In 2013, researchers published a shape model of asteroid Bennu based on years of observations from Puerto Rico’s Arecibo Observatory. Their model depicted a rough diamond shape. Five years later, the OSIRIS-REx spacecraft has reached the asteroid, and data obtained from spacecraft’s cameras corroborate those ground-based telescopic observations of Bennu.
The original model closely predicted the asteroid’s actual shape, with Bennu’s diameter, rotation rate, inclination and overall shape presented almost exactly as projected! This video shows the new shape model created using data from OSIRIS-REx’s approach to the asteroid.
One outlier from the predicted shape model is the size of the large boulder near Bennu’s south pole. The ground-based shape model calculated it to be at least 33 feet (10 meters) in height. Preliminary calculations show that the boulder is closer to 164 feet (50 meters) in height, with a width of approximately 180 feet (55 meters).
Also during the approach phase, OSIRIS-REx revealed water locked inside the clays that make up Bennu. The presence of hydrated minerals across the asteroid confirms that Bennu, a remnant from early in the formation of the solar system, is an excellent specimen for the OSIRIS-REx mission to study. Get all the details about this discovery HERE.
We sent the first humans to land on the Moon in 1969. Since then, only of 12 men have stepped foot on the lunar surface – but we left robotic explorers behind to continue gathering science data. And now, we’re preparing to return. Establishing a sustained presence on and near the Moon will help us learn to live off of our home planet and prepare for travel to Mars.
To help establish ourselves on and near the Moon, we are working with a few select American companies. We will buy space on commercial robotic landers, along with other customers, to deliver our payloads to the lunar surface. We’re even developing lunar instruments and tools that will fly on missions as early as 2019!
Through partnerships with American companies, we are leading a flexible and sustainable approach to deep space missions. These early commercial delivery missions will also help inform new space systems we build to send humans to the Moon in the next decade. Involving American companies and stimulating the space market with these new opportunities to send science instruments and new technologies to deep space will be similar to how we use companies like Northrop Grumman and SpaceX to send cargo to the International Space Station now. These selected companies will provide a rocket and cargo space on their robotic landers for us (and others!) to send science and technology to our nearest neighbor.
So who are these companies that will get to ferry science instruments and new technologies to the Moon?
Here’s a digital “catalogue” of the organizations and their spacecraft that will be available for lunar services over the next decade:
Astrobotic Technology, Inc.
Deep Space Systems
Firefly Aerospace, Inc.
Cedar Park, TX
Intuitive Machines, LLC
Lockheed Martin Space
Masten Space Systems, Inc.
Moon Express, Inc.
Cape Canaveral, FL
Orbit Beyond, Inc.
We are thrilled to be working with these companies to enable us to investigate the Moon in new ways. In order to expand humanity’s presence beyond Earth, we need to return to the Moon before we go to Mars.
The Moon helps us to learn how to live and work on another planetary body while being only three days away from home – instead of several months. The Moon also holds enormous potential for testing new technologies, like prospecting for water ice and turning it into drinking water, oxygen and rocket fuel. Plus, there’s so much science to be done!
The Moon can help us understand the early history of the solar system, how planets migrated to their current formation and much more. Understanding how the Earth-Moon system formed is difficult because those ancient rocks no longer exist here on Earth. They have been recycled by plate tectonics, but the Moon still has rocks that date back to the time of its formation! It’s like traveling to a cosmic time machine!
Join us on this exciting journey as we expand humanity’s presence beyond Earth.
On #WorldTeachersDay, we are recognizing our two current astronauts who are former classroom teachers, Joe Acaba and Ricky Arnold, as well as honoring teachers everywhere. What better way to celebrate than by learning from teachers who are literally out-of-this-world!
During the past Year of Education on Station, astronauts connected with more than 175,000 students and 40,000 teachers during live Q & A sessions.
Let’s take a look at some of the questions those students asked:
The view from space is supposed to be amazing. Is it really that great and could you explain?
Taking a look at our home planet from the International Space Station is one of the most fascinating things to see! The views and vistas are unforgettable, and you want to take everyone you know to the Cupola (window) to experience this. Want to see what the view is like? Check out earthkam to learn more.
What is the most overlooked attribute of an astronaut?
If you are a good listener and follower, you can be successful on the space station. As you work with your team, you can rely on each other’s strengths to achieve a common goal. Each astronaut needs to have expeditionary skills to be successful. Check out some of those skills here.
Are you able to grow any plants on the International Space Station?
