"Extraterrestrial visitors" bring something identical to what's on Earth.

(NLĐO) - The object that once streaked across Earth's sky may represent "trains of life" billions of years ago.

Earth was born in the Goldilocks "habitable zone" of the solar system, meaning it has the right temperature for liquid water to exist. But how water arrived on Earth remains a mystery.

A "strange visitor" named 67P/Churyumov-Gerasimenko, first spotted in the skies more than half a century ago, may hold the key.

67P/Churyumov-Geramenko, with the ESA Philae lander on its surface, is the Rosetta sub-planet in the mission that revealed the special connection between this comet and Earth - Graphic: ESA

A study recently published in the scientific journal Science Advances indicates that 67P/Churyumov-Gerasimenko, a comet belonging to the Jupiter family, possesses water with molecular characteristics similar to water on Earth.

Comets belonging to the Jupiter family are short-orbiting comets that, instead of traveling in large loops from the Oort Cloud to the region near the Sun—which is also near Earth—are held captive by Jupiter in a narrow orbit.

Their narrow orbits allow them to return to us more frequently and provide excellent research opportunities.

According to Sci-News, to determine the origin of water on space objects, scientists typically look for the ratio of deuterium (D) to ordinary hydrogen (H) in the water.

In 2014, 67P/Churyumov-Gerasimenko was removed from the list of potential water-carrying "spacecraft" by scientists, after the European Space Agency's (ESA) Rosetta mission showed its D-H ratio was three times that of Earth's oceans.

However, this time, a research team led by Dr. Kathleen Mandt from NASA's Goddard Space Flight Center showed that cometary dust had skewed those initial calculations.

They used an advanced statistical computing technique to automate the process of isolating deuterium-rich water in over 16,000 measurements by Rosetta.

By removing the confounding factor of deuterium-rich comet dust, scientists have shown that the water actually coming from the comet's body contains far less deuterium and has a D-H ratio similar to Earth's.

Therefore, they believe that this comet and other Jupiter-family comets represent the spacecraft that helped build the life-filled world on Earth.

According to increasingly accepted theories supported by ample evidence, early Earth lacked the necessary components for life to arise.

However, over time, many comets, asteroids, and other small meteoroids have acted as "vehicles for life," bringing the necessary components to create today's ecosystems.

These elements include water, prebiotic molecules, as well as other chemical components that facilitated the reactions that gave rise to the first life.

Source: https://nld.com.vn/khach-la-tu-hanh-tinh-khac-mang-thu-y-het-tren-trai-dat-196241207081002043.htm