Earth to Mars: 8 planets, their first views from Earth, and the cosmic discoveries that continue to intrigue astronomers

First telescopic observations of Mercury happened in 17th century when Galileo Galilei turned their telescopes toward the skies. First image by NASA's Mariner 10 in the 1970s

Telescopic observation of Venus were made by astronomers like Galileo Galilei and Johannes Kepler in the early 17th century. Images obtained through NASA's Mariner, Venera programs

The first photograph of Earth taken from space was captured on October 24, 1946, during a suborbital flight of a V-2 rocket launched by the United States

Telescopic observations of Mars date back to 17th century. The first detailed images were captured by telescopes, and spacecraft missions like NASA's Mariner and Viking missions

Jupiter has been observed through telescopes since the early 17th century. The first images were obtained through telescopic observations

Saturn has been observed through telescopes since the early 17th century. Early telescopic observations revealed its distinctive rings

Uranus was discovered by Sir William Herschel in 1781 through a telescope, but early observations did not show much detail due to its distance

Neptune was discovered mathematically in 1846 by Urbain Le Verrier and John Couch Adams, and its position was calculated before it was directly observed through telescopes