Exactly sixty years ago today, we opened our doors for the first time. And since then, we have opened up a universe of discovery and innovation.
There are so many achievements to celebrate from the past six decades, there’s no way we can go through all of them. If you want to dive deeper into our history of exploration, check out NASA: 60 Years and Counting.
In the meantime, take a moonwalk down memory lane with us while we remember a few of our most important accomplishments from the past sixty years!
In 1958, President Eisenhower signed the National Aeronautics and Space Act, which effectively created our agency. We officially opened for business on October 1.
To learn more about the start of our space program, watch our video: How It All Began.
Alongside the U.S. Air Force, we implemented the X-15 hypersonic aircraft during the 1950s and 1960s to improve aircraft and spacecraft.
The X-15 is capable of speeds exceeding Mach 6 (4,500 mph) at altitudes of 67 miles, reaching the very edge of space.
Dubbed the “finest and most productive research aircraft ever seen,” the X-15 was officially retired on October 24, 1968. The information collected by the X-15 contributed to the development of the Mercury, Gemini, Apollo, and Space Shuttle programs.
On July 20, 1969, Neil Armstrong and Buzz Aldrin became the first humans to walk on the moon. The crew of Apollo 11 had the distinction of completing the first return of soil and rock samples from beyond Earth.
Astronaut Gene Cernan, during Apollo 17, was the last person to have walked on the surface of the moon. (For now!)
The Lunar Roving Vehicle was a battery-powered rover that the astronauts used during the last three Apollo missions.
To learn more about other types of technology that we have either invented or improved, watch our video: Trailblazing Technology.
Our long-term Earth-observing satellite program began on July 23, 1972 with the launch of Landsat 1, the first in a long series (Landsat 9 is expected to launch in 2020!) We work directly with the U.S. Geological Survey to use Landsat to monitor and manage resources such as food, water, and forests.
Landsat data is one of many tools that help us observe in immense detail how our planet is changing. From algae blooms to melting glaciers to hurricane flooding, Landsat is there to help us understand our own planet better.
Off the Earth, for the Earth.
To learn more about how we contribute to the Earth sciences, watch our video: Home, Sweet Home.
Space Transportation System-1, or STS-1, was the first orbital spaceflight of our Space Shuttle program.
The first orbiter, Columbia, launched on April 12, 1981. Over the next thirty years, Challenger, Discovery, Atlantis, and Endeavour would be added to the space shuttle fleet.
Together, they flew 135 missions and carried 355 people into space using the first reusable spacecraft.
On January 16, 1978, we selected a class of 35 new astronauts–including the first women and African-American astronauts.
And on June 18, 1983, Sally Ride became the first American woman to enter space on board Challenger for STS-7.
Everybody loves Hubble! The Hubble Space Telescope was launched into orbit on April 24, 1990, and has been blowing our minds ever since.
Hubble has not only captured stunning views of our distant stars and galaxies, but has also been there for once-in-a-lifetime cosmic events. For example, on January 6, 2010, Hubble captured what appeared to be a head-on collision between two asteroids–something no one has ever seen before.
In this image, Hubble captures the Carina Nebula illuminating a three-light-year tall pillar of gas and dust.
To learn more about how we have contributed to our understanding of the solar system and beyond, watch our video: What’s Out There?
Cooperation to build the International Space Station began in 1993 between the United States, Russia, Japan, and Canada.
The dream was fully realized on November 2, 2000, when Expedition 1 crew members boarded the station, signifying humanity’s permanent presence in space!
Although the orbiting lab was only a couple of modules then, it has grown tremendously since then!
In just a few weeks, we’re launching a spacecraft to get closer to the Sun than any human-made object has ever gone.
The mission, called Parker Solar Probe, is outfitted with a lineup of instruments to measure the Sun’s particles, magnetic and electric fields, solar wind and more – all to help us better understand our star, and, by extension, stars everywhere in the universe.
Parker Solar Probe is about the size of a small car, and after launch – scheduled for no earlier than Aug. 6, 2018 – it will swing by Venus on its way to the Sun, using a maneuver called a gravity assist to draw its orbit closer to our star. Just three months after launch, Parker Solar Probe will make its first close approach to the Sun – the first of 24 throughout its seven-year mission.
Though Parker Solar Probe will get closer and closer to the Sun with each orbit, the first approach will already place the spacecraft as the closest-ever human-made object to the Sun, swinging by at 15 million miles from its surface. This distance places it well within the corona, a region of the Sun’s outer atmosphere that scientists think holds clues to some of the Sun’s fundamental physics.
