News
Mars rovers serve as scientists’ eyes and ears from millions of miles away – here are the tools Perseverance used to spot a potential sign of ancient life
Mars rovers: NASA’s Perseverance rover recently identified potential signs of past life on Mars at a site called Bright Angel through mineral analysis. Using five advanced instruments, scientists interpreted complex data, but uncertainty remains. Future sample analysis on Earth may confirm these intriguing findings amid looming budget cuts impacting Mars exploration.
Mars rovers
Ari Koeppel, Dartmouth College
NASA’s search for evidence of past life on Mars just produced an exciting update. On Sept. 10, 2025, a team of scientists published a paper detailing the Perseverance rover’s investigation of a distinctive rock outcrop called Bright Angel on the edge of Mars’ Jezero Crater. This outcrop is notable for its light-toned rocks with striking mineral nodules and multicolored, leopard print-like splotches.
By combining data from five scientific instruments, the team determined that these nodules formed through processes that could have involved microorganisms. While this finding is not direct evidence of life, it’s a compelling discovery that planetary scientists hope to look into more closely.
To appreciate how discoveries like this one come about, it’s helpful to understand how scientists engage with rover data — that is, how planetary scientists like me use robots like Perseverance on Mars as extensions of our own senses.
Experiencing Mars through data
When you strap on a virtual reality headset, you suddenly lose your orientation to the immediate surroundings, and your awareness is transported by light and sound to a fabricated environment. For Mars scientists working on rover mission teams, something very similar occurs when rovers send back their daily downlinks of data.
Several developers, including MarsVR, Planetary Visor and Access Mars, have actually worked to build virtual Mars environments for viewing with a virtual reality headset. However, much of Mars scientists’ daily work instead involves analyzing numerical data visualized in graphs and plots. These datasets, produced by state-of-the-art sensors on Mars rovers, extend far beyond human vision and hearing. https://www.youtube.com/embed/Wz3Nzo09qko?wmode=transparent&start=1 A virtual Mars environment developed by Planetary Visor incorporates both 3D landscape data and rover instrument data as pop-up plots. Scientists typically access data without entering a virtual reality space. However, tools like this give the public a sense for how mission scientists experience their work.
Developing an intuition for interpreting these complex datasets takes years, if not entire careers. It is through this “mind-data connection” that scientists build mental models of Martian landscapes – models they then communicate to the world through scientific publications.
The robots’ tool kit: Sensors and instruments
Five primary instruments on Perseverance, aided by machine learning algorithms, helped describe the unusual rock formations at a site called Beaver Falls and the past they record.
Robotic hands: Mounted on the rover’s robotic arm are tools for blowing dust aside and abrading rock surfaces. These ensure the rover analyzes clean samples.
Cameras: Perseverance hosts 19 cameras for navigation, self-inspection and science. Five science-focused cameras played a key role in this study. These cameras captured details unseeable by human eyes, including magnified mineral textures and light in infrared wavelengths. Their images revealed that Bright Angel is a mudstone, a type of sedimentary rock formed from fine sediments deposited in water.
Spectrometers: Instruments such as SuperCam and SHERLOC – scanning habitable environments with Raman and luminescence for organics and chemicals – analyze how rocks reflect or emit light across a range of wavelengths. Think of this as taking hundreds of flash photographs of the same tiny spot, all in different “colors.” These datasets, called spectra, revealed signs of water integrated into mineral structures in the rock and traces of organic molecules: the basic building blocks of life.
Subsurface radar: RIMFAX, the radar imager for Mars subsurface experiment, uses radio waves to peer beneath Mars’ surface and map rock layers. At Beaver Falls, this showed the rocks were layered over other ancient terrains, likely due to the activity of a flowing river. Areas with persistently present water are better habitats for microbes than dry or intermittently wet locations.
X-ray chemistry: PIXL, the planetary instrument for X-ray lithochemistry, bombards rock surfaces with X-rays and observes how the rock glows or reflects them. This technique can tell researchers which elements and minerals the rock contains at a fine scale. PIXL revealed that the leopard-like spots found at Beaver Falls differed chemically from the surrounding rock. The spots resembled patterns on Earth formed by chemical reactions that are mediated by microbes underwater.
Together, these instruments produce a multifaceted picture of the Martian environment. Some datasets require significant processing, and refined machine learning algorithms help the mission teams turn that information into a more intuitive description of the Jezero Crater’s setting, past and present.
The challenge of uncertainty
Despite Perseverance’s remarkable tools and processing software, uncertainty remains in the results. Science, especially when conducted remotely on another planet, is rarely black and white. In this case, the chemical signatures and mineral formations at Beaver Falls are suggestive – but not conclusive – of past life on Mars.
