Exoplanet with Clear Sky discovered

Exoplanet with Clear Sky discovered

Scientists discovered an exoplanet that has no clouds in its atmosphere.

Scientists are exploring all parts of the universe to find signs of life on them. Different missions are providing them with the necessary data to observe potential candidates. They are analyzing various exoplanets and the latest discovery has revealed that a team of researchers has found an exoplanet which has a cloud-free atmosphere. It is been regarded as an incredible breakthrough which will help the scientists to understand the behavior of the planets that are beyond our solar system. Dr. Nikolay Nikolov and his international team of astronomers have declared that WASP-96b, a gaseous exoplanet commonly known as Hot Saturn, has no clouds.

The experiment was performed in Chile in which they used an 8.2m long telescope of the European Southern Observatory to observe the atmospheric makeup of this planet. They measured the decrease of starlight as this planet passed in front of its host star. These measurements are then used to determine the atmospheric composition of the planet. Just like our fingerprints, atoms and molecules of different elements have a unique spectrum that can be used to detect their presence in celestial objects.

Clouds interact with the light released from a planet and this generally disturbs the spectrum that scientists study from Earth. However, the clear fingerprint of sodium was observed in case of WASP-96b. This led researchers to a conclusion that this can happen only if there are no clouds in the atmosphere of the planet.

WASP-96b is a typical gas giant which is often compared with Saturn because both of these planets have similar mass. Having said that, the size of this planet is 20% more than the largest planet of our solar system, Jupiter. It revolves around a sun-like star located between the southern jewels Fomalhaut and Achernar. It lies at a distance of 980 light years in the southern constellation Phoenix. It has happened for the first time ever that a cloudless planet has been found in the universe. Astronomers from all around the globe had predicted many times that a perfect spectrum of sodium can be observed in a cloud-free environment and WASP-96b did exactly that. Nikolov mentioned that in the following words:

We’ve been looking at more than twenty exoplanet transit spectra. WASP-96b is the only exoplanet that appears to be entirely cloud-free and shows such a clear sodium signature, making the planet a benchmark for characterization.”    

The characteristic spectrum of sodium looks like a camping tent. Nikolov told the world that this kind of a structure can be produced only deep inside the atmosphere of a planet. As the clouds get in the way of the light, the shape of the spectrum is changed. That’s the reason why this shape remained unobserved for so long. Traditionally, sodium was either missing or seen in form of a very narrow peak. Clouds usually originate in the hottest or coolest parts of a solar system. The overall energy budget of planetary atmospheres is highly dependent on the existence of clouds. Professor Jonathan J. Fortney, a co-author of the study from the Other Worlds Observatory (OWL) at the University of California, said,

It is difficult to predict which of these hot atmospheres will have thick clouds. By seeing the full range of possible atmospheres, from very cloudy to nearly cloud-free like WASP-96b, we’ll gain a better understanding of what these clouds are made of.”

Sodium is the 7th most abundant element in the universe. It is found in form of salts on our planet and is responsible for the salty taste of seawater and the white color of desert salt pans. Scientists were hopeful that massive gas giants will have sodium-rich atmospheres but there was no scientific evidence to back this claim. The discovery of WASP-96b has finally come to their aid as it solidifies their long-lasting prediction. The clear atmosphere of this exoplanet will allow the researchers to determine the abundances of other molecules as well. A co-author of the study from the Dublin City University, Ernst de Mooij, agreed to that:

“WASP-96b will also provide us with a unique opportunity to determine the abundances of other molecules, such as water, carbon monoxide and carbon dioxide with future observations.”

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