Astronomer Answers Cosmos Questions | Tech Support | WIRED

Age measured via cosmic microwave background

Scientists determine the universe is roughly 13.8 billion years old by studying the cosmic microwave background radiation, which represents the residual heat and tiny temperature fluctuations from the Big Bang.

Evidence suggests an infinite flat geometry

Current astrophysical research indicates we live in an infinite "flat" universe where light travels in parallel lines forever, rather than a curved finite structure that loops back on itself.

Dark components dominate the cosmos

Roughly 95% of the universe's mass-energy budget consists of dark matter, which provides invisible gravitational glue for galaxies, and dark energy, the mysterious force driving accelerating expansion.

Three possible apocalyptic scenarios

The universe may end through "heat death" (eventual cooling and darkness), the "big rip" (dark energy tearing apart all matter down to atoms), or the "big crunch" (gravitational collapse into a singularity).

3I Atlas is an interstellar comet

Unlike Oumuamua (asteroid-like) and Borisov (comet-like), 3I Atlas displays a distinct cometary tail confirming it as the third known object from outside our solar system, not an alien ship.

Spaghettification depends on black hole mass

Approaching a supermassive black hole like Sagittarius A* wouldn't immediately spaghettify you because the gravitational gradient is gentler than around smaller stellar-mass black holes.

Stars formed before galaxies existed

The first massive stars formed from primordial hydrogen and lived brief lives before exploding, creating the materials that clumped together to form the galaxies we see today.

Stellar mergers create extreme explosions

When massive stars or neutron stars collide, they release enormous energy including gamma-ray bursts and gravitational waves that ripple through the fabric of spacetime.

Light travel reveals the distant past

An observer 66 million light-years away would witness the asteroid impact that killed dinosaurs, while one a million light-years away would see Earth in its ice age without modern technology.

Asteroid belts are surprisingly sparse

The belt between Mars and Jupiter remains dispersed because Jupiter's immense gravity prevents planet formation, and spacecraft can navigate it easily without dodging dense fields of rocks.

Dwarf planets fail to dominate their orbits

Pluto was reclassified as a dwarf planet because it lacks gravitational dominance over its neighborhood and follows a highly inclined orbit compared to the other eight planets.

Solar activity threatens technology not Earth

While coronal mass ejections can damage satellites and power grids, Earth's magnetic field protects the surface, and operators now power down satellites when major geomagnetic storms are detected.