We Know the Moon Makes Tides, but What About Mars?

04.04.2024 - 00:09 / atlasobscura.com

Let’s be blunt. Astrology has no basis in scientific fact. The motions of the planets and moons don’t meaningfully bolster or perturb your life. But that doesn’t mean that the planets don’t affect one another—and lately, scientists have come to suspect that Mars may be literally stirring tides within the depths of our world.

Don’t worry—we’re now in the realm of astronomy and astrophysics. Planets, in a very real sense, do directly influence one another. The more massive they are, the larger their gravitational influence, and although Mars may be rather diminutive—about one-sixth the volume of Earth—it is close enough, and just about big enough, to affect us. Its gravitational field is ever-so-gently pulling at Earth enough to create swirling vortices in our oceans.

A recent study, published in the journal Nature Communications, came to this conclusion by looking at sediment cores extracted from deep-sea sites all over the world, from the Pacific Ocean to the Indian Ocean, from Arctic waters to those just shy of Antarctica. The cores are the geologic equivalent of pulling an ancient tome off the shelf of Earth’s great archive—sedimentary records of ever-changing climate and environmental conditions far below the waves.

It is not just the content of the water but the way it flows that can be preserved within these cores. This information matters for a range of reasons, not least because the movement of deep-sea water affects how heat is transported around the planet, which can induce climatic swings, from minor deviations to major events, as if the oceans are fiddling with a global thermostat. For this new study, an international team of scientists took a look at almost 300 sediment cores providing a chronicle of deep-sea aquatic shifts dating back 65 million years.

The cores tell a curious story, one in which deep-sea currents wax and wane over time. That isn’t unusual by itself: The ocean is rife with currents that don’t remain constant. But these most Stygian currents seem to change their behavior in a cyclical manner—they strengthen and weaken in aggregate over a 2.4-million-year cycle. And when they reach their peak they can be fairly potent, creating whirlpool-like maelstroms that can scar and erode the seafloor.

That the team connected these whirlpools to Mars may sound like a bit of a stretch. Why look off-world when there’s so much to understand about these processes here? But it’s long been known that, on geological timescales, small shifts in the way that planets orbit the Sun can lead to significant changes in their climates. Earth itself is known to be bound by multiple astronomical cycles, from those with relatively short periods of 19,000 years to others that recur every 400,000 years.

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