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Traces of atmospheric water found on five exoplanets

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Lisa Winter

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176 Traces of atmospheric water found on five exoplanets

Over the last few years astronomers have made considerable strides with exoplanets. We can detect them, determine if they are in the habitable zone of their respective stars, and now we are starting to learn more about what it’s like on the surface of the planet. Now, researchers claim that they have detected water in the atmospheres of five exoplanets. This announcement comes from two teams using the Hubble Space Telescope’s Wide Field Camera 3. Both teams published in the Astrophysical Journal

All of these planets are known as “hot Jupiters” which means they are large gas planets with very tight orbits. Liquid water is a prerequisite for life as we know it, though these plants are not habitable by any means. Detection of water was based on measuring the infrared signal which allowed scientists to determine how much light was absorbed or transmitted because of water content.


WASP-12b may sound familiar, because it also belongs on the IFLS list of Most Amazing Exoplanets. Located 800 light years from Earth, it orbits its star in about 1.1 Earth days. This orbit is so tight, in fact, that it is currently being consumed by its sun-like star. It is no longer spherical, but has been pulled into an oblong football shape. The planet will likely be completely consumed in the next 10 million years.

WASP-17b is located in the Scorpius constellation 1000 light years away. Though its radius is about twice the size of Jupiter, it has only half the mass and is called a puffy planet. This planet also had one of the strongest signals for water.

HD209458b had the strongest water signal out of all of the planets. It is located in the Pegasus constellation 150 light years away. It takes only 3.5 days for this planet to complete one orbit. This planet is also pretty cool because it is the first exoplanet whose atmosphere was confirmed, along with the components. Along with WASP-17b, HD209458b also presented the strongest signals out of this group of five.

WASP-19b takes less than 19 hours to orbit its star, which is one of the quickest ever discovered of an exoplanet. WASP-19b is located 815 light years away in the Vela constellation. Its radius is about 1.3 times larger than Jupiter, though the two have a similar mass. 


XO-1b is located in the Corona Borealis constellation, 560 light years away from Earth. It takes about 4 days to orbit the star. This planet is special because it was one of the first few to be discovered by monitoring the star’s brightness as it transits. Though its radius is larger than Jupiter’s, its mass is slightly lower.

Because of all of the atmospheric dust and haze from these gas giants, the signals aren’t very strong in general. However, due to the scorching temperatures of these planets, it’s pretty impressive that they still are able to have water at all. Hopefully future research and technologies will allow astronomers to discover water signatures on rocky planets residing in habitable zones, perhaps bringing us closer to the dream of finding an Earth-like planet out in the cosmos. 


spaceSpace and Physics
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  • water