Ten Years After Katrina

@dasandwichguy: What precautions do you take to curb the effects of weightlessness?

Chandra X-Ray Observatory, We Appreciate You

On July 23, 1999, the Space Shuttle Columbia blasted off from the Kennedy Space Center carrying the Chandra X-ray Observatory. In the two decades that have passed, Chandra’s powerful and unique X-ray eyes have contributed to a revolution in our understanding of the cosmos.

Since its launch 20 years ago, Chandra's unrivaled X-ray vision has changed the way we see the universe.

Chandra has captured galaxy clusters – the largest gravitationally bound objects in the universe – in the process of merging.

Chandra has shown us the powerful wind and shock fronts that rumble through star-forming systems.

And a star school, so to speak -- home to thousands of the Milky Way's biggest and brightest.

Carl Sagan said, "We are made of star-stuff." It's true. Most of the elements necessary for life are forged inside stars and blasted into interstellar space by supernovas. Chandra has tracked them.

Thank you Chandra X-Ray! To more adventures with you!

Check out Chandra’s 20th anniversary page to see how they are celebrating.

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Solar System 10 Things: Dust in the Wind, on Mars & Well Beyond

To most of us, dust is an annoyance. Something to be cleaned up, washed off or wiped away. But these tiny particles that float about and settle on surfaces play an important role in a variety of processes on Earth and across the solar system. So put away that feather duster for a few moments, as we share with you 10 things to know about dust.

1. "Dust" Doesn't Mean Dirty, it Means Tiny

Not all of what we call "dust" is made of the same stuff. Dust in your home generally consists of things like particles of sand and soil, pollen, dander (dead skin cells), pet hair, furniture fibers and cosmetics. But in space, dust can refer to any sort of fine particles smaller than a grain of sand. Dust is most commonly bits of rock or carbon-rich, soot-like grains, but in the outer solar system, far from the Sun's warmth, it's also common to find tiny grains of ice as well. Galaxies, including our Milky Way, contain giant clouds of fine dust that are light years across – the ingredients for future generations of planetary systems like ours.

2. Some Are Big, Some Are Small (and Big Ones Tend to Fall)

Dust grains come in a range of sizes, which affects their properties. Particles can be extremely tiny, from only a few tens of nanometers (mere billionths of a meter) wide, to nearly a millimeter wide. As you might expect, smaller dust grains are more easily lifted and pushed around, be it by winds or magnetic, electrical and gravitational forces. Even the gentle pressure of sunlight is enough to move smaller dust particles in space. Bigger particles tend to be heavier, and they settle out more easily under the influence of gravity.

For example, on Earth, powerful winds can whip up large amounts of dust into the atmosphere. While the smaller grains can be transported over great distances, the heavier particles generally sink back to the ground near their source. On Saturn's moon Enceladus, jets of icy dust particles spray hundreds of miles up from the surface; the bigger particles are lofted only a few tens of miles (or kilometers) and fall back to the ground, while the finest particles escape the moon's gravity and go into orbit around Saturn to create the planet's E ring.

3. It’s EVERYWHERE

Generally speaking, the space between the planets is pretty empty, but not completely so. Particles cast off by comets and ground up bits of asteroids are found throughout the solar system. Take any volume of space half a mile (1 kilometer) on a side, and you’d average a few micron-sized particles (grains the thickness of a red blood cell).

Dust in the solar system was a lot more abundant in the past. There was a huge amount of it present as the planets began to coalesce out of the disk of material that formed the Sun. In fact, motes of dust gently sticking together were likely some of the earliest seeds of the planet-building process. But where did all that dust come from, originally? Some of it comes from stars like our Sun, which blow off their outer layers in their later years. But lots of it also comes from exploding stars, which blast huge amounts of dust and gas into space when they go boom.

4. From a Certain Point of View

Dust is easier to see from certain viewing angles. Tiny particles scatter light depending on how big their grains are. Larger particles tend to scatter light back in the direction from which it came, while very tiny particles tend to scatter light forward, more or less in the direction it was already going. Because of this property, structures like planetary rings made of the finest dusty particles are best viewed with the Sun illuminating them from behind. For example, Jupiter's rings were only discovered after the Voyager 1 spacecraft passed by the planet, where it could look back and see them backlit by the Sun. You can see the same effect looking through a dusty windshield at sunset; when you face toward the Sun, the dust becomes much more apparent.

