Universe Today

What Happens When Light Goes Boom? Part 4: What Brad Bradington Is Good For

2026-04-19T02:20:00Z

Cherenkov radiation isn't just a beautiful phenomenon. It turns up in nuclear reactors, in the upper atmosphere, in gamma ray telescopes on three continents, in a cubic kilometer of Antarctic ice, and in hospital imaging suites. Here's what a light boom is actually good for.

"Immature" Lunar Soil Could Be Suitable for Roadways on the Moon

2026-04-18T22:44:14Z

Using lunar regolith simulant, a team of researchers demonstrated that "immature" regolith similar to what is expected around the Moon's southern polar region is suitable for rovers to drive on.

What Happens When Light Goes Boom? Part 3: Brad Bradington Sprints

2026-04-18T02:06:00Z

We have the crowd. We have the star. Now it's time to put them together. Here's exactly what happens — and why — when a charged particle outruns the local speed of light in a material. Also: why it's always blue.

How a Black Hole and a Shredded Star Could Light Up a Galaxy

2026-04-17T21:03:36Z

In 2014, a strange cloudy object called G2 made a close approach to Sagittarius A*, (Sag A*) the supermassive black hole at the heart of the Milky Way Galaxy. Astronomers were pretty excited, partly because they thought it might get torn apart by Sag A*'s intense gravitational pull. That didn't happen, and the event was a cosmic fizzle. Instead, G2 skipped around the black hole. Various observations showed that it wasn't just a gas cloud. It was likely a dusty protostellar object encased in a dusty cloud. Or perhaps several merged stars. But, it survived the flyby and continued on a shortened orbit.

Small Trojan Asteroids Defy Expectations

2026-04-17T18:47:15Z

Understanding the beginning of the solar system requires us to look at some very strange places. One such place is at the so-called “Trojan” asteroids that share Jupiter’s orbit in front of and behind it. But for a long time, these cosmic time capsules have held a mystery for astronomers: why are they color-coded? The populations of larger asteroids are very clear split into two distinct groups - the “reds” and the “less reds”, because apparently they’re all red to some extent. A new paper from researchers in Japan tried to solve this mystery by taking a close look at even smaller asteroids, and their findings, published in a recent edition of The Astronomical Journal, actually brings up a completely different question - why don’t smaller Trojan asteroids have the same color-coding?

Life Beyond Biosignatures: A New Method In The Search For Life

2026-04-17T17:37:00Z

Researchers from the Earth-Life Science Institute (ELSI) and National Institute for Basic Biology have developed a new method to detect extraterrestrial life without relying on traditional biosignatures. By modelling how life might spread between planets, they demonstrate that life could be detected through statistical patterns across planetary populations rather than on individual planets. This "agnostic biosignature" approach could assist in guiding future searches for life beyond Earth.

Comet R3 PanSTARRS at Perihelion

2026-04-17T15:10:00Z

We’re one comet down, and one to go for spring season 2026. We recently wrote about prospects for sungrazer C/2026 A1 MAPS and comet C/2025 R3 Pan-STARRS in April 2026. While the bad news is, Comet A1 MAPS disintegrated like so many sungrazers before it during its blistering close perihelion passage on April 4th, comet R3 Pan-STARRS put on an amazing dawn showing for early rising astrophotographers.

To Survive Deep Space, Astronauts May Owe a Debt to Microscopic Worms

2026-04-17T11:57:24Z

Living long-term on the Moon means surviving the devastating toll that deep space takes on a human body. Astronauts in low gravity environments suffer muscle and bone loss, vision-altering fluid shifts, and heavy radiation exposure - all of which are incredibly hazardous to our biology. So, to help future lunar explorers survive, a new crew just arrived at the International Space Station (ISS). That might not sound surprising, except this crew is composed of worms.

Watch This Dark Volcanic Ash Creep Across the Red Planet

2026-04-17T10:55:26Z

Mars is well known as a static, frozen desert. We tend to think of the only thing changing on the surface of the Red Planet is due to the occasional dust storm. But if you look closely - and are willing to wait decades - you’ll see the planet is very much alive - at least in the environmental sense. The European Space Agency just released some spectacular new images from the High Resolution Stereo Camera (HRSC) on its Mars Express Orbiter, one of which shows a surprisingly “fast” geological change happening in Utopia Planitia. A dark, ominous-looking blanket of volcanic ash is actively creeping across the bright red sands - and it's moving (relatively) fast.

