Category: sun

In Conversation with the Sun: Parker Solar Pro…

Our Sun powers life on Earth. It defines our days, nourishes our
crops and even fuels our electrical grids. In our pursuit of knowledge
about the universe, we’ve learned so much about the Sun, but in many ways we’re
still in conversation with it, curious about its mysteries.

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Parker Solar
Probe
will advance this conversation, flying
through the Sun’s atmosphere as close as 3.8 million miles from our star’s
surface, more than seven times closer to it than any previous spacecraft. If
space were a football field, with Earth at one end and the Sun at the other,
Parker would be at the four-yard line, just steps away from the Sun! This
journey will revolutionize our understanding of the Sun, its surface and solar
winds.

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Supporting Parker on its journey to the
Sun are our communications networks. Three networks, the Near Earth Network,
the Space
Network
and the Deep Space Network, provide our
spacecraft with their communications, delivering their data to mission
operations centers. Their services ensure that missions like Parker have
communications support from launch through the mission.

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For Parker’s launch
on Aug. 12, the Delta IV Heavy rocket that sent Parker skyward relied on the Space
Network. A team at Goddard Space Flight Center’s Networks Integration Center
monitored the launch, ensuring that we maintained tracking and communications
data between the rocket and the ground. This data is vital, allowing engineers
to make certain that Parker stays on the right path towards its orbit around
the Sun.

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The Space Network’s constellation of Tracking and Data
Relay Satellites
(TDRS) enabled constant communications coverage for
the rocket as Parker made its way out of Earth’s atmosphere. These satellites
fly in geosynchronous orbit, circling Earth in step with its rotation, relaying
data from spacecraft at lower altitudes to the ground. The network’s three collections
of TDRS over the Atlantic, Pacific and Indian oceans provide enough coverage
for continuous communications for satellites in low-Earth orbit.

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The Near Earth Network’s Launch
Communications Segment tracked early stages of Parker’s launch, testing our brand
new ground stations’ ability to provide crucial information about the rocket’s
initial velocity (speed) and trajectory (path). When fully operational, it will
support launches from the Kennedy spaceport, including upcoming Orion
missions. The Launch Communications Segment’s three ground stations are located
at Kennedy Space Center; Ponce De Leon, Florida; and Bermuda. 

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When Parker separated from the Delta IV
Heavy, the Deep Space Network took over. Antennas up to 230 feet in diameter at
ground stations in California, Australia and Spain are supporting Parker for
its 24 orbits around the Sun and the seven Venus flybys that gradually shrink
its orbit, bringing it closer and closer to the Sun. The Deep Space Network is
delivering data to mission operations centers and will continue to do so as
long as Parker is operational.

Near the
Sun, radio interference and the heat load on the spacecraft’s antenna makes
communicating with Parker a challenge that we must plan for. Parker has three
distinct communications phases, each corresponding to a different part of its
orbit.

When Parker comes closest to the Sun, the
spacecraft will emit a beacon tone that tells engineers on the ground about its
health and status, but there will be very little opportunity to command the
spacecraft and downlink data. High data rate transmission will only occur
during a portion of Parker’s orbit, far from the Sun. The rest of the time,
Parker will be in cruise mode, taking measurements and being commanded through
a low data rate connection with Earth.

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Communications infrastructure is vital to
any mission. As Parker journeys ever closer to the center of our solar system,
each byte of downlinked data will provide new insight into our Sun. It’s a
mission that continues a conversation between us and our star that has lasted many
millions of years and will continue for many millions more.

For more information about NASA’s mission
to touch the Sun: https://www.nasa.gov/content/goddard/parker-solar-probe

For more information about our satellite
communications check out: http://nasa.gov/SCaN


Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

Parker Solar Probe is Go for Launch

Tomorrow, Aug. 11, we’re launching a spacecraft to touch the Sun.

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The first chance to launch Parker Solar Probe is 3:33 a.m. EDT on Aug. 11 from Space Launch Complex 37 at Cape Canaveral Air Force Station in Florida. Launch coverage on NASA TV starts at 3 a.m. EDT at nasa.gov/live.

