Voyager 1 in the context of Starship

The Voyager Golden Records are two identical phonograph records, with one copy aboard each of the two Voyager spacecraft launched in 1977. The records contain sounds and data to reconstruct raster scan images selected to portray the diversity of life and culture on Earth, and are intended for any intelligent extraterrestrial life form who may find them. The records are a time capsule.

Although neither Voyager spacecraft is heading toward any particular star, Voyager 1 will pass within 1.6 light-years' distance of the star Gliese 445, currently in the constellation Camelopardalis, in about 40,000 years.

The Voyager program is an American scientific program that employs two interstellar probes, Voyager 1 and Voyager 2. They were launched in 1977 to take advantage of a favorable planetary alignment to explore the two gas giants Jupiter and Saturn and potentially also the ice giants, Uranus and Neptune—to fly near them while collecting data for transmission back to Earth. After Voyager 1 successfully completed its flyby of Saturn and its moon Titan, it was decided to send Voyager 2 on flybys of Uranus and Neptune.

After the planetary flybys were complete, decisions were made to keep the probes in operation to explore interstellar space and the outer regions of the Solar System. On 25 August 2012, data from Voyager 1 indicated that it had entered interstellar space. On 5 November 2019, data from Voyager 2 indicated that it also had entered interstellar space. On 4 November 2019, scientists reported that on 5 November 2018, the Voyager 2 probe had officially reached the interstellar medium (ISM), a region of outer space beyond the influence of the solar wind, as did Voyager 1 in 2012. In August 2018, NASA confirmed, based on results by the New Horizons spacecraft, the existence of a "hydrogen wall" at the outer edges of the Solar System that was first detected in 1992 by the two Voyager spacecraft.

A spacecraft is a vehicle that is designed to fly and operate in outer space. Spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, planetary exploration, and transportation of humans and cargo. All spacecraft except single-stage-to-orbit vehicles cannot get into space on their own, and require a launch vehicle (carrier rocket).

On a sub-orbital spaceflight, a space vehicle enters space and then returns to the surface without having gained sufficient energy or velocity to make a full Earth orbit. For orbital spaceflights, spacecraft enter closed orbits around the Earth or around other celestial bodies. Spacecraft used for human spaceflight carry people on board as crew or passengers from start or on orbit (space stations) only, whereas those used for robotic space missions operate either autonomously or telerobotically. Robotic spacecraft used to support scientific research are space probes. Robotic spacecraft that remain in orbit around a planetary body are artificial satellites. To date, only a handful of interstellar probes, such as Pioneer 10 and 11, Voyager 1 and 2, and New Horizons, are on trajectories that leave the Solar System.

The Voyager Golden Record contains 116 images and a variety of sounds. The items for the record, which is carried on both the Voyager 1 and Voyager 2 spacecraft, were selected for NASA by a committee chaired by Carl Sagan of Cornell University. Included are natural sounds (including some made by animals), musical selections from different cultures and eras, spoken greetings in 55 languages, human sounds like footsteps and laughter, and printed messages from President Jimmy Carter and U.N. Secretary-General Kurt Waldheim.

An interstellar probe is a space probe that has left—or is expected to leave—the Solar System and enter interstellar space, which is typically defined as the region beyond the heliopause. It also refers to probes capable of reaching other star systems.

As of 2024, there are five interstellar probes, all launched by the American space agency NASA: Voyager 1, Voyager 2, Pioneer 10, Pioneer 11 and New Horizons. Also as of 2025, Voyager 1 and Voyager 2 are the only probes to have actually reached interstellar space. The other three are on interstellar trajectories. Contact to Pioneer 10 and 11 was lost long before they reached interstellar space.

Voyager 2 is a space probe launched by NASA on August 20, 1977, as a part of the Voyager program. It was launched on a trajectory towards the gas giants (Jupiter and Saturn) and enabled further encounters with the ice giants (Uranus and Neptune). The only spacecraft to have visited either of the ice giant planets, it was the third of five spacecraft to achieve Solar escape velocity, which allowed it to leave the Solar System. Launched 16 days before its twin Voyager 1, the primary mission of the spacecraft was to study the outer planets and its extended mission is to study interstellar space beyond the Sun's heliosphere.

Voyager 2 successfully fulfilled its primary mission of visiting the Jovian system in 1979, the Saturnian system in 1981, Uranian system in 1986, and the Neptunian system in 1989. The spacecraft is in its extended mission of studying the interstellar medium. It is at a distance of 141.55 AU (21.2 billion km; 13.2 billion mi) from Earth as of November 2025.

