What is Mercury's most well-known feature?

Answer 1

The Caloris Basin, also called Caloris Planitia, is an impact crater on Mercury about 1300km in diameter, one of the largest impact basins in the solar system. Caloris is Latin for heat and the basin is so-named because the Sun is almost directly overhead every second time Mercury passes perihelion. The crater is surrounded by a ring of mountains about two kilometers tall.

Appearance
The Caloris Basin was discovered on images taken by the Mariner 10 probe in 1974. It was situated on the terminator - the line dividing the daytime and nighttime hemispheres - at the time the probe passed by, and so half the crater has never been imaged.

The crater is about 1300km (810 miles) in diameter, and is ringed by mountains up to 2km high. Inside the crater walls, the floor of the crater is filled by lava plains, similar to the maria of the Moon. Outside the walls, material ejected in the impact which created the basin extends for 1000 km, and concentric rings surround the crater.

The giant impact believed to have formed Caloris may have had consequences for the whole planet. At the exact antipode of the basin is a large area of hilly, grooved terrain, known as the 'Weird Terrain', which is thought by some to have been created as seismic waves from the impact converged on the opposite side of the planet . This hypothetical impact is also believed to have triggered volcanic activity on Mercury, resulting in the formation of smooth plains.

Answer 2

This is Mercury's well-known feature, and this was a surprise to all astronomers!! In the early 1970's, the Mariner 10 orbiter discovered that Mercury has a magnetic field. It had been conjectured that only planets with a molten metal core could possess a magnetic field. Mercury was always thought of to be too old and that it's core should have cooled by now. Nevertheless, the magnetic field is indeed weak compared to Earth, it does indeed exist. Some scientists believe, as do I, that because of its relativily low strength, Mercury's core has cooled ,and that the magnetic field is a residue of a stronger past magnetic field imprinted on its dense metallic content because Mercury is so dense, about 65% of the planet is comprised of it's metallic core. That used to be unheard of!!! Good Luck

Answer 3

Possibly the impact crater whose shockwaves are visible on the opposite side of the planet from where it exists?

Answer 4

craters :) never heard of any other prominent feature on mercury.

Answer 5

To me....?

No atmosphere.

A surface always facing the sun and burning away, and a surface that never faces the sun and is very cold.