Imagine you can build a satellite to study dark matter in the Milky Way. You want this satellite to start from the Milky Way's center and get to the extreme outer regions of the Milky Way's disk where dark matter should be the most pronounced. How far away from the Milky Way center will this satellite have to go?
Group of answer choices
about 1 au
about 1 light year
about 1,000,000 pc
less than 1,000 km
about 50,000 light years
The satellite will have to go about 50,000 light years away from the Milky Way center to reach the extreme outer regions of the Milky Way's disk where dark matter should be the most pronounced.
To determine how far away from the Milky Way's center the satellite will have to go to reach the extreme outer regions of the Milky Way's disk, we can consider the estimated size of the Milky Way.
The Milky Way is believed to have a diameter of about 100,000 light-years. Since we want the satellite to reach the outer regions of the disk where dark matter should be the most pronounced, we can estimate this distance as about half of the Milky Way's diameter, which is roughly 50,000 light-years.
Therefore, the closest option among the answer choices is "about 50,000 light years".
Dark matter is still not fully understood, so its exact distribution is uncertain. However, scientists believe that dark matter is present throughout the Milky Way, including in its outer regions. Therefore, to study dark matter in the most pronounced areas, the satellite would need to reach the extreme outer regions of the Milky Way's disk.
The Milky Way's diameter is estimated to be around 100,000 light-years. So, to reach the extreme outer regions, the satellite would have to travel approximately half of the Milky Way's diameter, which would be about 50,000 light-years away from the Milky Way's center.
Therefore, the correct answer is: about 50,000 light years.