What Happens When Light Goes Boom? Part 2: The Crowd, the Molasses, and the Speed of Light (Sort Of)

2026-04-17T02:06:00Z

Before Brad Bradington can sprint down the red carpet, we need to understand the crowd. Specifically, we need to understand why a crowd of atoms and molecules slows down light — and why that creates a loophole that changes everything.

Early Galaxies Were Surrounded by Huge Clouds of Hydrogen, and Astronomers Found a Whole Bunch!

2026-04-16T23:02:47Z

Astronomers using data from the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX) have discovered tens of thousands of gigantic hydrogen gas halos, called “Lyman-alpha nebulae,” surrounding galaxies 10 billion to 12 billion years ago.

The Moon Might Be More Prone To Fires

2026-04-16T16:41:44Z

Engineers love a good practical challenge, especially when it comes to spaceflight. But there’s one particular challenge facing the crewed missions of the near future that scares mission planners above almost all others - fire. For decades, we’ve relied on a NASA test known as NASA-STD-6001B to screen material flammability for flight. But space is much more complicated than an Earth-bound test provides for. A new paper from researchers at NASA’s Glenn Research Center and Johnson Space Center and Case Western Reserve University details a planned mission to test the flammability of materials on the Moon’s surface - where they expect flame to act much differently than it does here on Earth.

Why NASA’s Cheapest Missions Produce the Least Science

2026-04-16T14:12:01Z

To say NASA has been undergoing some massive administrative changes lately is a huge understatement. One of the more concerning ones, according to a new paper at the 57th Lunar and Planetary Science Conference by Ari Koeppel and Casey Dreier of the Planetary Society, is the trend towards the Silicon Valley mindset of “move fast and break things” - which they argue doesn’t work very well when it comes to producing valuable science.

What Happens When Light Goes Boom? Part 1: The Scientist Who Stared at a Glow

2026-04-16T02:06:00Z

In 1934, a Soviet physicist named Pavel Cherenkov shone gamma rays into a bottle of water and noticed a faint blue glow. So had others before him. They all shrugged and moved on. Cherenkov didn't. What he found — by refusing to dismiss something he didn't understand — turned into one of the most useful phenomena in modern physics.

Where's the Dividing Line Between A Star and A Planet? Ask the JWST.

2026-04-15T23:03:59Z

It's obvious that Earth is a planet. It's obvious that the Sun is a star. But for substellar objects like brown dwarfs, it's not so clear. Researchers are using the JWST to find a stronger dividing line between star and planet that depends on how they formed.

JWST Sees Smoking Gun for Black Hole Mergers in the Virgo Cluster

2026-04-15T21:43:15Z

A pair of dwarf galaxies in the giant Virgo Cluster show what can happen when these stellar cities interact. Scientists at the University of Michigan focused the James Webb Space Telescope (JWST) onto the galaxies NGC 4486B and UCD736 and found each of them sporting "overmassive" black holes at or near their hearts. Those supermassive black holes comprise a large fraction of each galaxy's mass.

The World Welcomes the Crew of Artemis II Home!

2026-04-15T19:54:49Z

After achieving their record-breaking 10-day flight around the Moon, the crew of the Artemis II mission returned home on Friday, April 10th, 2026.

Planetary Exploration With Four-Legged Rovers Carrying Only Two Instruments

2026-04-15T17:05:01Z

European researchers tested four-legged semi-autonomous rovers that carry only two instruments. These capable and agile robots could be part of the future exploration of Mars and the Moon. Their autonomy means they can do more with fewer instructions.

Catching the 2026 April Lyrid Meteor Shower

2026-04-15T13:53:00Z

April flowers mean one thing to springtime sky-watchers: it’s time for the Lyrid meteor shower. The Lyrids are always a good bet, and always make the top ten list for annual meteor showers. And to top it off, 2026 is a favorable year for the Lyrids, with the waxing crescent Moon mostly out of the way.

Stardust in the Clouds of Venus.

2026-04-15T11:33:29Z

Venus has been hiding a secret for fifty years. Just below its main cloud deck sits a mysterious layer of haze that spacecraft first detected in the 1970s and nobody could explain where it came from. Now a research team in Japan has finally cracked it, and the answer comes from the last place most people would think to look!