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.
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
Supporting Parker on its journey to the
Sun are our communications networks. Three networks, the Near Earth Network,
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.
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 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.
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.
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.
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
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.
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.
Our Spitzer Space Telescope is celebrating 15 years since its launch on August 25, 2003. This remarkable spacecraft has made discoveries its designers never even imagined, including some of the seven Earth-size planets of TRAPPIST-1. Here are some key facts about Spitzer:
1. Spitzer is one of our Great Observatories.
Our Great Observatory Program aimed to explore the universe with four large space telescopes, each specialized in viewing the universe in different wavelengths of light. The other Great Observatories are our Hubble Space Telescope, Chandra X-Ray Observatory, and Compton Gamma-Ray Observatory. By combining data from different kinds of telescopes, scientists can paint a fuller picture of our universe.
2. Spitzer operates in infrared light.
Infrared wavelengths of light, which primarily come from heat radiation, are too long to be seen with human eyes, but are important for exploring space — especially when it comes to getting information about something extremely far away. From turbulent clouds where stars are born to small asteroids close to Earth’s orbit, a wide range of phenomena can be studied in infrared light. Objects too faint or distant for optical telescopes to detect, hidden by dense clouds of space dust, can often be seen with Spitzer. In this way, Spitzer acts as an extension of human vision to explore the universe, near and far.
What’s more, Spitzer doesn’t have to contend with Earth’s atmosphere, daily temperature variations or day-night cycles, unlike ground-based telescopes. With a mirror less than 1 meter in diameter, Spitzer in space is more sensitive than even a 10-meter-diameter telescope on Earth.
3. Spitzer was the first spacecraft to fly in an Earth-trailing orbit.
Rather than circling Earth, as Hubble does, Spitzer orbits the Sun on almost the same path as Earth. But Spitzer moves slower than Earth, so the spacecraft drifts farther away from our planet each year.
This “Earth-trailing orbit” has many advantages. Being farther from Earth than a satellite, it receives less heat from our planet and enjoys a naturally cooler environment. Spitzer also benefits from a wider view of the sky by orbiting the Sun. While its field of view changes throughout the year, at any given time it can see about one-third of the sky. Our Kepler space telescope, famous for finding thousands of exoplanets – planets outside our solar system – also settled in an Earth-trailing orbit six years after Spitzer.
4. Spitzer began in a “cold mission.”
Spitzer has far outlived its initial requirement of 2.5 years. The Spitzer team calls the first 5.5 years “the cold mission” because the spacecraft’s instruments were deliberately cooled down during that time. Liquid helium coolant kept Spitzer’s instruments just a few degrees above absolute zero (which is minus 459 degrees Fahrenheit, or minus 273 degrees Celsius) in this first part of the mission.
5. The “warm mission” was still pretty cold.
Spitzer entered what was called the “warm mission” when the 360 liters of liquid helium coolant that was chilling its instruments ran out in May 2009.
At the “warm” temperature of minus 405 Fahrenheit, two of Spitzer’s instruments – the Infrared Spectrograph (IRS) and Multiband Imaging Photometer (MIPS) – stopped working. But two of the four detector arrays in the Infrared Array Camera (IRAC) persisted. These “channels” of the camera have driven Spitzer’s explorations since then.
6. Spitzer wasn’t designed to study exoplanets, but made huge strides in this area.
Exoplanet science was in its infancy in 2003 when Spitzer launched, so the mission’s first scientists and engineers had no idea it could observe planets beyond our solar system. But the telescope’s accurate star-targeting system and the ability to control unwanted changes in temperature have made it a useful tool for studying exoplanets. During the Spitzer mission, engineers have learned how to control the spacecraft’s pointing more precisely to find and characterize exoplanets, too.
Using what’s called the “transit method,” Spitzer can stare at a star and detect periodic dips in brightness that happen when a planet crosses a star’s face. In one of its most remarkable achievements, Spitzer discovered three of the TRAPPIST-1 planets and confirmed that the system has seven Earth-sized planets orbiting an ultra-cool dwarf star. Spitzer data also helped scientists determine that all seven planets are rocky, and made these the best-understood exoplanets to date.