After launch, Parker Solar Probe begins its daring journey to the Sun’s atmosphere, or corona, going closer to the Sun than any spacecraft in history and facing brutal heat and radiation.

Though Parker Solar Probe weighs a mere 1,400 pounds — pretty light for a spacecraft — it’s launching aboard one of the world’s most powerful rockets, a United Launch Alliance Delta IV Heavy with a third stage added.

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Even though you might think the Sun’s massive means things would just fall into it, it’s surprisingly difficult to actually go there.
Any object leaving Earth starts off traveling at about 67,000 miles per
hour, same as Earth — and most of that is in a sideways direction, so
you have to shed most of that sideways speed to make it to the Sun. All
that means that it takes 55 times more launch energy to go to the Sun
than it does to go to Mars. On top of its powerful launch vehicle,
Parker Solar Probe will use seven Venus gravity assists to shed sideways
speed.

Even though Parker Solar Probe will lose a lot of sideways speed, it’ll still be going incredibly fast as its orbit draws closer to the Sun throughout its seven-year mission. At its fastest, Parker Solar Probe will travel at 430,000 miles per hour — fast enough to get from Philadelphia to Washington, D.C. in one second — setting the record for the fastest spacecraft in history.

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But the real challenge was to keep the spacecraft from frying once it got there.

We’ve always wanted to send a mission to the corona, but we literally haven’t had the technology that can protect a spacecraft and its instruments from its scorching heat. Only recent advances have enabled engineers to build a heat shield that will protect the spacecraft on this journey of extremes — a tricky feat that requires withstanding the Sun’s intense radiation on the front and staying cool at the back, so the spacecraft and instruments can work properly.

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The 4.5-inches-thick heat shield is built like a sandwich. There’s a
thin layer of carbon material like you might find in your golf clubs or
tennis rackets, carbon foam, and then another thin piece of
carbon-carbon on the back. Even while the Sun-facing side broils at
2,500 degrees Fahrenheit, the back of the shield will remain a balmy 85
degrees — just above room temperature. There are so few particles in
this region that it’s a vacuum, so blocking the Sun’s radiation goes a
long way towards keeping the spacecraft cool.

Parker Solar Probe is also our first mission to be named after a living individual: Dr. Eugene Parker, famed solar physicist who in 1958 first predicted the existence of the solar wind.

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“Solar wind” is what Dr. Parker dubbed the stream of charged particles that flows constantly from the Sun, bathing Earth and our entire solar system in the Sun’s magnetic fields. Parker Solar Probe’s flight right through the corona allows it to observe the birth of the very solar wind that Dr. Parker predicted, right as it speeds up and over the speed of sound.  

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The corona is where solar material is heated to millions of degrees and where the most extreme eruptions on the Sun occur, like solar flares and coronal mass ejections, which fling particles out to space at incredible speeds near the speed of light. These explosions can also spark space weather storms near Earth that can endanger satellites and astronauts, disrupt radio communications and, at their most severe, trigger power outages.

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Thanks to Parker Solar Probe’s landmark mission, solar scientists will be able to see the objects of their study up close and personal for the very first time.

Up until now, all of our studies of the corona have been remote — that is, taken from a distance, rather than at the mysterious region itself. Scientists have been very creative to glean as much as possible from their remote data, but there’s nothing like actually sending a probe to the corona to see what’s going on.

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And scientists aren’t the only ones along for the adventure — Parker Solar Probe holds a microchip carrying the names of more than 1.1 million people who signed up to send their name to the Sun. This summer, these names and 1,400 pounds of science equipment begin their journey to the center of our solar system.

Three months later in November 2018, Parker Solar Probe makes its first close approach to the Sun, and in December, it will send back the data. The corona is one of the last places in the solar system where no spacecraft has visited before; each observation Parker Solar Probe makes is a potential discovery.

Stay tuned — Parker Solar Probe is about to take flight.

Keep up with the latest on the mission at nasa.gov/solarprobe or follow us on Twitter and Facebook.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com. 

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.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

Why Won’t Our Parker Solar Probe Melt?

