GK & Current Affairs!

CURRENT AFFAIRS - SCIENCE & TECHONLOGY Japan scientists detect rare, deep-Earth tremor | 27-Aug-2016 13:53

Scientists in Japan studying earthquakes have detected a rare deep-Earth tremor, known as an S wave microseism, for the first time.

Published in US journal Science, the study from researchers Kiwamu Nishida and Ryota Takagi from the National Research Institute for Earth Science and Disaster Prevention in Japan announced scientists successfully detected not only P wave microseisms triggered by a severe and distant North Atlantic storm, known as a weather bomb, but also S wave microseisms, too.

S waves refer to secondary waves, which are slow and move only through rock, not liquid.

NASA announces discovery of 104 new planets outside solar system | 19-Jul-2016 19:18

NASA has announced the discovery of 104 new planets outside our solar system including four that could have Earth-like, rocky surfaces. Scientists discovered the exoplanets in Hawaii using Kepler space telescope.

The unmanned Kepler mission has been scanning 150,000 stars in the Cygnus constellation for signs of orbiting bodies, particularly those that might be able to support life. Evan Sinukoff, an astronomer at the University of Hawaii who contributed to the research, said the diversity of planets is astounding.

 

HD 131399Ab – A Strange Planet Found by the Astronomers | 10-Jul-2016 18:01

HD 131399Ab isn’t the first planet found to have three suns. But it is the first such planet to be found in a wide-orbit system—by far the widest known within a multi-star system. This is weird because multi-star systems are usually so unstable that they ejects planets, which are subject to competing gravitation force from all those suns.This particular planet’s unexpected survival is therefore peculiar, and perhaps revealing. It could mean that such systems are more commonly hosts to planets that scientists tend to think, according to a paperpublished in the journal Science on Thursday.

HD 131399Ab is still just a baby, really, one of the youngest known exoplanets at just 16 million years old. That makes it sound sort of sweet and non-threatening, but you really don’t want to go there. It’s good we’re standing on this moon, in other words. (A moon that’s really only theoretical—quite likely to exist, given what scientists know about moons and planets, but not confirmed.) From here, the planet is clearly the brightest object in the sky. Not only can we get a good look at HD 131399Ab from this vantage point, but we’re spared its intense 1,000-degree heat, and from the fact that it doesn’t actually have a surface to stand on. Where the ground should be there are just clouds made of “cigarette-sized particles of silicate rock,” says the astronomer Kevin Wagner, who discovered HD 131399Ab. Wagner’s here with us, by the way, because he knows the most about this whole triple-sun situation we’re facing.

HD 131399Ab eventually gets to a point in its orbit—when it’s along a path between the three suns—in which it experiences near-constant daylight. That’s because the monster-sun is rising from one horizon as the smaller two suns are setting at the other.

Much of the time, though, HD 131399Ab’s orientation to its three suns is such that it gives the planet a sunny side and a dark side. This arrangement—daytime on one side, nighttime on the other—is the way things are on HD 131399Ab for most of the year. A year for the planet, however, lasts the equivalent of 550 Earth years.