Spitzer can also use a technique called microlensing to find planets closer to the center of our galaxy. When a star passes in front of another star, the gravity of the first star can act as a lens, making the light from the more distant star appear brighter. Scientists are using microlensing to look for a blip in that brightening, which could mean that the foreground star has a planet orbiting it. Microlensing could not have been done early in the mission when Spitzer was closer to Earth, but now that the spacecraft is farther away, it has a better chance of measuring these events.
7. Spitzer is a window into the distant past.
The spacecraft has observed and helped discover some of the most distant objects in the universe, helping scientists understand where we came from. Originally, Spitzer’s camera designers had hoped the spacecraft would detect galaxies about 12 billion light-years away. In fact, Spitzer has surpassed that, and can see even farther back in time – almost to the beginning of the universe. In collaboration with Hubble, Spitzer helped characterize the galaxy GN-z11 about 13.4 billion light-years away, whose light has been traveling since 400 million years after the big bang. It is the farthest galaxy known.
8. Spitzer discovered Saturn’s largest ring.
Everyone knows Saturn has distinctive rings, but did you know its largest ring was only discovered in 2009, thanks to Spitzer? Because this outer ring doesn’t reflect much visible light, Earth-based telescopes would have a hard time seeing it. But Spitzer saw the infrared glow from the cool dust in the ring. It begins 3.7 million miles (6 million kilometers) from Saturn and extends about 7.4 million miles (12 million kilometers) beyond that.
9. The “Beyond Phase” pushes Spitzer to new limits.
In 2016, Spitzer entered its “Beyond phase,” with a name reflecting how the spacecraft operates beyond its original scope.
As Spitzer floats away from Earth, its increasing distance presents communication challenges. Engineers must point Spitzer’s antenna at higher angles toward the Sun in order to talk to our planet, which exposes the spacecraft to more heat. At the same time, the spacecraft’s solar panels receive less sunlight because they point away from the Sun, putting more stress on the battery.
The team decided to override some autonomous safety systems so Spitzer could continue to operate in this riskier mode. But so far, the Beyond phase is going smoothly.
10. Spitzer paves the way for future infrared telescopes.
Spitzer has identified areas of further study for our upcoming James Webb Space Telescope, planned to launch in 2021. Webb will also explore the universe in infrared light, picking up where Spitzer eventually will leave off. With its enhanced ability to probe planetary atmospheres, Webb may reveal striking new details about exoplanets that Spitzer found. Distant galaxies unveiled by Spitzer together with other telescopes will also be observed in further detail by Webb. The space telescope we are planning after that, WFIRST, will also investigate long-standing mysteries by looking at infrared light. Scientists planning studies with future infrared telescopes will naturally build upon the pioneering legacy of Spitzer.
Read the web version of this week’s “Solar System: 10 Things to Know” article HERE.
Tomorrow, Aug. 11, we’re launching a spacecraft to touch the Sun.
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.
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
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.
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.
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.
“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.
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.
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.
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.
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.
Our Commercial Crew Program is
working with the American aerospace industry to develop and operate a
new generation of spacecraft to carry astronauts
to and from low-Earth orbit!
As we prepare to launch humans from American soil for the first time since the final space shuttle mission in 2011, get to know the astronauts who will fly with Boeing and SpaceX
as members of our commercial crew!
served as Chief of the NASA Astronaut Office from July 2012 to July
2015, where he was responsible for flight assignments, mission preparation, on-orbit
support of International Space Station crews and organization of astronaut
office support for future launch vehicles. Learn more about Bob.