Enceladus is the sixth-largest moon of Saturn and the 18th largest in the Solar System. It is about 500 kilometres (310 miles) in diameter, about a tenth of that of Saturn's largest moon, Titan. It is covered by clean, freshly deposited snow hundreds of meters thick, making it one of the most reflective bodies of the Solar System. Consequently, its surface temperature at noon reaches only −198 °C (75.1 K; −324.4 °F), far colder than a light-absorbing body would be. Despite its small size, Enceladus has a wide variety of surface features, ranging from old, heavily cratered regions to young, tectonically deformed terrain.

Enceladus was discovered on August 28, 1789, by William Herschel, but little was known about it until the two Voyager spacecrafts, Voyager 1 and Voyager 2, flew by Saturn in 1980 and 1981. In 2005, the spacecraft Cassini started multiple close flybys of Enceladus, revealing its surface and environment in greater detail. In particular, Cassini discovered water-rich plumes venting from the south polar region. Cryovolcanoes near the south pole shoot geyser-like jets of water vapour, molecular hydrogen, other volatiles, and solid material, including sodium chloride crystals and ice particles, into space, totalling about 200 kilograms (440 pounds) per second. More than 100 geysers have been identified. Some of the water vapour falls back as snow, now several hundred metres thick; the rest escapes and supplies most of the material making up Saturn's E ring. According to NASA scientists, the plumes are similar in composition to comets. In 2014, NASA reported that Cassini had found evidence for a large south polar subsurface ocean of liquid water with a thickness of around 10 km (6 mi). The existence of Enceladus's subsurface ocean has since been mathematically modelled and replicated.

Several space probes and the upper stages of their launch vehicles are leaving the Solar System, all of which were launched by NASA. Three of the probes, Voyager 1, Voyager 2, and New Horizons, are still functioning and are regularly contacted by radio communication, while Pioneer 10 and Pioneer 11 are now derelict. In addition to these spacecraft, some upper stages and de-spin weights are leaving the Solar System, assuming they continue on their trajectories.

These objects are leaving the Solar System because their velocity and direction are taking them away from the Sun, and at their distance from the Sun, its gravitational pull is not sufficient to pull these objects back or into orbit. They are not impervious to the gravitational pull of the Sun and are being slowed, but are still traveling in excess of escape velocity to leave the Solar System and coast into interstellar space.

The exploration of Jupiter has been conducted via close observations by automated spacecraft. It began with the arrival of Pioneer 10 into the Jovian system in 1973, and, as of 2024, has continued with eight further spacecraft missions in the vicinity of Jupiter and two more en route. All but one of these missions were undertaken by the National Aeronautics and Space Administration (NASA), and all but four were flybys taking detailed observations without landing or entering orbit. These probes make Jupiter the most visited of the Solar System's outer planets as all missions to the outer Solar System have used Jupiter flybys. On July 5, 2016, spacecraft Juno arrived and entered the planet's orbit—the second craft ever to do so. Sending a craft to Jupiter is difficult due to large fuel requirements and the effects of the planet's harsh radiation environment.

The first spacecraft to visit Jupiter was Pioneer 10 in 1973, followed a year later by Pioneer 11. Aside from taking the first close-up pictures of the planet, the probes discovered its magnetosphere and its largely fluid interior. The Voyager 1 and Voyager 2 probes visited the planet in 1979, and studied its moons and the ring system, discovering the volcanic activity of Io and the presence of water ice on the surface of Europa. Ulysses, intended to observe the Sun's poles, further studied Jupiter's magnetosphere in 1992 and then again in 2004. The Saturn-bound Cassini probe approached the planet in 2000 and took very detailed images of its atmosphere. The Pluto-bound New Horizons spacecraft passed by Jupiter in 2007 and made improved measurements of its and its satellites' parameters.

Pale Blue Dot is a photograph of Earth taken on February 14, 1990, by the Voyager 1 space probe from an unprecedented distance of over 6 billion kilometers (3.7 billion miles, 40.5 AU), as part of that day's Family Portrait series of images of the Solar System.

In the photograph, Earth's apparent size is less than a pixel; the planet appears as a tiny dot against the vastness of space, among bands of sunlight reflected by the camera. Commissioned by NASA and resulting from the advocacy of astronomer and author Carl Sagan, the photograph was interpreted in Sagan's 1994 book, Pale Blue Dot, as representing humanity's minuscule and ephemeral place amidst the cosmos.

