3D Mapping of Exoplanet WASP-18b

WASP-18b is a massive gas planet classified as a “very hot Jupiter,” located 400 light-years from Earth. Researchers from the University of Maryland and Cornell University have applied a new technique to create three-dimensional temperature maps of this planet, opening new avenues for understanding the atmospheres of exoplanets.

Utilizing 3D Mapping Technology

This study relies on a technique known as eclipse mapping or spectral eclipse mapping, marking the first time it has been used to construct a complete 3D temperature map. This method was developed from a two-dimensional map released in 2023 using highly sensitive observations from NASA’s James Webb Space Telescope.

According to Megan Wiener Mansfield, an assistant professor of astronomy at the University of Maryland and a co-author of the study, this technique is the only one capable of exploring all three dimensions simultaneously: latitude, longitude, and altitude, providing a higher level of detail for studying these celestial bodies.

Challenges in Observing Exoplanets

Observing exoplanets is a significant challenge because they are usually less bright than their stars, often contributing less than 1% of the total light. The eclipse mapping technique measures subtle changes in this light as the planet moves behind its star, revealing and concealing different regions.

This approach enables scientists to begin mapping atmospheric variations across many exoplanets observable by the James Webb Telescope, similar to how ground-based telescopes have documented Jupiter’s Great Red Spot and its distinctive clouds.

Results and Future Applications

Research has shown that WASP-18b is particularly suitable for this test due to its unique characteristics, with a mass about ten times that of Jupiter, completing its orbit in just 23 hours, and temperatures reaching 5,000 degrees Fahrenheit. These properties provide a relatively strong signal for the new mapping method.

The 3D analysis reveals spectrally distinct regions on the planet’s permanent day side, where a circular hot spot exists directly exposed to the star’s light, and winds are too weak to effectively distribute that heat.

Conclusion

This new study opens up vast possibilities for studying exoplanets in ways previously impossible. By using 3D mapping technology, scientists can now accurately and intricately determine atmospheric composition and thermal changes. Additionally, this advancement could lead to a better understanding of other exoplanets, including small rocky planets beyond gas giants like WASP-18b.