This summer, our Parker Solar Probe will launch to travel closer to the Sun than any mission before it, right into the Sun’s outer atmosphere, the corona.

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The environment in the corona is unimaginably hot: The spacecraft will travel through material with temperatures greater than 3 million degrees Fahrenheit. 

So…why won’t it melt? 

The Difference Between Heat and Temperature

Parker Solar Probe was designed from the ground up to keep its instruments safe and cool, but the nature of the corona itself also helps. The key lies in the difference between heat and temperature.

Temperature measures how fast particles are moving, while heat is the total amount of energy that they transfer. The corona is an incredibly thin and tenuous part of the Sun, and there are very few particles there to transfer energy – so while the particles are moving fast (high temperature), they don’t actually transfer much energy to the spacecraft (low heat).

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It’s like the difference between putting your hand in a hot oven versus putting it in a pot of boiling water (don’t try this at home!). In the air of the oven, your hand doesn’t get nearly as hot as it would in the much denser water of the boiling pot. 

So even though Parker Solar Probe travels through a region with temperatures of several million degrees, the surface of its heat shield will reach only about 2,500 F.

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The Heat Shield

Of course, thousands of degrees Fahrenheit is still way too hot for scientific instruments. (For comparison, lava from volcano eruptions can be anywhere between 1,300 to 2,200 F.) 

To withstand that heat, Parker Solar Probe is outfitted with a cutting-edge heat shield, called the Thermal Protection System. This heat shield is made of a carbon composite foam sandwiched between two carbon plates. The Sun-facing side is covered with a specially-developed white ceramic coating, applied as a plasma spray, to reflect as much heat as possible.

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The heat shield is so good at its job that even though the Sun-facing side of the shield will be at 2,500 F, the instruments in its shadow will remain at a balmy 85 F.

Parker Solar Probe Keeps its Cool

Several other designs on the spacecraft help Parker Solar Probe beat the heat. 

Parker Solar Probe is not only studying the Sun – it’s also powered by it. But even though most of the surface area of its solar arrays can be retracted behind the heat shield, even that small exposed segment would quickly make them overheat while at the Sun.  

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To keep things cool, Parker Solar Probe circulates a single gallon of water through its solar arrays. The water absorbs heat as it passes behind the arrays, then radiates that heat out into space as it flows into the spacecraft’s radiator. 

It’s also important for Parker Solar Probe to be able to think on its feet, since it takes about eight minutes for information to travel between Earth and the Sun. If we had to control the spacecraft from Earth, by the time we knew something went wrong, it would be too late to fix it. 

So Parker Solar Probe is smart: Along the edges of the heat shield’s shadow are seven sensors. If any of these sensors detect sunlight, they alert the central computer and the spacecraft can correct its position to keep the sensors – and the rest of the instruments – safely protected behind the heat shield.

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Over the course of its seven-year mission, Parker Solar Probe will make 24 orbits of our star. On each close approach to the Sun, it will sample the solar wind, study the Sun’s corona, and provide unprecedentedly close up observations from around our star – and armed with its slew of innovative technologies, we know it will keep its cool the whole time. 

Parker Solar Probe launches summer 2018 on its mission to study the Sun. Keep up with the latest on the mission at nasa.gov/solarprobe or follow us on Twitter and Facebook.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Tools of the Trade: How Parker Solar Probe Wil…

Our Parker Solar Probe will get closer to the Sun than any spacecraft has ever gone – it will fly right through the Sun’s corona, part of the Sun’s atmosphere.

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This spacecraft is full of cutting-edge technology, from its heat shield down to its guidance and control systems. It also carries four suites of advanced instruments designed to study the Sun in a multitude of ways.  

1. Measuring particles

Two of Parker Solar Probe’s instrument suites are focused on measuring particles – electrons and ions – within the corona.

One of these particle-measuring instrument suites is SWEAP (Solar Wind Electrons Alphas and Protons). SWEAP counts the most common particles in the solar wind – the Sun’s constant outflow of material – and measures their properties, like velocity, density and temperature. Gathering this information about solar wind particles will help scientists better understand why the solar wind reaches supersonic speeds and exactly which part of the Sun the particles come from.