Boe first dreamed of being an astronaut at age 5 after his parents woke him up to
watch Neil Armstrong take his first steps onto the lunar surface. Learn more
Josh Cassada holds a Master of Arts Degree and a Doctorate in Physics with a
specialty in high energy particle physics from the University of Rochester, in
Rochester, New York. He was selected as a NASA astronaut in 2013, and his first
spaceflight will be as part of the Commercial Crew Program. Learn more about
Ferguson served as a Navy pilot before becoming a NASA astronaut, and was
commander aboard Atlantis for the final space shuttle flight, as part of the
same crew as Doug Hurley. He retired from NASA in 2011 and has been an integral
part of Boeing’s CST-100 Starliner program. Learn more about Chris.
Victor Glover was selected as a NASA astronaut in 2013 while working as a Legislative Fellow in the United States Senate. His first spaceflight will be as part of the Commercial Crew Program. Learn more about Victor.
was a top flight test engineer at the United States Air Force Test
Pilot School. He also studied political science at the Università degli Studi
di Parma in Parma, Italy, in 2005, and became a NASA astronaut in 2009. Learn
more about Mike.
2009, Doug Hurley was one of the record-breaking 13 people living on the space
station at the same time. In 2011, he served as the pilot on Atlantis during the
final space shuttle mission, delivering supplies and spare parts to the
International Space Station. Now, he will be one of the first people to launch
from the U.S. since that last shuttle mission. Learn more about Doug.
Mann is a Naval Aviator and a test pilot in the F/A-18 Hornet. She was selected
as a NASA astronaut in 2013, and her first spaceflight will be as part of the Commercial
Crew Program. Learn more about Nicole.
has completed 7 spacewalks, totaling 50 hours and 40 minutes. She’s
also known for running. In April 2007, Suni ran the first marathon in space,
the Boston Marathon, in 4 hours and 24 minutes. Learn more about Suni.
Boeing and SpaceX are scheduled to complete their crew flight tests in mid-2019 and April 2019, respectively. Once enabled, commercial transportation to and from the International Space Station will empower more station use, more research time and more
opportunities to understand and overcome the challenges of living in space, which is critical for us to create a sustainable
presence on the Moon and carry out missions deeper into the solar system, including Mars!
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.
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).
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.
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.
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.
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.
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.
Gamma-ray bursts are the brightest, most violent explosions in the universe, but they can be surprisingly tricky to detect. Our eyes can’t see them because they are tuned to just a limited portion of the types of light that exist, but thanks to technology, we can even see the highest-energy form of light in the cosmos — gamma rays.
So how did we discover gamma-ray bursts?
We didn’t actually develop gamma-ray detectors to peer at the universe — we were keeping an eye on our neighbors! During the Cold War, the United States and the former Soviet Union both signed the Nuclear Test Ban Treaty of 1963 that stated neither nation would test nuclear weapons in space. Just one week later, the US launched the first Vela satellite to ensure the treaty wasn’t being violated. What they saw instead were gamma-ray events happening out in the cosmos!
Things Going Bump in the Cosmos
Each of these gamma-ray events, dubbed “gamma-ray bursts” or GRBs, lasted such a short time that information was very difficult to gather. For decades their origins, locations and causes remained a cosmic mystery, but in recent years we’ve been able to figure out a lot about GRBs. They come in two flavors: short-duration (less than two seconds) and long-duration (two seconds or more). Short and long bursts seem to be caused by different cosmic events, but the end result is thought to be the birth of a black hole.
Short GRBs are created by binary neutron star mergers. Neutron stars are the superdense leftover cores of really massive stars that have gone supernova. When two of them crash together (long after they’ve gone supernova) the collision releases a spectacular amount of energy before producing a black hole. Astronomers suspect something similar may occur in a merger between a neutron star and an already-existing black hole.
Long GRBs account for most of the bursts we see and can be created when an extremely massive star goes supernova and launches jets of material at nearly the speed of light (though not every supernova will produce a GRB). They can last just a few seconds or several minutes, though some extremely long GRBs have been known to last for hours!
A Gamma-Ray Burst a Day Sends Waves of Light Our Way!
