Composition of Earth, Venus and Mercury
| . | Earth . | Venus . | Mercury . |
|---|---|---|---|
| H ppm | 33 | 35 | 0.4 |
| C ppm | 446 | 468 | 5.1 |
| N ppm | 4.1 | 4.3 | 0.05 |
| O % | 30.1 | 30.9 | 14.4 |
| Mg % | 13.9 | 14.5 | 6.5 |
| Al % | 1.4 | 1.4 | 1.1 |
| Si % | 15.1 | 15.4 | 7.0 |
| S % | 2.9 | 1.6 | 0.2 |
| Fe % | 32.0 | 31.1 | 64.4 |
| Ni % | 1.8 | 1.7 | 3.9 |
| Ca % | 1.5 | 1.6 | 1.2 |
| . | Earth . | Venus . | Mercury . |
|---|---|---|---|
| H ppm | 33 | 35 | 0.4 |
| C ppm | 446 | 468 | 5.1 |
| N ppm | 4.1 | 4.3 | 0.05 |
| O % | 30.1 | 30.9 | 14.4 |
| Mg % | 13.9 | 14.5 | 6.5 |
| Al % | 1.4 | 1.4 | 1.1 |
| Si % | 15.1 | 15.4 | 7.0 |
| S % | 2.9 | 1.6 | 0.2 |
| Fe % | 32.0 | 31.1 | 64.4 |
| Ni % | 1.8 | 1.7 | 3.9 |
| Ca % | 1.5 | 1.6 | 1.2 |
Note Mars is similar to Earth but has a smaller atmosphere like Venus. The outer large planets Jupiter, Saturn, Uranus and Neptune are gaseous. From J.W. Morgan and E. Anders Proc. Natl. Acad. Sci. USA, 77, 1980, 6973–6977.