One instrument in the SWEAP suite is the Solar Probe Cup. Most of the instruments on Parker Solar Probe stay safe and cool in the shadow of the heat shield, but the Solar Probe Cup is one of the few that sticks out. That’s so it can capture and measure particles streaming straight out from the Sun, and it had to go through some intense testing to get ready for this position in the Sun’s incredibly hot corona.  

Credit: Levi Hutmacher/Michigan Engineering

The ISʘIS suite (pronounced EE-sis, and including the symbol for the Sun in its acronym) also measures particles. ISʘIS is short for Integrated Science Investigation of the Sun, and this instrument suite measures particles that move faster – and therefore have more energy – than the solar wind.

These measurements will help scientists understand these particles’ lifecycles – where they came from, how they got to be traveling so fast (these particles can reach speeds more than half the speed of light!) and what path they take as they travel away from the Sun and into interplanetary space.

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2. Taking pictures – but not of the Sun’s surface.

WISPR (Wide-Field Imager for Parker Solar Probe) has the only two cameras on Parker Solar Probe – but they’re not pointed directly at the Sun. Instead, WISPR looks out the side of the spacecraft, in the direction it’s traveling, looking at the space Parker Solar Probe is about to fly through. From that vantage point, WISPR captures images of structures within the corona like coronal mass ejections, or CMEs. CMEs are clouds of solar material that occasionally explode from the Sun at millions of miles per hour. Because this solar material is magnetized, CMEs can trigger geomagnetic storms when they reach Earth – which, in turn, can cause effects like auroras and even, in extreme cases, power outages.  

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Right now, our observations of events like these come from satellites orbiting near Earth, so WISPR will give us a whole new perspective. And, scientists will be able to combine WISPR’s images with Parker Solar Probe’s direct particle measurements to get a better idea of how these structures change as they travel.

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3. Studying electric & magnetic fields

The FIELDS instrument suite is appropriately named: It’s what scientists will use to study the electric and magnetic fields in the corona.

Electric and magnetic fields are key to understanding what happens, not only on the Sun, but throughout space, because they the primary driver accelerating charged particles. In particular, a process called magnetic reconnection – when magnetic field lines explosively realign, sending particles rocketing away at incredible speeds – is thought to drive solar explosions, as well as space weather effects on Earth, like the aurora.

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FIELDS measures electric and magnetic field at high time resolution, meaning it takes lots of measurements in a short amount of time, to track these processes and shed some light on the mechanics underlying the Sun’s behavior. FIELDS’ measurements are precisely synced up with those of the SWEAP suite (one of the sets of instruments studying particles) so that scientists can match up the immediate effects that electric and magnetic fields have on the material of the solar wind.

Parker Solar Probe launches summer 2018 on its mission to study the Sun. Keep up with the latest on the mission at nasa.gov/solarprobe or follow us on Twitter and Facebook.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

What’s a Blood Moon? And Other Lunar Eclipse Q…

Tonight, Australians, Africans, Europeans, Asians and South Americans will have the opportunity to see the longest lunar eclipse of the century. Sorry North America. 

Lunar eclipses occur about 2-4 times per year, when the Moon passes into the Earth’s shadow. In order to see a lunar eclipse, you must be on the night side of the Earth, facing the Moon, when the Earth passes in between the Moon and the Sun. Need help visualizing this? Here you go:

What’s the difference between a solar eclipse and a lunar eclipse?

An easy way to remember the difference between a solar eclipse and a lunar eclipse is that the word ‘eclipse’ refers to the object that is being obscured. During a solar eclipse, the Moon blocks the Sun from view. During a lunar eclipse, the Earth’s shadow obscures the Moon.

Why does the Moon turn red?  

You may have heard the term ‘Blood Moon’ for a lunar eclipse. When the Moon passes into the Earth’s shadow, it turns red. This happens for the exact same reason that our sunrises and sunsets here on Earth are brilliant shades of pinks and oranges. During a lunar eclipse, the only light reaching the Moon passes through the Earth’s atmosphere. The bluer, shorter wavelength light scatters and the longer wavelength red light passes through and makes it to the Moon.

