Mars is a dry, desert world devoid of any life (that we know of). But once upon a time, that wasn’t the case. Data collected by the robotic emissaries we’ve sent to explore the planet on our behalf indicate that the red planet was once a lush and wet world.
However, scientists are still trying to piece together Martian history to understand what happened to the planet’s water. While we know much of it was lost when the planet’s atmosphere was stripped away, what we don’t know is where the water originated from. Researchers uncovered a crucial clue in Martian meteorites found here on Earth.
“A lot of people have been trying to figure out Mars’ water history,” Jessica Barnes, an assistant professor of planetary sciences in the University of Arizona Lunar and Planetary Laboratory, said in a statement. “Like, where did water come from? How long was it in the crust (surface) of Mars? Where did Mars’ interior water come from? What can water tell us about how Mars formed and evolved?”

Like the Earth, Mars is made of different layers: a crust, mantle, and a core. Meteorites, like the ones that fell to Earth, are made of the Martian crust, which can tell us a lot about the planet’s composition when the pieces are analyzed. According to a study published this week in Nature Geoscience, there could be at least two distinct reservoirs of ancient water lurking below the Martian surface. Each with its own (different) chemical signature.
This means that Mars probably never had a global ocean of magma beneath its surface like we do on Earth.
For this study, Barnes and her team looked for clues as to the Mars’ water history by analyzing the ratio of two types (isotopes) of hydrogen. They’re not the first to do so, but previous results have been very inconsistent.
To better understand how the planet formed and where its water came from, the researchers examined two different meteorites: a coin-sized sample known as Black Beauty (or NWA 7034), which formed when a huge impact cemented together various pieces of the Martian crust, and Allan Hills 84001 (ALH84001), a sample once thought to contain Martian microbes. The data shows that water comes from two different sources.

The team was searching for different isotopes of hydrogen — light hydrogen and heavy hydrogen — which can help trace the origin of water in rocks. (Isotopes are variations of chemical elements, with different numbers of neutrons.)
“Light hydrogen” contains one proton (and no neutrons) in its nucleus, whereas “heavy hydrogen,” also known as deuterium, contains one proton and one neutron in its core. The ratio of these two isotopes act like a fossil record of water, telling a planetary scientist its origin.
Here on Earth, protium (or light hydrogen) is the most abundant isotope. It’s found in the atmosphere, in rocks, and the ocean. On Mars, however, deuterium (heavy hydrogen) is the most abundant in the atmosphere, while Martian rocks contain a range of ratios from Earth-like to Mars-like.
To better understand the vast variation, Barnes and her team decided to focus on samples they knew came from the Martian crust — Black Beauty and Alan Hills. The team found that both samples interacted with water at different point in Mars’ history, but had similar isotope ratios, that was very similar to younger rocks analyzed by the Curiosity rover.

This data suggested a surprising result: that the chemical composition of that water hasn’t changed for nearly 4 billion years.
“Martian meteorites basically plot all over the place, and so trying to figure out what these samples are telling us about water in the mantle of Mars has historically been a challenge,” Barnes said.”The fact that our data for the crust was so different prompted us to go back through the scientific literature and scrutinize the data.”
So the team compared their results to previous isotope studies, where the meteorites originated in the Martian mantle. They discovered that the isotope ratios were consistent with two types of volcanic rock, known as shergottite, that’s found in the Martian mantle.

