In astronomy, the Doppler effect is a phenomenon where the wavelength of light or sound appears to change depending on the relative motion between the observer and the source. This effect is commonly used to determine the speed and direction of celestial objects in space. When a star or galaxy is moving towards Earth, the light waves emitted by it are compressed, causing them to shift towards the blue end of the spectrum. This is known as blueshift. On the other hand, when a celestial object is moving away from us, the light waves are stretched, resulting in a shift towards the red end of the spectrum, known as redshift. By analyzing the amount of redshift or blueshift in the light emitted by stars and galaxies, astronomers can determine their velocity and distance from Earth. This information is crucial for understanding the movement and behavior of celestial objects in the vast expanse of space. Overall, the Doppler effect plays a significant role in the field of astronomy, allowing scientists to unravel mysteries of the universe and gain insights into the cosmic phenomena that shape our understanding of the cosmos.