Pluto nearly fills the frame in this black and white image from the Long Range Reconnaissance Imager (LORRI) aboard NASA’s New Horizons spacecraft, taken on July 13, 2015 when the spacecraft was 476,000 miles (768,000 kilometers) from the surface. This is the last and most detailed image sent to Earth before (NASA)

Three billion miles away, Pluto has sent a “love note” back to Earth, via NASA’s New Horizons spacecraft.

At about 4 p.m. EDT on July 13 – about 16 hours before closest approach – New Horizons captured this stunning image of one of Pluto’s most dominant features. The “heart,” estimated to be 1,000 miles (1,600 kilometers) across at its widest point rests just above the equator. (The angle of view displays mostly the northern hemisphere.) The heart’s diameter is about the same distance as from Denver to Chicago, in America’s heartland.

The newest image from the Long Range Reconnaissance Imager (LORRI) shows an almost perfectly shaped left half of a bright, heart-shaped feature centered just above Pluto’s equator, while the right side of the heart appears to be less defined.

The image shows for the first time that some surfaces on Pluto are peppered with impact craters and are therefore relatively ancient, perhaps several billion years old. Other regions, such as the interior of the heart, show no obvious craters and thus are probably younger, indicating that Pluto has experienced a long and complex geological history. Some craters appear partially destroyed, perhaps by erosion. There are also hints that parts of Pluto’s crust have been fractured, as indicated by the series of linear features to the left of the heart.

Below the heart are dark terrains along Pluto’s equator, including, on the left, the large dark feature informally known as the “whale.” Craters pockmark part of the whale’s head; areas that appear smooth and featureless may be a result of image compression.

New Horizons traveled nearly a decade to receive its summer valentine, launching on January 19, 2006. (NASA)