Get the Popular Science daily newsletterSometimes, it feels like there is not enough time in the day here on Earth to get everything done. If human life existed on the planet Uranus, its likely the same phenomenon might happen. But now we know that a single day on Uranus is 28 seconds longer than astronomers first calculated in the 1980s. By using a more accurate set of measurements taken with the NASA/ESA Hubble Space Telescope, it actually takes Uranus 17 hours, 14 minutes, and 52 seconds (not 17 hours, 14 minutes, and 24 seconds) to complete one full rotation. The findings are detailed in a study published April 7 in the journal Nature Astronomy.For astronomers, determining a planets interior rotation rate is challenging and scientists cant take direct measurements of Uranus. To try and solve this, the team on this study developed a new method to track the rotational motion of Uranus using the planets aurorae. Just like Earths northern and southern lights, these spectacular light displays are generated in its upper atmosphere by a surge of energetic particles near the planets magnetic poles. However, Uranus aurorae are a little different from those on Earth or the ones that occur on Jupiter or Saturn. Uranus aurorae behave in a unique and unpredictable manner, primarily due to the planets highly tilted magnetic field. This high tilt is significantly offset from its rotational axis, causing Uranus to essentially be lying on its side.The team used more than a decades worth of observations of Uranus unique aurorae taken with Hubble and refined the planets rotation period. This technique revealed that it completes a rotation 28 seconds longer than what was estimated during NASAs Voyager 2 flyby in 1986.Our measurement not only provides an essential reference for the planetary science community but also resolves a long-standing issue: previous coordinate systems based on outdated rotation periods quickly became inaccurate, making it impossible to track Uranus magnetic poles over time, Laurent Lamy, a study co-author and astronomer, said in a statement. With this new longitude system, we can now compare auroral observations spanning nearly 40 years and even plan for the upcoming Uranus mission.This visual showcases 3 images from the NASA/ESA Hubble Space Telescope of the dynamic aurora on Uranus in October 2022. These observations were made by the Space Telescope Imaging Spectrograph (STIS) and includes both visible and ultraviolet data. CREDIT: ESA/Hubble, NASA, L. Lamy, L. Sromovsky. ESA/Hubble, NASA, L. Lamy, L. SrAccording to the team, this breakthrough was possible due to the almost 35-year-old space telescopes long-term monitoring of the farthest planet from the sun. Over more than a decade, Hubble has regularly observed Uranus ultraviolet auroral emissions and this data enabled researchers to track the position of the magnetic poles with magnetic field models.The continuous observations from Hubble were crucial, said Lamy. Without this wealth of data, it would have been impossible to detect the periodic signal with the level of accuracy we achieved.Observing whats going on in Uranus magnetic field not only helps astronomers better understand Uranus magnetosphere, but also provide vital information for future uncrewed missions to the third largest planet in the solar system.In 2022, The Planetary Science Decadal Survey in the United States prioritized the Uranus Orbiter and Probe concept for future exploration. While that mission is not off the ground yet, thefindings from this study could set the stage for additional research that deepens our understanding of one of the solar systems most mysterious planets. It also highlights how the Hubble Space telescope and its ability to monitor a single celestial body for decades continues to be an indispensable tool.