Jupiter’s moon, Europa, has long been hypothesized to contain a vast, liquid water ocean beneath its icy crust. But has this crust remained stationary, or has it moved over millions of years since it could be separated from the ocean below? This is what two recent studies published in The Planetary Science Journal and JGR Planets hope to address as high-resolution images from NASA’s Juno spacecraft revealed some unique surface features on the small moon. These images and studies hold the potential to help scientists better understand what they refer to as “true polar wander” on Europa, which is a hypothesis stating that Europa’s outer icy shell moves freely since it’s allegedly detached from the ocean underneath.

“True polar wander occurs if Europa’s icy shell is decoupled from its rocky interior, resulting in high stress levels on the shell, which lead to predictable fracture patterns,” said Dr. Candy Hansen, who is a co-investigator on Juno, along with being lead author of The Planetary Science Journal study and a co-author on the JGR Planets study. “This is the first time that these fracture patterns have been mapped in the southern hemisphere, suggesting that true polar wander’s effect on Europa’s surface geology is more extensive than previously identified.”

Astronomers have discovered an enormous, low-density planet named WASP-193b, which is 50% larger than Jupiter but has a cotton candy-like density. This finding challenges current planetary formation theories, as scientists cannot explain how such a planet could form.

Astronomers have discovered a huge, fluffy oddball of a planet orbiting a distant star in our Milky Way galaxy. The discovery, reported on May 14 in the journal Nature Astronomy by researchers from at MIT, the University of Liège in Belgium, and elsewhere, is a promising key to the mystery of how such giant, super-light planets form.

The new planet, named WASP-193b, appears to dwarf Jupiter in size, yet it is a fraction of its density. The scientists found that the gas giant is 50 percent bigger than Jupiter, and about a tenth as dense — an extremely low density, comparable to that of cotton candy.

In response to these problems, the authors of the new paper came up with a simple suggestion: a tweak to Einstein’s theory at different distance scales.

“The modification is very simple: We assume the universal constant of gravitation is different on cosmological scales, compared to smaller (like solar system or galactic) scales,” Afshordi said. “We call this a cosmic glitch.”

One such feature is lunar #lobate #scarps, long curvilinear landforms due to thrust fault movement (older rocks are pushed above younger units leading to crustal shortening.

#Lunar #Landforms indicate Geologically Recent #Seismic #Activity on the #Moon.

The moon’s steadfast illumination of our night sky has been a source of wonder and inspiration for millennia. Since the first satellite images of its surface were taken in the 1960s, our understanding of Earth’s companion through time has developed immeasurably. A complex interplay of cosmic interactions and planetary systems, the moon’s surface displays a plethora of landforms evidencing its history.

One such feature is lunar lobate scarps, long (10 km) curvilinear landforms resulting from thrust fault movement, where older rocks are pushed above younger units leading to crustal shortening. These are thought to be some of the youngest landforms on the moon, forming within the last ~700 million years (the Copernican of the lunar geologic timescale). For context, this is considered geologically “young” as the universe is estimated to be 13.7 billion years old.

These lunar lobate scarps are the focus of new research, published in Earth and Planetary Science Letters, that use craters in the surrounding highland landscape as indicators of scarp movement and therefore are ideal candidates for estimating ages.