[3][4] Topographical data from Mars Global Surveyor are consistent with the models and also suggest that the elliptical crater has axes of length 10,600 km (6,600 mi) and 8,500 km (5,300 mi), centered on 67°N 208°E / 67°N 208°E / 67; 208, though this has been partially obscured by later volcanic eruptions that created the Tharsis bulge along its rim.

[7] The lack of magnetic anomalies observed in the northern hemisphere could be explained by such an impact, as the shock waves produced might have demagnetized the crust.

However, the moons' near circular orbits and low inclination relative to the Martian equator are not in agreement with the capture hypothesis.

[9] Analysis of Mars Global Surveyor data found mineral deposits similar to terminal moraines on Earth along the southern rim of the northern lowlands.

[10] Here, the tsunami generated by the impactor would have reached heights of 75 m (250 ft), and traveled 150 km (90 mi) past the southern rim.