These seven alien worlds could help explain how planets form

The Earth-sized astronomical bounty circles a dim star that flew under the radar of exoplanet researchers.

Seven alien, Earth-sized worlds bask in the cool, red light of their parent star. The planetary menagerie exists around a star overlooked by other exoplanet hunters, although it is just 12 parsecs (39 light years) from Earth.

Astronomers have found other seven-planet systems before, but this is the first to have so many Earth-sized worlds. All of them orbit at the right distance to possibly have liquid water somewhere on their surfaces.

“To have this system of seven is really incredible,” says Elisa Quintana, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “You can imagine how many nearby stars might harbour lots and lots of planets.”

Some of the planets were announced last year, but the authors debuted five newfound ones in a paper published on 22 February in Nature1. Because the system is so close to Earth, astronomers can study the planets’ atmospheres relatively easily. That could reveal an astonishing diversity of worlds, ranging in composition from rocky to icy

Source: These seven alien worlds could help explain how planets form : Nature News & Comment

www.economist.com/blogs/economist-explains/2017/02/economist-explains-0

A new study by Raj Chetty of Stanford University and a collective of other economists helps answer this question. By matching data from the Department of Education with 30m tax returns, Mr Chetty and his colleagues have constructed a data set that reveals to researchers both the income distributions of graduates of particular colleges, and how incomes vary depending on how rich the graduates’ parents were. The data show that attending an elite college is a good way of securing an upper-middle class lifestyle—graduates of Ivy League-calibre universities have roughly the same chance of breaking into the top 20% of the income distribution, regardless of family background. Paths to the upper-middle class exist for those who graduate from lesser-known universities too, since earnings can depend even more on what one studies than where. On average, graduates of lesser-known engineering colleges such as Kettering University and the Stevens Institute of Technology do just as well as those from the Ivy League.



www.economist.com/blogs/economist-explains/2017/02/economist-explains-0