# Earth and Mars planetary formation study

> Live situation record from CLSTR: https://clstr.news/situations/earth-and-mars-planetary-formation-study
> Updated: 2026-10-17T10:39:16.000Z. Sources: 7. Developments: 3.

Research led by the University of Copenhagen’s Center for Star and Planet Formation indicates that Earth and Mars developed through distinct formation pathways approximately 4.5 billion years ago. 

By analyzing chemical signatures in planetary crusts and mantles—specifically the depletion of moderately volatile elements like sodium, zinc, potassium, lithium, and manganese—researchers determined that the two planets utilized different primary growth mechanisms. 

Findings published in Nature Astronomy suggest that Earth’s mass is largely derived from pebble accretion, with at least 75 percent of its mass originating from two protoplanets that grew by accumulating millimeter- to centimeter-sized particles. Conversely, Mars formed primarily through collisions with kilometer-sized planetesimals, which accounted for roughly 73 percent of its mass, while pebble accretion contributed only about 27 percent. This research supports a hybrid model of rocky planet formation where the relative importance of accretion methods varies between worlds. 

Recent analysis of these volatile elements, which evaporate at high temperatures, has helped identify a specific chemical fingerprint in the planetary mantles. This confirms that Earth’s silicate portion was primarily formed through pebble accretion, with the remaining 25 percent coming from planetesimals similar to the asteroid Vesta, whereas Mars followed a reverse ratio of growth.

## Timeline

### 2026-10-17: Earth and Mars formation processes revealed through chemical analysis

Research reveals Earth and Mars formed via different accretion processes, while astronomers search for ‘superhabitable’ planets orbiting K-type stars that may support life longer than Earth.

2 sources. https://clstr.news/cluster/earth-and-mars-formation-processes-revealed-through-chemical-analysis

### 2026-10-04: Earth and Mars followed different formation pathways, study finds

A new study in Nature Astronomy reveals that Earth and Mars formed through different proportions of pebble accretion and planetesimal collisions, explaining their distinct chemical and physical structures.

2 sources. https://clstr.news/cluster/earth-and-mars-followed-different-formation-pathways-study-finds

### 2026-10-02: Earth and Mars formation processes differ, study finds

New research published in Nature Astronomy reveals that Earth and Mars formed via different processes, with Earth relying more on pebble accretion and Mars on planetesimal collisions.

3 sources. https://clstr.news/cluster/earth-and-mars-formation-processes-differ-study-finds

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Cite as: Earth and Mars planetary formation study. CLSTR, https://clstr.news/situations/earth-and-mars-planetary-formation-study