Saturn's hazy moon Titan is larger than Mercury, but its size is not the only way it's like a planet. Titan has a thick atmosphere, complete with its own "water cycle" -- except that it's way too cold on Titan for liquid water. Instead, rains of liquid hydrocarbons like ethane and methane fall onto icy mountains, run into rivers, and gather into great seas. Our Cassini spacecraft mapped the methane seas with radar, and its cameras even caught a glimpse of sunlight reflecting off the seas' surface. Learn more about Titan: saturn.jpl.nasa.gov/science/titan/
Jupiter's moon Ganymede is the largest in the solar system. It's bigger than Mercury and Pluto, and three-quarters the size of Mars. It's also the only moon known to have its own magnetic field. Details: solarsystem.nasa.gov/planets/ganymede/indepth
Triton is Neptune's largest moon, and the only one in the solar system to orbit in the opposite direction of its planet's rotation, a retrograde orbit. It may have been captured from the Kuiper Belt, where Pluto orbits. Despite the frigid temperatures there, Triton has cryovolcanic activity -- frozen nitrogen sometimes sublimates directly to gas and erupts from geysers on the surface. More on Triton: solarsystem.nasa.gov/planets/triton/indepth
The most famous geysers in our solar system (outside of those on Earth) belong to Saturn's moon Enceladus. It's a small, icy body, but Cassini revealed this world to be one of the solar system's most scientifically interesting destinations. Geyser-like jets spew water vapor and ice particles from an underground ocean beneath the icy crust of Enceladus. With its global ocean, unique chemistry and internal heat, Enceladus has become a promising lead in our search for worlds where life could exist. Get the details: saturn.jpl.nasa.gov/science/enceladus/
Jupiter's moon Io is subjected to tremendous gravitational forces that cause its surface to bulge up and down by as much as 330 feet (100 m). The result? Io is the most volcanically active body in the Solar System, with hundreds of volcanoes, some erupting lava fountains dozens of miles high. More on Io’s volcanoes: solarsystem.nasa.gov/planets/io/indepth
When Giovanni Cassini discovered Iapetus in 1671, he observed that one side of this moon of Saturn was bright and the other dark. He noted that he could only see Iapetus on the west side of Saturn, and correctly concluded that Iapetus had one side much darker than the other side. Why? Three centuries later, the Cassini spacecraft solved the puzzle. Dark, reddish dust in Iapetus's orbital path is swept up and lands on the leading face of the moon. The dark areas absorb energy and become warmer, while uncontaminated areas remain cooler. Learn more: saturn.jpl.nasa.gov/news/2892/cassini-10-years-at-saturn-top-10-discoveries/#nine
At half the size of Pluto, Charon is the largest of Pluto's moons and the largest known satellite relative to its parent body. The moon is so big compared to Pluto that Pluto and Charon are sometimes referred to as a double planet system. Charon's orbit around Pluto takes 6.4 Earth days, and one Pluto rotation (a Pluto day) takes 6.4 Earth days. So from Pluto's point of view Charon neither rises nor sets, but hovers over the same spot on Pluto's surface, and the same side of Charon always faces Pluto. Get the details: www.nasa.gov/feature/pluto-and-charon-new-horizons-dynamic-duo
Saturn's moon Mimas has one feature that draws more attention than any other: the crater Herschel, which formed in an impact that nearly shattered the little world. Herschel gives Mimas a distinctive look that prompts an oft-repeated joke. But, yes, it's a moon. More: olarsystem.nasa.gov/planets/mimas
In mythology, Mars is a the god of war, so it's fitting that its two small moons are called Phobos, "fear," and Deimos, "terror." Our Mars Reconnaissance Orbiter caught this look at Phobos, which is roughly 17 miles (27 km) wide. In recent years, NASA scientists have come to think that Phobos will be torn apart by its host planet's gravity. Details: www.nasa.gov/feature/goddard/phobos-is-falling-apart
Learn more about Phobos: solarsystem.nasa.gov/planets/phobos/indepth
Although decades have passed since astronauts last set foot on its surface, Earth's moon is far from abandoned. Several robotic missions have continued the exploration. For example, this stunning view of the moon's famous Tycho crater was captured by our Lunar Reconnaissance Orbiter, which continues to map the surface in fine detail today. More: www.lroc.asu.edu/posts/902
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On July 20, 1969, the world watched as Apollo 11 astronauts Neil Armstrong and Buzz Aldrin took their first steps on the Moon. It was a historic moment for the United States and for humanity. Until then, no human had ever walked on another world. To achieve this remarkable feat, we recruited the best and brightest scientists, engineers and mathematicians across the country. At the peak of our Apollo program, an estimated 400,000 Americans of diverse race and ethnicity worked to realize President John F. Kennedy’s vision of landing humans on the Moon and bringing them safely back to Earth. The men and women of our Ames Research Center in California’s Silicon Valley supported the Apollo program in numerous ways – from devising the shape of the Apollo space capsule to performing tests on its thermal protection system and study of the Moon rocks and soils collected by the astronauts. In celebration of the upcoming 50th anniversary of the Apollo 11 Moon landing, here are portraits of some of the people who worked at Ames in the 1960s to help make the Apollo program a success.
