Dust storms from Mars may be responsible for the zodiacal light, mysterious glow in the Earth’s night sky. The phenomenon is a beam of sunlight reflected by a mist of tiny particles towards the planet, occasionally visible after dark and just before dawn along the plane of the ecliptic, the strip where the Constellations of the Zodiac are found.
A team of scientists from the Juno mission was responsible for the discovery, published in the scientific journal Journal of Geophysical Research: Planets. An instrument aboard the NASA spacecraft happened to detect the small fragments in contact with the structure of the space probe, during its journey towards Jupiter.
The dust grains collided at a speed of about 16,000 km / h, which resulted in submillimetric chips in certain pieces of solar panels, but without serious damage. “Even though we are talking about objects with only a low amount of mass, they have a terrible impact,” said Jack Connerney, the project leader.
This observation occurred after a magnetometer, originally composed of cameras to determine Juno’s orientation in space and recognize star patterns, record unknown images of celestial objects. The device was designed by John Jørgensen, a professor at the Technical University of Denmark and involved in the research.
In this way, the scientists were surprised by the new capacity of the probe, becoming the largest and most sensitive detector of this type of space debris. “Each fragment we track records the impact of an interplanetary particle, allowing us to compile a distribution of dust along Juno’s path,” said Connerney.
To assist in the study, the mission team developed a computational model to predict the light reflected by the mist of dust, dispersed by the gravitational interaction with Jupiter, responsible for its scattering. Such an action depends on its inclination towards the ecliptic and its orbital eccentricity.
When the researchers connected the orbital elements of Mars, the distribution accurately predicted the revealing signature of the variation of the zodiacal light near the ecliptic. They claim that the dust fog ends on Earth, as the planet’s gravity attracts all the small particles. “This is the dust that we see as a zodiacal light,” said Jørgensen. The outer edge of the shiny layer extends just beyond Mars.
That’s because Jupiter’s gravity acts as a barrier, which prevents debris from spreading into deep space. Such influence is responsible for an almost circular orbit of dust around the Sun. “The only object we know of in an orbit with this characteristic is Mars, so we think that this must be the source of the phenomenon”, he pointed out.
Despite the evidence of the influence of the small particles of the Red Planet in the zodiacal light, scientists still do not know to explain the reasons that allow its exit from the Martian surface. However, the space agency points out that the development of the theme may help engineers to design materials for ships, aiming to better support the impacts in space.