
Back in 1986, Voyager 2 had discovered a surprisingly low amount of internal heat from Uranus when it passed the planet. Since then, scientists have thought of Uranus as the odd man out of the family of giant planets in our solar system, which also includes Jupiter, Saturn, and Neptune. These planets all have a tendency to release more heat into space than they take in from the sun.
According to a recent study, published Monday in Geophysical Research Letters, Uranus does have an internal heat source like its planetary siblings, which may have led scientists to misinterpret the data from Voyager 2. Uranus emits 12.5% more internal heat than it takes in from the Sun.
Compared to the other three giant planets, which release over 100% of the solar energy they receive, that is still a significant reduction in heat. However, the study that analyzed decades' worth of archival data on the ice giant shows that Uranus doesn't deviate significantly from the general knowledge of scientists regarding the formation and evolution of giant planets.
The researchers examined data on Uranus's global energy balance over an 84-year orbit of the Sun in order to arrive at this conclusion. The team discovered significant seasonal swings caused by the planet's erratic variations in sunlight exposure after combining this observational data with computational models.
The latest results align with a previous study on Uranus' energy balance that was published in May in the Monthly Notices of the Royal Astronomical Society.
The study, however, said that neither study provides a definitive explanation for why Uranus's internal heat is significantly lower than that of the other gas and ice giants. According to a statement from the researchers, Uranus might have had a "different interior structure or evolutionary history compared to the other giant planets."
Additionally, the study discovered that Uranus's energy levels fluctuate in accordance with its 20-year seasons. According to the study, these variations "provide observational constraints that can be used to develop theories of planetary formation for giant planets," in conjunction with the planet's heat budget.
As a result, Uranus is addressed as well as questioned in the paper, which the researchers point to as a compelling argument for further NASA exploration of the icy planet.
Liming Li, study co-author and physicist at the University of Houston, said, "By uncovering how Uranus stores and loses heat, we gain valuable insights into the fundamental processes that shape planetary atmospheres, weather systems, and climate systems," adding, "These findings help broaden our perspective on Earth's atmospheric system and the challenges of climate change."