What science can we learn from a lunar eclipse?

“During a lunar eclipse, the temperature swing is so dramatic that it’s as if the surface of the Moon goes from being in an oven to being in a freezer in just a few hours,” said Noah Petro, project scientist for our Lunar Reconnaissance Orbiter, or LRO, at our Goddard Space Flight Center in Greenbelt, Maryland.

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The Diviner team from LRO measures temperature changes on the Moon through their instrument on the spacecraft as well as through a thermal camera on Earth. How quickly or slowly the lunar surface loses heat helps scientists determine characteristics of lunar material, including its composition and physical properties.

When is the next lunar eclipse?

North Americans, don’t worry. If skies are clear, you can see the next lunar eclipse on January 21, 2019. The eclipse will be visible to North Americans, South Americans, and most of Africa and Europe.

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To keep an eye on the Moon with us check out nasa.gov/moon or follow us on Twitter and Facebook.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

The Sun is not silent. The low, pulsing hum of…

The Sun is not silent. The low, pulsing hum of our star’s heartbeat allows scientists to peer inside, revealing huge rivers of solar material flowing around before their eyes — er, ears.

Data from ESA (European Space Agency) and NASA’s Solar and Heliospheric Observatory (SOHO), sonified by the Stanford Experimental Physics Lab, captures the Sun’s natural vibrations and reveals what can’t be seen with the naked eye.

In this audiogram, our heliophysicist Alex Young explains how this simple sound connects us with the Sun and all the other stars in the universe.

This piece features low frequency sounds of the Sun. For the best listening experience, listen to this story with headphones. 🎧 

Read more: https://go.nasa.gov/2LMW42o

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

Meet Parker Solar Probe, Our Mission to Touch …

In just a few weeks, we’re launching a spacecraft to get closer to the Sun than any human-made object has ever gone.

The mission, called Parker Solar Probe, is outfitted with a lineup of instruments to measure the Sun’s particles, magnetic and electric fields, solar wind and more – all to help us better understand our star, and, by extension, stars everywhere in the universe.

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Parker Solar Probe is about the size of a small car, and after launch – scheduled for no earlier than Aug. 6, 2018 – it will swing by Venus on its way to the Sun, using a maneuver called a gravity assist to draw its orbit closer to our star. Just three months after launch, Parker Solar Probe will make its first close approach to the Sun – the first of 24 throughout its seven-year mission.

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Though Parker Solar Probe will get closer and closer to the Sun with each orbit, the first approach will already place the spacecraft as the closest-ever human-made object to the Sun, swinging by at 15 million miles from its surface. This distance places it well within the corona, a region of the Sun’s outer atmosphere that scientists think holds clues to some of the Sun’s fundamental physics.

For comparison, Mercury orbits at about 36 million miles from the Sun, and the previous record holder – Helios 2, in 1976 – came within 27 million miles of the solar surface. 

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Humanity has studied the Sun for thousands of years, and our modern understanding of the Sun was revolutionized some 60 years ago with the start of the Space Age. We’ve come to understand that the Sun affects Earth in more ways than just providing heat and light – it’s an active and dynamic star that releases solar storms that influence Earth and other worlds throughout the solar system. The Sun’s activity can trigger the aurora, cause satellite and communications disruptions, and even – in extreme cases – lead to power outages.

Much of the Sun’s influence on us is embedded in the solar wind, the Sun’s constant outflow of magnetized material that can interact with Earth’s magnetic field. One of the earliest papers theorizing the solar wind was written by Dr. Gene Parker, after whom the mission is named.

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Though we understand the Sun better than we ever have before, there are still big questions left to be answered, and that’s where scientists hope Parker Solar Probe will help.  

First, there’s the coronal heating problem. This refers to the counterintuitive truth that the Sun’s atmosphere – the corona – is much, much hotter than its surface, even though the surface is millions of miles closer to the Sun’s energy source at its core. Scientists hope Parker Solar Probe’s in situ and remote measurements will help uncover the mechanism that carries so much energy up into the upper atmosphere.