Our Fermi Gamma-ray Space Telescope detects a GRB nearly every day, but there are actually many more happening — we just can’t see them! In a GRB, the gamma rays are shot out in a narrow beam. We have to be lined up just right in order to detect them, because not all bursts are beamed toward us — when we see one it’s because we’re looking right down the barrel of the gamma-ray gun. Scientists estimate that there are at least 50 times more GRBs happening each day than we detect!
So what’s left after a GRB — just a solitary black hole? Since GRBs usually last only a matter of seconds, it’s very difficult to study them in-depth. Fortunately, each one leaves an afterglow that can last for hours or even years in extreme cases. Afterglows are created when the GRB jets run into material surrounding the star. Because that material slows the jets down, we see lower-energy light, like X-rays and radio waves, that can take a while to fade. Afterglows are so important in helping us understand more about GRBs that our Neil Gehrels Swift Observatory was specifically designed to study them!
Last fall, we had the opportunity to learn even more from a gamma-ray burst than usual! From 130 million light-years away, Fermi witnessed a pair of neutron stars collide, creating a spectacular short GRB. What made this burst extra special was the fact that ground-based gravitational wave detectors LIGO and Virgo caught the same event, linking light and gravitational waves to the same source for the first time ever!
For over 10 years now, Fermi has been exploring the gamma-ray universe. Thanks to Fermi, scientists are learning more about the fundamental physics of the cosmos, from dark matter to the nature of space-time and beyond. Discover more about how we’ll be celebrating Fermi’s achievements all year!
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.
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.
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.
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.
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.
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.
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.
Simulating alien worlds, designing spacecraft with origami and using tiny fossils to understand the lives of ancient organisms are all in a day’s work for interns at NASA.
Here’s how interns are taking our missions and science farther.
1. Connecting Satellites in Space
Becca Foust looks as if she’s literally in space – or, at least, on a sci-fi movie set. She’s surrounded by black, except for the brilliant white comet model suspended behind her. Beneath the socks she donned just for this purpose, the black floor reflects the scene like perfectly still water across a lake as she describes what happens here: “We have five spacecraft simulators that ‘fly’ in a specially designed flat-floor facility,” she says. “The spacecraft simulators use air bearings to lift the robots off the floor, kind of like a reverse air hockey table. The top part of the spacecraft simulators can move up and down and rotate all around in a similar way to real satellites.” It’s here, in this test bed on the Caltech campus, that Foust is testing an algorithm she’s developing to autonomously assemble and disassemble satellites in space. “I like to call it space K’nex, like the toys. We’re using a bunch of component satellites and trying to figure out how to bring all of the pieces together and make them fit together in orbit,” she says. A NASA Space Technology Research Fellow, who splits her time between Caltech and NASA’s Jet Propulsion Laboratory (JPL), working with Soon-Jo Chung and Fred Hadaegh, respectively, Foust is currently earning her Ph.D. at the University of Illinois at Urbana-Champaign. She says of her fellowship, “I hope my research leads to smarter, more efficient satellite systems for in-space construction and assembly.”
2. Diving Deep on the Science of Alien Oceans
Three years ago, math and science were just subjects Kathy Vega taught her students as part of Teach for America. Vega, whose family emigrated from El Salvador, was the first in her family to go to college. She had always been interested in space and even dreamed about being an astronaut one day, but earned a degree in political science so she could get involved in issues affecting her community. But between teaching and encouraging her family to go into science, It was only a matter of time before she realized just how much she wanted to be in the STEM world herself. Now an intern at NASA JPL and in the middle of earning a second degree, this time in engineering physics, Vega is working on an experiment that will help scientists search for life beyond Earth.