For comparison, Mercury orbits at about 36 million miles from the Sun, and the previous record holder – Helios 2, in 1976 – came within 27 million miles of the solar surface.
Humanity has studied the Sun for thousands of years, and our modern understanding of the Sun was revolutionized some 60 years ago with the start of the Space Age. We’ve come to understand that the Sun affects Earth in more ways than just providing heat and light – it’s an active and dynamic star that releases solar storms that influence Earth and other worlds throughout the solar system. The Sun’s activity can trigger the aurora, cause satellite and communications disruptions, and even – in extreme cases – lead to power outages.
Much of the Sun’s influence on us is embedded in the solar wind, the Sun’s constant outflow of magnetized material that can interact with Earth’s magnetic field. One of the earliest papers theorizing the solar wind was written by Dr. Gene Parker, after whom the mission is named.
Though we understand the Sun better than we ever have before, there are still big questions left to be answered, and that’s where scientists hope Parker Solar Probe will help.
First, there’s the coronal heating problem. This refers to the counterintuitive truth that the Sun’s atmosphere – the corona – is much, much hotter than its surface, even though the surface is millions of miles closer to the Sun’s energy source at its core. Scientists hope Parker Solar Probe’s in situ and remote measurements will help uncover the mechanism that carries so much energy up into the upper atmosphere.
Second, scientists hope to better understand the solar wind. At some point on its journey from the Sun out into space, the solar wind is accelerated to supersonic speeds and heated to extraordinary temperatures. Right now, we measure solar wind primarily with a group of satellites clustered around Lagrange point 1, a spot in space between the Sun and Earth some 1 million miles from us.
By the time the solar wind reaches these satellites, it has traveled about 92 million miles already, blending together the signatures that could shed light on the acceleration process. Parker Solar Probe, on the other hand, will make similar measurements less than 4 million miles from the solar surface – much closer to the solar wind’s origin point and the regions of interest.
Scientists also hope that Parker Solar
Probe will uncover the mechanisms at work behind the acceleration of solar
energetic particles, which can reach speeds more than half as fast as the speed
of light as they rocket away from the Sun! Such particles can interfere with
satellite electronics, especially for satellites outside of Earth’s magnetic
Stay tuned over the next few weeks to learn more about Parker Solar Probe’s science and follow along with its journey to launch. We’ll be posting updates here on Tumblr, on Twitter and Facebook, and at nasa.gov/solarprobe.
In July 2015, we saw Pluto up close for the first time and—after three years of intense study—the surprises keep coming. “It’s clear,” says Jeffery Moore, New Horizons’ geology team lead, “Pluto is one of the most amazing and complex objects in our solar system.”
1. An Improving View
These are combined observations of Pluto over the course of several decades. The first frame is a digital zoom-in on Pluto as it appeared upon its discovery by Clyde Tombaugh in 1930. More frames show of Pluto as seen by the Hubble Space Telescope. The final sequence zooms in to a close-up frame of Pluto taken by our New Horizons spacecraft on July 14, 2015.
2. The Heart
Pluto’s surface sports a remarkable range of subtle colors are enhanced in this view to a rainbow of pale blues, yellows, oranges, and deep reds. Many landforms have their own distinct colors, telling a complex geological and climatological story that scientists have only just begun to decode. The image resolves details and colors on scales as small as 0.8 miles (1.3 kilometers). Zoom in on the full resolution image on a larger screen to fully appreciate the complexity of Pluto’s surface features.
Just 15 minutes after its closest approach to Pluto, the New Horizons spacecraft captured this near-sunset view of the rugged, icy mountains and flat ice plains extending to Pluto’s horizon. The backlighting highlights more than a dozen layers of haze in Pluto’s tenuous atmosphere. The image was taken from a distance of 11,000 miles (18,000 kilometers) to Pluto; the scene is 780 miles (1,250 kilometers) wide.
5. Icy Dunes
Found near the mountains that encircle Pluto’s Sputnik Planitia plain, newly discovered ridges appear to have formed out of particles of methane ice as small as grains of sand, arranged into dunes by wind from the nearby mountains.
High resolution images of Pluto’s largest moon, Charon, show a surprisingly complex and violent history. Scientists expected Charon to be a monotonous, crater-battered world; instead, they found a landscape covered with mountains, canyons, landslides, surface-color variations and more.
