Start here · Essential guide
How Stars Are Born, Live and Die
Follow a star from a collapsing gas cloud through its long stable life to its final remnant, and see why a star's mass decides almost everything about its fate.
Space and Science
Stars, Galaxies and Telescopes
How stars live, how galaxies are built and how we observe them.
Dark Energy and the Expanding Universe
Learn how observations of distant exploding stars showed that cosmic expansion is speeding up, what dark energy means, and what scientists still do not know.
Dark Matter Explained
Why astronomers infer unseen matter from how galaxies rotate and bend light, which candidates have been proposed, and what remains genuinely unknown.
How Astronomers Find Planets Around Other Stars
A plain look at how astronomers detect worlds beyond our Solar System, from the transit dip and the stellar wobble to direct imaging and microlensing.
How Telescopes Work, from Backyard Lenses to Space Observatories
How lenses and mirrors collect and focus light, why bigger apertures show fainter objects, and why putting a telescope in space solves problems Earth's air creates.
Neutron Stars and Pulsars
How the collapsed core of a massive star becomes a city-sized, extremely dense neutron star, and why some of them sweep beams of radiation across space like lighthouses.
Supernovae: When Stars Explode
The main types of stellar explosions, how a white dwarf or a collapsing massive star can blow itself apart, and how supernovae scatter heavy elements through space.
The Milky Way: A Guide to Our Home Galaxy
A tour of our home galaxy's disk, bulge, spiral arms and halo, where the Solar System sits within it, and why we see a pale band of stars across the night sky.
What Evidence Supports the Big Bang
A plain-language review of the main observations behind the Big Bang model: galaxy redshifts, the cosmic microwave background, light-element abundances and cosmic structure.
What Is a Galaxy and Why Do They Come in Different Shapes
What a galaxy is, how spiral, elliptical and irregular galaxies differ, and how mergers, gas supply and star formation help shape them over billions of years.
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