5. Dust Storms Are Common on Mars

Local dust storms occur frequently on Mars, and occasionally grow or merge to form regional systems, particularly during the southern spring and summer, when Mars is closest to the Sun. On rare occasions, regional storms produce a dust haze that encircles the planet and obscures surface features beneath. A few of these events may become truly global storms, such as one in 1971 that greeted the first spacecraft to orbit Mars, our Mariner 9. In mid-2018, a global dust storm enshrouded Mars, hiding much of the Red Planet's surface from view and threatening the continued operation of our uber long-lived Opportunity rover. We’ve also seen global dust storms in 1977, 1982, 1994, 2001 and 2007.

Dust storms will likely present challenges for future astronauts on the Red Planet. Although the force of the wind on Mars is not as strong as portrayed in an early scene in the movie "The Martian," dust lofted during storms could affect electronics and health, as well as the availability of solar energy.

6. Dust From the Sahara Goes Global

Earth's largest, hottest desert is connected to its largest tropical rain forest by dust. The Sahara Desert is a near-uninterrupted brown band of sand and scrub across the northern third of Africa. The Amazon rain forest is a dense green mass of humid jungle that covers northeast South America. But after strong winds sweep across the Sahara, a dusty cloud rises in the air, stretches between the continents, and ties together the desert and the jungle.

This trans-continental journey of dust is important because of what is in the dust. Specifically, the dust picked up from the Bodélé Depression in Chad -- an ancient lake bed where minerals composed of dead microorganisms are loaded with phosphorus. Phosphorus is an essential nutrient for plant proteins and growth, which the nutrient-poor Amazon rain forest depends on in order to flourish.

7. Rings and Things

The rings of the giant planets contain a variety of different dusty materials. Jupiter's rings are made of fine rock dust. Saturn's rings are mostly pure water ice, with a sprinkling of other materials. (Side note about Saturn's rings: While most of the particles are boulder-sized, there's also lots of fine dust, and some of the fainter rings are mostly dust with few or no large particles.) Dust in the rings of Uranus and Neptune is made of dark, sooty material, probably rich in carbon.

Over time, dust gets removed from ring systems due to a variety of processes. For example, some of the dust falls into the planet's atmosphere, while some gets swept up by the planets' magnetic fields, and other dust settles onto the surfaces of the moons and other ring particles. Larger particles eventually form new moons or get ground down and mixed with incoming material. This means rings can change a lot over time, so understanding how the tiniest ring particles are being moved about has bearing on the history, origins and future of the rings.

8. Moon Dust is Clingy and Might Make You Sick

So, dust is kind of a thing on the Moon. When the Apollo astronauts visited the Moon, they found that lunar dust quickly coated their spacesuits and was difficult to remove. It was quite abrasive, causing wear on their spacesuit fabrics, seals and faceplates. It also clogged mechanisms like the joints in spacesuit limbs, and interfered with fasteners like zippers and Velcro. The astronauts also noted that it had a distinctive, pungent odor, not unlike gunpowder, and it was an eye and lung irritant.

Many of these properties apparently can be explained by the fact that lunar dust particles are quite rough and jagged. While dust particles on Earth get tumbled and ground by the wind into smoother shapes, this sort of weathering doesn't happen so much on the Moon. The roughness of Moon dust grains makes it very easy for them to cling to surfaces and scratch them up. It also means they're not the sort of thing you would want to inhale, as their jagged edges could damage delicate tissues in the lung.

9. Dust is What Makes Comets So Pretty

Most comets are basically clods of dust, rock and ice. They spend most of their time far from the Sun, out in the refrigerated depths of the outer solar system, where they're peacefully dormant. But when their orbits carry them closer to the Sun -- that is, roughly inside the orbit of Jupiter -- comets wake up. In response to warming temperatures, the ices on and near their surfaces begin to turn into gases, expanding outward and away from the comet, and creating focused jets of material in places. Dust gets carried away by this rapidly expanding gas, creating a fuzzy cloud around the comet's nucleus called a coma. Some of the dust also is drawn out into a long trail -- the comet's tail.

