Category: discovery

10 Things: Calling All Pluto Lovers

June 22 marks the 40th anniversary of Charon’s discovery—the dwarf planet Pluto’s largest and first known moon. While the definition of a planet is the subject of vigorous scientific debate, this dwarf planet is a fascinating world to explore. Get to know Pluto’s beautiful, fascinating companion this week.

1. A Happy Accident

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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

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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

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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

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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

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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

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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

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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

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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

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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.

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10 Things to Know About Explorer 1, America’s …

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

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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

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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

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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

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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

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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

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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

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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!

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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

9. Hold the Spacecraft In Your Hands

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Create your own iconic Explorer 1 photo (or re-create the original), with our Spacecraft 3D app. Follow @NASAEarth this week to see how we #ExploreAsOne. https://go.nasa.gov/2BmSCWi

10. What’s Next?

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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.

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#NASARemembers

Each year we hold a Day of Remembrance. Today, Jan. 25, we pay will tribute to the crews of Apollo 1 and space shuttles Challenger and Columbia, as well as other NASA colleagues who lost their lives while furthering the cause of exploration and discovery. 

#NASARemembers

Learn more about the Day of Remembrance HERE

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Finalists for a Future Mission to Explore the …

We’ve selected two finalists for a robotic mission that is planned to launch in the mid-2020s! Following a competitive peer review process, these two concepts were chosen from 12 proposals that were submitted in April under a New Frontiers program announcement opportunity.

What are they?

In no particular order…

CAESAR

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CAESAR, or the Comet Astrobiology Exploration Sample Return mission seeks to return a sample from 67P/Churyumov-Gerasimenko – the comet that was successfully explored by the European Space Agency’s Rosetta spacecraft – to determine its origin and history.

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This mission would acquire a sample from the nucleus of comet Churyumov-Gerasimenko and return it safely to Earth. 

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Comets are made up of materials from ancient stars, interstellar clouds and the birth of our solar system, so the CAESAR sample could reveal how these materials contributed to the early Earth, including the origins of the Earth’s oceans, and of life.

Dragonfly

A drone-like rotorcraft would be sent to explore the prebiotic chemistry and habitability of dozens of sites on Saturn’s moon Titan – one of the so-called ocean worlds in our solar system.

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Unique among these Ocean Worlds, Titan has a surface rich in organic compounds and diverse environments, including those where carbon and nitrogen have interacted with water and energy.

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Dragonfly would be a dual-quadcopter lander that would take advantage of the environment on Titan to fly to multiple locations, some hundreds of miles apart, to sample materials and determine surface composition to investigate Titan’s organic chemistry and habitability, monitor atmospheric and surface conditions, image landforms to investigate geological processes, and perform seismic studies.

What’s Next?

The CAESAR and Dragonfly missions will receive funding through the end of 2018 to further develop and mature the concepts. It is planned that from these, one investigation will be chosen in the spring of 2019 to continue into subsequent mission phases.

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That mission would be the fourth mission in the New Frontiers portfolio, which conducts principal investigator (PI)-led planetary science missions under a development cost cap of approximately $850 million. Its predecessors are the New Horizons mission to Pluto and a Kuiper Belt object, the Juno mission to Jupiter and OSIRIS-REx, which will rendezvous with and return a sample of the asteroid Bennu. 

Key Technologies

We also announced that two mission concepts were chosen to receive technology development funds to prepare them for future mission opportunities.

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The Enceladus Life Signatures and Habitability (ELSAH) mission concept will receive funds to enable life detection measurements by developing cost-effective techniques to limit spacecraft contamination on cost-capped missions.

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The Venus In situ Composition Investigations (VICI) mission concept will further develop the VEMCam instrument to operate under harsh conditions on Venus. The instrument uses lasers on a lander to measure the mineralogy and elemental composition of rocks on the surface of Venus.

The call for these mission concepts occurred in April and was limited to six mission themes: comet surface sample return, lunar south pole-Aitken Basin sample return, ocean worlds, Saturn probe, Trojan asteroid tour and rendezvous and Venus insitu explorer.

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What in the Universe is an Exoplanet?

Simply put, an exoplanet is a planet that orbits another star. 

All of the planets in our solar system orbit around the Sun. Planets that orbit around other stars outside our solar system are called exoplanets.

