Solar System: Things To Know This Week

Ocean Worlds Beyond Earth

We’re incredibly lucky to live on a planet drenched in water, nestled in a perfect distance from our sun and wrapped with magnetic fields keeping our atmosphere intact against harsh radiation and space weather.

We know from recent research that life can persist in the cruelest of environments here on Earth, which gives us hope to finding life thriving on other worlds. While we have yet to find life outside of Earth, we are optimistic about the possibilities, especially on other ocean worlds right here in our solar system.  

So…What’s the News?!

Two of our veteran missions are providing tantalizing new details about icy, ocean-bearing moons of Jupiter and Saturn, further enhancing the scientific interest of these and other “ocean worlds” in our solar system and beyond!

Cassini scientists announce that a form of energy for life appears to exist in Saturn’s moon Enceladus, and Hubble researchers report additional evidence of plumes erupting from Jupiter’s moon Europa.

The Two Missions: Cassini and Hubble

Cassini

Our Cassini spacecraft has found that hydrothermal vents in the ocean of Saturn’s icy moon Enceladus are producing hydrogen gas, which could potentially provide a chemical energy source for life.

Cassini discovered that this little moon of Saturn was active in 2005. The discovery that Enceladus has jets of gas and icy particles coming out of its south polar region surprised the world. Later we determined that plumes of material are coming from a global ocean under the icy crust, through large cracks known as “tiger stripes.” 

We have more evidence now – this time sampled straight from the plume itself – of hydrothermal activity, and we now know the water is chemically interacting with the rock beneath the ocean and producing the kind of chemistry that could be used by microbes IF they happened to be there.

This is the culmination of 12 years of investigations by Cassini and a capstone finding for the mission. We now know Enceladus has nearly all the ingredients needed for life as we know it.

The Cassini spacecraft made its deepest dive through the plume on Oct. 28, 2015. From previous flybys, Cassini determined that nearly 98% of the gas in the plume is water and the rest is a mixture of other molecules, including carbon dioxide, methane and ammonia. 

Cassini’s other instruments provided evidence of hydrothermal activity in the ocean. What we really wanted to know was…Is there hydrogen being produced that microbes could use to make energy? And that’s exactly what we found!

To be clear…we haven’t discovered microbes at Enceladus, but vents of this type at Earth host these kinds of life. We’re cautiously excited at the prospect that there might be something like this at Enceladus too!

Hubble

The Hubble Space Telescope has also been studying another ocean world in our solar system: Europa!

Europa is one of the four major moons of Jupiter, about the size of our own moon but very different in appearance. It’s a cold, icy world with a relatively smooth, bright surface crisscrossed with dark cracks and patches of reddish material.

What makes Europa interesting is that it’s believed to have a global ocean, underneath a thick crust of ice. In fact, it’s got about twice as much ocean as planet Earth!

In 2014, we detected evidence of intermittent water plumes on the surface of Europa, which is interesting because they may provide us with easier access to subsurface liquid water without having to drill through miles of ice.

And now, in 2016, we’ve found one particular plume candidate that appears to be at the same location that it was seen in 2014. 

This is exciting because if we can establish that a particular feature does repeat, then it is much more likely to be real and we can attempt to study and understand the processes that cause it to turn on or off. 

This plume also happens to coincide with an area where Europa is unusually warm as compared to the surrounding terrain. The plume candidates are about 30 to 60 miles (50 to 100 kilometers) in height and are well-positioned for observation, being in a relatively equatorial and well-determined location.

What Does All This Mean and What’s Next?

Hubble and Cassini are inherently different missions, but their complementary scientific discoveries, along with the synergy between our current and planned missions, will help us in finding out whether we are alone in the universe. 

Hubble will continue to observe Europa. If you’re wondering how we might be able to get more information on the Europa plume, the upcoming Europa Clipper mission will be carrying a suite of 9 instruments to investigate whether the mysterious icy moon could harbor conditions favorable for life. Europa Clipper is slated to launch in the 2020s.

