The Sky at Night: Answers to Questions from Across the Universe
Patrick Moore, Chris North
Format: PDF / Kindle (mobi) / ePub
Questions about the moon, the solar system, space travel, other planets, and more, answered by a popular astronomer
Celebrating the 55th anniversary of The Sky at Night, this book collects and answers questions sent in by viewers. With sections on the solar system, the bizarre and unexplained, space missions, and more, this is an exciting journey into space for the novice astronomer and the lifelong stargazer alike. Discover how scientists work out the gravity of planets, what the 'Great Attractor' is and the basic principles of space navigation. Learn how to start observing the sky, what event inspired Patrick to take up astronomy, and just how many of his cats are named after celestial bodies. From comets to black holes and Orion to eclipses, The Sky at Night is the ultimate introduction to the wonders and mysteries of the universe.
(Telford, Shropshire) Like many star names, Betelgeuse originates from the Arabic language. The Arabic language uses a different script to the Latin alphabet, and so translations were tricky. In Arabic, the star was commonly called yad-al-jauza’, which means ‘Hand of the Giant’. Mistranslations first turned this into bedelgeuze, through confusion over the Arabic equivalents of y and b. In the nineteenth century, European astronomers readdressed the origin of the name, and were understandably.
Notice that they seem to be moving away from us. As the Universe expands, the light from the galaxies is stretched to longer wavelengths, making them appear redder than they would if the Universe weren’t expanding. Another way to interpret this is that all the galaxies are moving away from ours, which would seem to imply that we are somewhere special. This expansion does not apply on relatively small scales, such as when considering galaxies within the same group, or cluster. On larger scales,.
Measurements being fairly instantaneous, but in cosmology that’s not always the case. The distances are so great that the light takes a very long time to travel from where it was emitted to our telescopes on Earth. In the intervening time, sometimes measured in billions of years, the Universe has expanded – so do you quote the distance when the light was emitted (when the Universe was smaller) or the distance now? The only handle we have for the distance to most objects across the Universe is.
Continuously at the Large and Small Magellanic Clouds. These two small galaxies lie more than 160,000 light years away, but are close enough that millions of individual stars can be seen. Between us and them is the Galactic Halo, a roughly spherical volume that surrounds our Galaxy and is where the majority of these MACHOs should reside – if they are real. A very small number of these microlensing events were seen, but many fewer than would be expected if black holes and other MACHOs were.
Normal matter, and ignore dark matter) was made of 75 per cent hydrogen, 25 per cent helium and a tiny smattering of lithium. As soon as stars formed, the nuclear fusion in their cores started converting hydrogen into helium and then into other heavier elements. This is where most of the carbon, nitrogen and oxygen come from in the Universe, along with a selection of other elements such as silicon, magnesium, calcium and iron. The even heavier elements, such as lead, gold and uranium, are created.