Uranus Spins Slower Than We Thought

Uranus has been keeping secrets. It turns out that the planet takes a bit longer to spin on its axis than we previously thought. This discovery came from a recent study that looked at data from the Hubble Space Telescope. The telescope has been watching Uranus for over a decade. It showed that Uranus completes one full rotation in 17 hours, 14 minutes, and 52 seconds. This is 28 seconds longer than what NASA's Voyager 2 spacecraft measured back in 1986. That might not sound like much, but it's enough to change how we map the planet's surface. The Voyager 2 spacecraft gave us our first close-up look at Uranus. It measured the planet's rotation based on radio signals from its auroras and magnetic field. This estimate was the best we had for a long time. It helped scientists create maps of Uranus and figure out where things are on the planet. However, there was a problem. The initial estimate had some built-in errors. These errors caused a 180-degree mistake in Uranus' longitude. This meant that the planet's magnetic axis got lost within a few years after Voyager 2's visit. As a result, the coordinate systems based on the old rotation period became unreliable. To fix this, a group of astronomers led by Laurent Lamy from the Paris Observatory used Hubble's data. They tracked the movement of Uranus' auroras from 2011 to 2022. By watching these light shows, they could pinpoint the planet's magnetic poles more accurately. This gave them a better estimate of Uranus' rotation period. The team's work shows that continuous observations are key to understanding distant planets. Without Hubble's long-term data, this precise measurement wouldn't have been possible. This new method can be used to study other celestial bodies with magnetic fields and auroras. It's not just for planets in our solar system. It could also help us learn about exoplanets and other far-off worlds. The updated rotation period gives us a more reliable way to map Uranus. It will stay accurate for decades until new missions provide even better data. This improvement is crucial for planning future trips to Uranus. It helps in designing orbital paths and choosing safe spots for atmospheric entry. The study highlights the importance of long-term observations and the value of revisiting old data with new techniques.