This future mission will be able to study the surface of Europa in great detail and assess the habitability of this moon. Whether there’s life there or not is a question for this future mission to discover!

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A Geminid meteor streaks across the sky as the Soyuz TMA-19M spacecraft is rolled out by train to the launch pad at the Baikonur Cosmodrome on Sunday, Dec. 13, 2015, in Kazakhstan. Credit: NASA/Joel Kowsky

Make a Wish! How to See the Geminid Meteor Shower

Every December, we have a chance to see one of our favorite meteor showers – the Geminids. To help you prepare, we’ve answered some of your most commonly asked questions. Happy viewing, stargazers!

These radar images of near-Earth object 3200 Phaethon were generated by astronomers at the National Science Foundation's Arecibo Observatory on Dec. 17, 2017. Observations of Phaethon were conducted at Arecibo from Dec. 15 through 19, 2017. At time of closest approach on Dec. 16 at 3 p.m. PST (6 p.m. EST, 2300 UTC), the asteroid was about 6.4 million miles (10.3 million kilometers) away, or about 27 times the distance from Earth to the Moon. Credit: Arecibo Observatory/NASA/NSF

What are the Geminids?

The Geminids are caused by debris from a celestial object known as 3200 Phaethon striking Earth’s atmosphere. Phaethon’s origin is the subject of some debate. Some astronomers consider it to be an extinct comet, based on observations showing some small amount of material leaving its surface. Others argue that it has to be an asteroid because of its orbit and its similarity to the main-belt asteroid Pallas.

All meteors appear to come from the same place in the sky, which is called the radiant. The Geminids appear to radiate from a point in the constellation Gemini, hence the name “Geminids.” The graphic shows the radiants of 388 meteors with speeds of 35 km/s observed by the NASA Fireball Network in December 2020. All the radiants are in Gemini, which means they belong to the Geminid shower. Credit: NASA

Why are they called the Geminids?

All meteors associated with a shower have similar orbits, and they all appear to come from the same place in the sky, which is called the radiant. The Geminids appear to radiate from a point in the constellation Gemini, hence the name “Geminids.”

A Geminid streaks across the sky in this photo from December 2019. Credit: NASA

When is the best time to view them?

The Geminid meteor shower is active for much of December, but the peak will occur during the night of Dec. 13 into the morning of Dec. 14, 2023. Meteor rates in rural areas can be upwards of one per minute this year with minimal moonlight to interfere.

What do I need to see them?

As with all meteor showers, all you need is a clear sky, darkness, a bit of patience, and perhaps warm outerwear and blankets for this one. You don’t need to look in any particular direction, as meteors can generally be seen all over the sky. If you want to take photographs, check out these helpful tips.

An infographic based on 2019’s meteor camera data for the Geminids. Credit: NASA

Do you have any advice to help me see the Geminids better?

Find the darkest place you can and give your eyes about 30 minutes to adapt to the dark. Avoid looking at your cell phone, as it will disrupt your night vision. Lie flat on your back and look straight up, taking in as much sky as possible.

A Geminid streaks across the sky in this photo from December 2011. Credit: NASA

What will the meteors look like?

According to Bill Cooke, lead for the Meteoroid Environment Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama, “Most meteors appear to be colorless or white, however the Geminids appear with a greenish hue. They’re pretty meteors!” Depending on the meteor’s chemical composition, the meteor will emit different colors when burned in the Earth’s atmosphere. Oxygen, magnesium, and nickel usually produce green.

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2016: This Year at NASA!

As 2016 comes to a close and prospects of the new year loom before us, we take a moment to look back at what we’ve accomplished and how it will set us ahead in the year to come.

2016 marked record-breaking progress in our exploration activities. We advanced the capabilities needed to travel farther into the solar system while increasing observations of our home and the universe, learning more about how to continuously live and work in space and, or course, inspiring the next generation of leaders to take up our journey to Mars and make their own discoveries.

