Why does Mars have no oceans?

Question

It used to so why does it not now?

Answer 1

That's something the scientists themselves would like to know!

The most likely reason is that as the Martian core cooled the magnetic field weakened and shut down. This exposed the atmosphere to the solar wind, which gradually eroded it away. As the atmosphere became thinner the greenhouse effect was reduced and the surface temperature dropped. Eventually it became too cold for liquid water to exist on the surface, and it all froze up in the polar ice and permafrost deposits. So now Mars is a cold desert.

The same thing will probably happen to Earth when its interior cools. It just happened to Mars first because Mars is much smaller than Earth, so it cooled more quickly and it had less radioactive materials inside it to decay and keep the core and mantle hot.

Answer 2

Mars ocean beds have taken a holiday - most vapour arrived at the earth - on Mars the Northern hemisphere contains water just under the surface- dis-colouring of top soil from pole down around the top clearly shows a wetted presence. Clouds and rain must be active there - though only in the northern parts. The dusty devils, tornados down south have not been fully covered nor taken care of.
It is expected that by Nasa standards a couple of seeds be planeted near the northend quite soon.

Answer 3

Three main reasons Mars lacks oceans.

1. Small planet; gravity is low for retaining atmosphere.

2. Lacks oxygen source to replenish an Earth-type atmosphere--sufficient plants. Oceans are replenished by plants putting out oxygen and taking in carbon dioxide emitted by other living things--the resulting rain in the atmosphere falling into ocean and land-based water reservoirs such as rivers and lakes and replenishing
both; the other replenishment source is snow, which Mars seems to lack also.

3. Its atmosphere formed millions of years ago and was gradually lost; the lack of atmosphere to screen incoming solar radiation caues it to be very cold, and without sufficient oxygen sources, there is no way for Mars to form water for either snow, nor water of any kind.

Answer 4

The atmospheric conditions in Mars now cannot support an oceanic habitat. Mars used to have a different climate thousands of years ago which could support oceans. Now, however, its climate is different and it cannot.

Answer 5

Something happened to make the water go away...at least the liquid water. Chances are, the atmosphere thinned and the planet was no longer able to hold liquid water. Atmosphere makes a lot of difference. There are speculations that Mars probably had a much thicker atmosphere at one point.

Answer 6

When Mars's molten iron core cooled, it lost its magnetosphere. Without its protection, the solar wind carried away its atmosphere little by little. As its atmosphere thinned the water either evaporated away with the atmosphere or was frozen in the poles.

Answer 7

About 4 million years ago the alien life forms of the zurog came and mined the oceans from mars. They would've done earth too but my great great great hairy grand mom hit them with her rolling pin.
umm... geo is right, but i felt like making something up

Answer 8

because it is way too cold for there to be any. even though they call it the red planet its too cold for any oceans!!!!!!!

Answer 9

It is under ground frozen.

Answer 10

There is no water. It is too cold for water to exist.