8. Ice Volcanoes
One of two potential cryovolcanoes spotted on the surface of Pluto by the New Horizons spacecraft. This feature, known as Wright Mons, was informally named by the New Horizons team in honor of the Wright brothers. At about 90 miles (150 kilometers) across and 2.5 miles (4 kilometers) high, this feature is enormous. If it is in fact an ice volcano, as suspected, it would be the largest such feature discovered in the outer solar system.
9. Blue Rays
Pluto’s receding crescent as seen by New Horizons at a distance of 120,000 miles (200,000 kilometers). Scientists believe the spectacular blue haze is a photochemical smog resulting from the action of sunlight on methane and other molecules in Pluto’s atmosphere. These hydrocarbons accumulate into small haze particles, which scatter blue sunlight—the same process that can make haze appear bluish on Earth.
On Jan. 1, 2019, New Horizons will fly past a small Kuiper Belt Object named MU69 (nicknamed Ultima Thule)—a billion miles (1.5 billion kilometers) beyond Pluto and more than four billion miles (6.5 billion kilometers) from Earth. It will be the most distant encounter of an object in history—so far—and the second time New Horizons has revealed never-before-seen landscapes.
Our Juno mission arrived at the King of Planets in July 2016. The intrepid robotic explorer has been revealing Jupiter’s secrets ever since.
Here are 10 historic Juno mission highlights:
1. Arrival at a Colossus
After an odyssey of almost five years and 1.7 billion miles (2.7 billion kilometers), our Juno spacecraft fired its main engine to enter orbit around Jupiter on July 4, 2016. Juno, with its suite of nine science instruments, was the first spacecraft to orbit the giant planet since the Galileo mission in the 1990s. It would be the first mission to make repeated excursions close to the cloud tops, deep inside the planet’s powerful radiation belts.
2. Science, Meet Art
Juno carries a color camera called JunoCam. In a remarkable first for a deep space mission, the Juno team reached out to the general public not only to help plan which pictures JunoCam would take, but also to process and enhance the resulting visual data. The results include some of the most beautiful images in the history of space exploration.
3. A Whole New Jupiter
It didn’t take long for Juno—and the science teams who hungrily consumed the data it sent home—to turn theories about how Jupiter works inside out. Among the early findings: Jupiter’s poles are covered in Earth-sized swirling storms that are densely clustered and rubbing together. Jupiter’s iconic belts and zones were surprising, with the belt near the equator penetrating far beneath the clouds, and the belts and zones at other latitudes seeming to evolve to other structures below the surface.
4. The Ultimate Classroom
The Goldstone Apple Valley Radio Telescope (GAVRT) project, a collaboration among NASA, JPL and the Lewis Center for Educational Research, lets students do real science with a large radio telescope. GAVRT data includes Jupiter observations relevant to Juno, and Juno scientists collaborate with the students and their teachers.
5. Spotting the Spot
Measuring in at 10,159 miles (16,350 kilometers) in width (as of April 3, 2017) Jupiter’s Great Red Spot is 1.3 times as wide as Earth. The storm has been monitored since 1830 and has possibly existed for more than 350 years. In modern times, the Great Red Spot has appeared to be shrinking. In July 2017, Juno passed directly over the spot, and JunoCam images revealed a tangle of dark, veinous clouds weaving their way through a massive crimson oval.
“For hundreds of years scientists have been observing, wondering and theorizing about Jupiter’s Great Red Spot,” said Scott Bolton, Juno principal investigator from the Southwest Research Institute in San Antonio. “Now we have the best pictures ever of this iconic storm. It will take us some time to analyze all the data from not only JunoCam, but Juno’s eight science instruments, to shed some new light on the past, present and future of the Great Red Spot.”
6. Beauty Runs Deep
Data collected by the Juno spacecraft during its first pass over Jupiter’s Great Red Spot in July 2017 indicate that this iconic feature penetrates well below the clouds. The solar system’s most famous storm appears to have roots that penetrate about 200 miles (300 kilometers) into the planet’s atmosphere.
7. Powerful Auroras, Powerful Mysteries
Scientists on the Juno mission observed massive amounts of energy swirling over Jupiter’s polar regions that contribute to the giant planet’s powerful auroras – only not in ways the researchers expected. Examining data collected by the ultraviolet spectrograph and energetic-particle detector instruments aboard Juno, scientists observed signatures of powerful electric potentials, aligned with Jupiter’s magnetic field, that accelerate electrons toward the Jovian atmosphere at energies up to 400,000 electron volts. This is 10 to 30 times higher than the largest such auroral potentials observed at Earth.