“My project is setting up an experiment to simulate possible ocean compositions that would exist on other worlds,” says Vega. Jupiter’s moon Europa and Saturn’s moon Enceladus, for example, are key targets in the search for life beyond Earth because they show evidence of global oceans and geologic activity. Those factors could allow life to thrive. JPL is already building a spacecraft designed to orbit Europa and planning for another to land on the icy moon’s surface. “Eventually, [this experiment] will help us prepare for the development of landers to go to Europa, Enceladus and another one of Saturn’s moons, Titan, to collect seismic measurements that we can compare to our simulated ones,” says Vega. “I feel as though I’m laying the foundation for these missions.”
3. Unfolding Views on Planets Beyond Our Solar System
“Origami is going to space now? This is amazing!” Chris Esquer-Rosas had been folding – and unfolding – origami since the fourth grade, carefully measuring the intricate patterns and angles produced by the folds and then creating new forms from what he’d learned. “Origami involves a lot of math. A lot of people don’t realize that. But what actually goes into it is lots of geometric shapes and angles that you have to account for,” says Esquer-Rosas. Until three years ago, the computer engineering student at San Bernardino College had no idea that his origami hobby would turn into an internship opportunity at NASA JPL. That is, until his long-time friend, fellow origami artist and JPL intern Robert Salazar connected him with the Starshade project. Starshade has been proposed as a way to suppress starlight that would otherwise drown out the light from planets outside our solar system so we can characterize them and even find out if they’re likely to support life. Making that happen requires some heavy origami – unfurling a precisely-designed, sunflower-shaped structure the size of a baseball diamond from a package about half the size of a pitcher’s mound. It’s Esquer-Rosas’ project this summer to make sure Starshade’s “petals” unfurl without a hitch. Says Esquer-Rosas, “[The interns] are on the front lines of testing out the hardware and making sure everything works. I feel as though we’re contributing a lot to how this thing is eventually going to deploy in space.”
4. Making Leaps in Extreme Robotics
Wheeled rovers may be the norm on Mars, but Sawyer Elliott thinks a different kind of rolling robot could be the Red Planet explorer of the future. This is Elliott’s second year as a fellow at NASA JPL, researching the use of a cube-shaped robot for maneuvering around extreme environments, like rocky slopes on Mars or places with very little gravity, like asteroids. A graduate student in aerospace engineering at Cornell University, Elliott spent his last stint at JPL developing and testing the feasibility of such a rover. “I started off working solely on the rover and looking at can we make this work in a real-world environment with actual gravity,” says Elliott. “It turns out we could.” So this summer, he’s been improving the controls that get it rolling or even hopping on command. In the future, Elliott hopes to keep his research rolling along as a fellow at JPL or another NASA center. “I’m only getting more and more interested as I go, so I guess that’s a good sign,” he says.
5. Starting from the Ground Up
Before the countdown to launch or the assembling of parts or the gathering of mission scientists and engineers, there are people like Joshua Gaston who are helping turn what’s little more than an idea into something more. As an intern with NASA JPL’s project formulation team, Gaston is helping pave the way for a mission concept that aims to send dozens of tiny satellites, called CubeSats, beyond Earth’s gravity to other bodies in the solar system. “This is sort of like step one,” says Gaston. “We have this idea and we need to figure out how to make it happen.” Gaston’s role is to analyze whether various CubeSat models can be outfitted with the needed science instruments and still make weight. Mass is an important consideration in mission planning because it affects everything from the cost to the launch vehicle to the ability to launch at all. Gaston, an aerospace engineering student at Tuskegee University, says of his project, “It seems like a small role, but at the same time, it’s kind of big. If you don’t know where things are going to go on your spacecraft or you don’t know how the spacecraft is going to look, it’s hard to even get the proposal selected.”
6. Finding Life on the Rocks
By putting tiny samples of fossils barely visible to the human eye through a chemical process, a team of NASA JPL scientists is revealing details about organisms that left their mark on Earth billions of years ago. Now, they have set their sights on studying the first samples returned from Mars in the future. But searching for signatures of life in such a rare and limited resource means the team will have to get the most science they can out of the smallest sample possible. That’s where Amanda Allen, an intern working with the team in JPL’s Astrobiogeochemistry, or abcLab, comes in. “Using the current, state-of-the-art method, you need a sample that’s 10 times larger than we’re aiming for,” says Allen, an Earth science undergraduate at the University of California, San Diego, who is doing her fifth internship at JPL. “I’m trying to get a different method to work.” Allen, who was involved in theater and costume design before deciding to pursue Earth science, says her “superpower” has always been her ability to find things. “If there’s something cool to find on Mars related to astrobiology, I think I can help with that,” she says.
