# Space Age

Given an age in seconds, calculate how old someone would be on:

   - Earth: orbital period 365.25 Earth days, or 31557600 seconds
   - Mercury: orbital period 0.2408467 Earth years
   - Venus: orbital period 0.61519726 Earth years
   - Mars: orbital period 1.8808158 Earth years
   - Jupiter: orbital period 11.862615 Earth years
   - Saturn: orbital period 29.447498 Earth years
   - Uranus: orbital period 84.016846 Earth years
   - Neptune: orbital period 164.79132 Earth years

So if you were told someone were 1,000,000,000 seconds old, you should
be able to say that they're 31 Earth-years old.

If you're wondering why Pluto didn't make the cut, go watch [this
youtube video](http://www.youtube.com/watch?v=Z_2gbGXzFbs).

## Running tests

In order to run the tests, issue the following command from the exercise
directory:

For running the tests provided, `rebar3` is used as it is the official build and
dependency management tool for erlang now. Please refer to [the tracks installation
instructions](http://exercism.io/languages/erlang/installation) on how to do that.

In order to run the tests, you can issue the following command from the exercise
directory.

```bash
$ rebar3 eunit
```

### Test versioning

Each problem defines a macro `TEST_VERSION` in the test file and
verifies that the solution defines and exports a function `test_version`
returning that same value.

To make tests pass, add the following to your solution:

```erlang
-export([test_version/0]).

test_version() ->
  1.
```

The benefit of this is that reviewers can see against which test version
an iteration was written if, for example, a previously posted solution
does not solve the current problem or passes current tests.

## Questions?

For detailed information about the Erlang track, please refer to the
[help page](http://exercism.io/languages/erlang) on the Exercism site.
This covers the basic information on setting up the development
environment expected by the exercises.

## Source

Partially inspired by Chapter 1 in Chris Pine's online Learn to Program tutorial. [http://pine.fm/LearnToProgram/?Chapter=01](http://pine.fm/LearnToProgram/?Chapter=01)

## Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.