
Blue Marble, a composite image of Earth released by NASA. What is the origin of water present on our home planet? Has water been here all along or was it brought to a young Earth by a foreign object such as an asteroid?
Water was present since the formation of Earth is the conclusion of a new University of Hawaii at Manoa research seeking to answer a coveted question.
What is the origin of water present on our home planet? Has water been here all along or was it brought to a young Earth by a foreign object such as an asteroid? Water has endowed Earth with life. It is this element that makes the difference between our home planet and many other arid ones. Water is ardently sought in all space explorations to understand whether another planet could harbor life in the same manner Earth does.
It seems that water and our solar system have a long-standing relationship. However, it is unclear how water was distributed in different parts of the solar system since the very beginning. Now, the newly published research, featuring in the Science journal, concludes that in the case of our home planet water was present since the formation of Earth.
Earth formed with water molecules already present. Dust particles that have helped in the formation of the planet were already rich in water. In addition they retained liquid water as our home planet was born.
Doctor Lydia Hallis, former postdoctoral fellow with the UH NASA Astrobiology Institute and current Marie Curie Research Fellow with the University of Glasgow, Scotland gathered a team that could find the evidence needed to answer the long standing question.
Thus, the research team led by Doctor Hallis took to finding what could be the most pristine sample of rocks indicative of Earth in its infancy. Since our home planet is about 4.6 billion years old, that wasn’t an easy task.
Nonetheless, the research team found their answer in samples of volcanic rocks collected from Baffin Island, Canada in 1985. These are the closest formations to the pristine environment of a young Earth.
Subjecting Baffin Island volcanic rocks to complex analysis and making use of the ion-microprobe instrument, the team looked at a variation of factors, including the deuterium-hydrogen ratio. The deuterium-hydrogen ratio provides a signature specific to the water composition of each asteroid, comet or planet.
Collectively using these tests offers the researchers the possibility to understand water origin. Deuterium is a hydrogen isotope or what we dub heavy water. With an atomic mass of two, deuterium is believed to have been stopped from ditribution around the solar system in its early creation phase. Hydrogen on the other hand is lighter and could have escaped more easily.
The deuterium-hydrogen ratio in the Baffin Island volcanic rocks didn’t present anything similar to the ratio found in an asteroid sample for instance. Water in the volcanic rocks was poor in deuterium, which leads to the conclusion it hasn’t been delivered to Earth through a collision.
On the contrary, water molecules have been retained by the dust grains forming the planet in the beginning. Water has been present here all along. The Baffin Island volcanic rocks have remained largely untouched by sediments from crust rocks. They are sourced from a pristine region that hasn’t been modified since the formation of our home planet.
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