Thread by @weatherindia

#LifeAfterDeath: James Webb Telescope to Hunt for Life on Planets Orbiting Dead Stars

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(📸: NASA Ames/JPL-Caltech/T. Pyle)

Following the recent discovery of phosphine in the clouds of #Venus, intense debates over the presence of life on our neighbouring planet are once again underway in full force.

#phosphineonvenus

And while scientists argue whether this phosphine is evidence for microbial life on #Venus, another group of researchers has devised a potential method to hunt for life outside our solar system—on planets orbiting dead stars!

#phosphineonvenus

Researchers from the USA's Cornell University, in a new study, have shown how @NASA's upcoming #JamesWebbSpaceTelescope, which is set to be launched in October 2021, could be used to find signatures of life on Earth-like planets orbiting white dwarfs.

@NASAWebb

When stars like our Sun die or exhaust all its fuel, all that remains of them is an exposed core—referred to as a white dwarf. These white dwarfs tend to be about 100 times smaller than our Sun, and roughly the same size as Earth.

Their comparatively smaller size allows astronomers the rare opportunity to characterise rocky planets when they transit across their respective dwarfs.

@NASAWebb

"If rocky planets exist around white dwarfs, we could spot signs of life on them in the next few years," said Lisa Kaltenegger, the corresponding author of the study, associate professor of astronomy in the College of Arts and Sciences, and director of the Carl Sagan Institute.

Moreover, the #JamesWebbSpaceTelescope, which is uniquely placed to find signatures of life on rocky exoplanets, will play the most vital role in this hunt.

@NASAWebb

Since the discovery of the first transiting giant planet orbiting a white dwarf (WD 1856+534b) earlier this week, we know that planets do revolve around such ‘dead’ stars.

@NASAWebb

And while the planet that was discovered turned out to be a gas giant, and therefore, incapable of sustaining life, its existence alone suggests that smaller rocky planets capable of supporting life could exist within the habitable zones of white dwarfs.

@NASAWebb

At present, #NASA's Transiting Exoplanet Survey Satellite is actively looking for such rocky planets around white dwarfs. If and when such a world is found, Kaltenegger and her team have developed the models and tools to identify signs of life in the planet's atmosphere.

Furthermore, the James Webb Space Telescope (@NASAWebb) is set to launch in the latter half of 2021 and begin this search.

If we do discover signs of life on such a dwarf-orbiting planet, its implications could be ginormous, considering most stars, including our Sun, will one day perish and end up becoming white dwarfs themselves.

@NASAWebb