Hank Cole did research on the design of the Saturn V rocket, which propelled humans to the Moon. An engineer, his work at Ames often took him to Edwards Air Force Base in Southern California, where he met Neil Armstrong and other pilots who tested experimental aircraft.
Caye Johnson came to Ames in 1964. A biologist, she analyzed samples taken by Apollo astronauts from the Moon for signs of life. Although no life was found in these samples, the methodology paved the way for later work in astrobiology and the search for life on Mars.
Richard Kurkowski started work at Ames in 1955, when the center was still part of the National Advisory Committee on Aeronautics, NASA’s predecessor. An engineer, he performed wind tunnel tests on aircraft prior to his work on the Apollo program.
Mike Green started at Ames in 1965 as a computer programmer. He supported aerospace engineers working on the development of the thermal protection system for the Apollo command module. The programs were executed on some of earliest large-scale computers available at that time.
Gerhard Hahne played an important role in certifying that the Apollo spacecraft heat shield used to bring our astronauts home from the Moon would not fail. The Apollo command module was the first crewed spacecraft designed to enter the atmosphere of Earth at lunar-return velocity – approximately 24,000 mph, or more than 30 times faster than the speed of sound.
Jim Arnold arrived at Ames in 1962 and was hired to work on studying the aerothermodynamics of the Apollo spacecraft. He was amazed by the image captured by Apollo 8 astronaut Bill Anders from lunar orbit on Christmas Eve in 1968 of Earth rising from beneath the Moon’s horizon. The stunning picture would later become known as the iconic Earthrise photo.
Howard Goldstein came to Ames in 1967. An engineer, he tested materials used for the Apollo capsule heat shield, which protected the three-man crew against the blistering heat of reentry into Earth’s atmosphere on the return trip from the Moon.
Richard Johnson developed a simple instrument to analyze the total organic carbon content of the soil samples collected by Apollo astronauts from the Moon’s surface. He and his wife Caye Johnson, who is also a scientist, were at our Lunar Receiving Laboratory in Houston when the Apollo 11 astronauts returned to Earth so they could examine the samples immediately upon their arrival.
William Borucki joined Ames in 1962. He collected data on the radiation environment of the Apollo heat shield in a facility used to simulate the reentry of the Apollo spacecraft into Earth’s atmosphere.
Join us in celebrating the 50th anniversary of the Apollo 11 Moon landing and hear about our future plans to go forward to the Moon and on to Mars by tuning in to a special two-hour live NASA Television broadcast at 1 pm ET on July 19. Watch the program at www.nasa.gov/live.
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The day has finally arrived. After years of work, a team of scientists is at Kennedy Space Center in the hopes of seeing their research liftoff to the International Space Station.
Join #NASAExplorers for the countdown, the emotion and, hopefully, the launch!
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On June 17, our MAVEN (Mars Atmosphere and Volatile Evolution Mission) will celebrate 1,000 Earth days in orbit around the Red Planet.
