What Would Happen if a Tiny Black Hole Passed Through Your Body?

In 1974, science fiction author Larry Niven wrote a murder mystery with an interesting premise: could you kill a man with a tiny black hole? I won’t spoil the story, though I’m willing to bet most people would argue the answer is clearly yes. Intense gravity, tidal forces, and the event horizon would surely lead to a messy end. But it turns out the scientific answer is a bit more interesting.

Continue reading “What Would Happen if a Tiny Black Hole Passed Through Your Body?”

Yes, the Odds of an Asteroid Striking Earth Have Doubled. No, You Don’t Need to Worry

The estimated trajectory of 2024 YR4. Credit: ESA/Planetary Defence Office

At the end of 2024, astronomers detected an asteroid in the night sky. It was given the designation Y, since it was discovered in the last half of December, and R4 since it was the 117th rock to be found in the last couple of weeks of December, and since it was discovered in 2024, it was assigned the name 2024 YR4. Naturally, once a rock is found, astronomers start keeping track of it, measuring its position to get a handle on its orbit. In this case, the estimated orbit put it at a 1% chance of striking Earth. As more measurements were taken, those odds have more than doubled. As of this writing, it now has a 2.3% chance of striking Earth on December 22, 2032. While you might think this resembles the plot of Don’t Look Up, none of this is too unusual.

Continue reading “Yes, the Odds of an Asteroid Striking Earth Have Doubled. No, You Don’t Need to Worry”

Even Microquasars are Powerful Particle Accelerators

Artist’s impression of a microquasar system. Credit: Science Communication Lab for MPIK/H.E.S.S.

The Earth is bathed in high-energy particles. Known as cosmic rays, most of them are protons striking us at nearly the speed of light. Fortunately, the atmosphere protects us from any significant harm, though the particles can strike with so much energy that they create a shower of lower energy particles that do reach Earth’s surface. That’s actually how we can detect most cosmic rays.

Continue reading “Even Microquasars are Powerful Particle Accelerators”

White Dwarfs Pause Their Cooling, Giving Planets a Second Chance for Habitability

A Ceres-like planet orbits a white dwarf star. Credit: Mark A. Garlick

When we first began searching for planets around other stars, one of the surprising discoveries was that there are planets orbiting white dwarfs. The first exoplanets we ever discovered were white dwarf planets. Of course, these planets were barren and stripped of any atmosphere, so we had to look at main sequence stars to find potentially habitable worlds. Or so we thought.

Continue reading “White Dwarfs Pause Their Cooling, Giving Planets a Second Chance for Habitability”

An Asteroid Has a 1% Chance of Impacting Earth in 2032

Artist's impression of asteroid 2024 YR4. Credit: ESA

The odds of a sizable asteroid striking Earth are small, but they’re never zero. Large asteroids have struck Earth in the past, causing regional devastation. A really large asteroid strike likely contributed to the extinction of the dinosaurs. So we shouldn’t be too surprised that astronomers have discovered an asteroid with a better than 1% chance of striking our world. Those odds are large enough we should keep an eye on them, but not large enough that we should start packing bags and fleeing to the hills.

Continue reading “An Asteroid Has a 1% Chance of Impacting Earth in 2032”

Black Hole Mergers Will Tell Us if the Universe Obeys Symmetry

Illustration of a black hole recoil and its mirror symmetrical recoil. Credit: Instituto Galego de Física de Altas Enerxías (IGFAE)

The structure of the cosmos is rooted in symmetry. As first demonstrated by Emmy Noether in 1918, for every physical law of conservation in the Universe, there is a corresponding physical symmetry. For example, all other things being equal, a baseball hit by a bat today will behave exactly the same as it did yesterday. This symmetry of time means that energy is conserved. Empty space is the same everywhere and in all directions. This symmetry of space means that there is conservation of linear and rotational momentum. On and on. This deep connection is now known as Noether’s Theorem, and it is central to all of modern physics.

Continue reading “Black Hole Mergers Will Tell Us if the Universe Obeys Symmetry”

A New Space Telescope is Giving Us New Insights Into Gamma Ray Bursts

Einstein Probe detects ancient X-ray burst (artist impression). Credit: OPENVERSE/Einstein Probe Science Center

The Einstein Probe was launched in January 2024 to look at X-ray transients, among other things. Its power comes from its Wide-field X-ray Telescope (WXT), which can capture 3600 square degrees of the sky in a single go. That’s an area 18,000 times the apparent area of the Moon. That is a huge patch of astronomical sky, so it’s not surprising that just two months later the probe saw a 17-minute burst of soft X-rays. Given the name EP240315a, it is an example of a fast X-ray transient (FXRT).

Continue reading “A New Space Telescope is Giving Us New Insights Into Gamma Ray Bursts”

A Fast Radio Burst Came From an Old, Dead Galaxy

Astronomers first detected the new FRB, dubbed FRB 20240209A, in February 2024 with the Canadian Hydrogen Intensity Mapping Experiment (CHIME). Credit: CHIME, Andre Renard, Dunlap Institute for Astronomy & Astrophysics, University of Toronto

Fast radio bursts (FRBs) are intense flashes of radio light that last for only a fraction of a second. They are likely caused by the intense magnetic fields of a magnetar, which is a highly magnetic neutron star. Beyond that, FRBs remain a bit of a mystery. We know that most of them originate from outside our galaxy, though the few that have occurred within our galaxy have allowed us to pin the source on neutron stars. We also know that some of them repeat, meaning that FRBs can’t be caused by a cataclysmic event such as a supernova. Thanks to one repeating FRB, we now know something new about them.

Continue reading “A Fast Radio Burst Came From an Old, Dead Galaxy”

Supersonic Winds Blowing on an Extreme Exoplanet

Artist’s visualisation of WASP-127b shows supersonic jet winds that move around the planet’s equator. Credit: ESO/L. Calçada

The exoplanet WASP-127b is an unusual world. It is about 30% larger than Jupiter but has just a fifth of Jupiter’s mass. It is an example of a super-puff planet because of its extremely low density. These puffy worlds are so unusual that we don’t know if they would resemble the gas giants of our solar system, or something more exotic, such as a large super-Earth. But a recent study of WASP-127b shows that super-puff worlds can have tremendous winds.

Continue reading “Supersonic Winds Blowing on an Extreme Exoplanet”

The First Supernovae Flooded the Early Universe With Water

This artist’s impression shows CR7 a very distant galaxy discovered using ESO’s Very Large Telescope. Credit: ESO/M. Kornmesser

Water is the essence of life. Every living thing on Earth contains water within it. The Earth is rich with life because it is rich with water. This fundamental connection between water and life is partly due to water’s extraordinary properties, but part of it is due to the fact that water is one of the most abundant molecules in the Universe. Made from one part oxygen and two parts hydrogen, its structure is simple and strong. The hydrogen comes from the primordial fire of the Big Bang and is by far the most common element. Oxygen is created in the cores of large stars, along with carbon and nitrogen, as part of the CNO fusion cycle.

Continue reading “The First Supernovae Flooded the Early Universe With Water”