Hubble Observes Exoplanet Atmosphere Changing over 3 Years | NASA/ESA
By combining several years of observations from the NASA/European Space Agency Hubble Space Telescope along with conducting computer modeling, astronomers have found evidence for massive cyclones and other dynamic weather activity swirling on a hot, Jupiter-sized planet 880 light-years away.
This video shows the temperature forecast spanning 130 exoplanet-days, across sunrise, noon, sunset and midnight, for the exoplanet WASP-121 b, also known as Tylos. The brighter yellow regions depict areas on the day side of the exoplanet where the temperature soars well above 2000 Kelvins because of its close proximity to its host star, roughly 2.6% of the distance between Earth and the Sun. Owing to the extreme temperature difference between the day and night sides, astronomers suspect evaporated iron and other heavy metals escaping into the higher layers of atmosphere on the day side partially fall back onto lower layers, making it rain iron on the night side. These heavy metals also escape the planet's gravity from the upper atmosphere.
It only takes WASP-121 b roughly 30 hours to complete an orbit around its star.
The Jupiter-sized planet WASP-121 b is no place to call home. For starters, it orbits very close to a star that is brighter and hotter than the Sun. The planet is so dangerously close to its star that its upper atmosphere reaches a blazing 3,400 degrees Fahrenheit—hotter than a steel blast furnace.
A torrent of ultraviolet light from the host star is heating the planet's upper atmosphere. This is causing the magnesium and iron gas to escape into space. Powerful gravitational tidal forces from the star have altered the planet's shape so that it appears more football shaped. By combining several years of Hubble Space Telescope observations with computer modelling, astronomers have found evidence for massive cyclones swirling on the hellish planet. The cyclones are repeatedly created and destroyed due to the large temperature difference between the star-facing side and dark night-time side of the exoplanet.
An international team of astronomers assembled and reprocessed Hubble observations of the exoplanet made in the years 2016, 2018 and 2019. This provided them with a unique dataset that allowed them not only to analyze the atmosphere of WASP-121 b, but also to compare the state of the exoplanet’s atmosphere across several years. They found clear evidence that the observations of WASP-121 b were varying in time. The team then used sophisticated modelling techniques to demonstrate that these temporal variations could be explained by weather patterns in the exoplanet's atmosphere, as seen here.
Video Credit: NASA, ESA, Q. Changeat et al., M. Zamani (ESA/Hubble)
Duration: 1 minute, 24 seconds
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