Just because a planet orbits a star (like Earth) does not mean that it is automatically stable for life. The planet must be within the habitable zone, which is the area around a star in which water has the potential to be liquid…aka not so close that all the water would evaporate, and not too far away where all the water would freeze.

Exoplanets are very hard to see directly with telescopes. They are hidden by the bright glare of the stars they orbit. So, astronomers use other ways to detect and study these distant planets by looking at the effects these planets have on the stars they orbit.

One way to search for exoplanets is to look for “wobbly” stars. A star that has planets doesn’t orbit perfectly around its center. From far away, this off-center orbit makes the star look like it’s wobbling. Hundreds of planets have been discovered using this method. However, only big planets—like Jupiter, or even larger—can be seen this way. Smaller Earth-like planets are much harder to find because they create only small wobbles that are hard to detect.

How can we find Earth-like planets in other solar systems?

In 2009, we launched a spacecraft called Kepler to look for exoplanets. Kepler looked for planets in a wide range of sizes and orbits. And these planets orbited around stars that varied in size and temperature.

Kepler detected exoplanets using something called the transit method. When a planet passes in front of its star, it’s called a transit. As the planet transits in front of the star, it blocks out a little bit of the star’s light. That means a star will look a little less bright when the planet passes in front of it. Astronomers can observe how the brightness of the star changes during a transit. This can help them figure out the size of the planet.

By studying the time between transits, astronomers can also find out how far away the planet is from its star. This tells us something about the planet’s temperature. If a planet is just the right temperature, it could contain liquid water—an important ingredient for life.

So far, thousands of planets have been discovered by the Kepler mission.

We now know that exoplanets are very common in the universe. And future missions have been planned to discover many more!

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Human Expansion Across Solar System

On this day in 1972, two NASA astronauts landed on the Moon. Now, 45 years later, we have been instructed to return to the lunar surface.

Today at the White House, President Trump signed the Space Policy Directive 1, a change in national space policy that provides for a U.S.-led program with private sector partners for a human return to the Moon, followed by missions to Mars and beyond.

Among other dignitaries on hand for the signing, were NASA astronauts Sen. Harrison “Jack” Schmitt, Buzz Aldrin, Peggy Whitson and Christina Koch.

Schmitt landed on the moon 45 years to the minute that the policy directive was signed as part of our Apollo 17 mission, and is the most recent living person to have set foot on our lunar neighbor. 

Above, at the signing ceremony instructing us to send humans back to the lunar surface, Schmitt shows First Daughter Ivanka Trump the Moon sample he collected in 1972.

The effort signed today will more effectively organize government, private industry and international efforts toward returning humans on the Moon, and will lay the foundation that will eventually enable human exploration of Mars.

To learn more, visit: https://www.nasa.gov/press-release/new-space-policy-directive-calls-for-human-expansion-across-solar-system

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Why Webb Needs to Chill

Our massive James Webb Space Telescope is currently being tested to make sure it can work perfectly at incredibly cold temperatures when it’s in deep space. 

How cold is it getting and why? Here’s the whole scoop…

Webb is a giant infrared space telescope that we are currently building. It was designed to see things that other telescopes, even the amazing Hubble Space Telescope, can’t see.  

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Webb’s giant 6.5-meter diameter primary mirror is part of what gives it superior vision, and it’s coated in gold to optimize it for seeing infrared light.  

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Why do we want to see infrared light?

Lots of stuff in space emits infrared light, so being able to observe it gives us another tool for understanding the universe. For example, sometimes dust obscures the light from objects we want to study – but if we can see the heat they are emitting, we can still “see” the objects to study them.

It’s like if you were to stick your arm inside a garbage bag. You might not be able to see your arm with your eyes – but if you had an infrared camera, it could see the heat of your arm right through the cooler plastic bag.

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Credit: NASA/IPAC

With a powerful infrared space telescope, we can see stars and planets forming inside clouds of dust and gas.

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We can also see the very first stars and galaxies that formed in the early universe. These objects are so far away that…well, we haven’t actually been able to see them yet. Also, their light has been shifted from visible light to infrared because the universe is expanding, and as the distances between the galaxies stretch, the light from them also stretches towards redder wavelengths. 

We call this phenomena  “redshift.”  This means that for us, these objects can be quite dim at visible wavelengths, but bright at infrared ones. With a powerful enough infrared telescope, we can see these never-before-seen objects.

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We can also study the atmospheres of planets orbiting other stars. Many of the elements and molecules we want to study in planetary atmospheres have characteristic signatures in the infrared.

