Tag Archives: ions

NILS discovers negative ions present on the moon’s surface

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of Negative Ion Laser Spectroscopy (NILS) Chinese Chang'e 6 Probe Negative ions have been detected on the surface of the moon. These ions are produced on the surface of the moon due to interactions with the solar wind.

The South Pole-Aitken Basin on the far side of the Moon is one of the largest and oldest impact features in the Solar System. It's easy to see in the elevation data: the low central area is dark blue and purple. The mountains on its edges, remnants of the outer ring, are red and yellow. Image credit: NASA/GSFC/University of Arizona.

The solar wind is a constant stream of radiation and particles emanating from the Sun. The Earth's magnetic field acts as a shield.

In contrast, the Moon has no magnetic field and a very thin atmosphere called the exosphere.

When the solar wind hits the Moon, it reacts with the surface, sending up secondary particles.

These particles may be positively or negatively charged, or may not be charged at all.

Positively charged particles have been measured from orbit before, but measuring negatively charged particles has been difficult.

Negative ions are short-lived and cannot reach orbit, which is why ESA scientists had to operate their instruments closer to the lunar surface.

“This is ESA's first operation on the lunar surface, a world first for science and our first lunar collaboration with China,” said Neil Melville, ESA's technical lead for the NILS experiment.

“We collected data in quantity and quality far beyond our expectations.”

“These observations on the Moon will help us to better understand the surface environment and serve as a precursor to exploring the distribution of negative ions on other atmosphere-less bodies in the Solar System, from planets to asteroids and other moons,” said NILS principal investigator Dr Martin Wieser.

Chang'e-6 is scheduled to successfully land in the South Pole-Aitken Basin on the far side of the moon on June 1, 2024.

NILS began collecting science data 280 minutes after landing. The first data collection period lasted 23 minutes, after which the instruments experienced a voltage drop. Several further data collection periods followed, during which communications were interrupted and restarted.

“The equipment was getting hot, so it was alternating between short periods of running at full power and longer periods of cooling down,” Melville said.

“The fact that we managed to stay within the thermal design limits and achieve a successful recovery in extremely hot conditions is testament to the quality of the research at the Swedish Institute of Astrophysics.”

Source: www.sci.news

Oxygen and carbon ions detected in Venus’s magnetosphere by BepiColombo

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In August 2021, ESA/JAXA BepiColombo spacecraft bound for Mercury Performed a second flyby of Venus, providing short-term observations of its guided magnetosphere. The spacecraft detected cold oxygen and carbon ions at a distance of about six planet radii, in an area of ​​the magnetosphere that has never been explored before.

Schematic illustration of planetary material escaping through the sides of Venus's magnetic sheath. The red line and arrow indicate the observation region and direction of BepiColombo as the ions escape (C+,oh+,H+) was observed. Image credit: Thibaut Roger / Europlanet 2024 RI / Hadid other.

Venus was similar to Earth in many ways during its formation, including the presence of large amounts of liquid water.

However, Venus eventually underwent a divergent evolution, leading to major differences between the two planets.

Unlike Earth, Venus is currently a very dry planet with no inherent magnetic field.

The continuous influence of the solar wind on the atmospheres of both planets results in significant atmospheric losses.

Venus' atmosphere is primarily composed of carbon dioxide and small amounts of nitrogen and other trace species, and is affected by interactions with the solar wind, leading to significant ion fluxes.

“This is the first time that positively charged carbon ions have been observed to be ejected from Venus's atmosphere,” said Dr. Lina Hadid, a researcher at the Plasma Physics Institute and CNRS.

“These are heavy ions that typically move slowly, so we're still trying to understand the mechanism.”

“An electrostatic 'wind' may be moving them away from Earth, or they may be accelerated by centrifugal action.”

“Unlike Earth, Venus does not generate an intrinsic magnetic field at its core.”

“Nevertheless, interactions between charged particles emitted by the sun (solar wind) and charged particles in Venus' upper atmosphere create a weak, comet-shaped 'induced magnetosphere' around the planet. ”

“Around the magnetosphere there is a region called the 'magnetic sheath' where the solar wind is slowed down and heated.”

On August 10, 2021, BepiColombo passed Venus to slow down and adjust its course towards its final destination, Mercury.

The probe soared up the long tail of the planet's magnetic sheath, emerging from the nose of the magnetic region closest to the sun.

Over a 90-minute observation period, BepiColombo's mass spectrometer (MSA) and mercury ion analyzer (MIA) will measure the number and mass of charged particles encountered, and detect chemical and Captured information about physical processes. magneto sheath.

“Characterizing the loss of heavy ions on Venus and understanding the escape mechanisms will help us understand how Venus's atmosphere evolved,” said Dr. Dominique Delcourt, principal investigator at MSA and researcher at the Plasma Physics Institute. “This is critical to understanding how water is lost.” .

“This result shows a unique result from measurements made during a flyby of a planet, in which the spacecraft may pass through areas that are generally inaccessible to orbiting spacecraft. '' said Dr. Nicolas Andre, a researcher at the Astrophysical and Planetary Institute.

of study It was published in the magazine natural astronomy.

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LZ Hadid other. BepiColombo's observations of cold oxygen and carbon ions on the side of Venus' induced magnetosphere. Nat Astron, published online on April 12, 2024. doi: 10.1038/s41550-024-02247-2

Source: www.sci.news