Plutonium in Earth Rocks Signals Long-ago Cosmic Collision

A small lump of rock pulled up from the Pacific Ocean seafloor in 1976 is giving scientists new clues about an ancient cosmic event. More than a hundred million years ago, two neutron stars collided. The resulting energetic kilonova sent a rain of long-lived elements, such as isotopes of plutonium, through space. Eventually, this stellar "debris" settled onto Earth. Some sank to the bottom of the ocean and got incorporated into a chunk of ferromanganese rock. Hidden inside were a few hundred atoms of plutonium radioisotopes. They provide the strongest clues about what created them in the merger and how long ago it happened.

What Would Happen if the Sun Stopped? Part 4: Black Hole Sun

Switch off fusion and, for ten thousand years, nothing happens. Then the Sun begins a slow, strange death: shrinking, briefly brightening, and coasting on gravitational heat for tens of millions of years. And the neutrinos give the whole thing away in just eight minutes.

What Would Happen if the Sun Stopped? Part 3: The Photon Traffic Jam

A photon born in the Sun's core takes around 100,000 years to fight its way to the surface, bouncing through a random walk so inefficient that the light on your face is older than human civilization. Why the Sun's surface is a hundred-millennia-delayed broadcast.

'High-Res' is the Secret to Finding Alien Life with the Next Great Space Telescope

We’re still in the definition phase of the Habitable Worlds Observatory (HWO), but it seems like every week a new research group comes out with a paper helping to contribute to what is shaping up to be one of the most important space telescopes of the 2040s. A new paper from a team of researchers led by Daniel Jaffe of the University of Texas at Austin contributes to this ongoing definition work by arguing that it’s time HWO adopted a high-resolution near-IR spectroscopy capability, - which sounds great in practice, but so far hasn’t been attempted due to technological limitations. But, according to the paper, two recent inventions finally make a working version of an extremely high resolution exoplanet hunter viable.

Lava planet has hydrogen-rich, active atmosphere

It’s 2158, and you’re chugging away on your PhD in Planetary Volcanology from the University of Utopia Planitia on Mars. Graduate students still get paid a sub-living wage, so you’ve been stuck eating freeze-dried ramen for the past three years. You’ve completed studying Jupiter’s moon, Io, but now you have to leave the solar system for a good exoplanet analog. While Io’s volcanism is caused by tidal heating, you need an exoplanet whose volcanism is caused by extreme heat from its host star. You recently secured funding from the Exoplanet Research Institute for a faster-than-light (FTL) ship, but the exoplanet is required to be less than 50 light-years away.

What Would Happen if the Sun Stopped? Part 2: Kelvin and Helmholtz at the Ready

How can the Sun keep shining with its furnace switched off? Two nineteenth-century aristocrats, Helmholtz and Lord Kelvin, worked out the answer mostly by accident. It comes down to stored heat, gravitational shrinking, and the strange self-regulating thermostat of hydrostatic equilibrium.

Are Alien Probes Hiding in Our Backyard? A New Study Says We’ve Barely Looked

Even at this early stage in our space faring age, humanity has already begun sending probes that will eventually reach other solar systems, even if that was not their original intention. Five robotic explorers - Pioneer 10 and 11, Voyager 1 and 2, and New Horizons - are all on escape velocities out of the solar system, and might someday enter another one. They will no longer be operational at that point, but they serve as a proof of concept that spacefaring civilizations do indeed build interstellar probes. Which raises the obvious question - has anyone else sent their own robotic explorers to ours? In a recent paper, published in the Proceedings of the IAU Centenary Symposium, astronomer T. Joseph W. Lazio, points out a painful truth - we still have no idea, and our technology will need to get much better if we plan to find out.