Observed for the first time from Earth a dark spot on the planet Neptune

Berlin. Using the European Southern Observatory’s (ESO) VLT telescope, located in northern Chile, a group of scientists was able to observe, for the first time from Earth, Dark spot on Neptuneas well as a smallest bright spotAccording to a study published in the journal Nature Astronomy on Thursday.

This is the first time that a dark spot on the planet has been observed using a ground-based telescope. These episodic phenomena have been detected in the blue background of Neptune’s atmosphere She is a mystery to the astronomical community These new findings provide additional clues about their nature and origin,” according to an ESO statement.

Great spots are common phenomena in the atmospheres of giant planets, such as the famous Great Red Spot on Jupiter, the most famous. The first time a dark spot was detected on Neptune was in 1989 thanks to NASA’s Voyager 2 observations..

ESO remembers that That spot disappeared after a few years. “Since the first discovery of the dark spot, I’ve always wondered what these elusive, short-lived dark events are,” says Patrick Irwin, a professor at the University of Oxford in the UK and lead researcher on the study.

Irwin and his team used data from the European Southern Observatory’s VLT to rule out the possibility that the dark spots were caused by a “clearing” in the clouds.

New observations indicate otherwise These dark spots are likely the result of darkening of air particles as a result of ice and clouds mixing in the atmosphereIt will be located in a layer below the main visible layer of Neptune’s haze.

ESO believes that reaching this conclusion was not an easy task, as dark spots are not permanent features of Neptune’s atmosphere and the astronomical community has not been able to study them in sufficient detail until now.

“An opportunity arose after NASA and the European Space Agency’s Hubble Space Telescope detected several dark spots in Neptune’s atmosphere, including one in the planet’s northern hemisphere that was first discovered in 2018. Irwin and his team immediately went to work, studying them. from the ground using an instrument suitable for these difficult observations.

Scientists Using the VLT’s Multi-Unit Spectroscopic Explorer (MUSE), they were thus able to divide the sunlight reflecting off Neptune and its spot into its colors or wavelengths, and obtained a three-dimensional spectrum.

In this way it was possible for them to study the spot in more detail, something that had not been done so far.

Because different wavelengths provide information about the different depths in Neptune’s atmosphere, the presence of the spectrograph allowed the team to better determine how high the dark spot is in the planet’s atmosphere. The spectrum also provided information about the chemical composition of the different layers of the atmosphere, giving clues as to why the spot appears dark.

There was also a surprising result. “And in the process we discovered a rare type of glowing deep cloud that had not been identified before, even from space.Michael Wong, study co-author and researcher at UCLA.

It appears as a bright spot next to the main, larger dark spot. The VLT data show that the new “deep bright cloud” was at the same level of atmosphere as the main dark spot. This means that it is a completely new type of phenomenon compared to the small “companion” clouds of methane ice, which were previously observed at high altitudes.

ESO estimates that features of such spots can now be studied by the astronomical community from Earth. “At first, we could only detect these points by sending a spacecraft there, like Voyager. Then we had the ability to discern them at a distance using Hubble. Finally, technology has evolved to allow this to be done from the Earth’s surface,” Wong concludes.