A day on Uranus is about half a minute longer than previously thought, according to new research.

Recent research published in Nature Astronomy has provided a revised estimate of the length of a day on Uranus, revealing that it lasts 17 hours, 14 minutes, and 52 seconds—28 seconds longer than the previous estimate made by NASA’s Voyager 2 spacecraft in 1986. This conclusion arose from a detailed analysis of 11 years of data collected by the Hubble Space Telescope, focusing on the planet's auroras and magnetic field. The improved precision in measuring Uranus' rotational period is vital for the scientific community as it allows for more accurate coordination when planning future missions to the planet, including potential atmospheric entry site selections for upcoming exploratory missions. Previously, the uncertainty surrounding Uranus' rotation had posed challenges, particularly distinguishing its magnetic axis. Laurent Lamy, the lead author of the study, highlighted the importance of the long-term data, marking the study as a resolution to a longstanding issue in planetary science. With a newfound capability to rely on a refined coordinate system, astronomers can now make more accurate comparisons between auroral observations extending over nearly 40 years. The methodology employed in this research underlines the significance of continuous astronomical observations and opens up new opportunities for understanding not just Uranus, but potentially similar exoplanets as well.