![Left: Average ocean fraction, calculated assuming a seawater freezing point of −1.8°𝐶 for Cases 1 and 3 and 0°𝐶 for Case 2. White shows the ice, and blue ocean. Middle: The mean near-surface air temperatures. Shown within the black contours are the regions where these vary between above and below freezing over the course of a single Earth year. Right: The mean surface temperatures. Also shown within the black contours are the regions where these vary between above and below freezing over the course of a single Earth year: these regions are narrower than the air ‘perifreezing zone’.-- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Sea-Ice.png?resize=1200%2C720&ssl=1)
[astro-ph.EP] Water worlds with potential deep oceans are at the forefront of currently observable exoplanetary habitability.
Oceanography
Posted inIcy Worlds
Amplified Cooling Of Snowball Earth From A Salt-albedo Feedback
[Climate of the Past] It is believed that the atmospheric circulation on Snowball Earth produced a net ablation zone exposing bare sea ice.
Posted inWater/Hycean Worlds & Oceanography
Iron Helped Scientists Trace Earth’s Oxygen. Now It’s Telling A Bigger Story
[Michigan State University] For decades, scientists have studied iron preserved in ancient rocks to reconstruct how Earth’s oceans and atmosphere became rich in oxygen. A new study suggests iron has […]
Posted inArctic / Antarctic / Alpine
Icy Ocean Planet Research: NASA ROSES-25 Amendment 71: New Opportunity A.16 Cryosphere
[NASA]. A.16 Cryosphere solicits high-impact efforts focused on sea ice, ice sheets, and glaciers. The expectation is that proposed investigations will use the wealth of data from NASA satellites and […]
Posted inWater/Hycean Worlds & Oceanography
Ocean World Exploration: 2026 American Samoa ROV + Mapping Exploration
[NOAA]. Most of the 13,581-square-mile National Marine Sanctuary of American Samoa lies far below the sunlit coral reefs visible from shore. Its protected waters include deep seamounts, abyssal plains, deep-sea […]
![Global maps of predicted pigment concentrations (left column) and pigment-to-chlorophyll-a ratios (right column) for May 2010 generated using the Random Forest model. Panels (a–f) show fucoxanthin, peridinin and zeaxanthin.-- [q-bio.OT]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/beyond.png?resize=1200%2C717&ssl=1)
Posted inBiosignatures & Paleobiology
Beyond Chlorophyll: Machine Learning Estimates Of Diagnostic Phytoplankton Pigments From Multispectral Ocean Colour Data
[q-bio.OT] Phytoplankton play a central role in marine ecosystems and the global carbon cycle, with different groups contributing differently to ocean biogeochemical processes.
Posted inWater/Hycean Worlds & Oceanography
MBARI Ocean World Expedition: Movement In The Deep
Editor’s note: When we start to mount Astrobiology missions to explore ocean worlds we’ll need ways for our robotic submersibles to observe and interact with whatever life forms they may […]
![This illustration contrasts Earth's oceans during ancient glaciations (left) with deglacial conditions (right). Syracuse University researchers found that oceans lost oxygen not just during warm periods, but repeatedly during Earth's deepest ice ages, a pattern preserved in manganese deposits within ancient seafloor rock. (Courtesy: Xubin Wang, generated with AI)-- [Syracuse University]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Metal-deposits.jpg?resize=1200%2C720&ssl=1)
Posted inBiogeochemical Cycles & Geobiology
Metal Deposits Linked To Oceanic Oxygen Loss During Ancient Ice Ages
[Syracuse University] An international team of researchers analyzed manganese and other chemical signatures preserved in more than 27,000 ancient seafloor samples collected from six continents. Across six major glaciations spanning […]
Posted inVenus
The Lost Oceans Of Venus
[Earth and Planetary Science Letters] Whether Venus once had oceans and, if so, when it lost them are critical issues in the understanding of habitability on exoplanets, as well as […]
Robotic One-Shot Exploration from Deep Ocean to Deep Space Workshop
Workshop Date: Thursday, October 1 (full day) Conference Dates: September 27 – October 1, Pittsburgh, PA, USA Many of the most compelling environments for scientific discovery are also among the […]