Could this be how Earth formed? Study claims that Earth was formed from smaller “planetary embryos” in the inner Solar System.

  • From collisions of smaller “planetary embryos”, Mars and Earth evolved.
  • According to a recent study, these ’embryos” were discovered in the inner Solar System.
  • Research contradicts another main contender theory regarding how Earth formed
  • It is possible that the planet was formed by collecting pebbles from outer Solar System.

A new study claims that Mars and Earth were created from smaller “planetary embryos” in the inner Solar System.

Scientists are hopeful that the discoveries will help them better understand the mechanisms behind the formation exoplanets of rocky rocks. 

This research is in contradiction to the main theory that our planet was formed by the accumulation of pebbles from outer Solar System, that then drifted towards the sun. 

Comparatively, late-stage growth of terrestrial planets is best described by planetary embryos that are Moon-sized or larger The Solar System eventually has full-sized, rocky planets.

The Earth and Mars evolved from collisions between smaller 'planetary embryos' in the inner Solar System, a new study has claimed. This supports the classic 'Wetherill-type' model but contradicts the other main competing theory for how our planet formed, which is that it grew by accumulating pebbles from the outer Solar System that drift inwards towards the sun

New research has shown that Mars and Earth evolved out of collisions among smaller ‘planetary embryos. While this supports the ‘Wetherill type’ theory, it contradicts the main alternative explanation for how the planet formed. It was created by colliding small pebbles of the outer Solar System with the sun.

In an attempt to establish which theory was correct for the Earth’s formation, researchers led by the University of Münster anWe analysed the compositions of molybdenum, zirconium, and titanium in 10 Martian meteorites. 

They included sample from the major Martian chemical reservoirs as well as measurements of molybdenum from 17 additional Martian meteorites.

According to scientists, this larger sample allowed them overcome any limitations from previous studies. 

Researchers compared the compositions of silicate and Mars’ early parts with meteorites from different regions of the Inner and Outer Solar System. 

It was found that the compositions of both planets were more similar to those of chondritic meteorites from the inner Solar System, which only has a fraction of material from outer Solar System. 

The researchers based their findings on this information. concluded that these terrestrial planets could not have formed through the accumulation of large pebbles from the outer Solar System, but instead likely evolved from collisions between inner Solar System materials.

Researchers compared isotopic compositions of the early silicate portion of the Earth and Mars with those of different groups of chondritic meteorites thought to come from the outer and inner Solar System

Researchers compared the compositions of silicate from Mars and Earth with meteorites of various chondritic groups thought to have come from the outer or inner Solar System.

‘Two fundamentally different processes of rocky planet formation exist, but it is unclear which one built the terrestrial planets of the solar system,’ the authors led by Christoph Burkhardt, of the University of Münster, wrote.

“They were either formed by collisions between planetary embryos of the inner solar systems or by the accretion sunward-drifting, millimetre-sized “pebbles” from the outer solar.

“We have shown that isotopic compositions on Mars and Earth are determined by two-component mixtures among inner solar systems materials. Material from the innermost solar disk is not sampled by meteorites. The contribution of outer solar material to the mix is very limited at a mere 1% by mass.” 

This refutes a pebble accumulation origin for the terrestrial planets, but is in line with collisional growth of inner solar system embryos. 

“The absence of any material of the outer solar systems in Earth or Mars suggests that there is a dust-drift boundary in the disk. This indicates the path of formation of rocky planets within the solar system.

Science Advances has published this research. 


Phosphorus is essential for the survival of life on Earth, even though it’s not nearly as common as oxygen, carbon or hydrogen.

It forms the backbone of long chains of nucleotides, which make up DNA. These are the building blocks for biological life.

Phosphorous is essential for cell membranes as well as the energy-carrying molecule ATP.

Phosphorous was likely brought to Earth by meteorites many billions of year ago.

According to some sources, meteorites may have been contaminated with schreibersite (a phosphorus-bearing minerals). 

Scientists recently developed a synthetic version of schreibersite that reacts chemically with organic molecules, showing its potential as a nutrient for life.