Published: Thu, April 20, 2017
Science | By Kerry Wheeler

Another nearby planet found that may be just right for life

Another nearby planet found that may be just right for life

An worldwide team of scientists has announced the discovery of a new "super-Earth" exoplanet (a planet with more mass than Earth, but not quite as big as our gas giants) that could represent our best chance of finding life outside of our solar system.

The planet, named LHS 1140b, circles a small, faint red dwarf star at a distance conducive to liquid water, which increases the likelihood of life.

The super-Earth LHS 1140 is in the constellation of Cetus about 40 light-years from Earth, according to the European Southern Observatory (ESO).

The exoplanet is estimated to be around 5 billion years old, and may not have always been so hospitable - it's likely that the red dwarf star when younger may have been more volatile, potentially stripping water from LHS 1140b's atmosphere, if it once had one. It is over six-times as massive as Earth and about 1.5-times larger - fitting the description of a so-called "super Earth": It's bigger and more massive than Earth but smaller and less massive than the next biggest planet, Neptune. But the hope is that by studying the atmosphere of all these planets in the habitable zone, we might find some of the biological signatures of living things.

"This is the most exciting exoplanet I've seen in the past decade", said Jason Dittmann of the Harvard-Smithsonian Center for Astrophysics (CfA).

Scientists believe that one of the major factors that governed the emergence of life on Earth was the presence of liquid water, and so telescopes target distant worlds capable of harboring this precious resource when searching for the hallmarks of life beyond our planet. LHS 1140b is described in Nature.

But given the size and location of LHS 1140b, the planet is an obvious candidate for further research. It's 40 percent wider than Earth but it has 6.6 times Earth's mass, giving it a gravitational pull three times stronger, Charbonneau said. Astronomers have now identified 52 potentially habitable planets and more than 3,600 planets outside our solar system. Therefore, some or all of the others also might not be rocky.

Proxima Centauri b may be a mere 4.2 light-years from Earth, but scientists suspect that it doesn't make a transit across its parent star.

But an atmosphere around a habitable M-dwarf planet has never been spotted. Large, next-generation telescopes will be needed to tease out these subtle signals.

Bottas beats Hamilton to take pole position at Bahrain GP
I was on Massa's pace and we know we're quicker than that, so that was a unusual change of events from the beginning of the race".

Half a million civilians flee fighting in Mosul
ISIS split from al Qaeda in 2014 and the two groups have since waged an acrimonious battle for recruits, funding and the mantle of global extremism.

Asus shows off a quartet of Radeon RX 500 cards
Alongside the launch of the RX 580 and RX 570 video cards, AMD released a new version its Radeon Crimson ReLive software suite. The RX 560 is a 1024:64:16 design with a base clock of 1175MHz compared with the RX 460's 1090MHz, for a gain of 8 percent.

"LHS 1140 spins more slowly and emits less high-energy radiation than other similar low-mass stars".

LHS 1140 b, then, could be one of the best targets for an atmospheric study.

This also allowed them to be sure that the planet is rocky, said HARPS team member Nicola Astudillo-Defru, because HARPS is the most precise instrument that can measure the "wobble" of the planet as the star tugs on it.

Although the planet is potentially habitable now, it might have faced a hellish past. If that did happen, it would have caused a runaway greenhouse effect like we see on Venus.

They say its large size indicates an ocean of lava could have roiled on its surface for millions of years, feeding a radiation-blocking atmosphere with steam.

For that duration, it would be easy for the planet to lose all of its potential water for good.

"We originally thought it was just something amusing going on in the atmosphere", Harvard astronomer Jason Dittmann, the study's lead author, told Gizmodo. The first planet outside our solar system was discovered in 1995.

Two giant telescopes under construction in Chile might be powerful enough, if aimed at 1140b, to recognize any oxygen molecules of the sort that animals need to breathe, assuming 1140b is swathed in oxygen.

LHS 1140 b was discovered using the MEarth-South telescope array at Cerro Tololo Inter-American Observatory.

Like this: