New research shows that our
Moon once had an atmosphere 3 to 4 billion years ago. It formed when volcanic eruptions
rocked the ancient satellite, propelling gases above its surface too rapidly
for them to seep into space. The surface of the Moon is peppered with impact
basins filled with volcanic basalt. These basalt plains, called maria, were
formed when plumes of magma from inside the Moon erupted to the surface,
creating lava flows.
Astronauts from the Apollo missions brought back samples
from the maria to Earth, and we now know that the lava flows contained carbon
monoxide and other gas components, sulfur, and even the building blocks of
water.
Our Moon has no atmosphere
now, as it lacks a strong enough magnetic field and sufficient mass to hold an
atmosphere around it. Unlike Earth, which has sufficient mass and magnetism to
hang on to an atmosphere, any atmosphere around the Moon would quickly be
stripped away by solar winds. However, the new research indicates that the
Moon did briefly have an atmosphere before that happened.
The team used the samples to
calculate how much gas rose and accumulated to form the transient atmosphere.
They found that the volcanic activity peaked about 3.5 billion years ago, which
was when the atmosphere was at its thickest.
Once it formed, it persisted for
around 70 million years before it was stripped away and lost in space. During
the period when the Moon had an atmosphere, it was almost three times closer to
Earth, and therefore would have appeared much bigger in the sky.
Universities Space Research
Association (USRA) Senior Staff Scientist David
Kring told Phys.org, “This work dramatically changes our view of the Moon
from an airless rocky body to one that used to be surrounded by an atmosphere
more prevalent than that surrounding Mars today.”
This new information has
important implications for future astronauts, planned lunar missions and space
exploration. The research suggests that volatiles from the atmosphere may have
been trapped near the lunar poles in cold, permanently shadowed areas. If this
is true, there may already be a source of ice on the Moon that astronauts and
colonists can use for drinking water, growing food, and other needs.
Icy
deposits stocked with captured volatiles could also provide fuel and air for
both lunar surface operations and even missions beyond the Moon. And whatever
already exists on the Moon won’t need to be ported from Earth — a tremendous
advantage given the expense of carrying cargo into space.
Via Futursim
Via Futursim