New study sheds light on the origins of Earth and Mars


A team of researchers from Denmark, Sweden and China has published a new study in Nature that reveals the composition and formation of the two most habitable planets in the Solar System: Earth and Mars.



The study is based on the analysis of silicon isotopes, which are variations of the same element with different numbers of neutrons, in different types of meteorites. Silicon is the most abundant refractory element in rocky planets, and its isotopic composition can trace the origin and evolution of planetary building blocks.


The researchers found that Earth and Mars have distinct silicon isotopic signatures that differ from those of chondrites, which are primitive meteorites that represent the undifferentiated material of the early Solar System. This means that chondrites are not the main source of material for terrestrial planets, as previously thought.


Instead, the study suggests that Earth and Mars were formed from material similar to early-formed differentiated asteroids, which are meteorites that have undergone melting and segregation into a metallic core and a silicate mantle. These asteroids formed in the inner Solar System and had a lower silicon isotopic ratio than chondrites.


The study also shows that the silicon isotopic ratio of asteroidal bodies correlates with their accretion ages, reflecting the mixing of material from different regions of the Solar System over time. Mars, which formed earlier than Earth, avoided incorporating material from the outer Solar System, which had a higher silicon isotopic ratio. Earth, on the other hand, required about 26 per cent of material from the outer Solar System to match its silicon isotopic composition.


The study supports the idea that Earth and Mars formed rapidly by collisional growth and pebble accretion within three million years after the birth of the Solar System. Pebble accretion is a process in which small dust grains stick together to form larger bodies that can gravitationally attract more pebbles.


The study has important implications for understanding how terrestrial planets form and evolve in different environments. It also provides new constraints for future missions to explore the geology and geochemistry of Earth's neighboring planets.


Spacequanta blogs 

Comments

Post a Comment

Popular posts from this blog

BepiColombo snaps stunning views of Mercury during third flyby

Image
The European-Japanese BepiColombo mission, which is on its way to explore the mysteries of Mercury, has captured some breathtaking images of the planet during its third and closest flyby on June 19, 2023. The spacecraft flew within 150 miles (236 kilometers) of Mercury's surface at 3:34 p.m. EDT (1934 GMT), taking advantage of the planet's gravity to adjust its trajectory towards its final destination. During the flyby, BepiColombo collected data on Mercury's environment and geology, and sent them back to Earth. The European Space Agency (ESA) released the first of these new images on Tuesday, less than 24 hours after the closest approach. The images reveal a geology bounty: a plethora of craters, ancient volcanic ridges and lava flows. Image credit ESA, JAXA One of the most curious features in the images is a crater that has only just received a new name: Edna Manley , after a Jamaican/British artist who died in 1987. "During our image planning for the flyby, we reali...
Read more

Hubble reveals the dazzling stars of NGC 6544

Image
  The NASA/ESA Hubble Space Telescope has captured a stunning image of the globular cluster NGC 6544 , a dense swarm of tens of thousands of stars that lies more than 8000 light-years away from Earth in the constellation Sagittarius . Globular clusters are ancient relics of the early universe, containing some of the oldest stars in the galaxy. They orbit around the center of the Milky Way, forming a spherical halo that extends far beyond the galactic disk. NGC 6544 is one of the closest globular clusters to the galactic plane, making it an interesting target for astronomers who want to study its origin and evolution. The image of NGC 6544 combines data from two of Hubble's instruments — the Advanced Camera for Surveys and Wide Field Camera 3 — as well as two separate astronomical observations. The first observation was designed to find a visible counterpart to the radio pulsar discovered in NGC 6544. A pulsar is the rapidly spinning remnant of a dead star, emitting twin beams of e...
Read more

First ever image of a multi-planet system around a Sun-like star

Image
Astronomers have captured the first ever image of a multi-planet system around a star similar to our Sun. The star, named TYC 8998-760-1, is located about 300 light-years away from Earth and is only 17 million years old. The image, taken by the SPHERE instrument on ESO's Very Large Telescope, shows two giant exoplanets orbiting the star at distances of 160 and 320 astronomical units (au), respectively. For comparison, Neptune orbits the Sun at about 30 au. Image credit : eso The discovery, published in The Astrophysical Journal Letters , is a milestone for direct imaging of exoplanets, which are planets outside our Solar System. Direct imaging is a challenging technique that requires blocking the bright light of the host star to reveal the fainter planets around it. Most of the exoplanets that have been directly imaged so far are either very young or very massive, and orbit very far from their stars. This makes them easier to detect, but also less representative of the majority of ...
Read more