SMART-1 views the edge of Luna Incognita: Mars on the Moon?

Mankind did not see the land called Luna Incognita, until the first probes sent images of the lunar farside.
Plaskett crater sits close to the Moon's north pole, on the edge of Luna Incognita. Plaskett has a diameter of 109 kilometres and displays a central peak. This peak was formed during the crater's formation and is composed of rocks, originally from beneath the Moon's surface, which were melted and thrown up by the impact. As they rose above the surface they 'froze' and formed the peak. By analysing such central peaks, planetary scientists can deduce the vertical composition of the Moon’s subsurface regions.

Plaskett crater could play a key role in preparing humans for their eventual journeys to Mars. On such a mission, Earth would dwindle to a point and the astronauts would lose the familiar view of their home planet. From the lunar near side the Earth is a brilliant object, four times wider than the full Moon seen from Earth. The Earth seems to wobble in the sky due to a lunar motion called libration. From the lunar poles libration takes the Earth below the horizon for about half the month.

From Plaskett, on the far side of the Moon, the Earth can only be seen from the crater’s northern rim for just a few days during a few months every year.

Image Credit: ESA/Space-X (Space Exploration Institute)
High resolution image

Plaskett crater is the bottom crater in this mosaic built with images taken by the advanced Moon Imaging Experiment (AMIE) on board ESA's SMART-1 spacecraft. Plaskett and its two companion craters sit near the Moon’s north pole.

The shadow lengths can be used to calculate the height of surface features. Data like this can be turned into virtual simulations of the surface to help engineers design suitable landers. From its rim, the full Earth would graze just above the horizon for only a few days per month. However some areas within the crater never see the Earth.

Rozhdestvenskiy is a large lunar crater of 177 kilometres diameter centered at 85.2° North and 155.4° West (just above Plaskett). Its northern rim is just 60 kilometres from the north pole.




Image Credit: U.S. Geological Survey

The Earth is only intermittently visible from the Plaskett crater rim on the Moon. This makes it an ideal place to test the kind of autonomous manned base that will be needed on Mars. For most of the time, the astronauts will be deprived a view of their home planet.

The above is a view from Clementine of the full Earth over the lunar north pole. The crater with a central peak in the foreground is Plaskett. It is centred at 82.1° North and 174° East, and it is 109 kilometres in diameter. On Earth, Africa is clearly visible and nearly cloud free.

"A human outpost there, on the edge of Luna Incognita, would allow us to study the effects of Earth-deprivation on a crew in a controlled way," says Bernard Foing, SMART-1's Project Scientist.

"It will allow us to simulate Mars operations and isolation, on the Moon, at a safe distance from a human base at the north pole."

European Space Agency News Release