10. We're Not the Only Ones Who're So Dusty

Dust in our solar system is continually replenished by comets whizzing past the Sun and the occasional asteroid collision, and it's always being moved about, thanks to a variety of factors like the gravity of the planets and even the pressure of sunlight. Some of it even gets ejected from our solar system altogether.

With telescopes, we also observe dusty debris disks around many other stars. As in our own system, the dust in such disks should evolve over time, settling on planetary surfaces or being ejected, and this means the dust must be replenished in those star systems as well. So studying the dust in our planetary environs can tell us about other systems, and vice versa. Grains of dust from other planetary systems also pass through our neighborhood -- a few spacecraft have actually captured and analyzed some them -- offering us a tangible way to study material from other stars.

Read the full version of ‘Solar System: 10 Things to Know’ article HERE. 

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Spilling the Sun’s Secrets

You might think you know the Sun: It looks quiet and unchanging. But the Sun has secrets that scientists have been trying to figure out for decades.  

One of our new missions — Parker Solar Probe — is aiming to spill the Sun’s secrets and shed new light on our neighbor in the sky.

Even though it’s 93 million miles away, the Sun is our nearest and best laboratory for understanding the inner workings of stars everywhere. We’ve been spying on the Sun with a fleet of satellites for decades, but we’ve never gotten a close-up of our nearest star.

This summer, Parker Solar Probe is launching into an orbit that will take it far closer to the Sun than any instrument has ever gone. It will fly close enough to touch the Sun, sweeping through the outer atmosphere — the corona — 4 million miles above the surface.

This unique viewpoint will do a lot more than provide gossip on the Sun. Scientists will take measurements to help us understand the Sun’s secrets — including those that can affect Earth.

Parker Solar Probe is equipped with four suites of instruments that will take detailed measurements from within the Sun's corona, all protected by a special heat shield to keep them safe and cool in the Sun's ferocious heat.

The corona itself is home to one of the Sun’s biggest secrets: The corona's mysteriously high temperatures. The corona, a region of the Sun’s outer atmosphere, is hundreds of times hotter than the surface below. That's counterintuitive, like if you got warmer the farther you walked from a campfire, but scientists don’t yet know why that's the case.

Some think the excess heat is delivered by electromagnetic waves called Alfvén waves moving outwards from the Sun’s surface. Others think it might be due to nanoflares — bomb-like explosions that occur on the Sun’s surface, similar to the flares we can see with telescopes from Earth, but smaller and much more frequent. Either way, Parker Solar Probe's measurements direct from this region itself should help us pin down what's really going on.

We also want to find out what exactly accelerates the solar wind — the Sun's constant outpouring of material that rushes out at a million miles per hour and fills the Solar System far past the orbit of Pluto. The solar wind can cause space weather when it reaches Earth — triggering things like the aurora, satellite problems, and even, in rare cases, power outages.

We know where the solar wind comes from, and that it gains its speed somewhere in the corona, but the exact mechanism of that acceleration is a mystery. By sampling particles directly at the scene of the crime, scientists hope Parker Solar Probe can help crack this case.

Parker Solar Probe should also help us uncover the secrets of some of the fastest particles from the Sun. Solar energetic particles can reach speeds of more than 50% the speed of light, and they can interfere with satellites with little warning because of how fast they move. We don't know how they get so fast — but it's another mystery that should be solved with Parker Solar Probe on the case.  

Parker Solar Probe launches summer 2018 on a seven-year mission to touch the Sun. Keep up with the latest on the Sun at @NASASun on Twitter, and follow along with Parker Solar Probe's last steps to launch at nasa.gov/solarprobe.

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The James Webb Space Telescope: A Story of Art & Science

Artists of all kinds were invited to apply for the chance to visit our Goddard Space Flight Center to be inspired by the giant, golden, fully-assembled James Webb Space Telescope mirror.

Art/Photo Credit: Jedidiah Dore

Webb has a mirror that is nearly 22 feet high and (to optimize it for infrared observations) is covered in a microscopic layer of actual gold.

Art/Photo Credit: Susan Lin

Because of Webb’s visually striking appearance, the project hosted a special viewing event on Wednesday, Nov. 2, 2016.