Jupiter has the most powerful auroras in the solar system, so the team was not surprised that electric potentials play a role in their generation. What puzzled the researchers is that despite the magnitudes of these potentials at Jupiter, they are observed only sometimes and are not the source of the most intense auroras, as they are at Earth.
8. Heat from Within
Juno scientists shared a 3D infrared movie depicting densely packed cyclones and anticyclones that permeate the planet’s polar regions, and the first detailed view of a dynamo, or engine, powering the magnetic field for any planet beyond Earth (video above). Juno mission scientists took data collected by the spacecraft’s Jovian InfraRed Auroral Mapper (JIRAM) instrument and generated a 3D fly-around of the Jovian world’s north pole.
Imaging in the infrared part of the spectrum, JIRAM captures light emerging from deep inside Jupiter equally well, night or day. The instrument probes the weather layer down to 30 to 45 miles (50 to 70 kilometers) below Jupiter’s cloud tops.
9. A Highly Charged Atmosphere
Powerful bolts of lightning light up Jupiter’s clouds. In some ways its lightning is just like what we’re used to on Earth. In other ways,it’s very different. For example, most of Earth’s lightning strikes near the equator; on Jupiter, it’s mostly around the poles.
10. Extra Innings
In June, we approved an update to Juno’s science operations until July 2021. This provides for an additional 41 months in orbit around. Juno is in 53-day orbits rather than 14-day orbits as initially planned because of a concern about valves on the spacecraft’s fuel system. This longer orbit means that it will take more time to collect the needed science data, but an independent panel of experts confirmed that Juno is on track to achieve its science objectives and is already returning spectacular results. The spacecraft and all its instruments are healthy and operating nominally.
Read the full web version of this week’s ‘Solar System: 10 Things to Know’ article HERE.
Astronomers James Christy and Robert Harrington weren’t even looking for satellites of Pluto when they discovered Charon in June 1978 at the U.S. Naval Observatory Flagstaff Station in Arizona – only about six miles from where Pluto was discovered at Lowell Observatory. Instead, they were trying to refine Pluto’s orbit around the Sun when sharp-eyed Christy noticed images of Pluto were strangely elongated; a blob seemed to move around Pluto.
The direction of elongation cycled back and forth over 6.39 days―the same as Pluto’s rotation period. Searching through their archives of Pluto images taken years before, Christy then found more cases where Pluto appeared elongated. Additional images confirmed he had discovered the first known moon of Pluto.
2. Forever and Always
Christy proposed the name Charon after the mythological ferryman who carried souls across the river Acheron, one of the five mythical rivers that surrounded Pluto’s underworld. But Christy also chose it for a more personal reason: The first four letters matched the name of his wife, Charlene. (Cue the collective sigh.)
3. Big Little Moon
Charon—the largest of Pluto’s five moons and approximately the size of Texas—is almost half the size of Pluto itself. The little moon is so big that Pluto and Charon are sometimes referred to as a double dwarf planet system. The distance between them is 12,200 miles (19,640 kilometers).
4. A Colorful and Violent History
Many scientists on the New Horizons mission expected Charon to be a monotonous, crater-battered world; instead, they found a landscape covered with mountains, canyons, landslides, surface-color variations and more. High-resolution images of the Pluto-facing hemisphere of Charon, taken by New Horizons as the spacecraft sped through the Pluto system on July 14 and transmitted to Earth on Sept. 21, reveal details of a belt of fractures and canyons just north of the moon’s equator.
5. Grander Canyon
This great canyon system stretches more than 1,000 miles (1,600 kilometers) across the entire face of Charon and likely around onto Charon’s far side. Four times as long as the Grand Canyon, and twice as deep in places, these faults and canyons indicate a titanic geological upheaval in Charon’s past.
6. Officially Official
In April 2018, the International Astronomical Union—the internationally recognized authority for naming celestial bodies and their surface features—approved a dozen names for Charon’s features proposed by our New Horizons mission team. Many of the names focus on the literature and mythology of exploration.
7. Flying Over Charon
This flyover video of Charon was created thanks to images from our New Horizons spacecraft. The “flight” starts with the informally named Mordor (dark) region near Charon’s north pole. Then the camera moves south to a vast chasm, descending to just 40 miles (60 kilometers) above the surface to fly through the canyon system.
8. Strikingly Different Worlds
This composite of enhanced color images of Pluto (lower right) and Charon (upper left), was taken by New Horizons as it passed through the Pluto system on July 14, 2015. This image highlights the striking differences between Pluto and Charon. The color and brightness of both Pluto and Charon have been processed identically to allow direct comparison of their surface properties, and to highlight the similarity between Charon’s polar red terrain and Pluto’s equatorial red terrain.
