Dr. Jasmina Blecic of New York University Abu Dhabi’s Centre for Astro, Particle and Planetary Physics, and her co-authors have published their findings on Wasp-18b in the scientific journal, Nature. The scientist has detected water on the planet 400 light years from Earth, using the James Webb Space Telescope. The water vapour was located on Wasp-18b using data from the James Webb, showing a much more detailed view of distant planets than earlier telescopes. Wasp-18b is what scientists call the gas giant and temperatures on its surface are 2,700°C – and higher inside.
“This is the first time we could see very small amounts of water in the atmosphere of this planet,” Dr Blecic told The National. “This demonstrates the capability of the James Webb Space Telescope to identify minuscule quantities of certain chemical species, opening the possibility of detecting these molecules in smaller, Earth-sized planets,” she added.
The planet has been observed since 2009 with a variety of telescopes, but astronomers were unable to tell whether it contained water or not. Most water on Wasp-18b is destroyed by the heat, but the high sensitivity of Nasa’s James Webb Space Telescope meant that it is capable of detecting even subtle indications of water vapour.
Detecting water on Earth-sized planets may be significant because it could indicate that these planets – unlike Wasp-18b – harbour life. Wasp-18b has a radius (the distance from the centre to the surface) about 10 times that of Earth, but it has a mass 3,000 times that of our planet. The water was detected by analysing the infrared light emitted by Wasp-18b as it passed behind its star and reappeared.
At 400 light years from Earth, Wasp-18b is at a distance that is difficult for the human mind to comprehend, given that one light year is about 150 million kilometres. Yet Wasp-18b is extremely near to us in the context of our galaxy, the Milky Way, which is about 100,000 light years across.
According to data published by NASA, there are an estimated 200 billion galaxies in the observable universe, which is about 94 billion light years across.