Here are a few of the top NASA stories of 2016...

International Space Station

One Year Mission…completed!

NASA astronaut Scott Kelly and Russian cosmonaut Mikhail Kornienko returned to Earth after spending a year in space. Testing the limits of human research, findings from their One Year Mission will help send humans farther into space than ever before.

Commercial Resupply

Commercial partners Orbital ATK and SpaceX delivered tons (yes literally tons) of cargo to the International Space Station. This cargo supported hundreds of science experiments and technology demonstrations crucial to our journey to Mars.

Mars

Expandable Habitats

The Bigelow Expandable Activity Module (BEAM) was one of the technology demonstrations delivered to the space station in April. Expandable habitats greatly decrease the amount of transport volume for future space missions.

Booster Test Firing

In June, a booster for our Space Launch System (SLS) rocket successfully fired up. It will be used on the first un-crewed test flight of SLS with the Orion spacecraft in 2018. Eventually, this rocket and capsule will carry humans into deep space and one day…Mars!

InSight

This year we updated the milestones for our InSight mission with a new target launch window beginning in May 2018. This mission will place a fixed science outpost on Mars to study its deep interior. Findings and research from this project will address one of the most fundamental questions we have about the planetary and solar system science…how in the world did these rocky planets form?

Solar System and Beyond

Juno

On July 4, our Juno spacecraft arrived at Jupiter. This mission is working to improve our understanding of the solar system’s beginnings by revealing the origin and evolution of Jupiter.

OSIRIS-REx

In September, we launched our OSIRIS-REx spacecraft…which is America’s first-ever asteroid sample return mission. This spacecraft will travel to a near-Earth asteroid, called Bennu, where it will collect a sample to bring back to Earth for study.

James Webb Space Telescope

In February, the final primary mirror segment of our James Webb Space Telescope was installed. This will be the world’s most powerful space telescope ever, and is scheduled to launch in 2018. Webb will look back in time, studying the very first galaxies ever formed.

Kepler

In May, our Kepler mission verified the discovery of 1,284 new planets. Kepler is the first NASA mission to find potentially habitably Earth-sized planets.

Earth Right Now

Earth Expeditions

Our efforts to improve life on Earth included an announcement in March of a collection of Earth Science field campaigns to study how our planet is changing. These Earth Expeditions sent scientists to places like the edge of the Greenland ice sheet to the coral reefs of the South Pacific to delve into challenging questions about how our planet is changing…and what impacts humans are having on it.

Small Satellites

In November, we announced plans to launch six next-generation Earth-observing small satellite missions. One uses GPS signals to measure wind in hurricanes and tropical systems in greater detail than ever before.

Aeronautics Research

Our efforts in 2016 to make air travel cleaner, safer and quieter included new technology to improve safety and efficiency of aircraft arrivals, departures and service operations.

X-Plane

In June, we highlighted our first designation of an experimental airplane, or X-plane, in a decade. It will test new electric propulsion technology.

Drone Technolgy

In October, we evaluated a system being developed for the Federal Aviation Administration to safely manage drone air traffic.

Technology

Electric Propulsion

We selected Aerojet Rocketdyne to develop and advanced electric propulsion system to enable deep space travel to an asteroid and Mars.

Spinoffs

Our technology transfer program continued to share the agency’s technology with industry, academia and other government agencies at an unprecedented rate.

Centennial Challenges

Our Centennial Challenges program conducted four competition events in 2016 to spark innovation and enable solutions in important technology focus areas.

Watch the full video recap of ‘This Year @NASA’ here:

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Extreme Science: Launching Sounding Rockets from The Arctic

This winter, our scientists and engineers traveled to the world's northernmost civilian town to launch rockets equipped with cutting-edge scientific instruments.

This is the beginning of a 14-month-long campaign to study a particular region of Earth's magnetic field — which means launching near the poles. What's it like to launch a science rocket in these extreme conditions?

