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McKenzie Prillaman is a science and health journalist based in Washington, DC. She holds a bachelor’s degree in neuroscience from the University of Virginia and a master’s degree in science communication from the University of California, Santa Cruz. She was the spring 2023 intern at Science News. More
It may come down to a coin toss as to whether the Milky Way collides with the Andromeda Galaxy within 10 billion years.
While scientists have previously reported that a convergence was certain, an analysis of the latest data suggests the odds are only about 50 percent, researchers report June 2 in Nature Astronomy. The Milky Way’s largest satellite system — the Large Magellanic Cloud — may be our galaxy’s saving grace, the study shows. More
Things may be moving on Venus’ surface.
In 1983, researchers discovered that the planet’s surface was speckled with strange, circular landforms. These rounded mountain belts, known as coronae, have no known Earthly counterparts, and they’ve remained enigmatic for decades. But hot plumes of rock upwelling from Venus’ mantle are shaping the mysterious landforms, a new analysis suggests. If true, that mean that Venus’ surface is tectonically active, and not merely a stagnant layer, researchers report May 14 in Science Advances. More
Bad news, earthlings. Computer simulations of the solar system’s future reveal a new risk facing us all: The gravitational tug of a passing star could either cause another planet to smack into Earth or else fling our planet into the sun or far away from it, where any inhabitants would freeze.
Blame Mercury. Astronomers have long known that the innermost planet’s orbit, which is fairly oval-shaped, can become even more elliptical due to gravitational jiggles from Jupiter. Passing stars exacerbate this danger, Nathan Kaib, an astronomer at the Planetary Science Institute who is based in Iowa, and Sean Raymond, an astronomer at the University of Bordeaux in France, report in work submitted to arXiv.org May 7. More
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
Astronomers have found a giant interstellar cloud surprisingly close to Earth.
Lurking about 300 light-years from our solar system, this immense cloud of gas and dust is the closest of its kind ever found to Earth, beating the previous record holder by roughly 90 light-years. Despite being some 5,500 times as massive as the sun, the cloud went unnoticed — until now.
That’s because the cloud does not contain much carbon monoxide, the molecule astronomers often use to probe these clouds, called molecular clouds. Astronomers found this cloud by scanning the sky for ultraviolet light coming from a molecular cloud’s main constituent, hydrogen molecules. The results, published April 28 in Nature Astronomy, reveal a crescent-shaped cloud that, if visible, would appear to viewers on Earth as the largest single structure in the night sky — roughly 40 full moons wide. 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
A potential dark galaxy — one made primarily of dark matter — may have been spotted in the local universe.
Dark galaxies are theoretical, starless systems whose discovery could help astronomers better understand galaxy formation. The new candidate was found within a large, fast-moving cloud of gas first seen in the 1960s. High-resolution observations of the cloud, reported April 18 in Science Advances, revealed a compact clump of gas that might be a dark galaxy. More
You may have already seen the headlines: Signs of life have reportedly been discovered on an alien world.
A team of astronomers led by Nikku Madhusudhan of the University of Cambridge used the James Webb Space Telescope to search for interesting molecules in the atmosphere of a planet outside our solar system called K2 18b. The team now says they’ve found molecules that, on Earth, are associated with life, in an abundance that is hard to explain otherwise. More
