Modern Astronomy is the astronomy in which we actually started looking at celestial bodies up close. Today there is a lot going on about the information of astronomy. Galileo was the first modern astronomer, just an interesting fact to throw in!
A telescope is a tool for atronomers. Yes!
Astronomers believe that the solar system is about 4.6 billion years old. This age is determined by studying the ages of rocks on Earth and meteorites from space that have been dated using radiometric dating techniques.
A telescope is a tool for atronomers. Yes!
They don't. Astronomers are people who study the cosmos from....earth!
The main physical information about astronomical objects give their spectra!
Astronomers believe that the solar system is about 4.6 billion years old. This age is determined by studying the ages of rocks on Earth and meteorites from space that have been dated using radiometric dating techniques.
An astronomer specializes in studying celestial objects such as planets, stars, galaxies, and cosmic phenomena. They use telescopes, satellites, and computer simulations to observe, analyze, and interpret data to better understand the universe and its origins.
Astronomers use azimuth and altitude as a coordinate system to locate celestial objects in the sky from a specific observer's perspective. Azimuth measures the angle along the horizon, indicating the cardinal direction (0° for North, 90° for East, etc.), while altitude measures the angle above the horizon. This system simplifies the process of tracking objects' positions as they move across the sky due to Earth's rotation. It is particularly useful for amateur astronomers and in practical observations.
Gravity. We cannot see or directly detect "dark matter", and the only reason why astronomers talk about "dark matter" is that galaxies like the Milky Way appear to be spinning too fast for gravity to hold them together. Or at least, for the gravity of the mass that we can SEE to hold them together. Gravity comes from matter, and we can't see enough matter, so it must be "dark matter". This may be in the form of trillions of invisibly-dim brown dwarf stars, or in black holes from which no light ever escapes - or it may be something entirely new. "Dark matter" is the something new.
Astronomers know that there isn't really a "celestial sphere", a globe of crystal in which the stars are embedded. But it is often convenient to talk of a "sphere" around the Earth, in which all the stars and planets move. And sometimes it makes the math a whole lot easier. Navigators do all their calculations AS IF all the stars were stuck to a crystal sphere, and the Moon and planets wandered around inside it.