Quasars as the new cosmic standard candles

In 1929, Edwin Hubble published observations that galaxies' distances and velocities are correlated, with the distances determined using their Cepheid stars. Harvard astronomer Henrietta Swan Leavitt had discovered that a ...

Image: Hubble surveys a snowman sculpted from gas and dust

The Snowman Nebula is an emission nebula that resides in the constellation Puppis in the southern sky, about 6,000 light-years away from Earth. Emission nebulae are diffuse clouds of gas that have become so charged by the ...

Chamber measurements find plants potentially important methane sink

As a greenhouse gas, methane has a much higher heat-trapping potential than carbon dioxide when considered over the course of a few decades. In recent years, researchers discovered a potentially important new source of atmospheric ...

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