Neptune and Uranus are the seventh and eighth planets from the sun, and as such share a lot of the same characteristics. Though they are different colors (Neptune is bluer than Uranus’ cyan hue) and have different numbers of rings and moons, both planets are ice giants that are similar sizes at just over 30,000 miles (50,000 kilometers) wide each. They also weigh about the same, with Neptune coming in at 1.024 × 10²⁶ kg (about 17 times the mass of Earth) and Uranus weighing 8.682 × 10²⁵ kg (about 14 times the mass of Earth). What’s more, both planets have upper atmospheres made up of mostly hydrogen, helium, and methane. Put simply, then, the characteristics of Neptune and those of Uranus are very similar despite their different colors.

Now, it seems the two worlds could have yet another thing in common, and this one is particularly intriguing when compared with Earth. Neptune and Uranus might be home to some incredibly deep oceans that make our own look like puddles.

Earth’s own oceans are already mysterious enough. They cover roughly 70% of the planet’s surface, yet only a small portion of our ocean has been explored, with the Nippon Foundation-Gebco stating that as of June 2024, just 26.1% of the entire seafloor had been mapped. The deepest trench in the ocean, known as the Challenger Deep, sits beneath the western Pacific Ocean, southwest of the U.S. territorial island of Guam, and is roughly 35,876 feet deep. Just what life is like at such depths remains somewhat of a mystery, with the deep ocean already proving to be home to prehistoric sea animals that are, frankly, nothing short of nightmare fuel. But the deepest ocean trenches on Earth are absolutely nothing compared to the depths of the oceans that might well exist on Neptune and Uranus.

As civilizations advance, they may need to migrate across the galaxy, and some researchers speculate they could use their own stars as massive engines.

New research explores the possibility of a binary stellar engine, particularly spider pulsars, as potential propulsion systems. By carefully manipulating these systems, a highly advanced extraterrestrial species.

A species is a group of living organisms that share a set of common characteristics and are able to breed and produce fertile offspring. The concept of a species is important in biology as it is used to classify and organize the diversity of life. There are different ways to define a species, but the most widely accepted one is the biological species concept, which defines a species as a group of organisms that can interbreed and produce viable offspring in nature. This definition is widely used in evolutionary biology and ecology to identify and classify living organisms.

What can Earth’s technosignatures—the potential signs of intelligence beyond Earth—teach us about finding technosignatures throughout the cosmos? Are we looking for the right technosignatures or do we need to refine our search methods or criterion? This is what a recent study published in The Astronomical Journal hopes to address as a team of researchers led by the SETI Institute essentially flipped the script to evaluate if current methods for detecting technosignatures are sufficient or could be modified going forward.

For the study, the researchers used a series of models to simulate the efficiency and distance that Earth’s technology in 2024 could be detected by an extraterrestrial civilization. This study comes as telescope instruments continue to advance, including identifying atmospheric compositions of exoplanets. Therefore, the goal of this work is to enhance this to potentially identify new methods in detecting technosignatures by using Earth as a control group as opposed to literally every other known world in the universe. In the end, the researchers found that extraterrestrial civilizations could potentially detect Earth technology as far as 12,000 light-years away, noting that the closer they travel to Earth, the more modern-day technology they would detect.

“One of the most satisfying aspects of this work was getting to use SETI as a cosmic mirror: what does Earth look like to the rest of the galaxy? And how would our current impacts on our planet be perceived,” said Dr. Sofia Sheikh, who is a postdoctoral researcher at the SETI Institute and lead author of the study. “While of course we cannot know the answer, this work allowed us to extrapolate and imagine what we might assume if we ever discover a planet, with, say, high concentrations of pollutants in its atmosphere.”