7. Taking Space Flight Farther
If everything goes as planned and a thruster like the one Camille V. Yoke is working on eventually helps send astronauts to Mars, she’ll probably be first in line to play the Mark Watney role. “I’m a fan of the Mark Watney style of life [in “The Martian”], where you’re stranded on a planet somewhere and the only thing between you and death is your own ability to work through problems and engineer things on a shoestring,” says Yoke. A physics major at the University of South Carolina, Yoke is interning with a team that’s developing a next-generation electric thruster designed to accelerate spacecraft more efficiently through the solar system. “Today there was a brief period in which I knew something that nobody else on the planet knew – for 20 minutes before I went and told my boss,” says Yoke. “You feel like you’re contributing when you know that you have discovered something new.”
8. Searching for Life Beyond Our Solar System
Without the option to travel thousands or even tens of light-years from Earth in a single lifetime, scientists hoping to discover signs of life on planets outside our solar system, called exoplanets, are instead creating their own right here on Earth. This is Tre’Shunda James’ second summer simulating alien worlds as an intern at NASA JPL. Using an algorithm developed by her mentor, Renyu Hu, James makes small changes to the atmospheric makeup of theoretical worlds and analyzes whether the combination creates a habitable environment. “This model is a theoretical basis that we can apply to many exoplanets that are discovered,” says James, a chemistry and physics major at Occidental College in Los Angeles. “In that way, it’s really pushing the field forward in terms of finding out if life could exist on these planets.” James, who recently became a first-time co-author on a scientific paper about the team’s findings, says she feels as though she’s contributing to furthering the search for life beyond Earth while also bringing diversity to her field. “I feel like just being here, exploring this field, is pushing the boundaries, and I’m excited about that.”
9. Spinning Up a Mars Helicopter
Chloeleen Mena’s role on the Mars Helicopter project may be small, but so is the helicopter designed to make the first flight on the Red Planet. Mena, an electrical engineering student at Embry-Riddle Aeronautical University, started her NASA JPL internship just days after NASA announced that the helicopter, which had been in development at JPL for nearly five years, would be going to the Red Planet aboard the Mars 2020 rover. This summer, Mena is helping test a part needed to deploy the helicopter from the rover once it lands on Mars, as well as writing procedures for future tests. “Even though my tasks are relatively small, it’s part of a bigger whole,” she says.
10. Preparing to See the Unseen on Jupiter’s Moon Europa
In the 2020s, we’re planning to send a spacecraft to the next frontier in the search for life beyond Earth: Jupiter’s moon Europa. Swathed in ice that’s intersected by deep reddish gashes, Europa has unveiled intriguing clues about what might lie beneath its surface – including a global ocean that could be hospitable to life. Knowing for sure hinges on a radar instrument that will fly aboard the Europa Clipper orbiter to peer below the ice with a sort of X-ray vision and scout locations to set down a potential future lander. To make sure everything works as planned, NASA JPL intern Zachary Luppen is creating software to test key components of the radar instrument. “Whatever we need to do to make sure it operates perfectly during the mission,” says Luppen. In addition to helping things run smoothly, the astronomy and physics major says he hopes to play a role in answering one of humanity’s biggest questions. “Contributing to the mission is great in itself,” says Luppen. “But also just trying to make as many people aware as possible that this science is going on, that it’s worth doing and worth finding out, especially if we were to eventually find life on Europa. That changes humanity forever!”
Read the full web version of this week’s ‘Solar System: 10 Things to Know” article HERE.