The Moon is Earth\'s satellite and Earth is also part of the Milky Way Galaxy. U
ID: 292587 • Letter: T
Question
The Moon is Earth's satellite and Earth is also part of the Milky Way Galaxy. Use this example to explain the similarity or difference between the terms "satellite" and "galaxy."
Distinguish between the celestial equator and the ecliptic. At what times of the year do they coincide? What is the significance of these lines for astronomers?
Describe the structure of an atom. Use the atomic number and atomic mass of any element to explain the meaning of the term isotope.
What is meant by the "Doppler Effect?" Explain how this is used by astronomers
Explanation / Answer
1.The moon is earth's satellite and both of them are the part of galaxy.
Satellite is a celestial body such as moon orbiting a larger celestial body, here earth.Many such planets and satellites constitutes the galaxy.
2.celestial equator is an imaginary projection of the terrestrial equator i.e both the equator and celestial sphere lie on the same plane. Where as the ecliptic is the path on which the earth revolves round the sun.
due to the axial tilt of the earth both the ecliptic and celestial equator are not on the same plane by inclined at an angle of 23.4 degrees.both of them co-incide during equinoxes occurs twice a year,20th march and 22-23 september.
3.The fundamental particle of matter is atom which is even smaller than molecules.
they are composed of three main components- proton and neutron (nucleus) & electrons.the protons are positively charged and electrons are negatively charged,the neutrons are neutral particle having high mass.
Isotopes are atoms of same element having same number of electrons and protons (atomic numbers) but different number of neutrons (mass number=protons+neutrons) .
4.Doppler effect is a phenomenon in which there is a change in wavelength and frequency when the source is moving with respect to the observer of the observer is moving with respect to the source.
In astronomy the doppler effect is studied with respect to electromagnet waves, results in red shift or blue-shift.It is used to study the speed at which the galaxy or stars are moving w.r.t to earth.