Photo Credit: Maggie Masetti

There was an overwhelming response to the event invitation and ultimately twenty-four people were selected to attend. They represented a broad range of artistic media and styles, including: watercolor, 3D printed sculpture, silk screening, acrylics, sumi-e (East Asian brush technique), comics, letterpress, woodwork, metalwork, jewelry making, fiber art, ink, mural painting, kite-making, tattooing, scientific illustration, poetry, songwriting, and video making.

Art/Photo Credit: Sue Reno

Project scientists and engineers spoke with visitors to give context to what they were seeing and explain why Webb is an engineering marvel, and how it will change our view of the universe. 

Among other things, Webb will see the first stars and galaxies that formed in the early universe and help us to better understand how planetary systems form and evolve. It will help us answer questions about who we, as humans, are and where we came from.

Art Credit: Jessica Lee Photo Credit: Maggie Masetti

The artists spent several hours sitting right in front of the telescope, where they sketched, painted, took photos and even filmed a music video.

Art Credit: Joanna Barnum Photo Credit: Maggie Masetti

While some of the pieces of art are finished, most of the artists went home with their heads full of ideas and sketchbooks full of notes. Stay tuned for more info on where you can see their final works displayed!

Art/Photo Credit: Susan Lin

Finished art from the event continues to be added HERE.

The James Webb Space Telescope is finishing environmental testing at our Goddard Space Flight Center in Greenbelt, Maryland. Next it will head to our Johnson Space Center in Houston for an end-to-end test at cryogenic temperatures. After that, it goes to Northrop Grumman to be mated with the giant tennis court-sized sunshield and the spacecraft bus.  The observatory will launch in October of 2018 from a European Space Agency (ESA) launch site in French Guiana, aboard an Ariane 5 rocket.  Webb is a collaboration of NASA, ESA, and the Canadian Space Agency (CSA).

Follow Webb on Facebook, Twitter and Instagram.

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10 Ground-breaking Earth Satellite Images from 2018

In 2018, our satellites captured beautiful imagery from throughout the solar system and beyond. However, some of our favorite visualizations are of this very planet. While this list is by no means exhaustive, it does capture some Earth satellite images from this year that are both visually striking as well as scientifically informative. This list also represents a broad variety of Earth’s features, as well as satellite instrumentation. Take a journey with our eyes in the sky!

10. Hurricane Florence

Before making landfall, Hurricane Florence churned in the Atlantic for a full two weeks — making it among the longest-lived cyclones of the 2018 season. When it finally did hit land on Sep. 14, the storm devastated the southeastern U.S. coast with intense winds, torrential rains and severe flooding.

This natural-color image was acquired by MODIS on the Terra Satellite on Sep. 12, 2018. 

Images like this, as well as other satellite information, were used to anticipate the impact of the storm. Our Disasters Program created flood proxy maps that were shared with the Federal Emergency Management Agency (FEMA) and the National Guard to estimate how many and which communities would be most affected by the storm, in order to help prepare recovery efforts ahead of time.

9. Australia’s Lake Eyre Basin

The Lake Eyre Basin covers one-sixth of Australia and is one of the world’s largest internally draining river systems. However, the rivers supported by this system are ephemeral, meaning that they only run for short periods of time following unpredictable rain — the rest of the time, the Basin is a dry, arid desert.

However, when the heavy rain comes, the basin erupts in an explosion of green. In this false-color image captured by the Operational Land Imager (OLI) on Landsat 8 on Apr. 25, 2018, you can see how the vegetation completely envelops the spaces where the water has receded. (Flood water is indicated by light blue, and vegetation is indicated by light green.)

Satellites are an excellent tool for tracking greening events that are followed by flooding. These events offer opportunities for predictive tools as well as recreation.

8. Alaska’s Chukchi Sea 

A Monet painting comes to life as the Chukchi Sea swirls with microscopic marine algae.

This image was captured off the Alaskan coast by OLI on Landsat 8 on Jun. 18, 2018. After the Arctic sea ice breaks up each spring, the nutrient-rich Bering Sea water mixes with the nutrient-poor Alaskan coastal water. Each type of water brings with it a different type of phytoplankton and the surface waters have just enough light for the algae to populate and flourish. The result is these mesmerizing patterns of turquoise and green.

