Privileged Planet: in a unique solar system (Introduction)

by David Turell , Tuesday, March 15, 2022, 14:54 (773 days ago) @ David Turell

Our solar system is like no other:

https://www.realclearscience.com/blog/2022/03/14/four_reasons_why_our_solar_system_is_r...

"To us, our solar system, situated in the suburbs of the Milky Way, seems normal, almost mundane. It's home after all, the only one we've ever known. But when astronomers began gazing earnestly at our stellar neighbors a few decades ago, they soon realized that, in many respects, our solar system contrasted sharply with others out there. In fact, it's downright strange. Here are four reasons why.

"1. Lots of Planets. Eight planets might not seem like much. One could number them off on two hands. But based on astronomers' observations thus far, such a count seems exceedingly rare. "Only one other known system, Kepler-90, contains as many planets as the solar system, according to The Extrasolar Planets Encyclopaedia," Harry Baker wrote for Space.com. Researchers at the Niels Bohr Institute estimated that only 1% of all solar systems in the Milky Way have the same number of planets as our solar system or more.

"2. Only One Sun. While the solar system is brimming with planets, it only has one lonely sun. More than half of all known stars exist in multiple-sun systems, so our sun is slightly out of the ordinary in this respect.

"3. Yellow Dwarf in the System. Our sun is what's called a G-type main-sequence star, more commonly known as a yellow dwarf. Each second, it fuses approximately 600 million tons of hydrogen into helium, sending out life-sustaining energy in the process. And it will continue to do so for another 5.4 billion years. The vast majority of stars, however are much smaller and cooler red dwarfs. About 85% of all stars in the Milky Way are red dwarfs.

"4. What's Up With Jupiter? Jupiter is the juggernaut of our solar system, with a mass more than two and a half times that of all the other planets combined. The simple fact that our solar system hosts a gas giant of this size sets us apart, says astrophysicist Sean Raymond. Just 10-15% of Sun-like stars have one. Moreover, he writes, most gas giants in other solar systems have tight, eccentric orbits around their stars, while Jupiter's is wide and nearly circular. "Only about one in a hundred stars like the Sun has a Jupiter like ours," he wrote.

"So feel free to revel in our weirdness, Pat Brennan wrote for NASA, as we have yet to spot a solar system quite like ours. But keep in mind that this may be biased by the ways we're looking."

Comment: Seems like 'finetuning' can be applied to our solar system