On April 7, a unique event occurred: Uranus passed in front of a distant star, creating a rare “stellar eclipse.” This allowed NASA scientists to study the atmosphere and rings of the ice giant, which usually remains a mystery due to its remoteness (almost 2 billion kilometers from the Sun).
During the hour-long event, light from a star 400 light-years away was refracted in the atmosphere of Uranus. Although the star dimmed, this effect provided clues to the planet’s stratosphere – its temperature, density and pressure. 30 astronomers from 18 observatories in North America recorded light changes, creating a light curve.
“These data will help us understand why Uranus’ upper atmosphere is hotter than models suggest,” explained NASA planetologist William Saunders.
In addition, the researchers obtained new data on the planet’s rings, its turbulence and orbital motion.
Aiming from billions of kilometers away
The success was preceded by a test run in November 2024, when scientists observed a similar eclipse through telescopes in Asia. Then it was possible to clarify the position of Uranus at 202 km – critical for pointing telescopes at an object moving billions of kilometers from Earth.
Interestingly, since the Voyager 2 flyby in 1986, the accuracy of determining the planet’s orbit has improved from 160 km to 100 km. “It’s like hitting a moving target from the other end of the solar system,” the scientists ironized.
Plans for 2031
Uranus is amazing with its 13 rings, 27 moons, and hot stratosphere. Its atmosphere is a mixture of hydrogen, helium, methane and ammonia that forms violent winds and storms. But the main mystery is the heating mechanism of the upper layers, which are hundreds of degrees hotter than expected.
NASA is already preparing for the next stellar eclipse in 2031, when Uranus will occlude a brighter star. Observations are planned from ground, air and space telescopes simultaneously, which will increase the accuracy of the data collected. “Each such event is a chance to solve at least one of the ice giant’s mysteries,” the researchers emphasize.
Uranus is a unique laboratory for studying the evolution of gas giants. Its study helps us understand not only our solar system, but also exoplanets of a similar type.
Previously, we reported the top 5 surprising facts about Uranus.
According to NASA