9. Quality Facetime
Charon neither rises nor sets, but hovers over the same spot on Pluto’s surface, and the same side of Charon always faces Pluto―a phenomenon called mutual tidal locking.
10. Shine On, Charon
Bathed in “Plutoshine,” this image from New Horizons shows the night side of Charon against a star field lit by faint, reflected light from Pluto itself on July 15, 2015.
Read the full version of this week’s ‘10 Things to Know’ article on the web HERE.
Sixty years ago, the hopes of Cold War America soared into the night sky as a rocket lofted skyward above Cape Canaveral, a soon-to-be-famous barrier island off the Florida coast.
1. The Original Science Robot
Sixty years ago this week, the United States sent its first satellite into space on Jan. 31, 1958. The spacecraft, small enough to be held triumphantly overhead, orbited Earth from as far as 1,594 miles (2,565 km) above and made the first scientific discovery in space. It was called, appropriately, Explorer 1.
2. Why It’s Important
The world had changed three months before Explorer 1’s launch, when the Soviet Union lofted Sputnik into orbit on Oct. 4, 1957. That satellite was followed a month later by a second Sputnik spacecraft. All of the missions were inspired when an international council of scientists called for satellites to be placed in Earth orbit in the pursuit of science. The Space Age was on.
3. It…Wasn’t Easy
When Explorer 1 launched, we (NASA) didn’t yet exist. It was a project of the U.S. Army and was built by Caltech’s Jet Propulsion Laboratory (JPL) in Pasadena, California. After the Sputnik launch, the Army, Navy and Air Force were tasked by President Eisenhower with getting a satellite into orbit within 90 days. The Navy’s Vanguard Rocket, the first choice, exploded on the launch pad Dec. 6, 1957.
4. The People Behind Explorer 1
University of Iowa physicist James Van Allen, whose proposal was chosen for the Vanguard satellite, had made sure his scientific instrument—a cosmic ray detector—would fit either launch vehicle. Wernher von Braun, working with the Army Ballistic Missile Agency in Alabama, directed the design of the Redstone Jupiter-C launch rocket, while JPL Director William Pickering oversaw the design of Explorer 1 and other upper stages of the rocket. JPL was also responsible for sending and receiving communications from the spacecraft.
5. All About the Science
Explorer 1’s science payload took up 37.25 inches (95 cm) of the satellite’s total 80.75 inches (2.05 meters). The main instruments were a cosmic-ray detector; internal, external and nose-cone temperature sensors; a micrometeorite impact microphone; a ring of micrometeorite erosion gauges; and two transmitters. There were two antennas in the body of the satellite and its four flexible whips formed a turnstile antenna that extended with the rotation of the satellite. Electrical power was provided by batteries that made up 40 percent of the total payload weight.
6. At the Center of a Space Doughnut
The first scientific discovery in space came from Explorer 1. Earth is surrounded by radiation belts of electrons and charged particles, some of them moving at nearly the speed of light, about 186,000 miles (299,000 km) per second. The two belts are shaped like giant doughnuts with Earth at the center. Data from Explorer 1 and Explorer 3 (launched March 26, 1958) led to the discovery of the inner radiation belt, while Pioneer 3 (Dec. 6, 1958) and Explorer IV (July 26, 1958) provided additional data, leading to the discovery of the outer radiation belt. The radiation belts can be hazardous for spacecraft, but they also protect the planet from harmful particles and energy from the Sun.
7. 58,376 Orbits
Explorer 1’s last transmission was received May 21, 1958. The spacecraft re-entered Earth’s atmosphere and burned up on March 31, 1970, after 58,376 orbits. From 1958 on, more than 100 spacecraft would fall under the Explorer designation.
8. Find Out More!
Want to know more about Explorer 1? Check out the website and download the poster celebrating 60 years of space science. go.nasa.gov/Explorer1
All of our missions can trace a lineage to Explorer 1. This year alone, we’re going to expand the study of our home planet from space with the launch of two new satellite missions (GRACE-FO and ICESat-2); we’re going back to Mars with InSight; and the Transiting Exoplanet Survey Satellite (TESS) will search for planets outside our solar system by monitoring 200,000 bright, nearby stars. Meanwhile, the Parker Solar Probe will build on the work of James Van Allen when it flies closer to the Sun than any mission before.