Rennell Island is part of the Solomon Islands, a country in the western Pacific Ocean located northeast of Australia and east of Papua New Guinea. Rennell, also known as Mu Nggava Island, is 210 kilometers (130 miles) south of Guadalcanal—the country’s main island.
This photo, taken by an astronaut aboard the International Space Station, shows Rennell Island silhouetted against the ocean glistening in the sunglint. A line of small cumulus clouds cast shadows over the sea to the north of the island.
The lake at the eastern end of the island—also featured by sunglint—is Lake Te Nggano (also called Tengano and Tegano). The lake is surrounded by a coral reef that rises above the sea and is densely forested, so it appears as dark as the rest of the island. Te Nggano is the largest lake in the western Pacific Ocean.
Sunglint in images can reveal subtle features on the surface of bodies of water (including the signature of internal currents). The brightest areas of sunglint in this image are along the east-facing coasts. This is where the relatively smooth surface of the water reflects more sunlight back to the astronaut’s camera on the space station. On this day, the water is likely to be smooth in these areas because it is sheltered from the westerly winds (indicated by faint streaks of wind on the surface of the water). Oil films are also known to help smooth water surfaces and affect sunglint.
The eastern third of Rennell Island is designated a World Heritage Site by UNESCO because of its many endemic species. Of the 50 bird species known on Rennell, 21 are endemic, and the island is also designated as a Important Bird Areas (OTHER). Crocker’s sea snake, now considered vulnerable, is a species that lives only in Lake Te Nggano. In 2013, the site was added to a list of World Heritage sites are at risk due to the effects of logging in the area.
Astronaut photo ISS068-E-39300 was captured on January 8, 2023, using a Nikon D5 digital camera using a focal length of 380 millimeters. It is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The photo was taken by a member of the Expedition 68 crew. The image was cropped and enhanced to improve contrast, and lens artifacts were removed. The International Space Station Program supporting laboratory as part of ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those pictures freely available on the Internet. Additional photos taken by astronauts and cosmonauts can be viewed at NASA/JSC Gateway to Astronaut Photography of Earth. Caption by Justin Wilkinson, Texas State University, JETS Contract with NASA-JSC, and Susan Runco (NASA retired).