This is a simulation of an instrumental landing of a space module.
The computer is out of order, and you have to manually operate the controls.
Use buttons 0 to 9 to control the thrust of the braking rockets.
To accomplish a perfect landing, you have to touch the ground
with a speed greater than -10m/s (note that you are descending,
thus it is a "negative" speed).
You can use the "Reverse gravity" feature to experience a weird effect: the planet gravity will be inverted, so that you'll have to "push" your module with your rockets to reach the planet's surface.
If you want to try to land on spots with a very high gravity (like the Sun), you can multiply the power of your bracking rockets.
Disable the "Show graphics" option if you want try a pure instrumental landing.
"Lunar Lander" is definitely one of the first videogames ever, created in the early ages of computer science, probably written and played by people who can put their hands on a computer in the '60s (mostly US scientists and MIT students).
In 1979, Atari created a coin op with a graphic version of this simulation which was Atari's first vector graphics game.
A clone of the Atari's game has been put into the LucasArts' adventure "the Dig", inside the "Pen Ultimate", the hand held computer of the space crew.
This enhanced version of Lunar Lander called "Space Lander" has been tested by many scientists, astronomers, and other people who work in the space field.
Damian Audley and David Palmer (NASA scientists) pointed out that the impact scar size resulting from the early formula used was grossly overestimated, other NASA researchers contributed with more information: Dave Williams told me that "Most studies of impact craters are limited to extremely high velocity
impacts (many km/sec) and would not be relevant to a spacecraft impact."
Jim Garvin said that "at non hypervelocity the impact scar will
be smaller (as there would be no cratering flow field established)." In a following letter he added that "When large meteorites fall to the Earth, for example, unless
they hit at many miles per SECOND, they essentially produce
what we call a percusion pit (they dig a hole not much bigger
than their diameter). However, if they collide with
Earth (or Mars) at 5-15 km per SECOND (cosmic velocities), then
they explode as they impact, essentially operating like
a Mother Natures "BOMB" and excavate a true crater, many times deeper
and wider than their size."
Thanks to Stephen R. Schmitt for the proper function to calculate the crater diameter.
Their help was really appreciated.