This means that the water within the meteorite samples came from two different sources. It also indicates that Mars lacked a global magma ocean, which would have made the mantle more consistent in its composition.
“These two different sources of water in Mars’ interior might be telling us something about the kinds of objects that were available to coalesce into the inner, rocky planets,” Barnes said.
Meaning two distinct planetary precursors with vastly different water contents could have collided, but never thoroughly mixed. And understanding how Mars formed is essential for understanding its past habitability and potential for life.
News
Tesla dispels reports of ‘sales suspension’ in California
“This was a “consumer protection” order about the use of the term “Autopilot” in a case where not one single customer came forward to say there’s a problem.
Sales in California will continue uninterrupted.”
Tesla has dispelled reports that it is facing a thirty-day sales suspension in California after the state’s Department of Motor Vehicles (DMV) issued a penalty to the company after a judge ruled it “misled consumers about its driver-assistance technology.”
On Tuesday, Bloomberg reported that the California DMV was planning to adopt the penalty but decided to put it on ice for ninety days, giving Tesla an opportunity to “come into compliance.”
Tesla enters interesting situation with Full Self-Driving in California
Tesla responded to the report on Tuesday evening, after it came out, stating that this was a “consumer protection” order that was brought up over its use of the term “Autopilot.”
The company said “not one single customer came forward to say there’s a problem,” yet a judge and the DMV determined it was, so they want to apply the penalty if Tesla doesn’t oblige.
However, Tesla said that its sales operations in California “will continue uninterrupted.”
It confirmed this in an X post on Tuesday night:
This was a “consumer protection” order about the use of the term “Autopilot” in a case where not one single customer came forward to say there’s a problem.
Sales in California will continue uninterrupted.
— Tesla North America (@tesla_na) December 17, 2025
The report and the decision by the DMV and Judge involved sparked outrage from the Tesla community, who stated that it should do its best to get out of California.
One X post said California “didn’t deserve” what Tesla had done for it in terms of employment, engineering, and innovation.
Tesla has used Autopilot and Full Self-Driving for years, but it did add the term “(Supervised)” to the end of the FSD suite earlier this year, potentially aiming to protect itself from instances like this one.
This is the first primary dispute over the terminology of Full Self-Driving, but it has undergone some scrutiny at the federal level, as some government officials have claimed the suite has “deceptive” naming. Previous Transportation Secretary Pete Buttigieg was vocally critical of the use of the name “Full Self-Driving,” as well as “Autopilot.”
News
New EV tax credit rule could impact many EV buyers
We confirmed with a Tesla Sales Advisor that any current orders that have the $7,500 tax credit applied to them must be completed by December 31, meaning delivery must take place by that date. However, it is unclear at this point whether someone could still claim the credit when filing their tax returns for 2025 as long as the order reflects an order date before September 30.
Tesla owners could be impacted by a new EV tax credit rule, which seems to be a new hoop to jump through for those who benefited from the “extension,” which allowed orderers to take delivery after the loss of the $7,500 discount.
After the Trump Administration initiated the phase-out of the $7,500 EV tax credit, many were happy to see the rules had been changed slightly, as deliveries could occur after the September 30 cutoff as long as orders were placed before the end of that month.
However, there appears to be a new threshold that EV buyers will have to go through, and it will impact their ability to get the credit, at least at the Point of Sale, for now.
Delivery must be completed by the end of the year, and buyers must take possession of the car by December 31, 2025, or they will lose the tax credit. The U.S. government will be closing the tax credit portal, which allows people to claim the credit at the Point of Sale.
🚨UPDATE: $7,500 Tax Credit Portal “Closes By End of Year”.
This is bad news for pending Tesla buyers (MYP) looking to lock in the $7,500 Tax Credit.
“it looks like the portal closes by end of the year so there be no way for us to guarantee the funds however, we will try our… pic.twitter.com/LnWiaXL30k
— DennisCW | wen my L (@DennisCW_) December 15, 2025
We confirmed with a Tesla Sales Advisor that any current orders that have the $7,500 tax credit applied to them must be completed by December 31, meaning delivery must take place by that date.
However, it is unclear at this point whether someone could still claim the credit when filing their tax returns for 2025 as long as the order reflects an order date before September 30.
If not, the order can still go through, but the buyer will not be able to claim the tax credit, meaning they will pay full price for the vehicle.
This puts some buyers in a strange limbo, especially if they placed an order for the Model Y Performance. Some deliveries have already taken place, and some are scheduled before the end of the month, but many others are not expecting deliveries until January.
Elon Musk
Elon Musk takes latest barb at Bill Gates over Tesla short position
Bill Gates placed a massive short bet against Tesla of ~1% of our total shares, which might have cost him over $10B by now
Elon Musk took his latest barb at former Microsoft CEO Bill Gates over his short position against the company, which the two have had some tensions over for a number of years.
Gates admitted to Musk several years ago through a text message that he still held a short position against his sustainable car and energy company. Ironically, Gates had contacted Musk to explore philanthropic opportunities.
Elon Musk explains Bill Gates beef: He ‘placed a massive bet on Tesla dying’
Musk said he could not take the request seriously, especially as Gates was hoping to make money on the downfall of the one company taking EVs seriously.
The Tesla frontman has continued to take shots at Gates over the years from time to time, but the latest comment came as Musk’s net worth swelled to over $600 billion. He became the first person ever to reach that threshold earlier this week, when Tesla shares increased due to Robotaxi testing without any occupants.
Musk refreshed everyone’s memory with the recent post, stating that if Gates still has his short position against Tesla, he would have lost over $10 billion by now:
Bill Gates placed a massive short bet against Tesla of ~1% of our total shares, which might have cost him over $10B by now
— Elon Musk (@elonmusk) December 17, 2025
Just a month ago, in mid-November, Musk issued his final warning to Gates over the short position, speculating whether the former Microsoft frontman had still held the bet against Tesla.
“If Gates hasn’t fully closed out the crazy short position he has held against Tesla for ~8 years, he had better do so soon,” Musk said. This came in response to The Gates Foundation dumping 65 percent of its Microsoft position.
Tesla CEO Elon Musk sends final warning to Bill Gates over short position
Musk’s involvement in the U.S. government also drew criticism from Gates, as he said that the reductions proposed by DOGE against U.S.A.I.D. were “stunning” and could cause “millions of additional deaths of kids.”
“Gates is a huge liar,” Musk responded.
It is not known whether Gates still holds his Tesla short position.