NASA's James Webb Space Telescope (JWST) has captured an extraordinary image of an unusually cold exoplanet in what scientists describe as a "chaotic" and "abnormal" planetary system. The discovery offers new insights into how planetary systems can develop in dramatically different ways from our own Solar System.
In addition to looking at distant stars, galaxies and exoplanets, the NASA/ESA/CSA James Webb Space Telescope will investigate our Solar System (Credit: Northrup Grumman)
The exoplanet, called 14 Herculis c, orbits a star located 60 light years away from Earth. What makes this discovery somewhat unusual is that the planet is one of the coldest ever directly imaged, with temperatures as low as minus 3 degrees Celsius. This is particularly significant because most of the nearly 6,000 known exoplanets that have been directly imaged are extremely hot, often reaching hundreds or thousands of degrees.
The planet is massive too at about seven times the weight of Jupiter but its cold temperature makes it much harder to detect and study. JWST’s infrared sensitivity allowed astronomers to capture this cold world, opening up entirely new possibilities for studying older, cooler planets that were previously beyond our reach.
“The colder an exoplanet, the harder it is to image, so this is a totally new regime of study that Webb has unlocked with its extreme sensitivity in the infrared,” - William Balmer, co-first author of the study and graduate student at Johns Hopkins University.
What makes the 14 Herculis system particularly unusual though is how its planets move. Unlike our Solar System, where planets orbit roughly in the same plane, the two planets in this system cross each other's paths like an "X," with their orbital planes tilted about 40 degrees relative to each other. This creates a complex gravitational system where the planets constantly tug and pull at one another.
This is the first time astronomers have ever captured an image of an exoplanet in such a misaligned system in a discovery that provides visual evidence of just how different planetary systems can be from our own.
The team of scientists behind the paper believe this chaotic arrangement helps us to understand the system's early history. The leading theory suggests that a third planet was once part of this system too but was violently ejected during the system's formation, causing the remaining two planets to scatter into their current unusual orbits.
Compared to our orderly Solar System, this discovery reminds us that planetary stability like our own isn't the norm throughout the universe. As researcher William Balmer noted, similar violent events could have occurred in our own Solar System's past, potentially affecting the fate of smaller planets like Earth, thankfully however, that never seems to have happened and we are here to tell the tale.
'The Blue Marble,' captured by Apollo 17 in December 1972 (Credit : NASA)
JWST’s detailed observations revealed another puzzle about 14 Herculis c. The planet appears dimmer than expected for an object of its mass and age, which the team attribute to "carbon disequilibrium chemistry.” This is a phenomenon where atmospheric churning brings molecules from warmer lower layers to the cold upper atmosphere very quickly creating an atmospheric composition that doesn't match what scientists would typically expect at such cold temperatures.
Future spectroscopic studies of 14 Herculis c could provide even more detailed information about its atmospheric composition and help scientists better understand the complex dynamics that shaped this remarkable system. The discovery demonstrates that the universe contains planetary arrangements far stranger and more diverse than we previously imagined, each with its own unique story of formation and evolution.
Source : Frigid Exoplanet in Strange Orbit Imaged by NASA’s Webb
