Perseverance Finds 3.9‑Billion‑Year‑Old Impact‑Built Rocks on Jezero Rim

Overview

• The Perseverance science team published new results on Wednesday, July 15, 2026, reporting that a 245‑foot (75‑meter) stack of layered bedrock at “Broom Point” on Jezero Crater’s rim was built by repeated high‑energy asteroid impacts.
• In‑place measurements show alternating breccias, fine‑grained dusty layers and abundant tiny dark glassy beads — textures that point to molten ejecta from impacts rather than volcanic origin.
• Some layers now tilt at angles exceeding about 80 degrees, which the team interprets as the result of a two‑stage deformation: an earlier Isidis‑basin‑scale impact that tilted the section and a later Jezero impact that fractured and uplifted it.
• Perseverance collected two core samples, named 'Main River' and 'Bell Island,' but those cores remain on Mars pending a future sample‑return mission that could provide laboratory radiometric ages needed to confirm absolute timing.
• If returned and dated on Earth, the cores could fix the rhythm of early solar‑system bombardment and test whether impacts triggered short‑lived flows by interacting with water or ice, offering a record of conditions that Earth no longer preserves.