NASA's Perseverance rover films first auroras from the surface of Mars

RNZ News15-05-2025

By
Ellen Phiddian
NASA's Perserverance rover has photographed images of an aurora from the surface of Mars.
Photo:
AFP / NASA/JPL-CALTECH/MSSS
Auroras on Mars don't look quite like they do on Earth - but they still produce a weird and fascinating light show.
NASA's Perseverance rover has snapped pictures of a visible-light aurora from the Martian surface.
It is the first time an aurora has been observed from the surface of a planet other than Earth, and the first time visible auroras have been seen on Mars.
The weak green light was photographed in March last year, with the pictures just released in a new study published in Science Advances.
Auroras on Earth are formed by particles from the Sun interacting with the planet's magnetic field.
But auroras have also been observed on nearly every other planet in the Solar System.
The light show was first detected around Mars 20 years ago from space.
Unlike Earth, Mars does not have a global magnetic field - instead, its magnetism is patchy and varies across the planet's surface.
This means its auroras are caused by slightly different phenomena.
One type of aurora Mars sees, called a solar energetic particle (SEP) aurora, comes from super-energised particles from the Sun hitting the Martian atmosphere directly.
These have been observed in ultraviolet light before, from NASA's MAVEN instrument that orbits around Mars.
But when the Sun emitted a solar flare and a coronal mass ejection (CME) in the direction of Mars last year, a team of researchers spotted an opportunity to see the auroras from the planet's surface.
They scrambled to ready the Perseverance rover, which is trundling through Mars' Jezero crater.
The team used computer models to predict when and where the aurora would be visible in the Martian sky, and what colour and intensity of light they could expect the rover to spot.
They expected particles from the CME would react with oxygen atoms in the Martian atmosphere, causing a faint glow in a very precise shade of green.
Elise Knutsen, a physicist at the University of Oslo and lead author of the study, said the team needed to pick a strong CME to test their models.
"When we saw the strength of this one, we estimated it could trigger an aurora bright enough for our instruments to detect," Dr Knutsen said.
Days after the solar flare, two instruments on Perseverance recorded the exact shade of green in Mars' sky the researchers had predicted.
Hannah Schunker, a physicist at the University of Newcastle who was not involved in the research, called the study a "neat observation".
"It's a nice test of the Martian atmosphere models - and also a little more indirectly, it can be used to test our models of the coronal mass ejections," Dr Schunker said.
The first visible-light image of a green aurora on Mars, left, taken by NASA's Perseverance rover. A comparison image, right, shows the night sky without the aurora but featuring the Martian moon Deimos.
Photo:
NASA/JPL-Caltech/ASU/MSSS/SSI
Disappointingly for future space travellers, it's unlikely the aurora would be as dazzling as those seen on Earth.
"Even on Earth, when we observe auroras, they often look quite different to the beautiful images we see," Dr Schunker said.
"The photographic images that are taken of the auroras on Earth are often exposed for some minutes, so you get these really bright, vivid colours. Whereas if you see it with your eyes, it doesn't look quite so bright and quite so vivid, although still impressive."
Mars, meanwhile, has fainter auroras to start with: lacking Earth's magnetism, the solar particles produce less light when they crash into the planet's atmosphere.
"There might be a detectable change in the atmosphere, but it would not be strong and it would not be very obvious to the eye," Dr Schunker said.
While it might not be the best light show in the Solar System, the research will be useful for better understanding solar weather from different angles, according to Dr Schunker.
"Mars is not aligned with Earth at the moment. So we would not have experienced this particular CME," she said.
We might be able to expect more observations like this in coming months, she said, thanks to "solar maximum": the point in its roughly 11-year cycle when the Sun produces the highest number of flares and sunspots.
This is why people on Earth have seen so many auroras in the past year, often much further away from the poles than they can normally be spotted.
"We're approaching, or we're in the middle of, solar maximum at the moment. We never know if we've reached solar maximum until we're on the other side of it," Dr Schunker said.
-
ABC

Hashtags

Try Our AI Features

Explore what Daily8 AI can do for you:

Comments

No comments yet...

RNZ News

17 hours ago

RNZ News

Experimental new drug results in up to 24pct weight loss, comes in a pill

By Deena Beasley , Reuters The full trial results were presented at the annual meeting of the American Diabetes Association in Chicago and published in the Lancet medical journal. Photo: 123rf Novo Nordisk on Friday (local time) said full results from early-stage trials show that its experimental drug, amycretin, helped overweight and obese adults lose up to 24 percent of their weight as the Danish company readies for late-stage studies to start next year. The company said side effects of the drug, tested as both a weekly injection and a daily pill, were mostly gastrointestinal with rates similar to other recent weight loss drugs. The [ full trial results[ were presented at the annual meeting of the American Diabetes Association in Chicago and published in the Lancet medical journal. Novo's head of development Martin Holst Lange said the Phase 3 amycretin program starting in 2026 will run "for a couple of years" after which the regulatory review process could start. The company earlier this month said it planned to start late-stage trials of the drug in the first quarter of 2026 after previously announcing the early-stage trial results. Amycretin has a dual-mode action. Like Novo's popular weight-loss drug Wegovy, it mimics the gut hormone GLP-1, but also targets receptors for a hunger-suppressing pancreatic hormone called amylin. Trial results showed that 20-milligram weekly injections of the drug helped overweight or obese patients without diabetes lose 22 percent of their weight over 36 weeks, with a 60-mg dose resulting in 24.3 percent weight loss. In the Phase 1 study of once-daily oral amycretin, patients received increasing doses, ranging from 3 mg to a final dose of 100 mg. Patients who took 50 mg of amycretin at the end of the 12-week trial reduced body weight by 10.4 percent on average, while those taking the maximum dose lost 13.1 percent of their weight, the company said. Novo said the weight loss did not plateau, suggesting that longer treatment could lead to greater weight loss. In a Lancet commentary, researchers not involved in the amycretin studies said that "while additional weight loss is welcome and helpful, our evolving concept of obesity management has now shifted towards an emphasis on the reduction of the risks and burdens of cardiovascular disease and other comorbidities". Commentators Tricia Tan, professor of metabolic medicine and endocrinology at Imperial College London, and endocrinologist Dr Bernard Khoo, said studies directly comparing GLP-1 drugs like Novo's Ozempic to drugs like amycretin will be needed to definitively establish their added value and place in obesity management. - Reuters

Prime Minister Christopher Luxon meets with Chinese President Xi Jinping in Beijing

NZ Herald

2 days ago

NZ Herald

Prime Minister Christopher Luxon meets with Chinese President Xi Jinping in Beijing

Kiwi PhD students heading to US for world-leading space scholarships Three Victoria University of Wellington students are off to the Jet Propulsion Laboratory in California this week where experts work on NASA missions. Video / NZ Herald

Crane driver snoozes through Donald Trump visit