Plot Questions
I just watched the movie and was wondering if there are some answers to these plot questions.
When they discovered the Petrova line and then discovered that it was a flow of astrophages from the Sun to Venus. And then Grace discovers that the astrophages are traveling to the CO2-rich atmosphere of Venus (bypassing Mercury) to breed and then return.
I would have liked some scenes discussing some alternatives to the plan that they eventually settled on. The Petrova line starts off thin and then arcs towards Venus where it spreads out. Once Grace killed one astrophage and then figured out its composition. Why was it not simpler to figure out an infrared-invisible filter to kill astrophages before they reached Venus or before they returned to the sun? They could have dismissed it by saying they couldn't filter them fast enough or the filter would get saturated too quickly or anything. But the movie didn't attempt to convince us that discovering a new organism, figuring out how it breeds, it being able to breed quick enough to fuel a starship with new engines invented and manufactured to take advantage of its high energy-density, and then make a 12 year trip to a distant star was a more feasible plan.
Why was it planned as a suicide mission due to the engines not having enough macrophages to return to Earth? Was it not possible to plot a course that included refilling astrophages as fuel when they showed the galaxy was littered with Petrova lines? They knew that the destination star had its own Petrova Line? Why wasn't it incorporated into the plan to refuel from those astrophages before returning home?
Did they need to collect a large sample of the amoebas that kill the astrophages and send them back? It was never going to be enough to replicate the population of amoebas required on Venus, so why wouldn't they just sequence the organism and transmit that data back to scientists on Earth instead? Or just use the amoebas to understand how to metabolize the astrophages and then send that mechanism back to Earth. They already had to evolve a strain that could survive the Nitrogen content of Venus' atmosphere, but what about it's gravity or radiation? The solution is going to end up highly-customized anyway. When the amoebas arrive on Earth, it's said that they will start growing more of them anyway. Wouldn't the data be enough (kind of like in another show where the instructions for a virus are sent to earth and then scientists on the ground create them). This felt like a contrivance to make that dangerous amoeba-collection mission happen.