The science of astronomy is broken into separate sub-disciplines. For example, planetary scientists study worlds planets, moons, rings, asteroids, and comets within our own solar system as well as those orbiting distant stars. Solar physicists focus on the Sun and its effects on the solar system. Their work also helps forecast solar activity such as flares, mass ejections, and sunspots.
Astrophysicists apply physics to the studies of stars and galaxies to explain exactly how they work. Radio astronomers use radio telescopes to study the radio frequencies given off by objects and processes in the universe. Ultraviolet, x-ray, gamma-ray, and infrared astronomy reveals the cosmos in other wavelengths of light. Astrometry is the science of measuring distances in space between objects. There are also mathematical astronomers who use numbers, calculations, computers, and statistics to explain what others observe in the cosmos.
Finally, cosmologists study the universe as a whole to help explain its origin and evolution across nearly 14 billion years of time. Astronomers use observatories equipped with powerful telescopes that help them magnify the view of dim and distant objects in the universe.
Astronomy tools, like the armillary sphere , were used by early astronomers and new tools came about as the study of astronomy evolved. They also use instruments called spectrographs that dissect the light from stars, planets, galaxies, and nebulae, and reveal more details about how they work. Specialized light meters called photometers help them measure the varying stellar brightnesses. Well-equipped observatories are scattered around the planet. They also orbit high above Earth's surface, with such spacecraft as Hubble Space Telescope providing clear images and data from space.
To study distant worlds, planetary scientists send spacecraft on long-term expeditions, Mars landers such as Curiosity , Cassini Saturn mission , and many, many others. Those probes also carry instruments and cameras that provide data about their targets.
Looking at the stars and galaxies helps us understand how our universe came into being and how it works. For example, knowledge of the Sun helps explain stars. Studying other stars gives insight into how the Sun works. As we study more distant stars, we learn more about the Milky Way. Mapping our galaxy tells us about its history and what conditions existed that helped our solar system form.
Charting other galaxies as far as we can detect teaches lessons about the larger cosmos. There is always something to learn in astronomy. Each object and event tells a tale of cosmic history. In a very real sense, astronomy gives us a sense of our place in the universe. The Moon also rises in the east and sets in the west, although its position will shift north or south depending on where you live and the time of year. You can also learn some shortcuts to help estimate positions in the night sky.
Sky positions are commonly measured in degrees, where 0 degrees is the horizon and 90 degrees is directly overhead. If Venus is reported to be 15 degrees from the moon at a given time, you'll know that means roughly one and a half outstretched fists. Learning which bright stars and constellations are visible as the seasons change will help as well, since the position of planets and other objects will often be described in relation to these standards. Even in major cities planets are usually still visible since they are brighter than most stars.
The most useful piece of equipment for stargazing these days is a good smartphone application. Free Online Astronomy Courses. Follow Show filters Sort by Relevancy.
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From Chemistry to Life 3 reviews. Universe or Multiverse? The best one to use as a guide is the Plough , since it is large, bright and visible year-round in the north. To use it to look at things in different directions, hold it so that the bottom edge corresponds to the compass direction you are facing.
The night sky changes in appearance over time. Stars keep the same positions relative to one another, but seem to move as a whole. Earth also orbits the Sun in about days, so stars are in slightly different positions at the same time each night. Observing this change will give you a good sense of the motion of our planet and how it affects our view of the heavens. Getting to know the night sky is easiest when you start simple and progress towards more difficult targets.
Some of them are quite bright, and many of their striking patterns and names have been with us for thousands of years.
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