Study Notes on Mercury, Venus, and Mars

Mapped by the Mariner 10 mission in 1974, revealing a heavily cratered surface akin to the Moon, but fewer maria-like basins.
MESSENGER (2011-2015) provided detailed information; flew past Mercury three times before orbiting.
Surface features include scarps (cracks) formed by core contraction, and possible past volcanic activity.
Interior characterized by a thick, ridged crust and a large, dense metallic core (60% of mass).
Theories on core formation: impact hypothesis and solar nebula drag hypothesis.
MESSENGER crashed into Mercury in April 2015; BepiColombo mission launched in 2018, expected to arrive in 2026.

Surface is hidden by clouds; radar mapping was developed in the late 1970s by Pioneer Venus.
Magellan mission (1990-1994) provided extensive surface data.
Features include mountain ranges, shield volcanoes, and evidence of possible volcanic activity.
Surface has been resurfaced recently (within 500 million years), indicating a lack of plate tectonics.
Interior is poorly understood; possibly has a thin crust with a deep mantle, and no strong magnetic field.

Notable for visible surface features: polar caps, canals, and varied landscapes.
Mariner 4 (1964) first successful mission to Mars, returning images of craters.
Mars has massive volcanoes like Olympus Mons and a giant canyon system, Valles Marineris.
Recent exploration through missions like Pathfinder, Spirit, Opportunity, and Curiosity:
- Spirit found evidence of ancient water in Gusev Crater and ended its mission in 2011.
- Opportunity discovered hematite on Meridiani Plains and confirmed signs of past water.
- Curiosity, launched in 2011, studies the climate and geology of Mars, revealing signs of ancient water flow and analyzing soil composition.