Question

1. It turns out that Mercury and Mars have the same gravity as one another – that is, you would weigh the same on the surface of Mercury as you would on the surface of Mars, despite the fact that Mercury is smaller. Why is this the case?  

2. that even if Venus used to have oceans (and maybe even life), there is no way for us to tell today whether this was ever the case. Thinking about what we discussed about Venus’s strange geological history, why do we not expect to find any clues to Venus’s ancient past?  

Answer 1

1) Weight of a body is a product of mass and gravity.

W=mg

Since gravity g is same on both, therefore for a body having a mass m will have same weight.

So it has nothing to do with the mass of the planet. It just depends on mass of body and gravity on the planet.

Answer 2

1. The surface gravity of a planet is dependent on both its mass and radius. While Mercury is smaller than Mars, it also has a greater density, meaning that its mass is relatively similar to that of Mars. As a result, the gravitational pull on the surface of Mercury is similar to that on the surface of Mars, despite their different sizes.

2. Venus has undergone significant geological activity, including massive volcanic eruptions and a greenhouse effect that caused its oceans to evaporate. This means that any evidence of past oceans or life on the planet would have been destroyed or buried by these geological processes. Additionally, Venus does not have plate tectonics like Earth, which means that its surface is not constantly being recycled and renewed, further reducing the likelihood of finding clues to its ancient past.