Track the location of the Voyager probes, currently between 13 and 15 billion miles away from Earth.

Intended to last four years, the Voyager spacecraft have lasted nearly five decades

Launched in 1977, the Voyager probes still send data from billions of miles away, guided by engineers who’ve turned down promotions to stay with the mission. The team continues to support the probes as they move 37,000 mph through space.

Voyager 1 and 2 are the only spacecraft to reach and study interstellar space

The Voyager Interstellar Mission extended beyond the original planetary flybys to explore the solar system's edge and beyond. Voyager 1 and 2 crossed the heliosheath—the boundary between the solar wind and the interstellar medium—in 2012 and 2018, respectively.

Voyager spacecraft defied expectations and only powered down after 47 years in space

Originally built for a four-year mission, Voyagers 1 and 2 used a rare planetary alignment and gravity assists to reach interstellar space. With limited power and aging systems, they will continue to send data until the mid-2030s. (Some readers may experience a paywall.)

Voyager science teams still collect valuable space data using four active tools

These instruments track magnetic fields, solar wind particles, radio emissions from the heliopause, and hydrogen levels in the outer heliosphere. Even though each Voyager sends data at just 160 bits per second, NASA receives 6–8 hours of tracking data daily.

Explore a NASA timeline of the entire Voyager mission

This infographic leads users through the entire Voyager mission timeline, starting at its conception and moving through launch, to each destination, and finally, the Voyagers' crossing into interstellar space.

Voyager mission's Golden Record captures Earth’s essence for alien discovery

Housed aboard Voyager 1 and 2, each record serves as a time capsule of human culture and a peaceful introduction to any intelligent life. Even if never played, the records can outlast humanity and travel through space for a billion years.

A return to Uranus

There's been only one mission to Uranus before—Voyager 2 passed by the ice giant in 1986 before heading off into interstellar space. NASA's recent planned itinerary for space missions lists Uranus as the highest priority over the next decade. The seventh planet is 20 times as far from the sun as Earth, and researchers say its study will shed light on how the outer half of the Solar System formed.

Planetary exploration and the search for extraterrestrial life kicked off with Viking

NASA's Viking 1 and 2 missions revealed Mars' geological activity and potential for past life through their evidence of past surface water. Viking 1 held the record for the longest Mars surface operation until the Opportunity rover surpassed it in 2010.

NASA fixed Voyager 1’s glitchy memory from 24 billion kilometers away

In November 2023, Voyager 1 began sending unusable data due to a stuck bit in a decades-old memory chip. After months of investigation, engineers managed to reroute the faulty code to a new memory location, restoring functionality in April 2024.

Voyager carries Earth's hopeful greeting into deep space as a message of peace

Along with scientific instruments, each Voyager carried a golden record containing multilingual greetings—ranging from Sumerian and Akkadian to Thai and Cantonese—music, and sounds of Earth intended for any intelligent life that might find it.

Voyager 1 captured Earth as a 'Pale Blue Dot' from 6 billion kilometers away

On Feb. 14, 1990, NASA's Voyager 1 space probe took the farthest photo of Earth ever captured. Earth appears so small in the image that it takes up less than a single pixel out of 640,000 in the photo's frame.

The 45 planets astronomers think are most likely to host alien life

The list includes familiar names like Proxima Centauri b (4 light-years away) and four planets in the TRAPPIST-1 system (about 40 light-years away), but even the nearest of those would take humanity roughly 114,000 years to reach at current spacecraft speeds. The list's real near-term value is as a targeting guide for the James Webb and upcoming Nancy Grace Roman space telescopes.

View a media gallery from the assembly of Voyager 1 and 2

This archive includes the many steps it took to put together each Voyager probe. Photos focus on individual parts, like the 8-track tape deck, the large dish-shaped antenna, and its long arm magnetometer boom.

Space probes propelled by lasers may one day visit distant planetary systems

Launched in 2016, Breakthrough Starshot is a project to send gram-sized spacecraft to the nearest stars and their planets at 10% to 20% the speed of light after being accelerated by ground-based laser systems. The project requires orders of magnitude advancements to current technology.

View galleries of images taken by the Voyager spacecraft, including close-ups of Uranus, Jupiter's Great Red Spot, Saturn's ring system, and Neptune's Great Dark Spot.

Voyager Station, the world's first space hotel, is planned for 2027

The structure spans 488 meters in diameter and will rotate to simulate one-sixth of Earth's gravity while circumnavigating the planet every 90 minutes. The Voyager Station is designed to accommodate 450 guests and 150 crew members, providing amenities such as restaurants, a sports hall, and a movie theater.

