QUICK FACTS
Where is it? Chiltepe Peninsula, Lake Managua, Nicaragua [12.236943676, -86.34017745]
What’s in the photo? Two volcanic lakes that look like a pair of eyes staring upward
Who took the photo? An unnamed astronaut on board the International Space Station
When was it taken? Jan. 21, 2014
This intriguing astronaut photo shows two volcanic lakes appearing to peer into space from a skull-like peninsula in Nicaragua, like a pair of heterochromatic googly eyes. This unusual scene, which is influenced by a subtle optical illusion, is completely unrecognizable from ground level.
If these lakes are considered eyes, then their head is the Chiltepe Peninsula, a rounded landmass that extends into the waters of Lake Managua. Known locally as Lago Xolotlán, it covers an area of around 400 square miles (1,040 square kilometers) in the heart of the Central American nation.
The peninsula, located around 10 miles (16 km) northwest of the capital city of Managua, was formed by a series of pyroclastic shield eruptions. During these blasts, mostly low-density materials, such as pumice, are violently ejected from beneath the surface, according to NASA’s Earth Observatory. These major eruptions ended around 17,000 years ago. However, more recent volcanic activity has occurred there within the past 2,000 years.
The smaller lake (on the left), which is around 1.1 miles (1.7 km) wide, is located within the Apoyeque caldera. The larger lake (on the right), known as Laguna Xiloa, is around 1.5 miles (2.4 km) across at its widest point. It was formed by an explosive outburst that occurred when magma from below Apoyeque interacted with submerged groundwater.
When viewed from space, the lakes appear side by side. However, the surface of the Apoyeque lake sits at an altitude of around 1,300 feet (400 m), while Laguna Xiloa is close to sea level — meaning you would not be able to see both unless you stood on the crater rim of Apoyeque.
Related: See all the best images of Earth from space
The two lakes are slightly different colors: Laguna Xiloa is a deep blue, while Apoyeque is greenish. If these bodies of water were really eyes, then they would be a rare example of heterochromia — a rare condition in which a person’s eyes are different colors.
At first glance, the two lakes have a fairly similar size and shape. However, Apoyeque’s lake is smaller and more rounded than Laguna Xiloa. The reason for this subtle illusion is that the rim of Apoyeque’s crater is much more closely aligned to the outline of Laguna Xiloa, making them seem more similar at first glance.
Explosive potential
Both Apoyeque and Laguna Xiloa are technically active volcanoes, but they have not erupted for millennia and are unlikely to do so anytime soon, according to the Smithsonian Institution’s Global Volcanism Program.
Laguna Xiloa last erupted approximately 6,000 years ago, whereas Apoyeque has had four major eruptions since then. The most recent and explosive of these is estimated to have occurred in around 50 B.C. and sculpted the shape of the crater that now holds its lake.
In 2012, a swarm of minor earthquakes was triggered by the movement of magma beneath Apoyeque, according to the Earth Observatory. However, this was not a sign of an imminent eruption.
If the larger volcano were to blow its top, it could impact some of the residents of Managua, as well as significantly endanger the residents of Bosques de Xiloa, a small town on the shores of Laguna Xiloa (visible in the satellite image).
