Space

On some Martian nights, a subtle, green glow hangs low in the sky, wreathing the horizon in every direction.

A visible Martian aurora has finally been observed for the first time, researchers report May 14 in Science Advances. The observation, made March 18, 2024, by the Perseverance rover, is also the first of an aurora from the surface of a planet that isn’t Earth. Moreover, it suggests future astronauts may witness ethereal Martian auroras with their own eyes. “It would be a dull or dim green glow to astronauts’ eyes,” says Roger Wiens, a planetary scientist at Purdue University in Lafayette, Ind.

Auroras can appear when charged particles from space interact with a planet’s atmosphere. They’ve already been spotted on Mercury, Jupiter and every other non-Earth planet in our solar system, but only from orbit. And in Mars’ sky, scientists had only been able to detect auroral wavelengths of light invisible to the naked eye, using instruments. So it wasn’t clear how Martian auroras would appear to future, landed astronauts.

On March 18, 2024, instruments aboard the Perseverance rover captured an image of a Martian aurora. Though relatively faint, the aurora’s green hues (left) can be made out by comparing the image with one of the typical inky Martian night (right). Due to the phenomenon’s subtle nature, the rover’s instruments were pointed at a low angle over the horizon to peer through a thick layer of the atmosphere. E.W. Knutsen et al/Science Advances 2025

Compared to many Earthly aurora photos, the new image from Mars is fuzzy. There are a couple reasons for that. First, Perseverance’s cameras perform less well at night, Wiens says. “The instruments aren’t tremendously more sensitive than human eyes,” he says.

And second, Mars doesn’t have a global magnetic field that concentrates auroras near its poles like Earth does. Instead, its crust is magnetized in patches. That means auroras can appear all over the planet, but they’re relatively dim. More

After 35 years, the Hubble Space Telescope is still churning out hits. In just the last year or so, scientists have used the school bus–sized observatory to confirm the first lone black hole, reveal new space rocks created by a NASA asteroid-impact mission and pinpoint the origin of a particularly intense, mysterious burst of radio waves.

These findings are a testament to the fact that there’s still plenty of science for the telescope to do. And there are some observations that simply can’t be done with any other telescope, including Hubble’s younger sibling, the James Webb Space Telescope. More

The carbon that once warmed Mars’ atmosphere has been locked in its rusty rocks for millennia. 

That’s the story revealed by a hidden cache of carbon-bearing minerals unearthed by NASA’s Curiosity rover along its route up a Martian mountain. The finding is the first evidence of a carbon cycle on the Red Planet, but also suggests that Mars lost its life-friendly climate because that carbon cycle was slow, researchers report in the April 18 Science. More

The James Webb Space Telescope has caught a distant galaxy blowing an unexpected bubble in the gas around it, just 330 million years after the Big Bang.

The galaxy, dubbed JADES-GS-z13-1, marks the earliest sign yet spotted of the era of cosmic reionization, a transformative period in the universe’s history when the first stars and galaxies began to reshape their environment, astronomers report in the March 27 Nature.

“It definitely puts a pin in the map of the first point where [reionization] very likely has already started,” says astrophysicist Joris Witstok at the University of Copenhagen. “No one had predicted that it would be this early” in the universe’s history. More

The nearest single star to the sun, Barnard’s star, has a brood of planets all its own. The red dwarf star, about six light-years from Earth, hosts four close-in planets each about two to three times the mass of Mars, astronomers report in the March 20 Astrophysical Journal Letters.

“Barnard’s star has a long history of claimed detections, but none of them could be confirmed for a long time,” says astronomer Ritvik Basant of the University of Chicago. “It’s pretty exciting to know what’s orbiting the nearest stars.” More

From monitoring Mercury to launching a new adventure to an icy moon of Jupiter, spacecraft and astronauts made great strides in 2024. Here are some of the highlights of this year in space.

New lunar visitors

The moon has been a hot destination for space agencies and private companies in recent years, and 2024 was no exception.

In January, the Japanese SLIM spacecraft made a successful but lopsided precision landing on a crater’s rim, marking the country’s first soft landing on the moon. The solar-powered Smart Lander for Investigating the Moon was designed to collect data for one lunar day, or about two weeks on Earth, before night fell and it got too dark and cold to survive. But SLIM surprised everyone by sending signals to Earth for three months.

China’s Chang’e 6 mission collected the first dirt samples from the moon’s far side and returned them to Earth in June for analysis.CLEP/CNSA

SLIM was joined by another unintentionally sideways lander in February. Odysseus, a spacecraft built by Houston-based company Intuitive Machines, touched down and toppled over near the lunar south pole. During its six-day mission, the probe sent back data that may be instructive for NASA’s Artemis mission, which aims to land humans on the moon in 2026 (SN: 3/23/24, p. 16).

Finally, China’s Chang’e 6 spacecraft grabbed the first samples from the farside of the moon in June (SN: 6/29/24, p. 12). The first look at the samples revealed soil that’s fluffier than soil from the nearside. A chemical analysis of the samples, reported in Nature, suggests the farside was volcanically active some 2.8 billion years ago (SN: 11/15/24). More

One of the most compelling potential signs of extraterrestrial communication might have an astrophysical explanation.

Called the “Wow!” signal, the bright burst of radio waves has defied our understanding since its discovery in the 1970s. Now, scientists using archived data from the Arecibo Observatory in Puerto Rico suggest a new possible source for the signal: a cosmic hydrogen cloud that emitted light like a laser.

“I think we have probably the best explanation so far,” says astrobiologist Abel Méndez of the University of Puerto Rico at Arecibo. Méndez, together with astrophysicist Kevin Ortiz Ceballos of the Harvard and Smithsonian Center for Astrophysics in Cambridge, Mass., and Jorge Zuluaga of the University of Antioquia, Colombia, submitted this idea to arXiv.org on August 16. More

Researchers may have figured out how a crucial ingredient that cells need to produce energy could form in deep space.

Calculations and lab experiments suggest that glyceric acid can arise from radiation blasting carbon dioxide and ethylene glycol in interstellar clouds, researchers report in the March 15 Science Advances.

The study is “a great start to understand how these molecules are formed in space,” says Anthony Remijan, an astrochemist at the National Radio Astronomy Observatory in Charlottesville, Va., who was not involved in the research. The finding suggests that “if you put the right mixture together, in the right conditions, maybe you can even afford more complex molecules in space,” he says. More