Chapter 1: A Major Breakthrough in Exoplanet Discovery

Recently, astronomers announced the exciting discovery of two rocky planets resembling Earth. One is situated 72 light-years away, while the other is a mere 31 light-years from our planet.

[Photo: M. Mizera / PTA / IAU100, CC BY 4.0, via Wikimedia Commons]

This groundbreaking finding is documented in a paper published on the arXiv.org science preprint platform. Authored by a global team of researchers, the article highlights the planet K2–415b, which lies 72 light-years from Earth. Its size is remarkably similar to Earth’s, boasting a radius just 1.015 times larger than our own.

However, the similarities largely end there. K2–415b orbits a red dwarf star, a type known for its small size and long lifespan. Specifically, the K2–415 star has only 16% of the Sun's mass.

How Are Exoplanets Detected?

The presence of K2–415b was indicated by data collected by the Kepler Telescope in 2017. To validate the existence of this planet, further infrared observations were conducted, which allowed scientists to measure the gravitational influence exerted by the planet on its star, ultimately determining its mass.

For K2–415b, this revealed a mass three times that of Earth, indicating that, despite its similar size, it is significantly denser than our planet.

A Planet with Limited Potential for Life

The transit data, which tracks the planet's passage between its star and Earth, allowed researchers to ascertain its radius and orbital period. K2–415b completes an orbit in just four Earth days, a common characteristic for planets near red dwarfs. While this star likely lies within the habitable zone, its proximity suggests conditions unfavorable for life.

Chapter 2: A Promising Candidate for Life

In contrast, another newly identified exoplanet, orbiting the red dwarf Wolf 1069, is located just 31 light-years away. The discovery was made by Diana Kossakowski’s team at the Max Planck Institute for Astronomy, as reported in the journal Astronomy & Astrophysics.

Wolf 1069b has a mass comparable to that of Earth and resides in its star's habitable zone. Astronomers believe it is a rocky planet with potential liquid water, making it a candidate for microbial life.

“This planet completes its orbit in 15.6 Earth days,” explains Kossakowski. “It is positioned at one-fifteenth the distance of Earth from the Sun.” Notably, despite being closer to its star, which is significantly smaller and dimmer than our Sun, conditions on Wolf 1069b may still support life.

Simulations suggest that if Wolf 1069b possesses an atmosphere, the average temperature could be around 13 degrees Celsius, allowing for the possibility of liquid water.

An intriguing aspect of Wolf 1069b is that it may always show the same face to its star, akin to how the Moon presents one side to Earth. This would result in perpetual daylight on one hemisphere and continuous night on the other.

[Photo: Trent Schindler, National Science Foundation, Public domain, via Wikimedia Commons]

Searching for Signs of Life

When can we expect to search for biosignatures—chemical markers indicating life—on planets like Wolf 1069b? “We will likely need to wait another decade for that,” Kossakowski states.

The Extremely Large Telescope, currently under construction in Chile, will enable the analysis of exoplanet atmospheres and potentially allow for the detection of molecules associated with life forms.

To date, over 5,000 exoplanets have been confirmed, but only a few resemble Earth in mass and are situated within their star's ecosphere. Wolf 1069b is notable as the sixth closest Earth-like planet found within a habitable zone.

This video explores the quest for Earth-like planets beyond our solar system, discussing the implications of these discoveries.

This video covers NASA's announcement of significant discoveries regarding habitable planets, shedding light on our understanding of life in the universe.

Source: arXiv.org