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Second, scientists hope to better understand the solar wind. At some point on its journey from the Sun out into space, the solar wind is accelerated to supersonic speeds and heated to extraordinary temperatures. Right now, we measure solar wind primarily with a group of satellites clustered around Lagrange point 1, a spot in space between the Sun and Earth some 1 million miles from us. 

By the time the solar wind reaches these satellites, it has traveled about 92 million miles already, blending together the signatures that could shed light on the acceleration process. Parker Solar Probe, on the other hand, will make similar measurements less than 4 million miles from the solar surface – much closer to the solar wind’s origin point and the regions of interest.

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Scientists also hope that Parker Solar
Probe will uncover the mechanisms at work behind the acceleration of solar
energetic particles, which can reach speeds more than half as fast as the speed
of light as they rocket away from the Sun! Such particles can interfere with
satellite electronics, especially for satellites outside of Earth’s magnetic
field.

Parker
Solar Probe will launch from Space Launch Complex 37 at Cape Canaveral Air
Force Station, adjacent to NASA’s Kennedy Space Center in Florida. Because of the enormous speed required to
achieve its solar orbit, the spacecraft will launch on a United Launch Alliance Delta IV Heavy, one of the most powerful rockets in the
world.

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Stay tuned over the next few weeks to learn more about Parker Solar Probe’s science and follow along with its journey to launch. We’ll be posting updates here on Tumblr, on Twitter and Facebook, and at nasa.gov/solarprobe.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Our Sun is More than Meets the Eye

The Sun may look unchanging to us here on Earth, but that’s not the whole story.

In visible light – the light our eyes can see – the Sun looks like an almost featureless orange disk, peppered with the occasional sunspot. (Important note: Never look at the Sun directly, and always use a proper filter for solar viewing – or tune in to our near-real time satellite feeds!)

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But in other kinds of light, it’s a different picture. The Sun emits light across the electromagnetic spectrum, including the relatively narrow range of light we can see, as well as wavelengths that are invisible to our eyes. Different wavelengths convey information about different components of the Sun’s surface and atmosphere, so watching the Sun in multiple types of light helps us paint a fuller picture.

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Watching the Sun in these wavelengths reveals how active it truly is. This image, captured in a wavelength of extreme ultraviolet light at 131 Angstroms, shows a solar flare. Solar flares are intense bursts of light radiation caused by magnetic events on the Sun, and often associated with sunspots. The light radiation from solar flares can disturb part of Earth’s atmosphere where radio signals travel, causing short-lived problems with communications systems and GPS.

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Looking at the Sun in extreme ultraviolet light also reveals structures like coronal loops (magnetic loops traced out by charged particles spinning along magnetic field lines)…

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…solar prominence eruptions…

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…and coronal holes (magnetically open areas on the Sun from which solar wind rushes out into space).

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Though extreme ultraviolet light shows the Sun’s true colors, specialized instruments let us see some of the Sun’s most significant activity in visible light.

A coronagraph is a camera that uses a solid disk to block out the Sun’s bright face, revealing the much fainter corona, a dynamic part of the Sun’s atmosphere. Coronagraphs also reveal coronal mass ejections, or CMEs, which are explosions of billions of tons of solar material into space. Because this material is magnetized, it can interact with Earth’s magnetic field and trigger space weather effects like the aurora, satellite problems, and even – in extreme cases – power outages.

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The Sun is also prone to bursts of energetic particles. These particles are blocked by Earth’s magnetic field and atmosphere, but they could pose a threat to astronauts traveling in deep space, and they can interfere with our satellites. This clip shows an eruption of energetic particles impacting a Sun-observing satellite, creating the ‘snow’ in the image.

We keep watch on the Sun 24/7 with a fleet of satellites to monitor and better understand this activity. And this summer, we’re going one step closer with the launch of Parker Solar Probe, a mission to touch the Sun. Parker Solar Probe will get far closer to the Sun than any other spacecraft has ever gone – into the corona, within 4 million miles of the surface – and will send back unprecedented direct measurements from the regions thought to drive much of the Sun’s activity. More information about the fundamental processes there can help round out and improve models to predict the space weather that the Sun sends our way.

