Light-Pollution

The Milky Way arching over the telescope domes of the Teide Observatory on the Izaña ridge in Tenerife, with Scorpius and Antares on the right and a faint glow of coastal light on the left horizon.

Astrotourism

Stargazing on Teide: how dark Tenerife's sky really is, and where to stand

Tenerife is the easiest high-altitude sky in Europe to get to: two international airports and a paved road up to the Teide cable car’s base station at 2,356 m. The catch is in the photometry. The professional observatory on the Izaña ridge measures its moonless zenith at 21.20 magnitudes per square arcsecond, half a magnitude brighter than La Palma’s Roque de los Muchachos, about 144 km to the west-northwest. Below I go through where that extra light comes from, which caldera viewpoints to use, what the guided tours cost, and what a winter trip to 28° north shows you that Cyprus can’t. ...

Artemis I, Crew-4, & Starlink Rockets on the Pad

Space news

SpaceX went public at $1.77 trillion — what that means for the night sky

On June 12, SpaceX raised $75 billion in the largest initial public offering in history. The company listed on the Nasdaq at $135 per share, valuing the business at approximately $1.77 trillion — putting it among the ten most valuable public companies on Earth. Within hours of the listing, a Falcon 9 carrying 29 Starlink satellites lifted off from Cape Canaveral. The symbolism wasn’t accidental. The reason SpaceX commands that valuation isn’t Starship, and it isn’t the Artemis HLS contract. It’s 10,400 satellites already in orbit, beaming internet to paying subscribers in 75+ countries. Starlink generates an estimated 58% of SpaceX’s total revenue. When public investors bought SpaceX stock this week, they bought a satellite internet company that also happens to build rockets. ...

JWST near-infrared image of the Cosmic Cliffs in the Carina Nebula, showing towering pillars of gas and dust backlit by young stars

Gear

Light pollution filters from a Bortle 7 balcony: what actually helps and what doesn't

I shoot from a fourth-floor balcony in Nicosia. Bortle 7 on a clear night, Bortle 8 when the football pitch lights are on. Every spring, someone in the astrophotography forums asks: “Which filter should I buy for light-polluted skies?” The answers range from “get an L-Pro” to “move to the countryside.” Neither is particularly useful if you’re standing on a balcony with a one-shot colour camera and two hours before the neighbour’s security light comes on. ...