The ESA’s Mars Express probe has been surveying Mars from orbit for more than twenty years. The way it has mapped the surface using its High Resolution Stereo Camera (HRSC) has drastically changed the way we see the Red Planet. In a recent article, the ESA shared a series of HRSC images highlighting the heavily cratered region known as Arabia Terra. The study of Martian craters offers insight into Mars’ geology, meteorology, and its long and turbulent history. The images were generated from the camera’s digital terrain model and the nadir and colour channels.

The image at the top shows the Arabia Terra region, a large plain in the Southern Highlands, heavily pockmarked with craters formed by impactors that struck the planet over time. The features are labelled (if you click on the image) and can be magnified. The volume of craters results from Arabia Terra being one of Mars’ oldest geological formations, with estimates ranging from 3.7 to 4.1 billion years old. It was during this time that geologically activity ceased in Mars’ interior, causing it to lose its planetary magnetosphere and leading to its atmosphere being slowly stripped away by solar wind.

*A bird’s-eye view of a region inside Trouvelot Crater, showing the dark, volcanic deposits covering the crater floor and a light-toned mound seen sitting within these deposits. Credit: ESA/DLR/FU Berlin*

Similar to how the Moon’s airless environment has preserved its craters, Mars’ thin atmosphere has kept these craters well-preserved. Some of the craters in the image are filled with dark material, while others are filled with lighter sands and rippling dunes. This suggests that some of this sand was deposited by Martian dust storms, while other material could have been ejected by the impacts themselves. Others still show signs of collapsing crater walls and worn-down rims, also indicative of wind-driven erosion.

To the left of Trouvelot Crater is an older, more eroded basin with a completely collapsed wall almost entirely covered in dark rock. This material has been shaped by wind into the characteristic rippling structures known as “barchan” dunes, which are notable for their crescent-shaped profile. Mars Express has imaged these dunes in multiple locations in the Northern Lowlands and the large volcanic region of Tharsis. The dark material, known as “mafic rock,” is mineral-rich and often associated with volcanism here on Earth.

*Close-up image showing the light-toned mound at the upper left, standing out amongst the dark rock. Credit: ESA/DLR/FU Berlin*

Once again, this is indicative of material ejected by impacts that was blown around by winds and eventually pulled down along the crater walls. The fact that Trouvelot cuts through this crater indicates that it is the younger of the two, and the commonality of craters with dark material suggests that the mechanisms involved are ubiquitous on Mars. Amid the dark material, there is a light-toned mound measuring about 20 km (~12.5 mi) long and covered in ridges and grooves. Such mounds have been observed in other locations, and are indicative that other processes may be at work.

One clue is the minerals observed in these mounds, which suggest they formed in the presence of flowing water. Whether this is the case remains the subject of scientific debate, and there are several ways in which they could have been deposited by water.

Further Reading: ESA

For months, former residents of the Pacific Palisades Bowl Mobile Estates have feared the uncommunicative owners of the property would seek to displace them in favor of a more lucrative development deal after the Palisades fire destroyed the rent-controlled, roughly 170-unit mobile home park.

A confidential memorandum listing the Bowl for sale indicates the owners intend to do exactly that.

The memorandum, quietly posted on a website associated with the global commercial real estate company CBRE, says that the Palisades fire created a “blank canvas for redevelopment” at a site “ideally positioned for a transformative residential or mixed-use project.”

“I just thought, oh my god, this is so much propaganda and false advertising,” said Lisa Ross, a 33-year resident of the Bowl and a Realtor. “How can they even get away with printing this?”

Neither the current owners of the Bowl nor the real estate companies listed on the memorandum responded to requests for comment.

The memorandum describes the current single-family residential zoning as “favorable” for developers; however, the city and mobile housing law experts have painted a different picture.

Fire debris at Pacific Palisades Bowl in January 2026.

(Myung J. Chun / Los Angeles Times)

“Multifamily and mixed-use development on this site is not allowed by existing zoning and land use regulations,” Mayor Karen Bass’s office said in a statement Wednesday, adding only low density single-family housing or reconstructing the mobile home park are currently allowed. “Mayor Bass will continue taking action and [work] with residents to restore the Palisades community.”

City Councilmember Traci Park also reiterated her focus on getting the mobile home park rebuilt and allowing residents to return, with a spokesperson noting she is not entertaining the potential for any rezoning efforts from a developer.

Zoning changes typically require a city council vote and are subject to the mayor’s approval or veto.

Beyond the zoning laws, the site is also currently governed by a state law requiring cities to preserve affordable housing along the coast and a city ordinance protecting mobile home residents against sudden displacement.

Spencer Pratt, a resident of the Palisades and an outspoken supporter of the neighborhood’s mobile home community, criticized the mayor and the owners in a statement to The Times. “It’s unfortunate that Karen Bass has not advocated for mobile home residents impacted by the fire,” he said, “and that the current owner of the Bowl is ignoring good faith offers from residents to buy the property.”

The mayor’s office disputed this, noting Bass recently led a delegation of Palisadians, including mobile home owners, to Sacramento to advocate for recovery. “Mayor Bass’ priority is getting every Palisadian home — single-family homeowners, town home owners, renters, mobile home owners.”

Los Angeles Mayor Karen Bass speaks during a private ceremony outside City Hall with faith leaders, LAPD officers and city officials to commemorate the one-year anniversary of the Eaton and Palisades fires on Jan. 7, 2026.

(Allen J. Schaben / Los Angeles Times)

Bass also advocated for the federal government to include the Bowl in its debris cleanup efforts; however, the Federal Emergency Management Agency ultimately refused to include it, unlike other mobile home parks impacted by the Palisades fire. Its reasoning: It could not trust the owners to rebuild the park as affordable housing.

Court rulings over the years found the owners routinely failed to maintain the infrastructure and worked to replace the park with an “upscale resort community.” Residents also accused the owners of attempting to circumvent rent control regulations.

After the fire, it ultimately took more than 13 months to begin cleaning up the debris.

Ross said she approached the owners with independent mobile home park developers who were interested in buying the fire-destroyed lot and letting residents rebuild within months. She also approached the owners with a proposition that the former residents band together to buy the park. She heard nothing back.

“They don’t communicate,” Ross said. “It’s a feuding family. That’s also why we had so many problems with maintenance and with upgrades in the park.”

Pratt, who is running for mayor against Bass, also called on private developers like Rick Caruso to step in and save the Bowl. (Caruso’s team noted his rebuilding nonprofit is looking into how to help residents of the Bowl.)

Ross is a fan of Pratt’s proposition. “We need those kinds of people — we need Rick Caruso. That would be great,” Ross said. To sweeten the deal: “I’ll cook for him. I would make him all his favorite dishes.”