For nearly two decades, the mysterious signals emanating from the enigmatic super-Earth ’55 Cancri e’ have perplexed astronomers. Now, a groundbreaking study suggests that the planet may be in a continuous cycle of losing and regrowing its atmosphere, offering a potential explanation for these strange transit signals. To put this theory to the test, scientists are looking to the James Webb Space Telescope (JWST).
55 Cancri e, often dubbed a “hellish” world, is approximately eight times the mass of Earth and was first discovered in 2004, situated some 40 light-years away from our home planet. Its remarkable proximity to its parent star, at less than 2% of the Earth-Sun distance, results in extreme conditions that have long defied a clear-cut explanation.
One of the most baffling aspects of this super-Earth, as highlighted in a paper accepted by the Astrophysical Journal Letters, is the peculiar nature of its transit signals. These signals manifest as the light observable from Earth when 55 Cancri e crosses in front of its parent star, essentially creating a miniature eclipse, as well as the light visible when the planet passes behind its star.
At times, during its “bald” phase, 55 Cancri e appears to emit no visible light from its atmosphere because it essentially lacks one, yet its scorching hot surface still emits infrared light. However, when the atmosphere expands, both visible light and the radiation from the planet’s surface become apparent in the transit signal.
In a groundbreaking hypothesis, researchers propose that the planet’s close proximity to its star triggers a continuous outgassing phenomenon. This involves the activation of massive volcanoes and thermal vents, which expel hot carbon-rich elements into the atmosphere. However, the planet’s extreme heat prevents it from retaining this atmosphere, causing it to be blown away, leaving the planet barren until the outgassing cycle resumes.
Intriguingly, unlike most planets, the atmosphere of 55 Cancri e is inherently unstable. The outgassing process attempts to build up the atmosphere, while the intense radiation and solar wind from the star work to disperse it. This imbalance in atmospheric processes may explain the irregular nature of the planet’s transit signals.
The James Webb Space Telescope (JWST) is poised to play a pivotal role in testing this hypothesis. By measuring the pressure and temperature of the planet’s atmosphere, scientists aim to determine whether an atmosphere is consistently present or if it experiences these fascinating fluctuations.
As the JWST embarks on this astronomical journey, it may very well unlock the long-standing mystery of the ‘Hell Planet,’ shedding light on the enigmatic signals that have tantalized astronomers for two decades.