This image represents one piece of much larger, incredibly complex ecosystem. While one would not normally associate the breaking up of sea ice with phytoplankton blooms, it is an intricate process of the phytoplankton life cycle. The size of the blooms have varied greatly from year to year, and experts are unsure why. Images like these can help scientists track the development of these blooms and link it to other environmental changes.

7. Hawaii’s Kilauea 

Sometimes fresh lava is best viewed in infrared.

This false-color image of Kilauea, captured by OLI on Landsat 8 on May 23, 2018, shows the infrared signal emitted by lava flowing toward the sea. The purple areas surrounding the glowing lava are clouds lit from below, indicating that this image was taken through a break in the clouds.

The Puʻu ʻŌʻō Kupaianaha eruption has been continuously spewing red-hot lava since 1983, making it the longest eruption at Kilauea in recorded history. However, new fissures opened up this year that forced many to evacuate the area. Hawaii’s largest lake evaporated in hours and hundreds of homes were destroyed in Vacationland and Kapoho. 

Imagery, seismometers and ground-based instruments were used to track the underground movement of magma. Infrared imagery can be incredibly helpful in disasters like this when you to view data that cannot be observed with the naked eye. 

6. California’s Woolsey Burn Scar

Nothing quite encapsulates the destruction of a wildfire like a photo from outer space.

This image of the Woolsey Fire aftermath in Southern California was captured on Nov. 18, 2018 by the Advanced Spaceborned Thermal Emission and Reflection Radiometer (ASTER) on the Terra satellite. This false-color infrared image has been enhanced to clearly show the burned vegetation (indicated by brown) and the vegetation that survived unscathed (indicated by green).

The Woolsey Fire clearly left its mark, with almost 152 square miles (394 square km) and 88% of the Santa Monica Mountains National Recreation Area badly burned. Images like this one can assist fire managers in the area plan for recovery. 

5. Bangladesh’s Padma River

As the years go by, the Padma River grows and shrinks, twists and turns. It never has a fixed shape, and as a result, thousands of people must regularly adapt to the constant changes in the river’s 75-mile (130-km) shoreline.

This image captured on Jan. 20, 2018 by OLI on Landsat 8 depicts one of the major rivers of Bangladesh. For thirty years, scientists have been tracking the erosion of the river with satellite imagery. Combinations of shortwave infrared, near infrared, and visible light are used to detect differences year-to-year in width, depth, and shape of the river. Sometimes the river splits off, but then rejoins again later. These patterns are created by the river carrying and depositing sediment, shaping the curves of the path of water.

Monitoring the Padma River is going to become especially important as a new bridge development project advances in the Char Janajat area. Although the bridge will most certainly help shorten travel times for citizens, nobody is quite sure how the river erosion might affect the construction and vice versa. 

4. Alaska’s Yakutat Glacier 

It’s hard to believe that Harlequin Lake was once all dry land — but it only started to form once Yakutat Glacier started melting. The lake appeared at the beginning of the twentieth century, and has been growing rapidly ever since.

In this hauntingly beautiful image, captured on Sep. 21 2018 by OLI on Landsat 8, the effect of climate change is apparent — especially when compared to earlier images of the region.

Unless the climate warming starts to reverse very soon — which scientists consider very unlikely — Yakutat could be gone as soon as 2070.

3. South Africa’s Theewaterskloof

Cape Town is a seaside city planted on the tip of South Africa. It’s a city known for its beaches and biodiversity — it also almost became known as the first major city to officially run out of water.

This image of Cape Town’s largest reservoir — Theewaterskloof — was acquired on Jul. 9th, 2018 by OLI on Landsat 8. By the time this photo was taken, the city’s main reservoirs stood at 55%. This was a huge increase from where it stood just six months earlier: just 13%.

The severe water shortage in the region started in 2015, only to become more threatening after three successive and unusually dry years. The entire city was preparing for Day Zero — the day the tap water would be shut off.  

Despite forecasts that Day Zero would arrive in April, a combination of heavier rains and local conservation efforts restored the majority of the reservoir. 

2. Aerosol Earth

Aerosols are all around us. From the smoke from a fire, to the dust in the wind to the salt in sea spray — these solid particles and liquid droplets are always swirling in our atmosphere, oftentimes unseen.

