The asteroid belt disappears

Between the orbits of Mars and Jupiter is a region in the shape of a ring called asteroid belt, which houses the vast majority of space rocks in our solar system. The asteroid belt is as old as the solar system itself, after having formed from remaining materials which did not co-decorate in an adult planet due to the gravitational influence of Jupiter.

During the 4.6 billion years, Jupiter continued to shape the asteroid belt through gravitational resonances – regions where the orbit of an asteroid aligns with that of Jupiter, Saturn or Mars. This can either throw an asteroid to the inner solar system, or outwards towards the jupiter orbit. Meanwhile, those who do not escape constantly collide with other asteroids in the belt, being gradually sprayed in dust. As such, the asteroid belt slowly disappears.

In a new study that has not yet been reviewed by peers, researchers led by planetary scientist Julio Fernández from Universidad de La REPUBLICA in Uruguay estimate the rate of depletion of the belt. The results, currently available on the Arxiv pre -permitted server, indicate that the active collised part of the asteroid belt loses approximately 0.0088% of its mass every million years.

An act of disappearing very slow

The active collised part of the belt refers to asteroids small enough to be involved in frequent collisions and dynamic ejections – all that, except the large primordial bodies such as Ceres, Vesta and Pallas. A loss of 0.0088% per million years may not seem much, but during the eons, it adds up.

Fernández and his colleagues estimate that 3.5 billion years ago, the asteroid belt can have contained 50% more mass, with a double rate of loss that it is today. This estimate is well correlated with a more intense impact rate reflected in the earth and the geological recordings of the moon, according to the researchers.

Where are lost asteroids end up? Well, according to researchers’ calculations, around 20% escape in space, occasionally crossing the orbit of the earth and even falls in our atmosphere as meteors. The remaining 80% get the ground in the meteoritic dust that filters in the zodiac cloud – a thick pancake -shaped cloud that orbit the sun in the inner solar system.

Will the asteroid belt completely disappear?

Previous research has estimated that the combined mass of all asteroids in the belt today is almost equivalent to only 3% of the mass of the moon. However, it would take much more years for the belt to disappear completely by spraying and dynamic ejections alone. The death of the sun – which would occur in about 5 billion years – will destroy it earlier than that.

This study provides an answer to an undoubtedly more important question: at what rate of asteroid belt ejection space that could potentially have an impact on the earth? In addition, by extrapolating the dynamic ejection rate over time, researchers present data that can help scientists better understand the history of impact that has shaped the surface of the planet.