Home https://server7.kproxy.com/servlet/redirect.srv/sruj/smyrwpoii/p2/ Science https://server7.kproxy.com/servlet/redirect.srv/sruj/smyrwpoii/p2/ Why the early magnetic field of the moon may be responsible for life on earth

Why the early magnetic field of the moon may be responsible for life on earth



The habitability of the planet depends on many factors. One is the existence of a strong and long-lasting magnetic field. These fields are generated thousands of kilometers below the planet’s surface in its liquid core and extend far into space – protecting the atmosphere from harmful solar radiation.

Without a strong magnetic field, the planet struggles to stay in a breathable atmosphere – which is bad news for life as we know it. A new study published in Science Advances suggests that the moon’s already extinct magnetic field may have helped protect our planet̵

7;s atmosphere, as life formed about 4 billion years ago.

Today, the Earth has a strong global magnetic field that protects the atmosphere and low-orbit satellites from harsh solar radiation. In contrast, the Moon has neither a breathing atmosphere nor a global magnetic field.

Global magnetic fields are generated by the movement of molten iron in the nuclei of planets and moons. Maintaining fluid movement requires energy, such as heat trapped in the core. When there is not enough energy, the field dies.

Without a global magnetic field, charged particles of the solar wind (radiation from the Sun) passing near a planet generate electric fields that can accelerate charged atoms, known as ions, outside the atmosphere. This process is happening on Mars today and as a result it is losing oxygen – something that is directly measured by the atmosphere of Mars and the mission of volatile evolution (Maven). The solar wind can also collide with the atmosphere and kill molecules in space.

The Maven team estimates that the amount of oxygen lost from Mars’ atmosphere throughout its history is equivalent to the contents of a 23-meter-thick global water layer.

[Read: The Moon’s surface is rusting — and Earth may be to blame]

Probing of ancient magnetic fields

The new study examines how the early fields of the Earth and the Moon may have interacted. But exploring these ancient fields is not easy. Scientists rely on ancient rocks that contain small grains that have magnetized during rock formation, saving the direction and strength of the magnetic field at that time and place. Such rocks are rare and the extraction of their magnetic signal requires careful and delicate laboratory measurement.

Photo of the ancient moon with magnetic field lines.