The Goddard Earth Observing System Forward Processing (GEOS FP) model uses mathematical equations to model what is happening in our atmosphere. The inputs for its equations — temperature, moisture, wind, etc. — come from our satellites and ground sensors.

This visualization was compiled on Aug. 24, 2018 — obviously a busy day for aerosols in our atmosphere. Swirls of sea salt (indicated by blue) reveal typhoons Soulik and Cimaron heading straight towards South Korea and Japan. A haze of black carbon (indicated by red) suffuse from agricultural burning in Africa and large wildfires in North America. And clouds of dust (indicated by purple) float off the Sahara desert.

1. Camp Fire

With nearly a hundred fatalities, hundreds of thousands of acres burned and billions of dollars of damage, the world watched in horror as Camp Fire grew to become the most destructive California wildfire in recorded history.

This image was captured on Nov. 8, 2018 by OLI on Landsat 8 on the same day Camp Fire ignited. It consolidates both visible light and shortwave-infrared light in order to highlight the active fire. Strong winds and dry conditions literally fanned the flames and spread this wildfire like a rash. 

This image has not only become the iconic portrait for Camp Fire, it is also sobering representation of how quickly a fire can grow out of control in a short amount of time. Even from space, you can almost smell the massive plumes of smoke and feel the heat of the fires.

Whether you realize it or not, our Earth satellite missions are collecting data everyday in order to monitor environmental changes and prepare for natural disasters.  If your interest is piqued by this list, head over to the Earth Observatory. The Earth Observatory updates daily with fresh, new content — brought to you by none other than our eyes in the sky. 

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Scary Space Stories to Tell in the Dark

The universe is full of dazzling sights, but there’s an eerie side of space, too. Nestled between the stars, shadowy figures lurk unseen. The entire galaxy could even be considered a graveyard, full of long-dead stars. And it’s not just the Milky Way – the whole universe is a bit like one giant haunted house! Our Nancy Grace Roman Space Telescope will illuminate all kinds of spine-chilling cosmic mysteries when it launches in 2027, but for now settle in for some true, scary space stories.

Flickering Lights

One of the first signs that things are about to get creepy in a scary movie is when the lights start to flicker. That happens all the time in space, too! But instead of being a sinister omen, it can help us find planets circling other stars.

Roman will stare toward the heart of our galaxy and watch to see when pairs of stars appear to align in the sky. When that happens, the nearer star – and orbiting planets – can lens light from the farther star, creating a brief brightening. That’s because every massive object warps the fabric of space-time, changing the path light takes when it passes close by. Roman could find around 1,000 planets using this technique, which is called microlensing.

The mission will also see little flickers when planets cross in front of their host star as they orbit and temporarily dim the light we receive from the star. Roman could find an additional 100,000 planets this way!

Galactic Ghosts

Roman is going to be one of the best ghost hunters in the galaxy! Since microlensing relies on an object’s gravity, not its light, it can find all kinds of invisible specters drifting through the Milky Way. That includes rogue planets, which roam the galaxy alone instead of orbiting a star…

…and solo stellar-mass black holes, which we can usually only find when they have a visible companion, like a star. Astronomers think there should be 100 million of these black holes in our galaxy.

Stellar Skeletons

Black holes aren’t the only dead stars hiding in the sky. When stars that aren’t quite massive enough to form black holes run out of fuel, they blast away their outer layers and become neutron stars. These stellar cores are the densest material we can directly observe. One sugar cube of neutron star material would weigh about 1 billion tons (or 1 trillion kilograms) on Earth! Roman will be able to detect when these extreme objects collide.

Smaller stars like our Sun have less dramatic fates. After they run out of fuel, they swell up and shrug off their outer layers until only a small, hot core called a white dwarf remains. Those outer layers may be recycled into later generations of stars and planets. Roman will explore regions where new stars are bursting to life, possibly containing the remnants of such dead stars.

Cosmic Cobwebs

If we zoom out far enough, the structure of space looks like a giant cobweb! The cosmic web is the large-scale backbone of the universe, made up mainly of a mysterious substance known as dark matter and laced with gas, upon which galaxies are built. Roman will find precise distances for more than 10 million galaxies to map the structure of the cosmos, helping astronomers figure out why the expansion of the universe is speeding up.

