Photo: Fiona Elliott/NIWA

We landed a camera on Venus before seeing parts of our own oceans – it’s time to ramp up observations closer to home

17 October 2023

Viewed from the Voyager 1 space probe as it passed beyond the edge of the solar system, Earth and Venus might not look too different – same diameter, similar mass and distance from the Sun.

While the timeline that brought Venus’ climate to where it is today is still being researched, the critical difference between the two planetary systems is the ocean. Venus possibly never had one, but oceans on Earth have shielded us from the worst climate impacts by storing around 90% of the heat captured by the changing atmosphere.

We have managed to land a camera on the surface of Venus, with the Soviet space probe Venera 9 in 1975. Like the “Earth rise” image captured during the Apollo 8 mission in 1968, this again proved the power of visual imagery. Yet we’re still learning about our own oceans.

The first images of the surface of Venus arrived a year before we discovered mid-ocean hydrothermal vents and three years before we first looked beneath an Antarctic ice shelf.

If we want to better understand the climate-regulating role of Earth’s oceans, we must increase the effort we put into observing them, with a focus on our planet’s largest heat sink, the Southern Ocean.

Direct observations

Thanks to a variety of Earth-orbiting satellites and resource-intensive computer simulations, we have made progress in observing Earth’s oceans.

But as powerful and all-encompassing as these observations are, we still make surprise discoveries, such as vent systems on the seafloor and life in under-ice cavities. This is why we need to continue exploring and ramp up our capacity to measure the oceans directly.

Nowhere is this more true than in the Southern Ocean, the connector of all oceans.

Several unique features distinguish the Southern Ocean from Earths’ other oceans. One is Antarctica’s sea ice – the continent’s skirt of frozen ocean that comes and goes with the seasons.

The dramatic decline in Antarctic sea ice is of concern to the climate science community because of its several major roles: as a mirror that reflects solar energy back into space, a pump that ventilates the deep ocean, and an essential habitat for polar life, from algae to Emperor penguins.

Read the full article in The Conversation