Home Science Space How Many Habitable Planets Are Out There?

How Many Habitable Planets Are Out There?

Thanks to new research using data from the Kepler space telescope, it’s estimated that there could be as many as 300 million potentially habitable planets in our galaxy. Some could even be pretty close, with several likely within 30 light-years of our Sun.

The findings will be published in The Astronomical Journal, and research was a collaboration of scientists from NASA, the SETI Institute, and other organizations worldwide. Co-author Jeff Coughlin, an exoplanet researcher at the SETI Institute and Director of Kepler’s Science Office said:

“This is the first time that all of the pieces have been put together to provide a reliable measurement of the number of potentially habitable planets in the galaxy. This is a key term of the Drake Equation, used to estimate the number of communicable civilizations — we’re one step closer on the long road to finding out if we’re alone in the cosmos.”

The Drake Equation is a probabilistic argument that details the factors to consider when estimating the potential number of technologically advanced civilizations in the galaxy that could be detected. The Drake Equation is also often considered to be a roadmap for astrobiology and guides much of the research at the SETI Institute. To develop a reasonable estimate, the researchers looked at exoplanets similar in size to Earth and thus most likely to be rocky planets.

An illustration representing the legacy of NASA's Kepler space telescope. After nine years in deep space collecting data that revealed our night sky to be filled with billions of hidden planets – more planets even than stars – NASA’s Kepler space telescope ran out of fuel needed for further science operations in 2018. (Image: NASA/Ames Research Center/W. Stenzel/D. Rutter. Source: A New View of Our Starry Night)
An illustration representing the legacy of NASA’s Kepler space telescope. After nine years in deep space collecting data that revealed our night sky to be filled with billions of hidden planets – more planets even than stars – NASA’s Kepler space telescope ran out of fuel needed for further science operations in 2018. (Image: NASA/Ames Research Center/W. Stenzel/D. Rutter. Source: A New View of Our Starry Night)

They also looked at so-called Sun-like stars, around the same age as our Sun and approximately the same temperature. Another consideration for habitability is whether the planet could have the conditions necessary to support liquid water.

Previous estimates about determining the number of potentially habitable exoplanets there are in our galaxy were heavily based on the planet’s distance from its star. This new research also considers how much light hits the planet from its star, which would impact the likelihood that the planet could support liquid water.

To do this, the team looked not only at Kepler data, but also at data from the European Space Agency’s Gaia mission about how much energy the planet’s star emits. By taking both Kepler and Gaia data into account, the results better reflect the diversity of stars, solar systems, and exoplanets in our galaxy. Co-author Michelle Kunimoto, who worked on this paper after finishing her doctorate on exoplanet occurrence rates at the University of British Columbia, said:

“Knowing how common different kinds of planets are is extremely valuable for the design of upcoming exoplanet-finding missions. Surveys aimed at small, potentially habitable planets around Sun-like stars will depend on results like these to maximize their chance of success.”

More research will be needed to understand the role a planet’s atmosphere has on its capacity to support liquid water. In this analysis, researchers used a conservative estimate of the atmosphere’s effect to estimate the occurrence of Sun-like stars with rocky planets that could have liquid water.

The Kepler mission, which officially ceased collecting data in 2018, has identified over 2,800 confirmed exoplanets, with several thousand more candidates waiting to be confirmed. So far, researchers have identified several hundred planets in the habitable zone of their star in Kepler data. It may take a while to find all 300 million!

Provided by: SETI Institute [Note: Materials may be edited for content and length.]

Follow us on Twitter or subscribe to our email list

Troy Oakes
Troy was born and raised in Australia and has always wanted to know why and how things work, which led him to his love for science. He is a professional photographer and enjoys taking pictures of Australia's beautiful landscapes. He is also a professional storm chaser where he currently lives in Hervey Bay, Australia.

Most Popular

Trump Team Battles Deep State Coup On Two Fronts

Ahead of the Dec. 14 electoral college meeting, the legal team for Pres. Trump is working feverishly on both the legal and legislative fronts...

4 Tips on How to Teach Kids Generosity During the Holidays

The Christmas holiday season is upon us and it will soon be time for celebrations, gift-giving, and other happy occasions. For many parents, this...

A Chinese Entrepreneur Predicts His Tragic Ending

In 1985, Sun Dawu, who has become a Chinese entrepreneur, and his wife started their business with a thousand chickens and 50 pigs. Ten...

Researchers Find Connection Between Household Chemicals and Gut Microbiome

A team of researchers for the first time has found a correlation between the levels of bacteria and fungi, the gut microbiome, in the...