Our planet is protected by a natural magnetic field that deflects most of the particles that flow out from the Sun — the solar wind — away from our atmosphere. But near the north and south poles, two oddities in Earth's magnetic field funnel these solar particles directly into our atmosphere. These regions are the polar cusps, and it turns out they're the ideal spot for studying how our atmosphere interacts with space.

The scientists of the Grand Challenge Initiative — Cusp are using sounding rockets to do their research. Sounding rockets are suborbital rockets that launch to a few hundred miles in altitude, spending a few minutes in space before falling back to Earth. That means sounding rockets can carry sensitive instruments above our atmosphere to study the Sun, other stars and even distant galaxies.

They also fly directly through some of the most interesting regions of Earth's atmosphere, and that's what scientists are taking advantage of for their Grand Challenge experiments.

One of the ideal rocket ranges for cusp science is in Ny-Ålesund, Svalbard, off the coast of Norway and within the Arctic circle. Because of its far northward position, each morning Svalbard passes directly under Earth's magnetic cusp.

But launching in this extreme, remote environment puts another set of challenges on the mission teams. These launches need to happen during the winter, when Svalbard experiences 24/7 darkness because of Earth's axial tilt. The launch teams can go months without seeing the Sun.

Like for all rocket launches, the science teams have to wait for the right weather conditions to launch. Because they're studying upper atmospheric processes, some of these teams also have to wait for other science conditions, like active auroras. Auroras are created when charged particles collide with Earth’s atmosphere — often triggered by solar storms or changes in the solar wind — and they're related to many of the upper-atmospheric processes that scientists want to study near the magnetic cusp.

But even before launch, the extreme conditions make launching rockets a tricky business — it's so cold that the rockets must be encased in styrofoam before launch to protect them from the low temperatures and potential precipitation.

When all is finally ready, an alarm sounds throughout the town of Ny-Ålesund to alert residents to the impending launch. And then it's up, up and away! This photo shows the launch of the twin VISIONS-2 sounding rockets on Dec. 7, 2018 from Ny-Ålesund.

These rockets are designed to break up during flight — so after launch comes clean-up. The launch teams track where debris lands so that they can retrieve the pieces later.

The next launch of the Grand Challenge Initiative is AZURE, launching from Andøya Space Center in Norway in March 2019.

 For even more about what it's like to launch science rockets in extreme conditions, check out one scientist's notes from the field: https://go.nasa.gov/2QzyjR4

For updates on the Grand Challenge Initiative and other sounding rocket flights, visit nasa.gov/soundingrockets or follow along with NASA Wallops and NASA heliophysics on Twitter and Facebook.

@NASA_Wallops | NASA’s Wallops Flight Facility | @NASASun | NASA Sun Science

10 Times More Galaxies!

The universe suddenly looks a lot more crowded…

We already estimated that there were about 100 billion galaxies in the observable universe, but new research shows that this estimate is at least 10 times too low!

First, what is the observable universe? Well, it is the most distant part of the universe we can see from Earth because, in theory, the light from these objects have had time to reach Earth.

In a new study using surveys taken by the Hubble Space Telescope and other observatories, astronomers came to the surprising conclusion that there are at least 10 times more galaxies in the observable universe than previously thought. This places the universe’s estimated population at, minimally, 2 trillion galaxies!

The results have clear implications for galaxy formation, and also helps shed light on an ancient astronomical paradox – why is the sky dark at night?

Most of these newly discovered galaxies were relatively small and faint, with masses similar to those of the satellite galaxies surrounding the Milky Way.

Using deep-space images from the Hubble Space Telescope and other observatories, astronomers converted the images into 3-D, in order to make accurate measurements of the number of galaxies at different epochs in the universe’s history.

In addition, they used new mathematical models, which allowed them to infer the existence of galaxies that the current generation of telescopes cannot observe. This led to the surprising conclusion that in order for the numbers of galaxies we now see and their masses to add up, there must be a further 90% of galaxies in the observable universe that are too faint and too far away to be seen with present-day telescopes.