Learn more about the exciting science this mission will investigate on Twitter and Facebook.

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How Well Do You Know Mercury?

Mercury is the smallest planet in our solar system and is only slightly larger than Earth’s moon. To give you some perspective, if the sun were as tall as a typical front door, Earth would be the size of a nickel and Mercury would be about as big as a green pea.

Mercury is the closest planet to the sun. Daytime temperatures can reach 430 degrees Celsius (800 degrees Fahrenheit) and drop to –180 degrees Celsius (-290 degrees Fahrenheit) at night.

Here are a few fun facts about Mercury:

Mercury takes only 88 Earth days to orbit the sun

If we could stand on Mercury’s surface when it is at its closest point to the sun, the sun would appear more than three times larger than it does here on Earth

Mercury is home to one of the largest impact basins in the solar system: the Caloris Basin. The diameter of this impact basin is the length of 16,404 football fields (minus the end zones) placed end to end!

Mercury is one of only two planets in our solar system that do not have moons (Venus is the other one)

Mercury completes three rotations for every two orbits around the sun. That means that if you wanted to stay up from sunrise to sunrise on Mercury, you’d be up for 176 Earth days…you’d need a LOT of coffee! 

Two missions have visited Mercury:

Mariner 10 was the first mission to Mercury, and 30 years later, our MESSENGER mission was the second to visit the planet. Mariner 10 was also the first spacecraft to reach one planet by using the gravity of another planet (in this case, Venus) to alter its speed and trajectory.

MESSENGER was the first spacecraft to orbit Mercury, The spacecraft had its own shades to protect it from the light of the sun. This is important since sunlight on Mercury can be as much as 11 times brighter than it is here on Earth. The spacecraft was originally planned to orbit Mercury for one year, but exceeded expectations and worked for over four years capturing extensive data. On April 30, 2015, the spacecraft succumbed to the pull of solar gravity and impacted Mercury’s surface.

Water Ice?

The MESSENGER spacecraft observed compelling support for the long-held hypothesis that Mercury harbors abundant water ice and other frozen volatile materials in its permanently shadowed polar craters.

This radar image of Mercury’s north polar region. The areas shown in red were captured by MESSENGER, compared to the yellow deposits imaged by Earth-based radar. These areas are believed to consist of water ice.

Mercury Transit of the Sun

For more than seven hours on Monday, May 9, Mercury will be visible as a tiny black dot crossing the face of the sun. This rare event – which happens only slightly more than once a decade – is called a transit.

Where: Skywatchers in Western Europe, South America and eastern North America will be able to see the entirety of the transit. The entire 7.5-hour path across the sun will be visible across the Eastern U.S. – with magnification and proper solar filters – while those in the West can observe the transit in progress at sunrise.

Watch: We will stream a live program on NASA TV and the agency’s Facebook page from 10:30 to 11:30 a.m. – an informal roundtable during which experts representing planetary, heliophysics and astrophysics will discuss the science behind the Mercury transit. Viewers can ask questions via Facebook and Twitter using #AskNASA. Unlike the 2012 Venus transit of the sun, Mercury is too small to be visible without magnification from a telescope or high-powered binoculars. Both must have safe solar filters made of specially-coated glass or Mylar; you can never look directly at the sun.

To learn more about our solar system and the planets, visit: http://solarsystem.nasa.gov/

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Solar System: Things To Know This Week

Weather permitting, you can observe the Moon most nights, unless it's a new moon, when the lighted side of the Moon faces away from Earth. The Moon is by far the brightest object in the night sky and there's plenty to see. But this week is special...

...October 28 is International Observe the Moon Night (also known as InOMN).

Here's all you need to know to join in and celebrate:

1. One Planet. One Moon. One Night.

Everyone on Earth is invited to join the celebration by hosting or attending an InOMN event and uniting on one day each year to look at and learn about the Moon together.

2. What's Up?

October's night skies are full of sights, from the first quarter Moon on InOMN to Saturn making a cameo appearance above the Moon October 23 and 24. Watch our What's Up video for details.

3. Be Social

Hundreds of events are planned around the globe. Click the top link on this page for a handy map. You can also register your own event.

