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Astronomers have long predicted that deep beneath Neptune’s thick blue clouds lies a super-hot body of water that, despite its high temperature, never boils because of its incredibly high-pressure atmosphere. Uranus, another planet in the outer solar system of similar size and composition, is also believed to have a similar water-rich interior. Unfortunately, due to their distances from Earth, it is hard to directly probe these two planets to test our assumption. But scientists have found novel ways of testing their theories about these ice giants from Earth.

As described in a newly-published study from Nature Astronomy, scientists recreated the pressure and temperature of the interiors of Neptune and Uranus in a lab. The aim of the experiments was to test hypotheses about the chemistry of the deep water within these planets. But the study could have additional implications for what we know about potentially habitable planets in other solar systems.

“We were seeking to extend our knowledge of the deep interior of ice giants and determine what water-rock interactions at extreme conditions might exist,” said lead author Taehyun Kim, of Yonsei University in South Korea. “Ice giants and some exoplanets have very deep water layers, unlike terrestrial planets. We proposed the possibility of an atomic-scale mixing of two of the planet-building materials (water and rock) in the interiors of ice giants.”

Circa 2020


Learn how a young team of additive manufacturing engineers helped bring 3D printed parts to the design of the GE9X, the world’s largest jet engine.

Stefka Petkova enjoys building things. It’s a passion she’s had since she was a small child when her dad, an electrician who liked to work on cars, kept the door to his workshop open. “I was exposed to that as a very young child and just got a lot of encouragement,” says Petkova, who she spent many afternoons watching him weld and wire automobiles.

Her childhood tinkering led her to study mechanical engineering at the University of North Florida, near America’s Space Coast, where she joined the school’s space club. She traveled with the club to Cocoa Beach to watch the liftoff of Space Shuttle Atlantis in 2011, NASA’s final flight in its Space Shuttle Program. “At the Atlantis launch, we were able to go in the overhaul facility, touch the space tiles protecting the shuttles and talk to the engineers,” she says. “It was an amazing experience.”

The continued growth of wireless and cellular data traffic relies heavily on light waves. Microwave photonics is the field of technology that is dedicated to the distribution and processing of electrical information signals using optical means. Compared with traditional solutions based on electronics alone, microwave photonic systems can handle massive amounts of data. Therefore, microwave photonics has become increasingly important as part of 5G cellular networks and beyond. A primary task of microwave photonics is the realization of narrowband filters: The selection of specific data, at specific frequencies, out of immense volumes that are carried over light.

Many photonic systems are built of discrete, separate components and long optical fiber paths. However, the cost, size, and production volume requirements of advanced networks call for a new generation of microwave photonic systems that are realized on a chip. Integrated microwave photonic filters, particularly in silicon, are highly sought after. There is, however, a fundamental challenge: Narrowband filters require that signals are delayed for comparatively long durations as part of their processing.

“Since the is so fast,” says Prof. Avi Zadok from Bar-Ilan University, Israel, “we run out of chip space before the necessary delays are accommodated. The required delays may reach over 100 nanoseconds. Such delays may appear to be short considering daily experience; however, the optical paths that support them are over ten meters long. We cannot possibly fit such long paths as part of a silicon chip. Even if we could somehow fold over that many meters in a certain layout, the extent of optical power losses to go along with it would be prohibitive.”

Circa 2020


Astronomers have found one of the largest structures in the known universe—a “wall” of galaxies that’s at least 1.4 billion light-years long. And given how close it is to us, it’s remarkable that we haven’t seen it before now.

What happened: An international team of scientists reported the discovery of the South Pole Wall in a paper published Thursday in the Astrophysical Journal. The structure is basically a curtain that stretches across the southern border of the universe (from the perspective of Earth) and consists of thousands of galaxies, along with huge amounts of gas and dust.

What do you mean by “wall”? Galaxies aren’t just strewn randomly throughout the universe. Along huge strands of hydrogen, galaxies collect into larger groupings of massive filaments, separated by giant voids of nearly empty space. Each filament is basically a wall of galaxies, stretching for hundreds of millions of light-years. They’re the biggest structures in the known universe. Other identified structures include the Great Wall, the Sloan Great Wall, the Hercules-Corona Borealis Great Wall, and the Bootes Void.