Voyager 1 is the farthest human-made object from Earth. After sweeping by Jupiter, Saturn, Uranus and Neptune, it is now almost 15 billion miles (24 billion kilometers) from Earth in interstellar space. Both Voyager 1 and its twin, Voyager 2, carry little pieces of humanity in the form of their Golden Records. These messages in a bottle include spoken greetings in 55 languages, sounds and images from nature, an album of recordings and images from numerous cultures, and a written message of welcome from Jimmy Carter, who was U.S. president when the spacecraft left Earth in 1977.

The Golden Records were built to last a billion years in the environment of space, but in a recent analysis of the paths and perils these explorers may face, astronomers calculated that they could exist for trillions of years without coming remotely close to any stars.

On March 26, the ESA's Solar Orbiter made its closest approach to the sun so far. It ventured inside Mercury's orbit and was about one-third the distance from Earth to the sun. It was hot but worth it.

The Solar Orbiter's primary mission is to understand the connection between the sun and its heliosphere, and new images from the close approach are helping build that understanding.

According to the ESA, the Solar Orbiter is the most complex scientific laboratory ever sent to the sun. It carries a robust suite of instruments, including a magnetometer, the Extreme Ultraviolet Imager, the Solar Wind Plasma Analyzer, and others. Its broad range of instruments allows it to observe solar events in multiple ways.

The spacecraft benefits from getting as close to the sun as it can. But close approaches make the Solar Orbiter hot. The spacecraft's first line of defense is its heat shield. It's a multi-layered titanium device mounted on a honeycomb aluminum support, with carbon fiber skins designed to shed heat. Between all that and the spacecraft's body, there are another 28 layers of insulation.