TOI-4994 b is classified as a "warm Saturn" because its size and density are similar to Saturn, but it’s much warmer due to its proximity to its star.
NASA’s planet-hunting satellite, TESS, has revealed another fascinating find—a planet slightly smaller than Saturn orbiting a star over 1,000 light-years away. This planet, named TOI-4994 b, belongs to a rare group of “warm Saturns,” a type of planet scientists are still trying to understand. Here’s what makes it special and why astronomers are excited about this discovery.
TOI-4994 b is classified as a “warm Saturn” because its size and density are similar to Saturn, but it’s much warmer due to its proximity to its star. While Saturn in our solar system is far from the Sun and cold, this exoplanet orbits much closer to its star—about 15% of the distance between Earth and the Sun—making it much hotter, with surface temperatures reaching around 445°C (717 K).
Despite its similarities to Saturn, TOI-4994 b offers a unique opportunity to study how planets form and evolve in extreme environments. So far, fewer than 20 such warm Saturns have been discovered, making this planet an important addition to our understanding of planetary diversity.
How Do Scientists Discover Planets Like This?
NASA’s TESS satellite works by detecting tiny dips in a star’s brightness, which happen when a planet passes—or “transits“—in front of it. In the case of TOI-4994 b, astronomers noticed a repeating pattern every 21.5 days, indicating the planet’s orbital period. To confirm the discovery, they used powerful ground-based telescopes, including the Las Cumbres Observatory Global Telescope.
The star home to this planet, called TOI-4994, is similar in size and mass to our Sun but is older, at approximately 6.3 billion years. It’s located about 1,079 light-years from Earth, which is roughly 10 quadrillion kilometers—a distance hard to imagine but common in space exploration.
Why Do Astronomers Study Planets Like TOI-4994 b?
Studying planets like TOI-4994 b can reveal how different types of planets form and interact with one another. Scientists believe TOI-4994 b’s current orbit might be the result of dramatic events, like collisions with other planets or gravitational pushes from its neighbors.
Future observations could also help astronomers measure the tilt of the planet’s orbit relative to its star’s rotation. This data will shed light on whether the planet’s path was shaped by violent interactions in its system’s early history.
For those new to astronomy, terms like “AU” (astronomical unit) or “light-years” might feel overwhelming. Simply put, an AU is the average distance between Earth and the Sun—about 150 million kilometers. A light-year, on the other hand, measures how far light travels in a year—nearly 9.5 trillion kilometers! By scaling discoveries like TOI-4994 b to these familiar concepts, scientists hope to make space exploration more understandable and engaging.