This is a list of active space probes which have escaped Earth orbit. It includes lunar space probes, but does not include space probes orbiting at the Sun–Earth Lagrangian points (for these, see List of objects at Lagrangian points). A craft is deemed "active" if it is still able to transmit usable data to Earth (regardless of whether it can receive commands).

The craft are further grouped by mission status – "en-route", "mission in progress" or "mission complete" – based on their primary mission. For example, though Voyager 1 is still contactable en-route to the Oort Cloud and has exited the Solar System, it is listed as "mission complete" because its primary task of studying Jupiter and Saturn has been accomplished. Once a probe has reached its first primary target, it is no longer listed as "en route" regardless of whether further travel is involved.

Mariner 10 was an American robotic space probe launched by NASA on 3 November 1973, to fly by the planets Mercury and Venus. It was the first spacecraft to visit Mercury and the first to perform a flyby of multiple planets.

Mariner 10 was launched approximately two years after Mariner 9 and was the last spacecraft in the Mariner program. (Mariner 11 and Mariner 12 were allocated to the Voyager program and redesignated Voyager 1 and Voyager 2.)

A multi-ringed basin (also a multi-ring impact basin) is not a simple bowl-shaped crater, or a peak ring crater, but one containing multiple concentric topographic rings; a multi-ringed basin could be described as a massive impact crater, surrounded by circular chains of mountains resembling rings on a bull's-eye. A multi-ringed basin may have an area of many thousands of square kilometres.

An impact crater of diameter bigger than about 180 miles (290 km) is referred to as a basin.

Prometheus /prəˈmiːθiːəs/ is an inner satellite of Saturn. It was discovered on 24 October 1980 from images taken by the Voyager 1 probe, and was provisionally designated S/1980 S 27.

In late 1985 it was officially named after Prometheus, a Titan in Greek mythology. It is also designated Saturn XVI.

Pandora is an inner satellite of Saturn. It was discovered in 1980 from photos taken by the Voyager 1 probe and was provisionally designated S/1980 S 26. In late 1985, it was officially named after Pandora from Greek mythology. It is also designated as Saturn XVII.

Pandora was thought to be an outer shepherd satellite of the F Ring. However, recent studies indicate that it does not play such a role, and that only Prometheus, the inner shepherd, contributes to the confinement of the narrow ring. It is more heavily cratered than nearby Prometheus and has at least two large craters 30 kilometres (19 mi) in diameter. The majority of craters on Pandora are shallow as a result of being filled with debris. Ridges and grooves are also present on the moon's surface.

Io, a moon of Jupiter, has a substantial presence of volcanoes, volcanic pits and lava flows on its surface. Volcanic activity on the moon was first discovered in 1979 by Linda Morabito, an imaging scientist working on Voyager 1. Observations of Io by passing spacecraft and Earth-based astronomers have revealed more than 150 active volcanoes. As of 2024, up to 400 such volcanoes are predicted to exist based on these observations. Io's volcanism makes the satellite one of only five known currently volcanically or cryovolcanically active worlds in the Solar System (the others being Earth, Venus, Saturn's moon Enceladus, and Neptune's moon Triton.)

First predicted shortly before the Voyager 1 flyby, the heat source for Io's volcanism comes from tidal heating produced by its forced orbital eccentricity. This differs from Earth's internal heating, which is derived primarily from radioactive isotope decay and primordial heat of accretion. Io's eccentric orbit leads to a slight difference in Jupiter's gravitational pull on the satellite between its closest and farthest points on its orbit, causing a varying tidal bulge. This variation in the shape of Io causes frictional heating in its interior. Without this tidal heating, Io might have been similar to the Moon, a world of similar size and mass, geologically dead and covered with numerous impact craters.

Dione (/daɪˈoʊni/) is the fourth-largest moon of Saturn. With a mean diameter of 1,123 km and a density of about 1.48 g/cm, Dione is composed of an icy mantle and crust overlying a silicate rocky core, with rock and water ice roughly equal in mass. Its trailing hemisphere is marked by large cliffs and scarps called chasmata; the trailing hemisphere is also significantly darker compared to the leading hemisphere.

The moon was discovered by Italian astronomer Giovanni Domenico Cassini in 1684 and is named after the Titaness Dione in Greek mythology. Dione was first imaged up-close by the Voyager 1 space probe in 1980. Later, the Cassini spacecraft made multiple flybys of Dione throughout the 2000s and 2010s as part of its campaign to explore the Saturn system.