How the Sun will become a white dwarf
After its giant phases, the Sun will leave a dense, cooling core. Fusion, mass loss and quantum pressure explain how a familiar...
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Space Facts
Extraordinary worlds, surprising connections, and the science behind them.
Why the Moon looks bigger near the horizon
A rising Moon can look enormous without growing wider in a fixed-zoom photograph. Perception, atmospheric effects and orbital distance each play different...
Why Mars looks red, but its rocks are not all red
Oxidized iron minerals colour fine dust that coats and circulates around Mars. Rover samples reveal a more varied planet beneath that familiar...
Why the Moon keeps so many ancient impact craters
Earth's weather and shifting crust erase or bury many impact scars. The Moon preserves a longer record, although new impacts and moving...
Why the Milky Way looks like a band across the sky
We live inside the Milky Way's stellar disk. Looking along that crowded plane produces a hazy band, while interstellar dust hides parts...
How Mercury preserves water ice so close to the Sun
Sunlit ground can reach about 430 degrees Celsius, but some polar crater floors never receive direct sunlight. MESSENGER's measurements reveal why local...
Why Webb must stay cold to see infrared light
Warm telescope hardware emits infrared light of its own. Webb’s layered sunshield limits that background, while MIRI needs additional refrigeration to observe...
Why the Moon turns red during a lunar eclipse
Earth blocks direct sunlight during a total lunar eclipse, but its atmosphere bends and filters a little light into the shadow. That...
Why Jupiter bulges at its equator
Jupiter’s rapid rotation helps make it about 7% wider across the equator than from pole to pole. Radio measurements reveal how its...
Why meteor showers seem to radiate from one point
Particles in a meteor stream arrive along nearly parallel paths. Perspective makes their trails appear to spread from a shared region of...
Why the Moon is slowly moving away from Earth
Laser measurements reveal that the Moon’s mean distance grows by about 3.8 centimetres a year. Tidal interactions transfer angular momentum from Earth’s...
How rockets produce thrust in the vacuum of space
A rocket accelerates its own exhaust, producing a force on the vehicle in the opposite direction. Chemical engines also carry the ingredients...