Space
Why Is the Night Sky Dark? Olbers’ Paradox and the Age of the Universe
With billions of stars out there, why isn’t the night sky ablaze with light? Olbers’ paradox, the finite age of the universe and cosmic expansion, explained.
Space
Planets, stars, black holes and the big questions of the universe.
Space
Why Does the Moon Change Shape? Moon Phases Explained Simply
Why does the Moon go from crescent to full? Why lunar phases have nothing to do with Earth’s shadow, and how to tell a waxing Moon from a waning one.
Space
What Is a Black Hole? How They Form and What Happens Inside
What is a black hole, how does it form and what is the event horizon? A clear guide to the objects not even light can escape — and their first images.
Space
What Is a Light-Year? Making Sense of Space’s Enormous Distances
Is a light-year a unit of time or distance? How big a light-year really is, why looking at stars means looking into the past, and the scale of the universe.
Space
How Does the Sun Shine? The Story of Nuclear Fusion in Its Core
How does the Sun produce light and heat, how does its energy reach us and when will it burn out? Nuclear fusion in the core and the Sun’s layers, explained.
Space
Why Do Stars Twinkle? The Atmosphere Behind the Flicker
Why do stars twinkle while planets shine steadily? How starlight bends in Earth’s atmosphere, and how astronomers fight the twinkle to get sharp images.
Space
Why Is Mars Red? The Rusty Secret of the Red Planet
What gives Mars its red colour? The iron-oxide dust covering its surface, the 2025 discovery of traces of water, and why Martian sunsets are blue.
Space
What Causes the Seasons? The Secret of Earth’s Tilted Axis
Are the seasons caused by Earth moving closer to the Sun? How the tilt of Earth’s axis creates summer and winter, explained step by step with diagrams.