it had passed just under 9km, its velocity would have been < escape velocity at that height and we'd have nabbed it...? Don't know if that's right or how to do the maths, but interesting to be able to calculate the change in orbit due to such a graze.

 

 

[Star101]

Most important calculation is....will it eventually hit us!! 

[furrysocks2]

The moon seems to affect it each time round as well, crazy that they can forecast anything given how much orbits change due to gravity of planets, their moons, Yarkovsky effect, etc.

https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2012TC4;cad=1;orb=1