Water discovered for first time in atmosphere of habitable exoplanet

Water discovered for first time in atmosphere of habitable exoplanet
Until the late 20th century, astronomers had only identified the planets in our own solar system. But everything changed in 1995, when the discovery of the first exoplanet orbiting a Sun-like star was confirmed. Videographic on exoplanets. (AFP)
Updated 12 September 2019

Water discovered for first time in atmosphere of habitable exoplanet

Water discovered for first time in atmosphere of habitable exoplanet
  • Water is crucial in the search for life, in part because it carries oxygen

PARIS: 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.

“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 analyze the starlight filtered through K2-18b’s atmosphere.
They found the unmistakable signature of water vapor. Exactly how much remains uncertain, but computer modelling suggested concentrations between 0.1 and 50 percent.
By comparison, the percentage of water vapor 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.

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 kilometers — 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.”
 


Elon Musk to offer $100 million prize for ‘best’ carbon capture technology

Elon Musk to offer $100 million prize for ‘best’ carbon capture technology
Updated 22 January 2021

Elon Musk to offer $100 million prize for ‘best’ carbon capture technology

Elon Musk to offer $100 million prize for ‘best’ carbon capture technology
  • Capturing planet-warming emissions is becoming a critical part of many plans to keep climate change in check

Tesla chief and billionaire entrepreneur Elon Musk on Thursday took to Twitter to promise a $100 million prize for development of the “best” technology to capture carbon dioxide emissions.
Capturing planet-warming emissions is becoming a critical part of many plans to keep climate change in check, but very little progress has been made on the technology to date, with efforts focused on cutting emissions rather than taking carbon out of the air.
The International Energy Agency said late last year that a sharp rise in the deployment of carbon capture technology was needed if countries are to meet net-zero emissions targets.
“Am donating $100M toward a prize for best carbon capture technology,” Musk wrote in a tweet, followed by a second tweet that promised “Details next week.”
Tesla officials did not immediately respond to a request for additional information.
Musk, who co-founded and sold Internet payments company PayPal Holdings Inc, now leads some of the most futuristic companies in the world.
Besides Tesla, he heads rocket company SpaceX and Neuralink, a startup that is developing ultra-high bandwidth brain-machine interfaces to connect the human brain to computers.
Newly-sworn-in US President Joe Biden has pledged to accelerate the development of carbon capture technology as part of his sweeping plan to tackle climate change. On Thursday, he named Jennifer Wilcox, an expert in carbon removal technologies, as the principal deputy assistant secretary for fossil energy at the US Department of Energy.