According to Wikipedia, as of November 1, 2021, 4,864 extrasolar planets have been identified. One of the closest multiple-planet solar systems to our own is around the star Gliese 876, about 15 light-years away, and it contains four planets. One takes 63.8 Earth days to revolve, at a distance of 3.07 x 107 kilometers from Gliese 876. Another planet takes 130 Earth days to revolve. How far is this second planet from Gliese 876?

Respuesta :

Using kepler's law:

[tex]\frac{T1^2}{r1^2}=\frac{T2^2}{r2^2}[/tex]

Where:

T1 = Planet's period of the first planet

T2 = Planet's period of the second planet

r1 = Average distance to Gliese of the first planet

r2 = Average distance to Gliese of the second planet

First, we need to do a conversion:

[tex]\begin{gathered} T1=63.8days\times\frac{24h}{1day}\times\frac{60min}{1h}\times\frac{60s}{1min}=5512320s \\ T2=130days\frac{24h}{1day}\times\frac{60m\imaginaryI n}{1h}\times\frac{60s}{1m\imaginaryI n}=11232000s \end{gathered}[/tex]

Now, solving for r2:

[tex]\begin{gathered} r2=\sqrt{\frac{r1^2\cdot T2^2}{T1^2}} \\ r2=\sqrt{\frac{(3.07\times10^7)^2(11232000)^2}{(5512320)^2}} \\ r2\approx62554858.93km \end{gathered}[/tex]

Answer:

62554858.93 km