What ionized the universe?

The sparsely distributed hot gas that exists in the space between galaxies, the intergalactic medium, is ionized. The question is, how? Astronomers know that once the early universe expanded and cooled enough, hydrogen (its ...

Spanning disciplines in the search for life beyond Earth

The search for life beyond Earth is riding a surge of creativity and innovation. Following a gold rush of exoplanet discovery over the past two decades, it is time to tackle the next step: determining which of the known exoplanets ...

Saturn's radiation belts: A stranger to the solar wind

The radiation belts of Earth and Saturn differ more strongly than previously assumed. In these belts, very energetic particles, such as electrons and protons, move around the planet at high velocities - captured by its magnetic ...

An Earth-like atmosphere may not survive Proxima b's orbit

Proxima b, an Earth-size planet right outside our solar system in the habitable zone of its star, may not be able to keep a grip on its atmosphere, leaving the surface exposed to harmful stellar radiation and reducing its ...

SOHO image: Here comes the sun

The Solar and Heliospheric Observatory (SOHO) has been watching the Sun for almost 20 years. In that time it has seen solar activity ramp up and die down repeatedly. Its Extreme ultraviolet Imaging Telescope has taken images ...

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