The myriad small faint galaxies from the early universe merged over time into the larger galaxies we can now observe.

That means that over 90% of the galaxies in the universe have yet to be studied! In the near future, the James Webb Space Telescope will be able to study these ultra-faint galaxies and give us more information about their existence.

So back to the question…Why is the sky dark at night if the universe contains an infinity of stars? Researchers came to the conclusion that indeed there actually is such an abundance of galaxies that, in principle, every patch in the sky contains part of a galaxy.

However, starlight from the galaxies is invisible to the human eye and most modern telescopes due to other known factors that reduce visible and ultraviolet light in the universe. Those factors are the reddening of light due to the expansion of space, the universe’s dynamic nature, and the absorption of light by intergalactic dust and gas. All combined, this keeps the night sky dark to our vision.

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Cool Space GIFs from the Internet

There’s a lot of historical and archived space footage on the internet and we’re excited to see that the public (you!) have taken it to create many other products that teach people about exploration, space and our universe. Among those products are GIFs. Those quick videos that help you express what you’re trying to say via text, or make you laugh while surfing the web.

Are space GIFs the new cat videos of the internet? Don’t know, but we sure do like them!

Here are a few neat space GIFs from the internet…

This GIF of the Cat Eye Nebula shows it in various wavelengths…

Followed by a GIF of a cat in space…floating in front of the Antennae galaxies...

One time, a frog actually photobombed the launch of our LADEE spacecraft…someone on the internet gave him a parachute…

Want to see what it’s like to play soccer in space? There’s a GIF for that…

There are also some beautiful GIFs looking through the Cupola window on the International Space Station…

This warped footage from the International Space Station gives us ride around the Earth…

While this one encourages us to explore the unknown...

When our New Horizons spacecraft flew by dwarf planet Pluto in 2015, the internet couldn’t get enough of the Pluto GIFs...

NASA GIFs

Want to dive into a black hole of other fun space GIFs? Check out our GIPHY page HERE.

Want to use our GIFs?! You can! Our GIFs are accessible directly from the Twitter app. Just tap or click the GIF button in the Twitter tool bar, search for NASAGIF, and all NASA GIFs will appear for sharing and tweeting. Enjoy!

GIF Sources

Cat Eye GIF: https://giphy.com/gifs/astronomy-cZpDWjSlKjWPm Cat GIF: https://giphy.com/gifs/cat-HopYL0SamcCli Frog GIF: https://giphy.com/gifs/nasa-photo-rocket-NOsCSDT2rUgfK Soccer GIF: https://giphy.com/gifs/yahoo-astronauts-zerogravity-QF1ZomA11zofC Cupola 1 GIF: https://giphy.com/gifs/nasa-Mcoxp6TgvQm6A Cupola 2 GIF: https://giphy.com/gifs/timelapse-space-11f3o8D2rQWzCM Earth GIF: http://giphy.com/gifs/earth-milky-way-international-space-station-ONC6WgECm5KEw Explore GIF: https://giphy.com/gifs/text-timelapse-lapse-Vj7gwAvhgsDYs Pluto 1 GIF: https://giphy.com/gifs/l46CzjUnYFfeMXiNO Pluto 2 GIF: https://giphy.com/gifs/pluto-dbV1LkFWWob84

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How to Safely Watch the Aug. 21 Solar Eclipse

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!

Photographing the 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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Solar System: Things to Know This Week

Our solar system is a jewel box filled with a glittering variety of beautiful worlds--and not all of them are planets. This week, we present our solar system's most marvelous moons.

1. Weird Weather: Titan

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/

2. Icy Giant: Ganymede

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

3. Retrograde Rebel: Triton

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

4. Cold Faithful: Enceladus

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/

5. Volcano World: Io

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

6. Yin and Yang Moon: Iapetus

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

7. A Double World: Charon and Pluto

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

8. "Death Star" Moon: Mimas

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

9. Don't Be Afraid, It's Just Phobos

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

10. The Moon We Know Best

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

Discover more lists of 10 things to know about our solar system HERE.