Because infrared light comes from objects that are warm, in order to detect the super faint heat signals of things that are really, really far away, the telescope itself has to be very cold. How cold does the telescope have to be? Webb’s operating temperature is under 50K (or -370F/-223 C). As a comparison, water freezes at 273K (or 32 F/0 C).

How do we keep the telescope that cold? 

Because there is no atmosphere in space, as long as you can keep something out of the Sun, it will get very cold. So Webb, as a whole, doesn’t need freezers or coolers – instead it has a giant sunshield that keeps it in the shade. (We do have one instrument on Webb that does have a cryocooler because it needs to operate at 7K.)

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Also, we have to be careful that no nearby bright things can shine into the telescope – Webb is so sensitive to faint infrared light, that bright light could essentially blind it. The sunshield is able to protect the telescope from the light and heat of the Earth and Moon, as well as the Sun.  

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Out at what we call the Second Lagrange point, where the telescope will orbit the Sun in line with the Earth, the sunshield is able to always block the light from bright objects like the Earth, Sun and Moon.

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How do we make sure it all works in space? 

By lots of testing on the ground before we launch it. Every piece of the telescope was designed to work at the cold temperatures it will operate at in space and was tested in simulated space conditions. The mirrors were tested at cryogenic temperatures after every phase of their manufacturing process.

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The instruments went through multiple cryogenic tests at our Goddard Space Flight Center in Maryland.

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Once the telescope (instruments and optics) was assembled, it even underwent a full end-to-end test in our Johnson Space Center’s giant cryogenic chamber, to ensure the whole system will work perfectly in space.  

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What’s next for Webb? 

It will move to Northrop Grumman where it will be mated to the sunshield, as well as the spacecraft bus, which provides support functions like electrical power, attitude control, thermal control, communications, data handling and propulsion to the spacecraft.

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Learn more about the James Webb Space Telescope HERE, or follow the mission on Facebook, Twitter and Instagram.

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The National Space Council

October 5 marks the first meeting of the National Space Council since 1993. But what is it and why does it matter? Let us explain by taking a trip back in history…

We’ve teleported back to 1958…President Dwight Eisenhower is in office and the National Aeronautics and Space Council was created with the signing of the Space Act that year. President Eisenhower chaired the first National Aeronautics and Space Council (NASC). That council continued during the Kennedy, Johnson and Nixon Administrations during which we put an American in outer space with John Glenn in 1962 and put humans on the moon starting in 1969. That Council was disbanded in 1973.

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In 1989, President George H.W. Bush’s Administration reinstated what was known as the National Space Council, which was designed to help chart national space policy and the roles of multiple federal agencies such as NASA. The Space Council disbanded again in 1993.

On June 30, 2017, President Trump signed an executive order reestablishing the National Space Council – which brings us to today. The current National Space Council will bring a unified national perspective on space policy to the Administration by coordinating the views of the civilian, commercial and national security sectors.

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So now that you have a bit of the history…why does this matter?

With the Oct. 5 meeting, titled “Leading the Next Frontier: An Event with the National Space Council,” Vice President Mike Pence will convene this council and have participation from acting NASA Administrator Robert Lightfoot, as well as a number of Trump Administration cabinet members and senior officials, and aerospace industry leaders.

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During the council’s first meeting, we will hear from experts who represent various parts of the space industry: Civil Space, Commercial Space and National Security Space.

You can watch the first meeting of the National Space Council starting at 10 a.m. EDT HERE.

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Our Cassini spacecraft has been traveling in space for almost 20…

Our Cassini spacecraft has been traveling in space for almost 20 years, exploring Saturn, its rings and even some of its moons. This mission has revealed never-before-seen events that are changing our understanding of how planetary systems form and what conditions might lead to habitats for life.

Cassini will complete its remarkable story of exploration with an intentional plunge into Saturn’s atmosphere, ending its mission.  

Participate in our Grand Finale Events

Wednesday, Sept. 13

1 p.m. EDT – News Conference from our Jet Propulsion Laboratory with a detailed preview of final mission activities
Watch HERE.

Thursday, Sept 14

4:00 – 5:00 p.m. EDT – NASA Social Live Broadcast with mission experts
Watch HERE.

Friday, Sept. 15

7:00 – 8:30 a.m. EDT – Live commentary on NASA TV and online of the spacecraft’s final dive into Saturn’s atmosphere.
Watch HERE.