There actually are tools, such as mass spectrometers, that can show definitively whether a rock sample contains evidence of biological activity. However, these instruments are currently too fragile, heavy and power-intensive for Mars missions.
Fortunately, Perseverance has collected and sealed rock core samples from Beaver Falls and other promising sites in Jezero Crater with the goal of sending them back to Earth. If the current Mars sample return plan can retrieve these samples, laboratories on Earth can scrutinize them far more thoroughly than the rover was able to.
Investing in our robotic senses
This discovery is a testament to decades of NASA’s sustained investment in Mars exploration and the work of engineering teams that developed these instruments. Yet these investments face an uncertain future.
The White House’s budget office recently proposed cutting 47% of NASA’s science funding. Such reductions could curtail ongoing missions, including Perseverance’s continued operations, which are targeted for a 23% cut, and jeopardize future plans such as the Mars sample return campaign, among many other missions.
Perseverance represents more than a machine. It is a proxy extending humanity’s senses across millions of miles to an alien world. These robotic explorers and the NASA science programs behind them are a key part of the United States’ collective quest to answer profound questions about the universe and life beyond Earth.
Ari Koeppel, Earth Sciences Postdoctoral Scientist and Adjunct Associate, Dartmouth College
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Food and Beverage
Philly-Style Chicken Cheesesteak Sandwiches: An Easy, Cheesy Dinner
Bring sandwich night home with these Philly-style chicken cheesesteaks. Thinly sliced chicken, sautéed onions and peppers, and melted cheese fill toasted hoagie rolls for a satisfying meal in about 35 minutes.
Food & Drink
Easy Philly Chicken Cheesesteak Recipe
Tender chicken, golden onions, sautéed peppers, and melted cheese tucked into a toasted hoagie roll—this Philly-style chicken cheesesteak brings plenty of comfort to the dinner table without a complicated ingredient list.
Inspired by the beef cheesesteak, this chicken version makes a satisfying lunch, a casual weekend meal, or an easy dinner when you want something warm and filling. The trick is to slice the chicken thin, give it room to brown, and melt the cheese right over the filling before scooping everything into the rolls.
This home-style recipe includes bell peppers, with mushrooms as an optional addition. Make it your own with creamy white American cheese, mild provolone, or a slice of each.
Recipe at a Glance
● Servings: 4 sandwiches
● Prep time: Approximately 15 minutes
● Cook time: Approximately 20 minutes
● Total time: Approximately 35 minutes
● Equipment: Large skillet with a lid, cutting board, sharp knife, and a separate skillet or oven for toasting rolls
Ingredients
For the filling
● 1½ pounds boneless, skinless chicken breasts or thighs, very thinly sliced across the grain
● 1 medium yellow onion, thinly sliced
● 1 large green bell pepper, seeded and thinly sliced
● 2 tablespoons olive oil or neutral cooking oil, divided
● 1 teaspoon garlic powder
● ½ teaspoon paprika
● ½ teaspoon salt, or to taste
● ½ teaspoon freshly ground black pepper
● 8 slices provolone or white American cheese, or a combination
For the sandwiches
● 4 hoagie rolls
● 2 tablespoons softened butter
● Mayonnaise, optional
● Hot sauce or sliced pickled peppers, optional
Optional addition: 8 ounces sliced mushrooms. Cook them with the vegetables, working in batches if needed so they brown instead of steam.
How to Make Philly-Style Chicken Cheesesteaks
1. Slice and season the chicken
Slice the chicken as thinly as you comfortably can, cutting across the grain. Toss with the garlic powder, paprika, salt, and black pepper.
Kitchen tip: If the chicken is difficult to slice, place it in the freezer for 15–20 minutes to firm it slightly first. This optional chilling time is additional to the recipe’s listed prep time.
2. Sauté the onions and peppers
Heat 1 tablespoon of oil in a large skillet over medium-high heat. Add the onion and bell pepper. Cook for approximately 6–8 minutes, stirring occasionally, until softened and lightly browned.
Transfer the vegetables to a plate.
3. Cook the chicken
Add the remaining tablespoon of oil to the skillet. Add the chicken in an even layer, cooking in batches if necessary.
Cook for approximately 5–7 minutes, turning and separating the pieces as they cook. Timing will vary with the thickness of the chicken and the heat of your pan. Cook until the chicken reaches 165°F, checking the thickest pieces with a food thermometer.
Use a spatula to break the cooked chicken into smaller, sandwich-friendly pieces.
4. Toast the rolls
While the chicken cooks, split the hoagie rolls without cutting all the way through. Spread the cut sides with softened butter.
Toast them butter-side down in a separate skillet over medium heat until lightly golden. Alternatively, toast them cut-side up under the broiler, watching closely.
