Re: do these planets still exist
In order for planets to form you need a stable(ish) solar system and lots of time (think: in the millions of years). Now, usually the planets start to form from discs of material, dust etc... surrounding their start shortly after the star's birth. Close enough that you start the "millions of years" clock from star birth.
It's reasonable to assume, then, that these planets have orbited that star since about 3-10 million years after its birth. A Red Dwarf star burns longer the smaller it is and these stars (according to the article) are smaller than our sun meaning they could go on for more than 15, 20 billion years. I can't find info on the mass of Kepler 442, the star Kepler 442b orbits so will have to leave the guess as to its age in the billions of years.
This means the planets have been around for likely billions of years and, at least up until 470 years ago, in a stable system.
So the chances of them undergoing some catastrophic event that has destroyed them is 470 divided by those billions of years. Sufficiently small for us to conclude they're so overwhelmingly likely to still be there now that it's not statistically credible to propose that they are not.
Good question, though!
Biting the hand that feeds IT