4. Don't Just Stand There

Here are some activities for enhanced Moon watching.

5. Impress Your Friends with Moon Knowledge

Download InOMN flyers and handouts, Moon maps and even some pre-made presentations. There's even a certificate to mark your participation.

6. Guide to the Face of the Moon

Almost dead center on the Earth-facing side of the Moon is the Surveyor 6 robotic spacecraft impact side. Apollo 12 and 14 are a bit to the left. And Apollo 11 - the first steps on the moon - are to the right. This retro graphic tells the whole story.

7. Moon Shots

NASA photographers have done some exceptional work capturing views of the Moon from Earth. Here are a few galleries:

You can't have a solar eclipse without the Moon.

The 2016 "Supermoon" was pretty spectacular.

The Moon gets eclipsed, too.

That IS a Moon - AND the International Space Station.

The Moon is always a great photo subject.

Some spooky shots of the 2014 "Supermoon."

And 2013.

Tips from a NASA pro for photographing the Moon.

8. Walking on the Moon

Twelve human beings walked on the face of the Moon. Here are some of the best shots from the Apollo program.

9. Moon Watch

Our Lunar Reconnaissance Orbiter is up there right now, mapping the moon and capturing some spectacular high-resolution shots.

10. Keep Exploring

Make our Moon portal your base for further lunar exploration.

Check out the full version of ‘Ten Things to Know This Week’ HERE.

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See the Closest Ever Images of the Sun

Solar Orbiter just released its first scientific data — including the closest images ever taken of the Sun.

Launched on February 9, 2020, Solar Orbiter is a collaboration between the European Space Agency and NASA, designed to study the Sun up close. Solar Orbiter completed its first close pass of the Sun on June 15, flying within 48 million miles of the Sun’s surface.

This is already closer to the Sun than any other spacecraft has taken pictures (our Parker Solar Probe mission has flown closer, but it doesn’t take pictures of the Sun). And over the next seven years, Solar Orbiter will inch even closer to the Sun while tilting its orbit above the plane of the planets, to peek at the Sun’s north and south poles, which have never been imaged before.

Here’s some of what Solar Orbiter has seen so far.

The Sun up close

Solar Orbiter’s Extreme Ultraviolet Imager, or EUI, sees the Sun in wavelengths of extreme ultraviolet light that are invisible to our eyes.

EUI captured images showing “campfires” dotting the Sun. These miniature bright spots are over a million times smaller than normal solar flares. They may be the nanoflares, or tiny explosions, long thought to help heat the Sun’s outer atmosphere, or corona, to its temperature 300 times hotter than the Sun’s surface. It will take more data to know for sure, but one thing’s certain: In EUI’s images, these campfires are all over the Sun.

The Polar and Helioseismic Imager, or PHI, maps the Sun’s magnetic field in a variety of ways. These images show several of the measurements PHI makes, including the magnetic field strength and direction and the speed of flow of solar material.

PHI will have its heyday later in the mission, as Solar Orbiter gradually tilts its orbit to 24 degrees above the plane of the planets, giving it a never-before-seen view of the poles. But its first images reveal the busy magnetic field on the solar surface.

Studying space

Solar Orbiter’s instruments don’t just focus on the Sun itself — it also carries instruments that study the space around the Sun and surrounding the spacecraft.

The Solar and Heliospheric Imager, or SoloHi, looks out the side of the Solar Orbiter spacecraft to see the solar wind, dust, and cosmic rays that fill the space between the Sun and the planets. SoloHi captured the relatively faint light reflecting off interplanetary dust known as the zodiacal light, the bright blob of light in the right of the image. Compared to the Sun, the zodiacal light is extremely dim – to see it, SoloHi had to reduce incoming sunlight by a trillion times. The straight bright feature on the very edge of the image is a baffle illuminated by reflections from the spacecraft’s solar array.

This first data release highlights Solar Orbiter’s images, but its in situ instruments also revealed some of their first measurements. The Solar Wind Analyser, or SWA instrument, made the first dedicated measurements of heavy ions — carbon, oxygen, silicon, and iron — in the solar wind from the inner heliosphere.

Read more about Solar Orbiter’s first data and see all the images on ESA’s website.

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