5. Combine the filling and melt the cheese
Return the cooked vegetables to the skillet with the chicken and toss together. Reduce the heat to low.
Arrange the filling into four portions and place two slices of cheese over each portion. Cover the skillet briefly, just until the cheese melts. If your skillet is too small, melt the cheese over two portions at a time.
6. Fill and serve
Spread a little mayonnaise inside the rolls if desired. Scoop a portion of cheesy chicken and vegetables into each roll.
Finish with hot sauce or pickled peppers if you like a little heat, and serve immediately.
Tips for a Better Sandwich
Keep the chicken thin. Thin slices cook quickly and make the sandwich easier to bite into.
Give the pan some space. Crowding traps moisture. Cooking in batches helps the chicken develop a browned surface.
Choose a sturdy roll. A roll with a soft interior and enough structure to hold the filling works well. Light toasting helps it stand up to the juices.
Pick your cheese. White American gives the filling a creamy texture. Provolone adds a mild, slightly tangy flavor. Combining them gives you a little of both.
Adjust the vegetables. Try red bell pepper for a sweeter filling, add mushrooms, or keep it simple with onions and cheese.
What to Serve With Chicken Cheesesteaks
French fries, potato wedges, coleslaw, or a crisp green salad all make easy sides. For a simple lunch, add a dill pickle and a handful of potato chips.
Can You Make the Filling Ahead?
Yes. Cook the chicken and vegetables ahead, then keep the filling separate from the rolls. Reheat it until hot throughout before adding cheese and assembling the sandwiches. Toast the rolls just before serving for the best texture.
A Comfort-Food Favorite for Your Dinner Rotation
These Philly-style chicken cheesesteaks turn a handful of everyday ingredients into a hearty meal. With tender chicken, sautéed vegetables, and cheese melted into every serving, they’re an easy option for sandwich night.
What goes on your chicken cheesesteak—provolone, white American, mushrooms, or extra peppers? Tell us in the comments.
Find more recipes and meal inspiration in the STM Daily News Food & Drink section.
Related reading from STM Daily News
- Easy Homemade Chicken Alfredo Recipe Another comforting chicken dinner to try.
- Fried Chicken from the Comfort of Home More inspiration for homemade chicken meals.
- How to Make Country Style Lemonade A refreshing drink to serve with your sandwiches.
- STM Daily News Food & Drink Explore more recipes, food news, and meal ideas.
Helpful cooking reference
Safe Minimum Internal Temperatures — FoodSafety.gov Supports the recipe’s instruction to cook chicken to 165°F.
- Philadelphia Cheesesteaks — Visit Philadelphia — Explore Philadelphia’s signature sandwich and cheesesteak culture. Visit Philadelphia
- A Guide to the Best Cheesesteaks in Philadelphia — Includes shops serving traditional and chicken variations. Visit Philadelphia
- Chicken From Farm to Table — USDA — Guidance on handling, thawing, cooking, and storing chicken. Food Safety and Inspection Service
- Leftovers and Food Safety — USDA — Helpful storage and reheating guidance for leftover sandwich filling. Food Safety and Inspection Service
Daily News
Major Construction Begins on Metro’s East San Fernando Valley Light Rail Line
LA Metro has moved the East San Fernando Valley Light Rail Transit Project into major construction. The 6.7-mile Van Nuys Boulevard line will add 11 stations, connect with the G Line and regional rail services, and is now targeted for completion in early 2032.
After years of utility relocation and planning, LA Metro is moving into major construction on a new rail line along Van Nuys Boulevard. The milestone also comes with a revised early-2032 completion target.
LA Metro has officially marked the beginning of major construction on the East San Fernando Valley Light Rail Transit Project, moving one of the region’s most important rail projects from preparatory work into full-scale construction.
Metro held a groundbreaking ceremony on October 19, 2026, for the 6.7-mile line, which will run along Van Nuys Boulevard from the G Line busway north to San Fernando Road in Pacoima. The project will add 11 light-rail stations serving Van Nuys, Panorama City, Arleta and Pacoima.
This was not the project’s first groundbreaking. Metro held an earlier ceremony in December 2022 when crews began relocating utility infrastructure. The new milestone is more consequential for riders: the major-construction phase covers the guideway, stations, traction-power substations, rail systems and a maintenance and storage facility.
From utility work to a new rail corridor
The project has spent several years in utility relocation, property acquisition, design and other early work. Metro’s current construction timeline shows major work continuing from 2026 through 2032, with phased traffic changes and K-rail installations expected along Van Nuys Boulevard.
When completed, trains are expected to operate every seven to 10 minutes during peak periods. The line will connect directly with the G Line and provide access to the Van Nuys Metrolink and Amtrak station. It is also expected to become an important transfer point for the future Sepulveda Transit Corridor and a planned Metrolink station in Pacoima.
