Plasma happens when gas gets heated to a very high temperature and the atoms lose their electrons. Find out more about this state of matter. Science Trek is available to stream on pbs.org and the free ...

A galaxy made almost entirely of dark matter, an elusive form of matter that doesn’t interact with light, was spotted by Hubble 250 million light-years from Earth.

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The universe is mostly a ghost story we don’t understand. Everything we know of, the stars, the planets, and everything on ...

Now physicists from the University of Washington are taking a big swing at answering that question. All matter exerts gravitational force. The more mass the object has, the greater the force. Yet, a ...

NASA's Hubble Space Telescope captures the magnificent starry population of the Coma Cluster of galaxies, one of the densest known galaxy collections in the universe — and where the effect of dark ...

Galaxies are far more than the sum of their stars. Long before stars even formed, dark matter clumped up and drew regular matter together with its gravity, providing the invisible scaffolding upon ...

The universe is packed with riddles, but few are as stubborn or as fascinating as dark matter. First proposed in 1933 by astronomer Fritz Zwicky, this elusive substance refuses to play by the rules: ...

Scientists have long been puzzled by dark matter, an elusive substance that makes up about 27% of the universe. Recent breakthroughs in research are shedding light on its mysterious nature, ...

Only recently have scientists realized that most of the universe is neither gaseous, liquid or solid. It is plasma, a lively, tricky, often dangerous state of matter whose distinctive characteristic ...

At the end of a lecture on astronomy, describing how the planets orbit the Sun, a little old lady at the back of the room stood up and said: "What you've told us is all rubbish. The world is really a ...