Around 8:00 a.m. EDT – Expected time of last signal and science data from Cassini
Watch HERE.

9:30 a.m. EDT – Post-mission news conference
Watch HERE.

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Planets: As Seen by Voyager

The Voyager 1 and 2 spacecraft explored Jupiter, Saturn, Uranus and Neptune before starting their journey toward interstellar space. Here you’ll find some of those images, including “The Pale Blue Dot” – famously described by Carl Sagan – and what are still the only up-close images of Uranus and Neptune.

These twin spacecraft took some of the very first close-up images of these planets and paved the way for future planetary missions to return, like the Juno spacecraft at Jupiter, Cassini at Saturn and New Horizons at Pluto.

Jupiter

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Photography of Jupiter began in January 1979, when images of the brightly banded planet already exceeded the best taken from Earth. They took more than 33,000 pictures of Jupiter and its five major satellites. 

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Findings:

  • Erupting volcanoes on Jupiter’s moon Io, which has 100 times the volcanic activity of Earth. 
  • Better understanding of important physical, geological, and atmospheric processes happening in the planet, its satellites and magnetosphere.
  • Jupiter’s turbulent atmosphere with dozens of interacting hurricane-like storm systems.

Saturn

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The Saturn encounters occurred nine months apart, in November 1980 and August 1981. The two encounters increased our knowledge and altered our understanding of Saturn. The extended, close-range observations provided high-resolution data far different from the picture assembled during centuries of Earth-based studies.

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Findings:

  • Saturn’s atmosphere is almost entirely hydrogen and helium.
  • Subdued contrasts and color differences on Saturn could be a result of more horizontal mixing or less production of localized colors than in Jupiter’s atmosphere.
  • An indication of an ocean beneath the cracked, icy crust of Jupiter’s moon Europa. 
  • Winds blow at high speeds in Saturn. Near the equator, the Voyagers measured winds about 1,100 miles an hour.

Uranus

The Voyager 2 spacecraft flew closely past distant Uranus, the seventh planet from the Sun. At its closest, the spacecraft came within 50,600 miles of Uranus’s cloud tops on Jan. 24, 1986. Voyager 2 radioed thousands of images and voluminous amounts of other scientific data on the planet, its moons, rings, atmosphere, interior and the magnetic environment surrounding Uranus.

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Findings:

  • Revealed complex surfaces indicative of varying geologic pasts.
  • Detected 11 previously unseen moons.
  • Uncovered the fine detail of the previously known rings and two newly detected rings.
  • Showed that the planet’s rate of rotation is 17 hours, 14 minutes.
  • Found that the planet’s magnetic field is both large and unusual.
  • Determined that the temperature of the equatorial region, which receives less sunlight over a Uranian year, is nevertheless about the same as that at the poles.

Neptune

Voyager 2 became the first spacecraft to observe the planet Neptune in the summer of 1989. Passing about 3,000 miles above Neptune’s north pole, Voyager 2 made its closest approach to any planet since leaving Earth 12 years ago. Five hours later, Voyager 2 passed about 25,000 miles from Neptune’s largest moon, Triton, the last solid body the spacecraft had the opportunity to study.

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Findings: 

  • Discovered Neptune’s Great Dark Spot
  • Found that the planet has strong winds, around 1,000 miles per hour
  • Saw geysers erupting from the polar cap on Neptune’s moon Triton at -390 degrees Fahrenheit

Solar System Portrait

This narrow-angle color image of the Earth, dubbed ‘Pale Blue Dot’, is a part of the first ever ‘portrait’ of the solar system taken by Voyager 1. 

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The spacecraft acquired a total of 60 frames for a mosaic of the solar system from a distance of more than 4 billion miles from Earth and about 32 degrees above the ecliptic.

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From Voyager’s great distance, Earth is a mere point of light, less than the size of a picture element even in the narrow-angle camera.

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“Look again at that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives.” – Carl Sagan

Both spacecraft will continue to study ultraviolet sources among the stars, and their fields and particles detectors will continue to search for the boundary between the Sun’s influence and interstellar space. The radioisotope power systems will likely provide enough power for science to continue through 2025, and possibly support engineering data return through the mid-2030s. After that, the two Voyagers will continue to orbit the center of the Milky Way.

Learn more about the Voyager spacecraft HERE.

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