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.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com. 

Happy 4th of July… From Space!

In Hollywood blockbusters, explosions and eruptions are often among the stars of the show. In space, explosions, eruptions and twinkling of actual stars are a focus for scientists who hope to better understand their births, lives, deaths and how they interact with their surroundings. Spend some of your Fourth of July taking a look at these celestial phenomenon:

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Credit: NASA/Chandra X-ray Observatory

An Astral Exhibition

This object became a sensation in the astronomical community when a team of researchers pointed at it with our Chandra X-ray Observatory telescope in 1901, noting that it suddenly appeared as one of the brightest stars in the sky for a few days, before gradually fading away in brightness. Today, astronomers cite it as an example of a “classical nova,” an outburst produced by a thermonuclear explosion on the surface of a white dwarf star, the dense remnant of a Sun-like star.

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Credit: NASA/Hubble Space Telescope

A Twinkling Tapestry

The brilliant tapestry of young stars flaring to life resemble a glittering fireworks display. The sparkling centerpiece is a giant cluster of about 3,000 stars called Westerlund 2, named for Swedish astronomer Bengt Westerlund who discovered the grouping in the 1960s. The cluster resides in a raucous stellar breeding ground located 20,000 light-years away from Earth in the constellation Carina.

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Credit: NASA/THEMIS/Sebastian Saarloos

An Illuminating Aurora

Sometimes during solar magnetic events, solar explosions hurl clouds of magnetized particles into space. Traveling more than a million miles per hour, these coronal mass ejections, or CMEs, made up of hot material called plasma take up to three days to reach Earth. Spacecraft and satellites in the path of CMEs can experience glitches as these plasma clouds pass by. In near-Earth space, magnetic reconnection incites explosions of energy driving charged solar particles to collide with atoms in Earth’s upper atmosphere. We see these collisions near Earth’s polar regions as the aurora. Three spacecraft from our Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission, observed these outbursts known as substorms.

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Credit: NASA/Hubble Space Telescope//ESA/STScI

A Shining Supermassive Merger

Every galaxy has a black hole at its center. Usually they are quiet, without gas accretions, like the one in our Milky Way. But if a star creeps too close to the black hole, the gravitational tides can rip away the star’s gaseous matter. Like water spinning around a drain, the gas swirls into a disk around the black hole at such speeds that it heats to millions of degrees. As an inner ring of gas spins into the black hole, gas particles shoot outward from the black hole’s polar regions. Like bullets shot from a rifle, they zoom through the jets at velocities close to the speed of light. Astronomers using our Hubble Space Telescope observed correlations between supermassive black holes and an event similar to tidal disruption, pictured above in the Centaurus A galaxy. 

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Credit: NASA/Hubble Space Telescope/ESA

A Stellar Explosion

Supernovae can occur one of two ways. The first occurs when a white dwarf—the remains of a dead star—passes so close to a living star that its matter leaks into the white dwarf. This causes a catastrophic explosion. However most people understand supernovae as the death of a massive star. When the star runs out of fuel toward the end of its life, the gravity at its heart sucks the surrounding mass into its center. At the turn of the 19th century, the binary star system Eta Carinae was faint and undistinguished. Our Hubble Telescope captured this image of Eta Carinae, binary star system. The larger of the two stars in the Eta Carinae system is a huge and unstable star that is nearing the end of its life, and the event that the 19th century astronomers observed was a stellar near-death experience. Scientists call these outbursts supernova impostor events, because they appear similar to supernovae but stop just short of destroying their star.

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Credit: NASA/GSFC/SDO

An Eye-Catching Eruption

Extremely energetic objects permeate the universe. But close to home, the Sun produces its own dazzling lightshow, producing the largest explosions in our solar system and driving powerful solar storms.. When solar activity contorts and realigns the Sun’s magnetic fields, vast amounts of energy can be driven into space. This phenomenon can create a sudden flash of light—a solar flare.The above picture features a filament eruption on the Sun, accompanied by solar flares captured by our Solar Dynamics Observatory.

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