Uranus and Neptune: Study reveals ‘true colors’ of two planets

A study published today (5) in the Monthly Notices of the Royal Astronomical Society Neptune is changing the way we know the planet. “While Voyager 2’s familiar images of Uranus were broadcast in a format closer to the ‘true’ color, those of Neptune were actually stretched and enhanced and thus artificially made very blue,” the authors write.

According to study leader Patrick Irwin, a professor at the University of Oxford in England, The two planets actually have similar shades of blue-green. But the first images of Neptune, transmitted by the Voyager 2 spacecraft in the summer of 1989, were darkened to emphasize its clouds, streaks and winds.

At the time, planetary scientists already knew the procedure for saturating the blue giant’s color, and the images were released with captions explaining this, Irwin said in a statement. But “this distinction was lost over time.”

Neptune’s natural colors are being restored

To restore Neptune’s colors to their original state, the team used new images from NASA’s Hubble Space Telescope and the European Space Agency’s (ESA) Very Large Telescope. With more modern instruments than Voyager 2 (built in 1977), it was possible to obtain the spectrum of the “true visible colors” of the two planets.

Scientists then took Voyager 2’s original images and rebalanced them in light of new data taken in ultraviolet, visible, and near-infrared wavelengths. The bluish color of the planets’ atmosphere is due to the methane layer that absorbs the reddish hue of sunlight.

The study concludes that Uranus is slightly whiter in color, possibly because the “still and slow” nature of its atmosphere allows methane haze to accumulate. This increases the degree of reflection of the red parts of sunlight.

Changes in the colors of Uranus

The study also addressed another mystery, the color change that occurs during Uranus’ 84-year orbit around the Sun. To do this, the authors compared images of the icy planet with brightness measurements recorded by the Lowell Observatory in Flagstaff. USA in blue and green wavelengths between 1950-2016.

This data showed A greener Uranus during the solstices (summer and winter)when one of the poles of the planet, practically turning sideways, points towards the Sun, this can be attributed to the presence of accumulated methane ice particles.

At equinox times, when the Sun is directly over the equator, the situation changes and the hue changes to the lightest blue. Near the poles, methane is half as abundant as seen at Uranus’ equator, according to the study.

Did you like the content? Therefore, at TecMundo, always keep up to date with the latest studies on the planets in our solar system and take the opportunity to understand why Neptune is cooling down when it should be warming up.