Tiny Lunar Transformers, a Cosmic Expansion Showdown, and Artemis Astronauts Trekking Through Iceland
There is something undeniably charming about the idea of small, round robots rolling across the powdery gray surface of the moon, splitting open like tiny mechanical clams to reveal cameras tucked inside. That image — part science fiction, part Saturday morning cartoon — is now a documented reality, and it is only one of several stories worth savoring from the latest space science roundup.
From baseball-sized autonomous rovers waddling across lunar terrain, to a bitter astrophysical feud over whether the universe is speeding up or slowing down, to astronauts hauling themselves across Icelandic lava fields in preparation for humanity’s return to the moon — the menu of space news this week is rich, varied, and a little spicy.
Baseball-Sized “Transformers” on the Moon
Let’s start with the cutest item. During Japan’s first successful lunar landing a couple of years ago, a pair of small spherical robots were deployed from the lander. Each one is about the size of a baseball and weighs roughly half a pound — a featherweight profile that matters enormously when every ounce launched into space costs money and engineering effort.
Once released, each sphere cracks open down the middle. The two halves splay outward and function like spinning wheels, allowing the little robot to waddle and roll across hard, uneven terrain. A camera sits nestled in the center, capturing images of the lunar surface and of the lander itself. They are autonomous, meaning they navigate without human joystick input, scouting terrain ahead of larger, more expensive rovers and reaching places those bigger machines simply cannot go.
A new study published last week in the journal Science Robotics analyzed how these miniature explorers performed on the lunar surface. The verdict, at least from outside experts, is encouraging. Roger Wiens, a planetary scientist who was not involved in the program, praised the design’s redundancy — the idea that you can send several cheap units and still accomplish your mission even if one or two fail.
“These are not expensive devices. You can have several of them. And if one or two fails, then you still have others,” Wiens said.
The moon’s gravity is only one-sixth of Earth’s, which means these little rovers actually bounce as they move. That low-gravity bounce is not a bug — it is a feature that makes the design attractive for other destinations. Wiens imagines them hopping across small asteroids, where movement is so easy you have to be careful not to accidentally launch yourself out of orbit entirely.
“These could go to small asteroids, where hopping is extremely easy,” he said. “I can see these things going to a number of places. We’ll have transformers on various planets and asteroids, eventually.”
The Universe: Speeding Up or Slowing Down?
From tiny robots to the biggest question imaginable: is the expansion of the universe accelerating or decelerating?
Almost 30 years ago, astronomers discovered that the universe is not only expanding but that the expansion is speeding up. That finding reshaped cosmology and introduced the concept of dark energy as a dominant force driving the cosmos apart. But in the last few years, a group of scientists from Yonsei University in South Korea challenged that consensus, claiming the expansion is actually slowing down.
Now a paper published last week in the Monthly Notices of the Royal Astronomical Society pushes back on the slowdown claim, arguing the traditional framework still holds. The debate continues.
So how do astronomers actually measure something as vast as cosmic expansion? The standard method relies on observing a specific type of exploding star — a supernova — and measuring its brightness. Astronomers then correct for variables such as how long the supernova remains bright and how much dust sits between Earth and the explosion, which can dim the light.
The South Korean team argues that astrophysicists have been leaving out a crucial variable: the age of the stars’ home galaxy. When that factor is included in the corrections, they say, the math points to a slowing expansion rather than an accelerating one. If true, it would be a discovery that forces a fundamental rethink of modern cosmology.
The Yonsei team has already posted a rebuttal to the new paper, maintaining that the standard supernova measurement method is fundamentally flawed.
But other astronomers remain skeptical. Experts say the community has spent nearly 30 years fine-tuning the supernova method, and there are independent measurement techniques that also support the conclusion that the universe’s expansion is speeding up.
Priyamvada Natarajan, an astrophysicist at Yale University who was not involved in this work, expressed skepticism but framed the dispute as a healthy part of the scientific process.
“Scientists by nature are skeptical, and even for an idea that has been validated and accepted — if there is a new argument, we do take it seriously, and we interrogate it,” she said.
The stakes are existential in the most literal sense. If the expansion is accelerating, everything in the universe will eventually drift so far apart that the cosmos dies a cold, lonely death billions of years from now. If the expansion is slowing, the universe could eventually collapse inward in what astronomers call the “big crunch.” Either way, none of us will be around to see the outcome.
Artemis Astronauts Train in Iceland and Hawaii
Closer to home — and within a timeframe that actually matters to people alive today — NASA’s Artemis program continues to prepare crews for returning humans to the moon and eventually sending them onward to Mars.
The crew for Artemis III has been selected. This mission will involve extensive maneuvers in low Earth orbit as part of preparation for future lunar landings. One of the newly selected astronauts, Andre Douglas, who served on the backup crew for Artemis II, described a grueling training exercise: a 24-mile hike completed over two days in Iceland, designed to build land navigation skills under difficult conditions.
“We did a, like, 24-mile hike in two days in Iceland just to go through a hard challenge of land navigation as if we’re learning how to be really good operators,” Douglas said.
Iceland is not chosen at random. Its rocky, volcanic terrain and the actual mineral composition of its rocks closely resemble lunar conditions. Apollo-era astronauts trained there decades ago and described it as the closest earthly analog to the moon’s surface they had encountered. Two NASA astronauts are scheduled to return to Iceland this July for additional training.
NASA is also using Earth-based sites to simulate Mars missions. Astronaut candidates have trekked through lava beds in Hawaii Volcanoes National Park, carrying heavy packs, conducting geological fieldwork, and operating under conditions of limited and delayed communication with a simulated mission control — all to approximate the isolation and operational challenges of a real Martian expedition.
From half-pound robots bouncing across the moon to cosmologists arguing over the ultimate fate of everything, the stories this week remind us that space science operates on every scale imaginable — and sometimes the smallest devices raise the biggest questions about where we go next.