Planets shine by reflected sunlight. How can planets be brighter than stars?
Approxinmately how many times brighter than Mars is Earth's full moon? (i do know the Moon's apparent magnitude equals -12.6)
Could we see the sun if it were 32.6 light years from Earth?
PLEASE someone help, I really don't understand it!!!!!
Planets can appear brighter than stars because they are relatively closer to us than most stars in the night sky. Stars emit light of their own, while planets do not. Instead, planets shine by reflecting sunlight that reaches them from our Sun.
To determine how much brighter Earth's full moon is compared to Mars, we can compare their apparent magnitudes. The apparent magnitude is a measure of how bright an object appears to us from Earth. A lower magnitude value indicates a brighter object.
The apparent magnitude of Mars can vary depending on its position in its orbit. On average, it ranges between -2.94 to 1.87. On the other hand, the apparent magnitude of the Moon at full phase is approximately -12.6, which is significantly brighter.
To determine the relative brightness, we can calculate the difference in magnitudes using the formula: Brightness ratio = 2.512^(magnitude difference).
For example, to find the brightness ratio between Earth's full moon (-12.6) and Mars (-2.94), we calculate it as follows: Brightness ratio = 2.512^(-12.6 - (-2.94)).
Simplifying the calculation gives us a brightness ratio of approximately 1,449,170 times brighter. Therefore, Earth's full moon appears about 1.4 million times brighter than Mars.
Regarding the visibility of the Sun from a distance of 32.6 light years, the answer is no. Light travels at a speed of about 186,282 miles per second (299,792 kilometers per second). Since light takes 8 minutes and 20 seconds to reach Earth from the Sun, the distance covered in 32.6 years is much larger than the 32.6 light-years.
Given that the Sun is roughly 93 million miles (150 million kilometers) away from Earth, even though light emitted by the Sun 32.6 years ago would be reaching Earth, it would still be many light-years away from 32.6 light-years. Therefore, we would not be able to see the Sun if it were at that distance.