A planet just outside our solar system has been discovered by astronomers, and its known to have water and temperatures similar to Earth.
Its the only planet outside our solar system with conditions which could support life, and sits around 110 light years away.
The exoplanet (a planet outside the solar system) has been named K2-18b. Its eight times the size of Earth, lying in the constellation of Leo in the northern sky, and has been described as the holy grail for planet hunters seeking an Earth-like planet with water in its atmosphere. The discovery of water in the atmosphere means life could be found there.
Speaking about the discovery, first author Dr. Angelos Tsiaras, of University College Londons Centre for Space Exochemistry Data (CSED), said:
Finding water in a potentially habitable world other than Earth is incredibly exciting.
K2-18b is not Earth 2.0 as it is significantly heavier and has a different atmospheric composition.
However, it brings us closer to answering the fundamental question – is the Earth unique?
The water vapour found in K2-18b comes from the evaporation of water or ice on the planet, and though vapour has been found on other far away planets, this is the first to be the ideal distance from the solar systems star to allow life to develop.
The team, whose findings are reported in Astronomical Journal, say the waters source could exist in liquid form – a pre-requisite for life.
They combined data from 2016 and 2017 captured by the Hubble Space Telescope with their own algorithms to analyse starlight filtered through the atmosphere.
The results revealed the molecular signature of water vapour, while also indicating the presence of hydrogen and helium, which produces energy.
Other vital molecules, including nitrogen and methane, may also be present but remain undetectable with current observations. Further studies are required to estimate cloud coverage and the percentage of atmospheric water present.
K2-18b was first discovered in 2015, and is one of hundreds of super-Earths – planets with a mass between Earth and Neptune – found by NASAs Kepler spacecraft. While more super-Earths are expected to be uncovered in the coming years, K2-18b is the most promising so far. However, as the planet orbits an active red dwarf, its environment is expected to be more hostile than Earth.
Look! A cosmic block party
@NASAHubble captured 50 spiral and dwarf galaxies hanging out in our cosmic neighborhood. What looks like a swarm or cloud of stars in the middle is actually a dwarf galaxy! Learn more about your celestial neighbors: https://t.co/XSC5VZ9u6M pic.twitter.com/5JZGgEmY2S
— NASA (@NASA) September 6, 2019
Co-author Dr Ingo Waldmann, also of UCL CSED, said:
With so many new super-Earths expected to be found over the next couple of decades, its likely this is the first discovery of many potentially habitable planets.
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 next generation of space telescopes, including the NASA/ESA/CSA James Webb Space Telescope and ESAs ARIEL mission, will be able to characterise atmospheres in more detail as they will carry more advanced instruments.
ARIEL is expected to launch in 2028, and will observe 1,000 planets in detail to get a truly representative picture of what they are like.
Co-author Prof Giovanna Tinetti, also of UCL CSED and principal investigator for ARIEL, said: Read More – Source