How long can an asteroid 'survive'?

[Admin]

Asteroids are left over from the early solar system. Here's how they get destroyed.

How long can an asteroid 'survive'? : Read more

 

[rod]

I read this report originally on livescience.com, sister site of space.com.

My note. Asteroids that are NEO-NEAs do not last this long (440 Myr), various reports indicate perhaps 10 Myr time spans, that includes Centaurs much farther out in the solar system. However, this provides a number in the article. Min lifetime 440E+6 years, max lifetime 4E+9 years, some large asteroid lifetimes are not known so perhaps 10 Gyr is used for their max lifetimes in the solar system.

Some summary thoughts here. This brief report suggests some asteroids can last 440E+6 years, some 4E+9 years, and some large asteroids perhaps 1E+10 years in the solar system. Asteroids also have cosmic ray exposure ages for pieces returned to Earth as well as radiometric ages. This is true of meteorites too. A complete list of these different ages obtained and shown I do not see in a database for example showing all. Many asteroids said to have at least a 4 Gyr lifetime, would need to complete perhaps 1E+9 orbits around the Sun or more.

 

[rod]

"Jopek et al. (1995) integrated the orbits of 17 bolides for 1 Myr in the past. They found that half of the studied cases belonged to the ‘fast-track’ category – in the terminology coined by Froeschle et al. (1995) – in or near a secular resonance or an MMR with Jupiter, and the rest were ‘slow-track’ objects. The estimated dynamical lifetime of the asteroids was found to be less that 1 Myr.", ref - Resonant mechanisms that produce near-Sun asteroids, https://arxiv.org/abs/2304.00561, 02-April-2023. "All near-Earth asteroids (NEAs) that reach sufficiently small perihelion distances will undergo a so-called super-catastrophic disruption. The mechanisms causing such disruptions are currently unknown or, at least, undetermined."

Modeling various asteroid lifetimes in our solar system can be fun

"One of the primary goals of this study is to compute 𝜏lq, the effective dynamical small-𝑞 lifetimes of NEAs (𝑞
∗ < 𝑞 < 𝑞𝑙), classified according to the resonances they are trapped in. Gladman et al. (1997, 2000); Foschini et al. (2000) suggest that the typical dynamical lifetimes of NEAs are ∼ 10^7 yr. In particular, Gladman et al. (1997) calculated the time-scales of the half-life decay of active particles according to each resonance, and found it to be between 2-2.5 Myr for 𝜈6 and 3:1J MMR, ∼ 0.5 Myr for 5:2J and much longer for the rest 8:3J, 7:3J, 9:4J and 2:1J MMRs. Farinella et al. (1994) found that, in general, near-Sun NEAs trapped in resonances have lifetime of the order of 10^6 yr, while 3:1J MMR may drastically raise the eccentricity of an NEA in < 10^5 yr. Jopek et al. (1995) suggest that the objects they studied collided with the Sun within a few 10^5 yr,
while Foschini et al. (2000) argue that the recorded dynamical life times range from 10^5 yr to as long as > 10^7 yr."

Perhaps someday, a complete list of various dynamic ages calculated, radiometric ages reported, and younger cosmic ray exposure ages will be presented like I see for the exoplanet sites.