Since its launch in November 2013 and its orbit insertion in September 2014, MAVEN has been exploring the upper atmosphere of Mars. MAVEN is bringing insight to how the sun stripped Mars of most of its atmosphere, turning a planet once possibly habitable to microbial life into a barren desert world.
10. Unprecedented Ultraviolet View of Mars
Revealing dynamic, previously invisible behavior, MAVEN was able to show the ultraviolet glow from the Martian atmosphere in unprecedented detail. Nightside images showed ultraviolet “nightglow” emission from nitric oxide. Nightglow is a common planetary phenomenon in which the sky faintly glows even in the complete absence of eternal light.
9. Key Features on the Loss of Atmosphere
Some particles from the solar wind are able to penetrate unexpectedly deep into the upper atmosphere, rather than being diverted around the planet by the Martian ionosphere. This penetration is allowed by chemical reactions in the ionosphere that turn the charged particles of the solar wind into neutral atoms that are then able to penetrate deeply.
8. Metal Ions
MAVEN made the first direct observations of a layer of metal ions in the Martian ionosphere, resulting from incoming interplanetary dust hitting the atmosphere. This layer is always present, but was enhanced dramatically by the close passage to Mars of Comet Siding Spring in October 2014.
7. Two New Types of Aurora
MAVEN has identified two new types of aurora, termed “diffuse” and “proton” aurora. Unlike how we think of most aurorae on Earth, these aurorae are unrelated to either a global or local magnetic field.
6. Cause of the Aurorae
These aurorae are caused by an influx of particles from the sun ejected by different types of solar storms. When particles from these storms hit the Martian atmosphere, they can also increase the rate of loss of gas to space, by a factor of ten or more.
5. Complex Interactions with Solar Wind
The interactions between the solar wind and the planet are unexpectedly complex. This results due to the lack of an intrinsic Martian magnetic field and the occurrence of small regions of magnetized crust that can affect the incoming solar wind on local and regional scales. The magnetosphere that results from the interactions varies on short timescales and is remarkably “lumpy” as a result.
4. Seasonal Hydrogen
After investigating the upper atmosphere of the Red Planet for a full Martian year, MAVEN determined that the escaping water does not always go gently into space. The spacecraft observed the full seasonal variation of hydrogen in the upper atmosphere, confirming that it varies by a factor of 10 throughout the year. The escape rate peaked when Mars was at its closest point to the sun and dropped off when the planet was farthest from the sun.
3. Gas Lost to Space
MAVEN has used measurements of the isotopes in the upper atmosphere (atoms of the same composition but having different mass) to determine how much gas has been lost through time. These measurements suggest that 2/3 or more of the gas has been lost to space.
2. Speed of Solar Wind Stripping Martian Atmosphere
MAVEN has measured the rate at which the sun and the solar wind are stripping gas from the top of the atmosphere to space today, along with details of the removal process. Extrapolation of the loss rates into the ancient past – when the solar ultraviolet light and the solar wind were more intense – indicates that large amounts of gas have been lost to space through time.
1. Martian Atmosphere Lost to Space
The Mars atmosphere has been stripped away by the sun and the solar wind over time, changing the climate from a warmer and wetter environment early in history to the cold, dry climate that we see today.
Maven will continue its observations and is now observing a second Martian year, looking at the ways that the seasonal cycles and the solar cycle affect the system.
For more information about MAVEN, visit: www.nasa.gov/maven
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On Aug. 21, 2017, a solar eclipse will be visible in North America. Throughout the continent, the Moon will cover part – or all – of the Sun’s super-bright face for part of the day.
Since it’s never safe to look at the partially eclipsed or uneclipsed Sun, everyone who plans to watch the eclipse needs a plan to watch it safely. One of the easiest ways to watch an eclipse is solar viewing glasses – but there are a few things to check to make sure your glasses are safe:
Glasses should have an ISO 12312-2 certification
They should also have the manufacturer’s name and address, and you can check if the manufacturer has been verified by the American Astronomical Society
Make sure they have no scratches or damage
To use solar viewing glasses, make sure you put them on before looking up at the Sun, and look away before you remove them. Proper solar viewing glasses are extremely dark, and the landscape around you will be totally black when you put them on – all you should see is the Sun (and maybe some types of extremely bright lights if you have them nearby).
