The new discovery of six alien planets orbiting a sun-like star may only be a small part of the data released today (February 2) from NASA’s Kepler planet-hunting mission, but it is important as the most compact planetary arrangement around a single star. yet discovered.

The six planets orbiting Kepler-11 are all larger than Earth, with the largest comparable in size to Uranus and Neptune. When it comes to exoplanets, they are relatively small worlds.

Kepler-11 is located approximately 2,000 light years from Earth. Astronomers have used observations made by the Kepler spacecraft to detect the six planets that pass – pass in front of – the star.

The innermost planet, Kepler-11b, is 10 times closer to its star than Earth is to the sun. Going outward, the other planets are Kepler-11c, Kepler-11d, Kepler-11e, Kepler-11f, and the farthest planet, Kepler-11g, which is half as far from its star as Earth is. is from the sun.

None of the extrasolar planets are inside the so-called “habitable zone” – orbits where water could exist in liquid form on their surface, the scientists said.

The five inner planets of the Kepler-11 system are between 2.3 and 13.5 times the mass of Earth. The orbits of the five would fit within Mercury’s orbit in our solar system, and all would revolve around their star in less than 50 Earth days.

The sixth planet is the largest of the group and has an undetermined mass. Its orbit is smaller than that of Venus and it orbits every 118 days.

The densities of the six extraterrestrial worlds were found to be lower than those of Earth.

All of the Kepler-11 planets orbit their parent star in roughly the same plane, which is similar to the layout of our solar system.

“Kepler-11 is a remarkable system whose architecture and dynamics provide clues to its formation,” said Jack Lissauer, a member of the Kepler science team at NASA’s Ames Research Center in Moffett Field, California.

“These six planets are mixtures of rock and gas, possibly including water,” said Lissauer, one of the authors of a new study on the Kepler-11 system. “Rocky material makes up most of the mass of the planets, while gas takes up most of their volume. By measuring the sizes and masses of the five inner planets, we determined that they were among the confirmed planets of lowest mass beyond our solar system. “

Planets Kepler-11d, Kepler-11e, and Kepler-11f contain a significant amount of light gas, indicating that they formed a few million years after the system was formed.

With warm atmospheres of hydrogen and helium, these planets are not considered habitable, but researchers want to deepen the analysis of the Kepler-11 system to better understand its history and the processes of formation of planetary systems in general.