The star collections known as galaxies formed much sooner in the early universe than previously estimated, according to an analysis of data from the Hubble Space Telescope. Galaxies were well established within 2.5 billion years of the big bang.
Like terrestrial storms, solar storms trigger effects that range from beautiful to annoying to dangerous. But what causes them? Here we explain four different kinds of solar outbursts that can impact us here on Earth.
The Perseid meteor shower and its ilk provide the sodium atoms in the middle atmosphere that light up when astronomers tickle them with a laser – a key step in adaptive optics, which are used by ground-based observatories.