Never use solar viewing glasses while looking through a telescope, binoculars, camera viewfinder, or any other optical device. The concentrated solar rays will damage the filter and enter your eyes, causing serious injury. But you can use solar viewing glasses on top of your regular eyeglasses, if you use them!
If you don’t have solar viewing glasses, there are still ways to watch, like making your own pinhole projector. You can make a handheld box projector with just a few simple supplies – or simply hold any object with a small hole (like a piece of cardstock with a pinhole, or even a colander) above a piece of paper on the ground to project tiny images of the Sun.
Of course, you can also watch the entire eclipse online with us. Tune into nasa.gov/eclipselive starting at noon ET on Aug. 21!
For people in the path of totality, there will be a few brief moments when it is safe to look directly at the eclipse. Only once the Moon has completely covered the Sun and there is no light shining through is it safe to look at the eclipse. Make sure you put your eclipse glasses back on or return to indirect viewing before the first flash of sunlight appears around the Moon’s edge.
You can look up the length of the total eclipse in your area to help you set a time for the appropriate length of time. Remember – this only applies to people within the path of totality.
Everyone else will need to use eclipse glasses or indirect viewing throughout the entire eclipse!
Whether you’re an amateur photographer or a selfie master, try out these tips for photographing the eclipse.
#1 — Safety first: Make sure you have the required solar filter to protect your camera.
#2 — Any camera is a good camera, whether it’s a high-end DSLR or a camera phone – a good eye and vision for the image you want to create is most important.
#3 — Look up, down, and all around. As the Moon slips in front of the Sun, the landscape will be bathed in long shadows, creating eerie lighting across the landscape. Light filtering through the overlapping leaves of trees, which creates natural pinholes, will also project mini eclipse replicas on the ground. Everywhere you can point your camera can yield exceptional imagery, so be sure to compose some wide-angle photos that can capture your eclipse experience.
#4 — Practice: Be sure you know the capabilities of your camera before Eclipse Day. Most cameras, and even many camera phones, have adjustable exposures, which can help you darken or lighten your image during the tricky eclipse lighting. Make sure you know how to manually focus the camera for crisp shots.
#5 —Upload your eclipse images to NASA’s Eclipse Flickr Gallery and relive the eclipse through other peoples’ images.
Learn all about the Aug. 21 eclipse at eclipse2017.nasa.gov, and follow @NASASun on Twitter and NASA Sun Science on Facebook for more. Watch the eclipse through the eyes of NASA at nasa.gov/eclipselive starting at 12 PM ET on Aug. 21.
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Did you ever wonder how we spots asteroids that may be getting too close to Earth for comfort? Wonder no more. Our Planetary Defense Coordination Office does just that. Thanks to a variety of ground and space based telescopes, we’re able to detect potentially hazardous objects so we can prepare for the unlikely threat against our planet.
Near-Earth objects (NEOs) are asteroids and comets that orbit the Sun, but their orbits bring them into Earth’s neighborhood – within 30 million miles of Earth’s orbit.
These objects are relatively unchanged remnant debris from the solar system’s formation some 4.6 billion years ago. Most of the rocky asteroids originally formed in the warmer inner solar system between the orbits of Mars and Jupiter, while comets, composed mostly of water ice with embedded dust particles, formed in the cold outer solar system.
Our Near-Earth Object (NEO) Observations Program finds, tracks and monitors near-Earth asteroids and comets. Astronomers supported by the program use telescopes to follow up the discoveries to make additional measurements, as do many observatories all over the world. The Center for Near-Earth Object Studies, based at our Jet Propulsion Laboratory, also uses these data to calculate high-precision orbits for all known near-Earth objects and predict future close approaches by them to Earth, as well as the potential for any future impacts.
