Saturday, July 18, 2026

The Grand Tack, or not

Kyplanet is pulling up Franklin et al. ... from 2004. Franklin's team suggested that Jupiter captured the Hilda asteroids (those 3:2's) on a tack of 0.45 AU inward. This is a problem for the Grand Tack which predicts a much longer inward migration, pulled back by Saturn. Zheng et al. also dispute the grandness of any tack. D'Angelo and Marzari in 2012 questioned if Saturn had that force if Jupiter ever wandered within 4 AU of the nascent Sun.

At least Franklin as a 2004 paper is vulnerable to later data, especially since we've now been visiting the Jovian-region 'stroids. Vokrouhlický et al. want to know how the slow-short-tack theory of Franklin's team can account for the dispersed ...distribution of Hilda inclinations. Overall that 2004 paper is treated as a minority-report (although not yet refuted).

More trouble for Grand Tack might be that it doesn't actually explain what it was supposed to explain, namely Mars' tiny mass. Other constraints we don't got include whatever other large bodies were in this system and might have been yeeted.

No comments:

Post a Comment