Is it alright to ask a question and provide a possible if highly hypothetical speculative suggestion?mfb said:101955 Bennu is a near Earth asteroid, and quite a prominent one: it has a 0.04% probability to hit Earth in the 22nd century, and 10% chance to hit it within the next millions of years.
As comparison: an impact of an asteroid as large as Bennu happens on average every ~100,000 years, which corresponds to a 0.1% chance of such an impact per century.
It was chosen as target for the mission because it is easy to access and because a better understanding of it helps to predict its future orbit and also future orbits of similar objects.
The claim in Wiki is different.TEFLing said:Spinning up tells me the object is gravitationally differentiating. With higher density material, sinking towards the center. Pushing lower density material towards the surface.
No, it is many orders of magnitude too small for that.TEFLing said:Spinning up tells me the object is gravitationally differentiating.
so, plausibly, solar radiative heating also underlies the particle emissions?jbriggs444 said:The claim in Wiki is different.
https://en.wikipedia.org/wiki/101955_Bennu
"Due to the uneven emission of thermal radiation from its surface as Bennu rotates in sunlight, the rotation period of Bennu decreases by about one second every 100 years"
The listed reference for that claim is https://www.asteroidmission.org/?latest-news=nasa-mission-reveals-asteroid-big-surprises
https://www.forbes.com/sites/jamiec...-asteroid-worth-more-than-our-global-economy/Forbes - A NASA spacecraft will depart this August on a mission to explore a metal-rich asteroid called 16 Psyche—speculated to be a highly valuable object—in an effort to determine exactly what it’s made of.
It will be NASA’s first visit to a metallic asteroid, as opposed to a rocky or icy one, though it has been studied by the Hubble Space Telescope.
16 Psyche is strange. Shaped like a potato and about 140 miles in diameter, it’s more reflective than anything else in the asteroid belt between Mars and Jupiter. So bright, in fact, that it’s presumed to be composed largely of metal‚ specifically nickel, iron or gold.
Asteroid-deflection is something NASA is very interested in perfecting well in advance of aa large asteroid being spotted that’s heading straight for Earth. On October 22, 2022 NASA’s Double Asteroid Redirection Test (DART) will smash a 500kg spacecraft into binary asteroid 65803 Didymos and its moonlet Dimorphos (also called “Didymoon.”) The idea is that by creating a “kinetic deflection” on Dimorphos it will ever so slightly change the trajectory of both objects.