A new NASA-supported study suggests that Jupiter may have played a surprisingly important role in helping Earth acquire some of the key ingredients needed for life more than 4.5 billion years ago.
Scientists have long wondered where Earth got essential elements such as phosphorus and nitrogen, which are necessary for living organisms.
These elements are found in DNA, cells, and many biological processes.
The new research, published in Science Advances, provides fresh clues about how these life-supporting ingredients were distributed throughout the young solar system.
More than 4.5 billion years ago, the solar system formed from a giant cloud of gas and dust surrounding the young sun.
Within this swirling disk, tiny particles gradually stuck together to form larger objects called planetesimals. These bodies were the building blocks of planets, moons, asteroids, and other objects.
Many planetesimals collided with one another, breaking apart and scattering fragments across the solar system. Some of these fragments eventually became part of Earth and other planets. Others survive today as asteroids or meteorites that occasionally fall to Earth.
Meteorites provide scientists with valuable information about the early solar system because they preserve materials that formed before Earth existed. In this study, researchers focused on two major types of meteorites: iron meteorites and chondrites.
Iron meteorites come from the earliest generation of planetesimals and are mostly made of iron and nickel. Chondrites are rocky meteorites that formed from a second generation of planetesimals around two to three million years later.
The researchers examined the ratio of phosphorus to nitrogen in these ancient objects. By combining laboratory experiments with computer models, they reconstructed how these elements were distributed across the young solar system.
Their results revealed an unexpected pattern. In the earliest generation of planetesimals, phosphorus-to-nitrogen ratios were higher in the outer solar system and lower closer to the sun. However, in the later generation, the pattern was reversed, with higher ratios in the inner solar system.
The scientists believe this change may have been caused by Jupiter. As the giant planet formed and grew larger, its powerful gravity acted like a barrier, limiting the movement of material between the inner and outer regions of the solar system.
This gravitational influence may have trapped more phosphorus-rich material in the inner solar system, where Earth was forming. As a result, Earth may have received much of its phosphorus and nitrogen from nearby planetesimals rather than from objects that migrated inward from the outer solar system.
The team’s computer models showed that Earth’s current phosphorus-to-nitrogen signature is best explained if most of these elements came from inner solar system material.
The findings suggest that Jupiter may have done more than shape the orbits of planets and asteroids. It may also have helped determine where the chemical ingredients for life ended up.
Scientists now wonder whether other planetary systems need a Jupiter-like giant planet to create habitable worlds with a similar supply of life-essential elements.
Source:NASA .
