Lesson: Hubble’s Law Physics
In this lesson, we will learn how to use the formula v = H₀d (Hubble’s law) to calculate the distance to faraway galaxies using the recession velocity.
The galaxy NGC 87 has been observed to be moving away from Earth at a speed of 3,420 km/s. Using a value of 20.8 km/s/Mly for the value of the Hubble constant, find the distance between NGC 87 and Earth. Give your answer to the nearest megalight-year.
Edwin Hubble observed that the light from very distant galaxies was redshifted and that the farther away a galaxy was, the greater its redshift. What does this say about very distant galaxies?
Astronomers often measure the distance to faraway galaxies in units of megalight-years.
What is the unit symbol for a light-year?
What is the unit symbol for a megalight-year?
How many light-years are there in a megalight-year?