The New Horizons spacecraft has detected previously unknown features on the surface of Pluto, which include a pair of markings which resemble a doughnut and a whale. The features were seen in a composite photo compiled from images taken between June 27 and July 3.

The Long Range Reconnaissance Imager (Lorri) aboard New Horizons was used to record the raw photographs, which were then supplemented with data from the Ralph instrument. This data was compiled together, producing a map of Pluto's surface. Astronomers have known for years that the dwarf planet exhibits light and dark regions, but this map will allow mission planners to study the body from a constant perspective. This will assist researchers in learning more about the size of the features as well as other characteristics of the formations.

The doughnut seen by New Horizons stretches 200 miles from side-to-side. Although it resembles some geological features, such as asteroid impacts or volcanoes, astronomers are uncertain what formed this feature seen on Pluto.

The whale, located to the right of the doughnut on the map, is believed to be 1,860 miles in length. This is one of the darkest areas on the icy dwarf planet. Just ahead of the whale is the brightest area on the distant body. Astronomers believe the region, stretching 990 miles from side to side, could be coated in frozen carbon monoxide, methane and/or nitrogen.

"We're at the 'man in the moon' stage of viewing Pluto. It's easy to imagine you're seeing familiar shapes in this bizarre collection of light and dark features. However, it's too early to know what these features really are," said John Spencer of the Southwest Research Institute, deputy leader of the Geology, Geophysics and Imaging team.

A KMZ version of the map of Pluto can be downloaded for viewing in Google from the website for the John Hopkins Applied Physics Laboratory.

"These maps will both rapidly improve as new data is returned by New Horizons. The map will automatically update when new, improved maps of Pluto become available from the mission," John Hopkins researchers reported on their website.

A bright heart was also seen by astronomers utilizing the Lorri instrument on July 7, and the photo was released the following day. The image was recorded from a distance of five million miles from the dwarf planet.

Mission planners believe the images recorded at closest approach will be 500 times more detailed than this latest set of images.

The whale and doughnut are each located on the hemisphere of Pluto, which will be seen by New Horizons when that vehicle makes its closest approach to the body on July 14.