# Why did they go to visit the first water planet in Interstellar?

In interstellar, the first planet they visit is the closest one to Gargantua, and hence the one with the biggest time dilation effect (1 hour on the planet = 7 years in the Earth).

Now, if we make some maths:

The trip from Earth takes 8 months + 14 months = ~2 years to reach that system.

We are told the Lazarus missions departured from Earth ~10 years ago.

This gives the Astronaut (Miller) around 12 years (In earth time) as maximum to reach that planet, land, set up a base, explore, make the first tests and send back some information.

However, all this time (12 years in earth time) are the equivalent in that planet to less than 2 hours which is by far not enough time to perform the necessary tasks to decide whether that planet is good or not to host life.

This planet should have been left many more years so the astronaut there could have enough time to perform some tests and exploration. At least few days in the planet, which would be the equivalent to hundreds of years in Earth time.

Therefore, this planet was absurd to be visited even in first instance as even if it was possible to be hosted by life, they would need a lot of Earth time to figure it out.

Then, why did they even bother with that planet at all? Either in first case (Miller) and in the second case (The endurance mission)?

• While I must say, its a pretty good point, one also needs to remember "wheat and okra are dead. Corn would die too".They din't quite have much time. Once they landed on Miller's planet, they headed for the beacon, which may have been the reason why they thought Miller found something positive as soon as she arrived. Commented Dec 11, 2017 at 14:21
• @Daniel Ortega This always bothered me, and add to it that it's -sort of- a time sensitive mission. Commented Dec 11, 2017 at 15:05
• If I remember right there was an explanation about this in the movie. Something about this one being the most promising and ideal earth-like situation. They were blinded to its unfitness, by all the things that made it seem that much better than the other options. Commented Dec 11, 2017 at 19:20

This planet should have been left many more years so the astronaut there could have enough time to perform some tests and exploration.

They didn't know that the miller's planet is that close to gargantua, as Romilly mentioned:

The planet is much closer to gargantua than we thought.

So, they had no idea about this to consider sending pioneers sooner. Even if they did, 2 days on that planet is equal to 336 years on earth, before even the Apollo 11, or Apollo 0!

As Doyle mentioned:

Dr Mann's data is promising, but it's gonna take us months to get there, and Edmund's is even further. Miller hasn't sent much, but what she has sent is very promising. It's water, it's organics... And think about the resources including time that would be spent trying to get back here.

So it's a matter of resource and time too.

Also, Romilly used the time to study the black hole, to help Professor Brand. Cooper's plan was very important on making the decision to actually visit the planet.

• I like your answer. However, it does not explain why when they are in the proximity of Miller's planet they do not make the appropiate calculations to determine that Miller has "just arrived" into the planet so they can discard it and check the other two instead. Commented Dec 21, 2017 at 10:55

Even though answers here are pretty good, I would still like to share my point of view on this great question.

They didn't expect giant waves smashing whole surface.

As Cooper says on Miller's planet after being smashed by giant wave

We are not ready for this

Why did they decide to land on Miller's planet?

Miller was still broadcasting at the time - at least they thought so. They just wanted to land on the ground, pick up Miller's data (together with Miller her-self) and get back to the Endurance - this trip would take few minutes (half hour at worst) ~ 3.5 years on Earth - and then get back to Endurance ASAP with all the data they need to deeply investigate. Then, according to that research choose whether they have to travel to Dr. Manns and/or Edmunds planets, or if the data was good enough, estabilish base on Miller's planet and eventually some of them (at least Cooper) get back to home - Earth.

Important thing to keep in mind - their main goal was to save human race, not people on Earth. Most important to nderstand why did they do so, is what Doyle have said

Dr Mann's data is promising, but it's gonna take us months to get there, and Edmund's is even further. Miller hasn't sent much, but what she has sent is very promising. It's water, it's organics... And think about the resources including time that would be spent trying to get back here.

A little bit of explanation, even though its self-explaining enough - At the time, it was "the best" (in terms of being able to live there and also similiar to the Earth) planet out of these three, and traveling to Dr. Manns planet (Edmund was not broadcasting already) and back would take too much resources, while picking up data from Miller's planet would take "just" few months/years at worst (if there were no giant waves, they didn't know about) and they would still have enough fuel/resources to travel to Dr. Mann's and Edmund's planets.

As you have mentioned

However, all this time (12 years in earth time) are the equivalent in that planet to less than 2 hours which is by far not enough time to perform the necessary tasks to decide whether that planet is good or not to host life.

there were some speculative things about Miller's planet in Interstellar

1) If we know waves keep coming in cca. 1 hour intervals, she sent the data almost few minutes (hour at worst) after landing - which none scientist would probably do.

2) They would have to be blind to not seeing the giant wave while landing and/or getting out of ranger - maybe even from the space.

3) How did they know there is so low water level allowing them the landing, while they didn't know there are so huge waves.

Good question. My only thought is that the survival of humanity depended on finding a new, habitable planet. They weren't being picky. Humans identified every planet they could possibly reach and inhabit, and there were only 3 of them. They had to investigate all 3, even if the water planet was so close to Gargantua that it could only be explored cursorily while taking decades / generations of earth time.