Water Discovered For First Time On Potentially Habitable Planet

A handout artist’s impression released on September 11, 2019, by ESA/Hubble shows the K2-18b super-Earth, the only super-Earth exoplanet known to host both water and temperatures that could support life.  M. KORNMESSER / ESA/Hubble / AFP

 

Water has been discovered for the first time in the atmosphere of an exoplanet with Earth-like temperatures that could support life as we know it, scientists revealed Wednesday.

Eight times the mass of Earth and twice as big, K2-18b orbits in its star’s “habitable zone” at a distance — neither too far nor too close — where water can exist in liquid form, they reported in the journal Nature Astronomy.

“This planet is the best candidate we have outside our solar system” in the search for signs of life, co-author Giovanna Tinetti, an astronomer at University College London, told AFP.

“We cannot assume that it has oceans on the surface but it is a real possibility.”

Of the more than 4,000 exoplanets detected to date, this is the first known to combine a rocky surface and an atmosphere with water.

Most exoplanets with atmospheres are giant balls of gas, and the handful of rocky planets for which data is available seem to have no atmosphere at all.

Even if they did, most Earth-like planets are too far from their stars to have liquid water or so close that any H2O has evaporated.

Discovered in 2015, K2-18b is one of hundreds of so-called “super-Earths” — planets with less than ten times the mass of ours — spotted by NASA’s Kepler spacecraft.

Future space missions are expected to detect hundreds more in the coming decades.

 ‘Is Earth unique?’ 

“Finding water in a potentially habitable world other than Earth is incredibly exciting,” said lead-author Angelos Tsiaras, also from UCL.

“K2-18b is not ‘Earth 2.0’,” he said. “However, it brings us closer to answering the fundamental question: is the Earth unique?”

Working with spectroscopic data captured in 2016 and 2017 by the Hubble Space Telescope, Tsiaras and his team used open-source algorithms to analyse the starlight filtered through K2-18b’s atmosphere.

They found the unmistakable signature of water vapour. Exactly how much remains uncertain, but computer modelling suggested concentrations between 0.1 and 50 percent.

By comparison, the percentage of water vapour in Earth’s atmosphere varies between 0.2 percent above the poles, and up to four percent in the tropics.

There was also evidence of hydrogen and helium as well. Nitrogen and methane may also be present but with current technology remain undetectable, the study said.

Further research will be able to determine the extent of cloud coverage and the percentage of water in the atmosphere.

First of many 

Water is crucial in the search for life, in part because it carries oxygen.

“Life as we know is based on water,” said Tinetti.

K2-18b orbits a red dwarf star about 110 light years distant — a million billion kilometres — in the Leo constellation of the Milky Way, and is probably bombarded by more destructive radiation than Earth.

“It is likely that this is the first of many discoveries of potentially habitable planets,” said UCL astronomer Ingo Waldmann, also a co-author.

“This is not only because super-Earths like K2-18b are the most common planets in our galaxy, but also because red dwarfs — stars smaller than our Sun — are the most common stars.”

The new generation of space-based star gazing instruments led by the James Webb Space Telescope and the European Space Agency’s ARIEL mission will be able to describe exoplanet atmospheres in far greater detail.

ARIEL, slated for a 2028 launch, will canvas some 1,000 planets, a large enough sampling to look for patterns and identify outliers.

“Over 4,000 exoplanets have been detected but we don’t know much about their composition and nature,” said Tinetti. “By observing a large sample of planets, we hope to reveal secrets about their chemistry, formation and evolution.”

AFP

Missing Thai Boys ‘Found Alive’ In Caves Nine Days After

This photo taken and released by the Royal Thai Navy on July 2, 2018 shows a group of foreign divers preparing to search flooded section of Tham Luang cave at the Khun Nam Nang Non Forest Park in the Mae Sai district of Chiang Rai province as the rescue operation continues for a missing children’s football team and their coach. ROYAL THAI NAVY / AFP

 

A Thai youth football team of 12 teenaged boys and their 25-year-old coach were “found safe” late Monday deep in a cave in northern Thailand nine days after they went missing, a provincial governor told reporters.

“We found all 13 safe… we will take care of them until they can move,” Chiang Rai governor Narongsak Osottanakorn said.

