Asteroid Bennu is old before its time thanks to the sun

I note here info from the paper used.

Reference, Alignment of fractures on Bennu’s boulders indicative of rapid asteroid surface evolution,, published 23-May-2022.

On asteroids, fractures develop due to stresses driven by diurnal temperature variations at spatial scales ranging from sub-millimetres to metres. However, the timescales of such rock fracturing by thermal fatigue are poorly constrained by observations. Here we analyse images of the asteroid (101955) Bennu obtained by the Origins, Spectral Interpretation, Resource Identification and Security-Regolith Explorer (OSIRIS-REx) mission and show that metre-scale fractures on the boulders exposed at the surface have a preferential meridional orientation, consistent with cracking induced by diurnal temperature variations. Using an analytical model of fracture propagation, we suggest that fractures the length of those on Bennu’s boulders can be produced in 10^4–10^5 years. This is a comparable or shorter timescale than mass movement processes that act to expose fresh surfaces and reorient boulders and any preferential direction signature. We propose that boulder surface fracturing happens rapidly compared with the lifetime in near-Earth space of Bennu and other carbonaceous asteroids. The damage due to this space-weathering process has consequences for the material properties of these asteroids, with implications for the preservation of the primordial signature acquired during the accretional phases in the protoplanetary disk of our solar system."

My note. The abstract and report presents indications of a young surface on Bennu with some aging taking place in 10^4 to 10^5 years. I note that the long age paradigm (meteorite dating going back to Clair Patterson in mid-50s) must be maintained. Note, "...the primordial signature acquired during the accretional phases in the protoplanetary disk of our solar system."

The postulated protoplanetary disk is dated some 4.5 or 4.6 Gyr ago, not observable in the solar system today. The inventory of *young stars* showing disks/discs with a wide variety of sizes (diameters in AU, masses in earth masses for total dust and gas), differ substantially than the one solar mass, MMSN used in protoplanetary disc modeling for our solar system, and thus Bennu interpretation. A good, concise and complete catalogue is lacking (unlike the exoplanet sites). Here is a partial list I use, Catalog of Circumstellar Disks

Interesting, just published another report on Jupiter's ring system and at least some parts cannot be older than 10^7 years old,