Advances in search for habitable planets
*Humans must adopt vegetarian diets to stop climate change, UN report warns
Scientists have advanced in the quest for another habitable planet with the recent discovery of two Earth-like planets just 12.5 light years from the solar system could harbour liquid water on their surfaces and have the potential to also be home to alien life.
The light-year is a unit of length used to express astronomical distances and measures about 9.46 trillion kilometres or 5.88 trillion miles. As defined by the International Astronomical Union, a light-year is the distance that light travels in vacuum in one Julian year.
According to the report first published by the New Scientist, both planets could support water, even if the scientists do not know what its atmosphere is like. They claim that even if the planet’s atmosphere is relatively thin in comparison to Earth’s, or it is far thicker, it may still be a viable world for life and water.
Orbiting around Teegarden’s star, the worlds, dubbed Teegarden’s star b and c, were first detected in June 2019 by the Calar Alto Observatory’s CARMENES survey. Teegarden’s star is a dim, red M dwarf located 12.5 light years from Earth. The star was named after the United States National Aeronautic Space Agency (NASA) astrophysicist, Bonnard Teegarden, who led the team that first discovered it back in 2003.
Astrophysicists Amri Wandel of the Hebrew University of Jerusalem and Tel Aviv University’s Lev Tal-Or calculated the kind of atmospheres that would be needed in order for Teegarden’s planets to have liquid water on their surfaces.The planets’ tidal locking means that if they didn’t have atmospheres then they would have both a hot and cold side, but with an atmosphere, there is the potential for winds to transport heat around their surfaces.
The duo found that as long as the planets have atmospheres that are between a third and 17 times as dense as the Earth’s, there would probably be at least one region on one of the two worlds’ that can support liquid water.
Wandel told the New Scientist: “Tidally-locked planets like Teegarden’s planets may be more likely to harbour liquid water and, by extension, life than their counterparts.”
Also, scientists at NASA have discovered the closest Earth-like planet just 31 light years away that could be habitable. The discovery was made by NASA’s Transiting Exoplanet Survey Satellite (TESS) technology.The planet, called GJ 357 d, orbits a star around 31 light years away in the so-called habitable zone, an area far enough from its star to not be too hot but close enough to not be too cold.
In this region, it is possible for liquid water to exist on the surface of a planet if it is rocky, although further research is needed to work out whether GJ 357 d’s atmosphere is dense and warm enough to host liquid water.
The news comes just days after three new planets were found in a star system just 73 light years away from Earth — including two planets that may be ‘missing links’ in planetary formation. Meanwhile, a United Nation (UN)-backed report has warned the world must turn towards healthy plant-based diets to stop climate change.
According to the Creating a Sustainable Food Future report, the food system accounts for between 25 and 30 per cent of greenhouse gases, and is choking the life from fresh and coastal waterways with excess nitrogen. In order to feed the predicted 9.8 billion people on Earth in 2050, the world will need to produce 56 per cent more food compared to 2010.
If the level of meat and dairy consumption rises in line with current food habits, six million square kilometres (2.3 million square miles) of forests would need to be converted to agriculture – an area twice the size of India.
According to the Creating a Sustainable Food Future report, two-thirds would be changed to pasture land, with the final third being used for crops.Overall, studies have shown that going vegetarian can reduce your carbon emissions from food by half. Going vegan can reduce this further still.