AFP

WWII Bomb Discovery To Force Mass Evacuation In Germany

FILE COPY Demolition expert Roger Flakowski poses next to a defused World War II bomb on April 13, 2018 in Neu-Ulm, southern Germany, where around 12,000 residents had to be evacuated due to the disposal of the bomb. Photo Credit: Stefan Puchner / dpa / AFP

 

The discovery of an unexploded World War II bomb will force a mass evacuation around Berlin’s central railway station Friday, covering several government ministries and a hospital, police said.

Buildings and streets in a radius of 800 metres (875 yards) around the site north of the busy train station will be cleared from 0700 GMT until the 500-kilogramme (1,100-pound) explosive is safely defused, they said on Twitter Wednesday.

The evacuation zone covers the central railway station, the economy and transport ministries, an army hospital and the embassies of Indonesia and Uzbekistan, a police spokesman told AFP.

Police said it was not yet clear how many thousands of people would be affected but predicted to local media that “it will be big, it will be a major hassle”.

The Deutsche Bahn rail company and urban transport operators prepared for large-scale disruptions around the central hub for trains, trams and buses.

The bomb, which was discovered during construction work on Heidestrasse in the district of Mitte, was “safe for now”, police said, reassuring nearby residents that “there is no immediate danger”.

Allied planes blasted Nazi Germany during the Second World War, and vast urban and industrial areas remain littered with unexploded bombs and other ordnance often found during construction projects.

Last Friday in the state of Bavaria, an ordnance disposal team defused a 500-kilogramme bomb which had forced the evacuation of 12,000 people in the city of Neu-Ulm — the third unexploded bomb to be disarmed in recent weeks in the city of 50,000 people

AFP

Scientists Discover 100 million-Year-Old Spider With Scorpion-Like Tail

This handout image obtained via the Nature website on February 5, 2018 shows a Photo of the holotype of the dorsal view of a Chimerachne yingi spider.  BO WANG / NATURE PUBLISHING GROUP / AFP

 

Two teams of scientists on Monday unveiled a “missing-link” species of spider with a scorpion-like tail found perfectly preserved in amber in Southeast Asia’s forests after at least 100 million years.

In studies published side-by-side in Nature Ecology and Evolution, one team argued that male sex organs and silk thread-producing teats link the creature to living spiders.

The other team pointed to the long tail and a segmented body to argue that Chimerarachne yingi belongs instead to a far more ancient and extinct lineage at least 380 million years old.

Either way, the researchers agree that C. yingi fills a yawning gap in the evolutionary saga of the nearly 50,000 species of spiders that spin webs and trap prey around the world today.

“It’s a missing link between the ancient Uraraneida order, which resemble spiders but have tails and no silk-making spinnerets, and modern spiders, which lack tails,” said Bo Wang, a palaeobiologist at the Chinese Academy of Sciences in Nanjing and lead author of the study, suggesting C. yingi has more in common with their present-day, eight-legged cousins.

Remarkably, the previously unknown species was simultaneously discovered by two groups of scientists, each of which unearthed two specimens locked in translucent amber teardrops.

By coincidence, both teams submitted their findings to the same journal, which coordinated the joint release.

With a total body length of about six millimetres (one fifth of an inch) — half taken up by the tail — C. yingi is, truly, an itsy bitsy spider.

The filaments made by four nipples extruding from the back end of its abdomen were probably not there to spin webs, the researchers speculated.

– Venom glands –
“Spinnerets are used to produce silk for a whole host of reasons: to wrap eggs, to make burrows, to make sleeping hammocks, or just to leave behind trails,” said Paul Selden, Wang’s co-author and a professor at the University of Kansas.

C. yingi also boasts pincer-like appendages, called pedipalps, used to transfer sperm to the female during mating, a signature trait of all living spiders.

Its whip-like tail or flagellum, also known as a telson, likely “served a sensory purpose,” Wang told AFP.

By contrast, modern spiders use silk spun into webs to monitor changes in their surroundings.

They also have venom secreted from special-purpose glands, but neither of the studies was able to confirm that C. yingi could poison its prey.

Both teams used X-ray computed tomography scanning technology to remotely dissect their specimens.

The new species was discovered in the jungles of Myanmar, which yields nearly 10 tonnes of amber every year.

“It has been coming into China where dealers have been selling to research institutions,” Wang said.

Amber has been crucial for tracing the early ancestors of spiders — but only up to a certain point.

“Spiders have soft bodies and no bones, so they don’t fossilise very well, so we rely on special conditions — especially amber — to find them,” Wang explained.

But working back in time, the trail of animal remains in amber ends about 250 million years ago, making it very difficult to trace the spider’s earliest origins.

AFP