https://www.vice.com/en_us/article/wxjjky/scientists-discover-anomalies-deep-under-the-surface-of-mars

Scientists have found evidence of strange mass anomalies buried deep underground on Mars, according to a study based on observations captured by NASA’s InSight lander. The new research also reports a slight acceleration in the planet’s rotation and bolsters the theory that Mars lacks a solid inner core, which has implications for its past habitability. 

These latest results from InSight, which ended its mission in December 2022, open a new window into Mars’ subterranean layers, including its core and mantle, and suggest that its rotational rate may shift due to unexplained dynamics in its interior, atmosphere, or ice caps. In addition to probing the modern structure of Mars, InSight’s observations yield details about the formation and evolution of the planet over the past 4.5 billion years, which could shed light on the tantalizing question of whether it was ever inhabited by alien life.