Scientists determine the orbit of an asteroid by comparing measurements of its position as it moves across the sky to the predictions of a computer model of its orbit around the Sun. The more observations that are used and the longer the period over which those observations are made, the more accurate the calculated orbit and the predictions that can be made from it.
At the start of 2019, the number of discovered NEOs totaled more than 19,000, and it has since surpassed 20,000. An average of 30 new discoveries are added each week. More than 95 percent of these objects were discovered by NASA-funded surveys since 1998, when we initially established its NEO Observations Program and began tracking and cataloguing them.
Currently the risk of an asteroid striking Earth is exceedingly low, but we are constantly monitoring our cosmic neighborhood. Have more questions? Visit our Planetary Defense page to explore how we keep track of near-Earth objects.
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From space, we can see a swirling brown mass making its way across the Atlantic – dust from the Sahara Desert – the largest hot desert in the world. It’s a normal phenomenon. Every year, winds carry millions of tons of dust from North Africa, usually during spring and summer in the Northern Hemisphere.
June 2020 has seen a massive plume of dust crossing the ocean. It’s so large it’s visible from one million miles away in space.
Dust clouds this large can affect air quality in regions where the dust arrives. The particles can also scatter the Sun’s light, making sunrises and sunsets more vibrant.
Dust particles in the air are also known as aerosols. We can measure aerosols, including dust, sea salt and smoke, from satellites and also use computer models to study how they move with the wind.
Following the transport of dust from space shows us how one of the driest places on Earth plays a role in fertilizing the Amazon rainforest. There are minerals in Saharan dust, like phosphorous, that exist in commercial fertilizers, helping seed the rainforest.
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Let the planet-hunting begin!
Our Transiting Exoplanet Survey Satellite (TESS), which will scan the skies to look for planets beyond our solar system—known as exoplanets—is now in Florida to begin preparations for launch in April. Below, 10 Things to know about the many, many unknown planets out there awaiting our discovery.
We call planets in our solar system, well, planets, but the many planets we’re starting to discover outside of our solar system are called exoplanets. Basically, they’re planets that orbit another star.
Remember the major 2016 announcement that we had discovered seven planets 40 light-years away, orbiting a star called TRAPPIST-1? Those are all exoplanets. (Here’s a refresher.)
Just last month, our Kepler telescope discovered 95 new exoplanets beyond our solar system (on top of the thousands of exoplanets Kepler has discovered so far). The total known planet count beyond our solar system is now more than 3,700. The planets range in size from mostly rocky super-Earths and fluffy mini-Neptunes, to Jupiter-like giants. They include a new planet orbiting a very bright star—the brightest star ever discovered by Kepler to have a transiting planet.
How many more exoplanets are out there waiting to be discovered? TESS will monitor more than 200,000 of the nearest and brightest stars in search of transit events—periodic dips in a star’s brightness caused by planets passing in front—and is expected to find thousands of exoplanets.
Our upcoming James Webb Space Telescope, will provide important follow-up observations of some of the most promising TESS-discovered exoplanets. It will also allow scientists to study their atmospheres and, in some special cases, search for signs that these planets could support life.
TESS is scheduled to launch on a SpaceX Falcon 9 rocket from Cape Canaveral Air Force Station nearby our Kennedy Space Center in Florida, no earlier than April 16, pending range approval.
In 1995, 51 Pegasi b (also called "Dimidium") was the first exoplanet discovered orbiting a star like our Sun. This find confirmed that planets like the ones in our solar system could exist elsewhere in the universe.
A recent statistical estimate places, on average, at least one planet around every star in the galaxy. That means there could be a trillion planets in our galaxy alone, many of them in the range of Earth’s size.
Of course, our ultimate science goal is to find unmistakable signs of current life. How soon can that happen? It depends on two unknowns: the prevalence of life in the galaxy and a bit of luck. Read more about the search for life.
No need to be an astronaut. Take a trip outside our solar system with help from our Exoplanet Travel Bureau.
Read the full version of this week’s ‘10 Things to Know’ article HERE.
