The Raditladi quadrangle (H-4) is one of fifteen quadrangles on Mercury. It runs from 270 to 180° longitude and 20 to 70° latitude. Named after the

Raditladi Basin Raditladi is a large impact crater on Mercury (planet), Mercury with a diameter of 263 km. Inside its peak ring there is a system of concentric extensional trough (geology), troughs (graben), which are rare surface features on Mercury. The ...

, it was mapped in detail for the first time after ''

MESSENGER Messenger, Messengers, The Messenger or The Messengers may refer to: People * Courier, a person or company that delivers messages, packages, or mail * Messenger (surname) * Bicycle messenger, a bicyclist who transports packages through cities * M ...

'' entered orbit around Mercury in 2011. It had not been mapped prior to that point because it was one of the six quadrangles that was not illuminated (with the exception of a thin strip of its territory along the eastern border with

Shakespeare quadrangle The Shakespeare quadrangle is a region of Mercury running from 90 to 180° longitude and 20 to 70° latitude. It is also called Caduceata. The Borealis quadrangle is north of Shakespeare quadrangle. To the west is Raditladi quadrangle, and to ...

) when ''

Mariner 10 ''Mariner 10'' was an American Robotic spacecraft, robotic space probe launched by NASA on 3 November 1973, to fly by the planets Mercury (planet), Mercury and Venus. It was the first spacecraft to perform flybys of multiple planets. ''Marin ...

'' made its flybys in 1974 and 1975. These six quadrangles continued to be known by their

albedo feature In planetary geology, an albedo feature is a large area on the surface of a planet (or other Solar System body) which shows a contrast in brightness or darkness (albedo) with adjacent areas. Historically, albedo features were the first (and usu ...

names, with this one known as the Liguria quadrangle. The

Caloris basin Caloris Planitia is a plain within a large impact basin on Mercury, informally named Caloris, about in diameter. It is one of the largest impact basins in the Solar System. "Calor" is Latin for "heat" and the basin is so-named because the Su ...

is centered in Raditladi quadrangle, though it overlaps significantly with the Tolstoj and

Shakespeare William Shakespeare ( 23 April 1564 – 23 April 1616) was an English playwright, poet and actor. He is widely regarded as the greatest writer in the English language and the world's pre-eminent dramatist. He is often called England's natio ...

quadrangles. The

Borealis quadrangle The Borealis quadrangle is a list of quadrangles on Mercury, quadrangle on Mercury (planet), Mercury surrounding the Poles of astronomical bodies, north pole down to 65° latitude. It was mapped in its entirety by the ''MESSENGER'' spacecraft, ...

is north of Raditladi quadrangle. To the west is

Hokusai quadrangle The Hokusai quadrangle (H-5) is one of fifteen quadrangles on the planet Mercury. It runs from 360 to 270° longitude and 20 to 70° latitude. Named after the Hokusai crater, it was mapped in detail for the first time after ''MESSENGER'' ente ...

, and to the east is

. To the southwest is

Eminescu quadrangle The Eminescu quadrangle (H-9) is one of fifteen quadrangles on Mercury. It runs from 216 to 288° longitude and from -25 to 25° latitude. Named after the Eminescu crater, it was mapped in detail for the first time after ''MESSENGER'' entered ...

, and to the southeast is

Tolstoj quadrangle The Tolstoj quadrangle in the equatorial region of Mercury runs from 144 to 216° longitude and -25 to 25° latitude. It was provisionally called "Tir", but renamed after Leo Tolstoy by the International Astronomical Union in 1976. Also calle ...

References

Surface features of Mercury by quadrangle {{Mercury-planet-stub