🪐intro to astronomy review

Mercury’s composition

Written by the Fiveable Content Team • Last updated August 2025
Written by the Fiveable Content Team • Last updated August 2025

Definition

Mercury’s composition primarily consists of a large metallic core and a silicate mantle and crust. It has a high density, indicating a significant proportion of heavy elements such as iron.

5 Must Know Facts For Your Next Test

  1. Mercury's core makes up about 85% of its radius, which is unusually large compared to other terrestrial planets.
  2. The planet's surface is composed mainly of silicate rocks and dust.
  3. Mercury has a very thin atmosphere composed mostly of oxygen, sodium, hydrogen, helium, and potassium.
  4. The high density of Mercury suggests it contains a larger percentage of metal than Earth or Venus.
  5. Data from the MESSENGER spacecraft indicates that Mercury's surface contains sulfur in higher concentrations than expected.
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