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Extraterrestrial life
Extraterrestrial life is life that may exist and originate outside the planet Earth, the only place in the universe currently known by humans to support life. Its existence is currently purely ... > more -
Space exploration
Space exploration is the physical exploration of outer space, both by human spaceflights and by robotic spacecraft. While the observation of objects in space—known as astronomy—pre-dates ... > more -
Physical cosmology
Physical cosmology, as a branch of astrophysics, is the study of the large-scale structure of the universe and is concerned with fundamental questions about its formation and evolution. Cosmology ... > more -
Dark matter
In astrophysics and cosmology, dark matter is hypothetical matter of unknown composition that does not emit or reflect enough electromagnetic radiation to be observed directly, but whose presence can ... > more -
European Space Agency
The European Space Agency (ESA), established in 1975, is an inter-governmental organisation dedicated to exploration of space with currently 17 member states. ESA has ambitious space plans that may ... > more -
Barred spiral galaxy
A barred spiral galaxy is a spiral galaxy with a band of bright stars emerging from the center and running across the middle of the ... > more
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