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This Week @ NASA--April 14, 2017

Cassini and the Hubble Space Telescope, two of our long-running missions, are providing new details about the ocean-bearing moons of Jupiter and Saturn. Hubble's monitoring of plume activity on Europa and Cassini's long-term investigation of Enceladus are laying the groundwork for our Europa Clipper mission, slated for launch in the 2020s. Also, Shane Kimbrough returns home after 171 days aboard the Space Station, celebrating the first Space Shuttle mission and more!

Ocean Worlds

Our two long-running missions, Cassini and the Hubble Space Telescope,  are providing new details about “ocean worlds,” specifically the moons of Jupiter and Saturn. 

The details – discussed during our April 13 science briefing – included the announcement by the Cassini mission team that a key ingredient for life has been found in the ocean on Saturn's moon Enceladus. 

Meanwhile, in 2016 Hubble spotted a likely plume erupting from Jupiter’s moon Europa at the same location as one in 2014, reenforcing the notion of liquid water erupting from the moon.

These observations are laying the groundwork for our Europa Clipper mission, planned for launch in the 2020s.

Welcome Home, Shane!

Shane Kimbrough and his Russian colleagues returned home safely after spending 173 days in space during his mission to the International Space Station.

Meet the Next Crew to Launch to the Station

Meanwhile, astronaut Peggy Whitson assumed command of the orbital platform and she and her crew await the next occupants of the station, which is slated to launch April 20.

Student Launch Initiative

We’ve announced the preliminary winner of the 2017 Student Launch Initiative that took place near our Marshall Space Fight Center, The final selection will be announced in May. The students showcased advanced aerospace and engineering skills by launching their respective model rockets to an altitude of one mile, deploying an automated parachute and safely landing them for re-use.

Langley’s New Lab

On April 11, a ground-breaking ceremony took place at our Langley Research Center for the new Systems Measurement Laboratory. The 175,000 square-foot facility will be a world class lab for the research and development of new measurement concepts, technologies and systems that will enable the to meet its missions in space explorations, science and aeronautics.

Yuri’s Night

Space fans celebrated Yuri’s Night on April 12 at the Air and Space Museum and around the world. On April 12, 1961, cosmonaut Yuri Gagrin became the first person to orbit the Earth.

Celebrating the First Space Shuttle Launch

On April 12, 1981, John Young and Bob Crippin launched aboard Space Shuttle Columbia on STS-1 a two-day mission, the first of the Shuttle Program’s 30-year history.

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Holiday Lights...In Space

Holiday lights don’t come in one shape or size, just like they don’t only appear on Earth. Take a look at a few of these celestial light shows:

1. Galactic Wreath of Lights

This festive image captured by our Hubble Space Telescope resembles a holiday wreath made of sparkling lights. This galactic wreath is located around 6,500 light-years away.

2. Red and Green Aurora

This beautiful aurora was captured by Astronaut Scott Kelly while aboard the International Space Station. He shared it with his Twitter followers on June, 22 during his Year in Space mission. This image of Earth’s aurora is festive with its red and green lights.

3. Holiday Snow Angel

Our Hubble Space Telescope captured this stunning image of what looks like a soaring, celestial snow angel. This picture shows a bipolar star-forming region, called Sharpless 2-106.

4. Cosmic Holiday Ornament

This festive-looking nearby planetary nebula resembles a glass-blown holiday ornament with a glowing ribbon entwined. This cosmic decoration was spotted by our Hubble Space Telescope.

5. Holiday Lights on the Sun

Even the sun gets festive with it’s festive looking solar flares. This significant flare was seen by our Solar Dynamics Observatory (SOHO) on Dec. 19, 2014. Even though solar flares are powerful bursts of radiation, it cannot pas through Earth’s atmosphere to physically affect humans on the ground. That said, when intense enough, the radiation can disturb the atmosphere in the layer where GPS and communications signals travel.

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