Deep within the depths of our Milky Way Galaxy, there is one more solar system that is like a small copy of our own. Except this planetary system is just a bit older about 7 billion years. Using data and pictures gathered by NASA’s Kepler spacecraft, a global team of assistants discovered an antique solar system about the star Kepler-444. It is assessed to be an enormous 11.2 billion years old. By comparison, scientists consider our own solar system is just 4.6 billion years old. That means that when our sun was born, the Kepler-444 star system was at that time older than our sun is now. It also means Kepler-444 moulded soon after the Milky Way Galaxy merged 13.2 billion years ago.
“It’s an old member of the galaxy, and its age made us very enthusiastic,” Sarbani Basu, a professor of astrophysics at Yale and one of the scientists, tells Popular Science. “This planet system made when the Milky Way was very, very young.” Basu and her team printed their discoveries today in The Astrophysical Journal.
“This planet system formed when the Milky Way was very, very young.”
At the heart of the terrestrial system, Kepler-444 is a sun-like star, and the scientists claim it is about 75% of our sun’s size. Kepler-444 boasts five planets in its orbit, yet these planets are reasonably small, with sizes between those of Mercury and Venus. They also circle the star much more thoroughly than our planets do: The mixture of their orbits is equal to less than one-tenth of Earth’s distance from the Sun. Guessing out all of these particulars about Kepler-444 and its planets needed four years’ worth of imaging and data from the Kepler spacecraft.
Kepler delivered vital seismic information about Kepler-444 over that four-year period. According to Basu, the tremendously high temperatures of a star cause certain matter in its outer layers to heat up and boil, warning the entire star to shake. These oscillations occasionally change the brightness of the star by tiny amounts. The scientists studied these intermissions of dimming and brightening to figure out the size, age, and structure of Kepler-444 — a procedure recognized as asteroseismology.
“With these pounding frequencies, we can conclude how many times per second a star beats, and those pulses are connected to the structure of a star,” says Basu. “So we can work backwards and study what the star looks like on the inside. And the construction of the star was only imaginable if the star is only so many years old.”
To regulate the amount of planets circling Kepler-444, the scientists focused on the dimming of the star as the planets passed in front of it. A transiting planet dims the star much more meaningfully than its daily pulses, and the scientists were able to calculate these dips in light to study more about Kepler-444’s planetary disc.
"If you have planets this old in comfortable zones, there is the possibility for really antique life.”
Of the many things they collected about this particular solar system, the scientists were astonished to come to know that the star had planets surrounding it at all. Since it was born when the Milky Way Galaxy was so young, the planetary system made in a surrounding with very few elements, so the star itself is likely consist of of very few metals. Scientists have long hypothesized that metal-heavy surroundings are required for planets to form about a star, so this dicovery opens up the possibility for even more solar systems that were never thought probable.
With an upsurge in the number of latent planets in our galaxy, there comes an rise in chances that extra-terrestrial life is waiting nearby. Plus, this study means there are many possible planets that are billions of years older than initially thought; that means they may have been sheltering life for some time. “In this specific case, the planets are not in a comfortable zone,” says Basu, “but if you have planets this old in comfortable zones, there is the possibility for truly ancient life.” That's pretty thrilling, because the older these lifeforms are, the better the likelihood that they are intelligent. On Earth at least, it took fairly long time for modest lifeforms to advance into intelligent beings.
So the Milky Way may be home to fairly a few progressive civilizations or at least the chances of that happening just improved.
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