The Hubble Space Telescope made discoveries within our solar system and across the universe

The observatory helped confirm the presence of water on Jupiter's moon Europa, and uncovered seasonal variations on planets like Uranus. It also observed exoplanets and gravitational lensing, proved the existence of supermassive black holes at the centers of galaxies, and detected the accelerated expansion of the universe.

By measuring radio signals transmitted to and received from distant spacecraft, NASA's Deep Space Network can determine a spacecraft's position and speed and send commands to alter its trajectory.

The Viking landers were the first spacecraft to conduct experiments on Mars

NASA’s Viking 1 and 2 missions tested soils for signs of life, captured images, and studied the Martian atmosphere, revealing evidence of ancient water flow, volcanic soil, and a thin carbon dioxide atmosphere.

Viking established entry, descent, and landing methods for future planetary visits

The most significant engineering challenge was slowing the Viking lander, which would move through space at nearly 29,000 kilometers per hour before reaching Mars. This required the invention of supersonic parachute technology, which is still used today.

Congress settled for the Viking program after canceling the Voyager Mars program

NASA's proposed Voyager missions to Mars and Venus in the 1970s were canceled due to budget cuts and the Apollo 1 fire. The Viking program's smaller scope—focused on data collection—was the economically viable alternative to manned Mars mission proposals.

Explore how far you've traveled through space while living on Earth

Using the "Cosmic Odometer," users can enter their birthday and learn how far they have moved through space due to the combined effects of Earth's rotation around its axis, the planet's orbit around the sun, the solar system's trajectory through the Milky Way, and the galaxy's motion through the universe.

The Deep Space Network is an array of giant radio antennas at three locations on Earth to keep NASA in constant communication with spacecraft billions of miles away.

Aliens may be closer to Earth than scientists have previously assumed

The hunt for extraterrestrial life is often associated with traveling far into the depths of space for clues. But answers could be closer than we think. Modern space missions have demonstrated our capability of sending probes beyond the solar system, making it plausible that other civilizations could do the same.

View the first photos ever taken from the Martian surface, courtesy of NASA's Viking Project.

Neptune is the farthest planet from the sun, orbiting 30 times farther than Earth and taking 165 years to complete one revolution.

James Webb Space Telescope aims to unlock secrets of the early universe

Decades in the making, JWST is designed to study the universe in infrared light, allowing it to see through cosmic dust and observe ancient galaxies, star formation, and potentially life-supporting exoplanets. The Webb will orbit the sun at a stable point 1.5 million kilometers from Earth.

ESA’s Juice and NASA’s Europa Clipper will search for habitability near Jupiter

Three of Jupiter’s moons—Ganymede, Europa, and Callisto—possess subsurface oceans that may support life. While Clipper will perform flybys of Europa, Juice will be the first spacecraft to orbit a moon in the outer Solar System.

Galileo’s discovery of Jupiter’s moons led to multiple scientific advancements

Beyond challenging Earth-centric views upon their discovery in 1610, the Galilean moons were also later analyzed to contribute to early astrometry and astronomical interferometry. Measurements of eclipses were also used to estimate the speed of light.

The USSR’s Venera program made the only successful landings on Venus

While the Soviet space program is famous for launching the first satellite and human into orbit, its most extraordinary feat was the Venera missions—probes that captured data, images, and audio from Venus’s brutal surface. No other nation has repeated the achievement.

Universal limit to technological development may prevent finding alien civilizations

Given the vastness of the Universe, detecting alien life may require technological progress beyond the limits of what is sociologically viable and physically possible. Although interstellar civilizations are unlikely, messaging techniques and probes may improve the odds of successful communication with other intelligent life.

In 2025, the European Space Agency created the first artificial solar eclipse in space when one spacecraft cast a shadow onto another spacecraft to enable observations of the sun's outermost atmosphere.

Explore a timeline of every mission to Mars through 2020

The US has conducted the most missions (23) and has the highest success rate (74%), followed by Russia (18 missions at 5%). The first successful orbiter was Mariner 4, while Viking 1 was the first successful lander.

Read the NASA overview of the results of Viking’s biological experiments on Mars

Three experiments on the Viking 1 and 2 landers searched for signs of metabolic activity in soil samples, indicating the presence of microorganisms. No definitive evidence of life was found in any experiment or lander imaging.

