SPST 200 UND Determine if an Exoplanet is Inhabited by Non Intelligent Life Discussion

1) [5 points] How might you determine if an exoplanet is inhabited by non-intelligent life (microbes, dinosaurs, etc.)? How might you determine it is inhabited by intelligent life? What kinds of detections, measurements and signs would you use and look for? Assuming the planet is inhabited by life up to or slightly more advanced than humans, what might they be able to determine about Earth and its inhabitants?

2) [5 points] Briefly discuss why it is unlikely that a 5 solar mass B5V star would have a planet occupied by a native civilization of intelligent aliens.

3) [6 points] In the year 2017, a newly discovered comet passed perihelion. The elements of its orbit on the in-bound trajectory were: a = 275 AU, e = 0.998, and i = 89°.

A) What year did this comet last pass perihelion? (How long does it take for an object to repeat an orbit?)

B) What world famous ancient structure was constructed within a few decades of this comet’s previous perihelion passage?

C) How close did the comet come to the Sun during the 2017 perihelion passage?

4) [5 points] Calculate escape velocity for a spherical planet 10,000 km in diameter with a density of 4000 kg/m³. Show your work. (Be careful to use consistent units.)

Escape velocity, v_esc =

5) [4 points] One of Einstein’s famous equations, E = mc², is often used in pop culture to signal a “stereotypical smart person”. However, we learned one way this seemingly high-fallutin’ equation relates to the lives of stars. What do the terms in the equation mean? What does it have to do with stars?