The corridor already has a substantial transit market. Metro reported that bus Lines 233 and 761, which serve Van Nuys Boulevard, recorded nearly 20,000 boardings in September 2026. The agency also says approximately 19 percent of households in the project area lack access to a car, compared with about 8 percent countywide.
Those figures help explain why this project matters beyond its construction footprint. It is intended to give residents in some of the Valley’s most transit-dependent communities more reliable access to jobs, schools, healthcare and the wider regional transit network.
The opening target has moved to 2032
Metro’s current project page lists an estimated completion date of early 2032. That is later than the 2031 opening forecast the agency publicized when it celebrated an $893-million federal grant in September 2024. Earlier plans were more optimistic still: when utility work began in 2022, Metro said the first segment could open between 2028 and 2030.
The project’s financial scale has also grown clearer. In May 2026, the Metro Board established a life-of-project budget of approximately $3.999 billion and authorized the next phase of its progressive design-build contract with San Fernando Transit Constructors, a joint venture of Skanska and Stacy and Witbeck.
That authorization increased the construction contract’s value to roughly $2.431 billion. Funding for the larger project combines federal, state and local sources, including revenue from Los Angeles County’s Measure M transportation sales tax.
Rail returns to Van Nuys Boulevard
The East San Fernando Valley line will restore passenger rail to Van Nuys Boulevard for the first time since Pacific Electric ended streetcar service there in 1952. It will also become the first major new Metro rail project in the San Fernando Valley since the subway reached North Hollywood in 2000.
The historical parallel is significant. Van Nuys Boulevard once developed around electric railway service before the region shifted heavily toward automobiles and buses. Metro is now rebuilding rail in the same broad corridor, but as part of a modern network designed to connect local riders with bus rapid transit, regional rail and future high-capacity projects.
The current project ends in Pacoima. Metro continues to study a separate 2.5-mile northern extension that would reach the Sylmar/San Fernando Metrolink station. That extension is not included in the segment now entering major construction.
For riders, the October groundbreaking does not mean trains are imminent. Several years of disruptive and technically complex work remain, and the schedule has already moved beyond earlier forecasts. Still, it represents a tangible transition: the East San Fernando Valley line is no longer primarily a planning exercise or utility-relocation program. Metro has begun building the infrastructure that will carry trains.
That makes this a major step in Los Angeles County’s long effort to restore frequent rail transit to communities that lost it generations ago—and another chapter in The Long Track Back.
Primary sources
- LA Metro: Major construction will soon be underway
- LA Metro project page: East San Fernando Valley Light Rail Transit
- LA Metro Board meeting, May 28, 2026 — project budget and contract authorization
- LA Metro: $893 million federal grant announcement, September 6, 2024
- LA Metro: Advanced utility-work groundbreaking, December 2, 2022
This article is part of The Long Track Back, STM Daily News’ continuing coverage of how Los Angeles is rebuilding and expanding a passenger-rail network after decades of automobile-centered grow
For generations, the Santa Monica Pier sign has marked the start of a day at the beach. Now, the familiar blue neon landmark is preparing for a journey of its own.
Santa Monica scheduled removal of the 1941 sign for October 20–22, with shipment to Las Vegas anticipated October 26. The timetable is subject to change, according to the city’s October 19 announcement.
The temporary removal accompanies replacement of the aging bridge connecting Ocean Avenue to the pier. It also creates an opportunity to preserve the historic sign.
YESCO will restore it at its Las Vegas facility. The company’s experience includes work on the “Welcome to Fabulous Las Vegas” sign.
Crews will repair neon tubing, treat rust, repaint components and address structural needs while retaining historic features. The sign will remain in secure storage during bridge construction.
Once the project is finished, it will return above the new bridge at a slightly greater height for visibility and vehicle clearance. The city’s latest announcement targets project completion by 2028, ahead of the Los Angeles Olympics and Paralympics.
Meanwhile, visitors can photograph a lighted, half-scale replica near Pier Burger.
For anyone who associates that glowing arch with Southern California memories, its absence will be noticeable. The restoration is intended to ensure future generations can make memories beneath it, too.
Source: City of Santa Monica — October 19, 2026 announcement
Related Links
- City of Santa Monica: Official sign restoration announcement — October 19, 2026. Primary source for removal dates, shipment to Las Vegas, YESCO’s restoration work and the sign’s planned return.
- Santa Monica Daily Press: Sign restoration during bridge rebuild — October 20, 2026. Additional local reporting on the project and visitor access.
- LAist: Sign removal and how to watch — Reporting on the removal schedule and public viewing opportunities.
Follow more Southern California stories at STM Daily News.
