NASA's Kepler Telescope discovers 7 fiery exoplanets, uncovering a harsh new solar system beyond our own
NASA's Kepler telescope identifies a system of seven scorching exoplanets orbiting a distant star, offering insights into extreme planetary conditions beyond our solar system.
Mercury, the closest planet to the sun in our solar system, endures extreme solar radiation seven times more intense than that experienced on Earth, making it a perpetually 'fried' celestial body. A team of astronomers, utilizing data collected by NASA's retired Kepler space telescope, has discovered a constellation of seven planets orbiting a star within the Milky Way galaxy. These planets face harsher conditions than Mercury, marking the second-largest collection of exoplanets identified orbiting a star beyond our solar system.
Though larger than Earth, these newfound planets are smaller than Neptune, one of the gas giants in our solar system. All seven planets boast orbits nearer to their star, Kepler-385, than Mercury's average distance from the sun.
"All of the planets are 'fried' more intensely than any planet in our solar system," said astronomer Jack Lissauer of NASA's Ames Research Center in California, lead author of the study set to be published in the Journal of Planetary Science and currently posted on the arXiv research site.
The hunt for exoplanets has led scientists to identify over 5,500 planets beyond our solar system, including numerous stars hosting multiple exoplanets. Kepler-385's remarkable seven-planet system is surpassed only by the eight planets orbiting the star Kepler-90 and equaled by TRAPPIST-1. For reference, our solar system comprises eight planets.
The Kepler space telescope, which concluded its mission in 2018, detected exoplanets by observing faint dimming in a star's brightness when a planet passed in front of it from Earth's perspective.
Roughly 4,400 planets have been cataloged from the telescope's observations spanning from its launch in 2009 to its retirement. The ongoing analysis of its data has led to the identification of Kepler-385's exoplanetary population.
This diverse array of planetary systems demonstrates that not all systems mirror our solar system. Many of these systems likely contain more than eight planets, yet telescopes have yet to discern smaller exoplanets.
Kepler-385, positioned about 5,000 light-years from Earth, is approximately 10 percent larger in diameter and mass compared to our sun, exhibiting slightly greater luminosity and warmth. The smallest of its seven planets, about 20 percent larger than Earth, resides closest to the star, approximately 4 percent of the distance between Earth and the sun.
Lissauer notes that these close-in planets, potentially rocky and tidally locked, experience extreme conditions: scorching heat on the side facing the star, perpetually dark and freezing on the opposite side due to a likely lack of atmosphere.
"Both of them are likely to be rocky, and tidally locked, showing the same face to their star all the time, as the moon does to Earth," Lissauer said. "This makes them especially hot near the point closest to the star. But as any atmosphere is likely to long ago have boiled away, their hemispheres facing away from the star are perpetually dark and extremely cold."
Most of the other planets are about 2.4 times larger than Earth, believed to possess thick atmospheres and high surface temperatures.
"All likely have thick atmospheres, and are hot everywhere on their surfaces, which may be well below their cloud tops," Lissauer said. "The outer planet orbits at about 40 percent of the Earth-sun distance. Its distance is slightly less than the average distance between the sun and Mercury."
The potential for life on these planets appears remote, primarily due to their extreme conditions. Lissauer explains that detecting smaller, Earth-sized planets further from the star may prove challenging but could potentially expand our understanding of these planetary systems.
"The chance of life on any of these seven planets is indeed pretty remote," Lissauer said. "There may well be additional planets orbiting farther from the star that we don't know about because they are more difficult to detect. In particular, if there were an Earth-sized planet in the system at the Earth-sun distance, we would not have detected it."