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On July 20, 1969 the Apollo Mission Control Center landed men on the Moon with only seconds of fuel left.
Just after the spacecraft safely touched down on the lunar surface, Charlie Duke said to the crew, “Roger, Tranquility. We copy you on the ground. You got a bunch of guys about to turn blue—we’re breathing again. Thanks a lot.” The hard work and preparation of the men who stayed back on Earth was what made John F. Kennedy’s dreams of space exploration come true.
Today, the facility these men worked in has been restored to its Apollo-era appearance, forever preserving this National Historic Landmark.
It took the restoration crew roughly six years to return the Apollo Mission Control Room to its original retro appearance. Every inch of the room was cleaned and restored by workers, enhancing the 1960s pistachio palette seen on the consoles, as well as ridding the room of 50-year-old gum stuck in places people thought would never be found. Let that be a lesson to us all.
From the artifacts sitting on the consoles to the displays projected at the front of the room, every detail has been carefully put in its proper place. Peep the American flag hanging in the back of the room—this flag went to the Moon on Apollo 17, was planted in the ground, then returned home as a souvenir. Next to the flag, a duplicate of the plaque placed on the Moon hangs on the wall.
Perhaps the only aspect of the room that wasn’t preserved was the thick stench of smoke, burnt coffee, banana peels and pizza boxes. But the ashtrays, pipes, cigarettes and coffee mugs sit in the room as reminders of the aroma. And yes, the Styrofoam cup is authentic to the ‘60s—it’s not an original artifact, but we’re certain this one will last for years to come.
In case you’re worried we didn’t get detailed enough, check the binders in the room. Each one is filled with authentic documents that would’ve been used during the Apollo missions. Some of the documents have been recreated, but many of them were copied from originals that employees had saved for 50 years.
Each console was rigged to send tubes throughout the building, often filled with important documents, but also stuffed with sandwiches and cake (all of the essentials to send men to the Moon).
Several of the surviving Apollo alumni visited mission control for the grand opening of the room at the end of June. Except for the smoke, they say the room looks just as they remember it did 50 years ago. It’s one giant leap—back in time.
This week, you can watch us salute our #Apollo50th heroes and look forward to our next giant leap for future missions to the Moon and Mars. Tune in: https://go.nasa.gov/Apollo50thEvents
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Astronauts train all over the world, including at Johnson Space Center. Here, they learn not just how to live aboard the International Space Station, but also how to conduct science in microgravity.
Astronauts serve as the eyes and hands of researchers while their experiments are in space, so they must be trained in everything from using a microscope, to maintaining the equipment for combustion experiments.
Check out this week’s episode of NASA Explorers as we go to class with an astronaut.
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Cracks growing across Antarctica’s Brunt Ice Shelf are poised to release an iceberg with an area about twice the size of New York City, (about 604 square miles). It is not yet clear how the remaining ice shelf will respond following the break, posing an uncertain future for scientific infrastructure and a human presence on the shelf that was first established in 1955.
NASA Earth Observatory image by Joshua Stevens, using Landsat data from the U.S. Geological Survey. Story by Kathryn Hansen, with image interpretation by Chris Shuman (NASA/UMBC).
The above image, from the Operational Land Imager (OLI) on Landsat 8, shows the area on January 23, 2019. The crack along the top of the image—the so-called Halloween crack—first appeared in late October 2016 and continues to grow eastward from an area known as the McDonald Ice Rumples. The rumples are due to the way ice flows over an underwater formation, where the bedrock rises high enough to reach into the underside of the ice shelf. This rocky formation impedes the flow of ice and causes pressure waves, crevasses, and rifts to form at the surface.
The more immediate concern is the rift visible in the center of the image. Previously stable for about 35 years, this crack recently started accelerating northward as fast as 4 kilometers per year.
Calving is a normal part of the life cycle of ice shelves, but the recent changes are unfamiliar in this area. The edge of the Brunt Ice Shelf has evolved slowly since Ernest Shackleton surveyed the coast in 1915, but it has been speeding up in the past several years.
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