Mass of Mercury
The mass of the planet Mercury is 3.30 x 1023 kg. Just to put this in perspective, Mercury's mass comprises 5.5% the mass of the Earth.
Mercury might have a low mass, but that's because it's a very small planet. It's actually unusually dense, and probably has a large core comprised mostly of iron. According to scientists, Mercury consists of 70% metallic and 30% silicate material.
Its density is 5.43 g/cm3the second highest in the Solar System after the Earth. Mercury would actually be denser than Earth if it were the same size, but the Earth's greater gravity compresses itself more tightly.
The high mass and density comes from the planet's core made of mostly iron. Astronomers think that Mercury might have been impacted by a large planetesimal early on in its history. This impact hurled the lighter material off the planet and it was carried away by the Sun's solar wind. Another possibility is that Mercury was around when the Sun was newly forming and had a much higher mass. The intense solar wind of the newly forming Sun could have been strong enough to turn its outer layers of rock into gas and then blast it away, leaving only its iron core.
Filed under: Astronomy
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