How a pulsar's properties led to the discovery of the first exoplanets

In 1992, astronomers examining the radio waves emitted by PSR B1257+12 as it swept past detectors every 0.006219 seconds noticed occasional deviations at regular intervals. Further analysis revealed the existence of two planets beyond our solar system orbiting the neutron star, causing it to wobble and affecting pulsar timing.

Visualizing the history of Saturn and its rings

Every 13 to 16 years, Saturn's rings become far less visible because its plane becomes exactly even with Earth's. This visual-rich essay explores the history of humanity's perception of Saturn, from Galileo's first sighting (and dubbing the rings "ears") to the idea that the rings won't last more than a few hundred millions years more. Explore this fascinating planet here.

Units involving light, such as light-seconds and light-years, describe the distances traveled by light across that amount of time.

Since 2017, Virgo has helped LIGO localize astronomical phenomena

The detector near Pisa, Italy, coordinates its experimental runs with those in Hanford, Washington, and Livingston, Louisiana. Scientists can triangulate the locations of celestial events that generate gravitational waves using signal arrival times, just as earthquake locations can be determined from measurements at three seismic stations.

New ways of seeing the cosmos have redrawn the map of human identity

From Galileo’s crude spyglass to the James Webb Space Telescope, each technological leap has expanded our observational reach and redefined philosophical and moral conceptions of our place in the universe. Identifying signs of life through the study of exoplanet atmospheres would represent the next great revolution.

See to the edge of the universe with this two-decade astronomy project

A New Mexico telescope has captured astronomical data for two decades to compile this map of the universe. Starting from earth and ending at the "edge" of the universe, it shows one slice of the cosmos: a total of 200,000 galaxies.

Space archaeology studies space trash in the context of heritage and social meaning

Some orbiting objects, such as Elon Musk's Tesla, have symbolic or historical importance, despite being functionally worthless. The oldest human-made object in Earth's orbit is Vanguard 1, a grapefruit-sized satellite launched in 1958. The strangest may be an experimental, inflatable space station containing live cockroaches.

The first proposed experiment in the search for extraterrestrial intelligence (SETI) began with the mathematician and astronomer Carl Friedrich Gauss, who is credited with the idea of drawing a right triangle and three squares on Earth's surface to signal to aliens using the language of mathematics.

In 1676, Danish astronomer Ole Rømer determined that light did not travel instantaneously by observing a delay in the appearance of solar eclipses on Jupiter when it was farther from Earth.

View 60 years of NASA space exploration

Established in 1958—a year after the Soviet Union launched Sputnik 1—the National Aeronautics and Space Administration has taken humanity into outer space and helped reveal the nature of the universe. Historic moments include the Apollo 11 mission putting humanity on the Moon and construction of the International Space Station.

How scientists study Earth's geocorona, the farthest portion of the planet's exosphere

Seen via ultraviolet radiation scattered by neutral hydrogen in the region, observations by the ESA/NASA Solar and Heliospheric Observatory indicate that the geocorona extends roughly 50 times Earth's diameter above its surface. At this distance, the geocorona extends beyond the Moon's orbit.

Potential LIGO sites were selected in pairs, approximately 3,000 kilometers apart

The 1,864-mile distance meant gravitational wave signals would be detected no more than 10 milliseconds apart, ruling out many background signals. The sites needed sufficient plots of nearly flat land, proximity to infrastructure (e.g., electricity), and adequate distance from urban areas and geologically active areas to reduce environmental noise.

Since 1989, storms resembling Jupiter's Great Red Spot have been observed on Neptune, but darker and lasting no more than a few years.

Explore a timeline of NASA's exploration of Mars

NASA has studied Mars extensively over 60 years using telescopes, orbiters, and rovers. From April 2021 to January 24, the Ingenuity helicopter completed its technology demonstration objective by flying more than 17 kilometers above the Martian surface.

Galileo's Jupiter discovery shattered Earth-centered universe beliefs

Using a telescope inspired by Dutch designs, Galileo spotted four moons orbiting Jupiter in 1610, providing undeniable evidence against geocentrism and fueled support for the heliocentric model. Galileo’s original telescope design stretched 20 meters long—a feat of optical engineering for its time.

Gaia mapped two billion stars in the Milky Way

Using geometric parallax, the European Space Agency mission made position measurements accurate to 2.78 × 10⁻¹⁰ degrees, revealing large-scale galactic structure and dynamics. Remnants of ancient galactic mergers were also identified within the Milky Way.