Heliophysics - Blog Posts

See the Closest Ever Images of the Sun

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

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

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

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

The Sun up close

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

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

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

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

Studying space

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

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

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

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

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Things That Go Bump in the Gamma Rays

Some people watch scary movies because they like being startled. A bad guy jumps out from around a corner! A monster emerges from the shadows! Scientists experience surprises all the time, but they’re usually more excited than scared. Sometimes theories foreshadow new findings — like when there’s a dramatic swell in the movie soundtrack — but often, discoveries are truly unexpected. 

Scientists working with the Fermi Gamma-Ray Space Telescope have been jumping to study mysterious bumps in the gamma rays for a decade now. Gamma rays are the highest-energy form of light. Invisible to human eyes, they’re created by some of the most powerful and unusual events and objects in the universe. In celebration of Halloween, here are a few creepy gamma-ray findings from Fermi’s catalog.

Stellar Graveyards

If you were to walk through a cemetery at night, you’d expect to trip over headstones or grave markers. Maybe you’d worry about running into a ghost. If you could explore the stellar gravesite created when a star explodes as a supernova, you’d find a cloud of debris expanding into interstellar space. Some of the chemical elements in that debris, like gold and platinum, go on to create new stars and planets! Fermi found that supernova remnants IC 443 and W44 also accelerate mysterious cosmic rays, high-energy particles moving at nearly the speed of light. As the shockwave of the supernova expands, particles escape its magnetic field and interact with non-cosmic-ray particles to produce gamma rays. 

Ghost Particles

But the sources of cosmic rays aren’t the only particle mysteries Fermi studies. Just this July, Fermi teamed up with the IceCube Neutrino Observatory in Antarctica to discover the first source of neutrinos outside our galactic neighborhood. Neutrinos are particles that weigh almost nothing and rarely interact with anything. Around a trillion of them pass through you every second, ghost-like, without you noticing and then continue on their way. (But don’t worry, like a friendly ghost, they don’t harm you!) Fermi traced the neutrino IceCube detected back to a supermassive black hole in a distant galaxy. By the time it reached Earth, it had traveled for 3.7 billion years at almost the speed of light!

Black Widow Pulsars

Black widows and redbacks are species of spiders with a reputation for devouring their partners. Astronomers have discovered two types of star systems that behave in a similar way. Sometimes when a star explodes as a supernova, it collapses back into a rapidly spinning, incredibly dense star called a pulsar. If there’s a lighter star nearby, it can get stuck in a close orbit with the pulsar, which blasts it with gamma rays, magnetic fields and intense winds of energetic particles. All these combine to blow clouds of material off the low-mass star. Eventually, the pulsar can eat away at its companion entirely.

Dark Matter

What’s scarier than a good unsolved mystery? Dark matter is a little-understood substance that makes up most of the matter in the universe. The stuff that we can see — stars, people, haunted houses, candy — is made up of normal matter. But our surveys of the cosmos tell us there’s not enough normal matter to keep things working the way they do. There must be another type of matter out there holding everything together. One of Fermi’s jobs is to help scientists narrow down the search for dark matter. Last year, researchers noticed that most of the gamma rays coming from the Andromeda galaxy are confined to its center instead of being spread throughout. One possible explanation is that accumulated dark matter at the center of the galaxy is emitting gamma rays!

Fermi has helped us learn a lot about the gamma-ray universe over the last 10 years. Learn more about its accomplishments and the other mysteries it’s working to solve. What other surprises are waiting out among the stars?

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Counting Down to ICON's Launch

In October 2018, we're launching the Ionospheric Connection Explorer, or ICON, to study Earth's dynamic interface to space.

The region of Earth's atmosphere on the edge of space plays a crucial role in our technology and exploration. This is where many of our satellites — including the International Space Station — orbit, and changing conditions in this region can cause problems for those satellites and disrupt communications signals.

This part of the atmosphere is shaped by a complicated set of factors. From below, regular weather on Earth can propagate upwards and influence this region. From above, electric and magnetic fields and charged particles in space — collectively called space weather — can also trigger changes. ICON's goal is to better understand this region and how it's shaped by these outside influences.  

10-mile-per-hour sensitivity

Though the ICON spacecraft zooms around Earth at upwards of 14,000 miles per hour, its wind-measuring instrument, named MIGHTI, can detect changes in wind speed smaller than 10 miles per hour. MIGHTI measures the tiny shifts in color caused by the motion of glowing gases in the upper atmosphere. Then, by making use of the Doppler effect — the same phenomenon that makes an ambulance siren change pitch as it passes you — scientists can figure out the gases' speed and direction.

97-minute orbital period

ICON circles Earth in just over an hour and a half, completing nearly 15 orbits per day. Its orbit is inclined by 27 degrees, so over time, its measurements will completely cover the latitudes scientists are most interested in, near the equator.

8 1/3-foot solar panel

ICON doesn't carry any onboard fuel. Instead, its single solar panel — measuring about 100 inches long and 33 inches wide, a little bit bigger than a standard door — produces power for the spacecraft. In science mode, ICON draws about 209-265 Watts of power.

7 years of teamwork

Now getting ready for launch, the ICON team has been hard at work ever since the idea for the mission was selected for further study in 2011.  

634 pounds

How much does good science weigh? In ICON's case, about as much as vending machine. The observatory weighs 634 pounds altogether.

5 snapshots per minute from FUV

Because ICON travels so fast, its Far Ultraviolet instrument takes eight snapshots per second of passing structures. This avoids blurring the images and captures the fine detail scientists need. But available bandwidth only allows FUV to send 5 images per minute, so the instrument uses a de-blurring technique called time-delay integration to combine 12 seconds' worth of data into a single image.

Image credit: Mark Belan

4 types of instruments collecting data in tandem

ICON carries four distinct instruments to study Earth's boundary to space.

2 MIGHTIs (Michelson Interferometer for Global High-resolution Thermospheric Imaging): Built by the Naval Research Laboratory in Washington, D.C., to observe the temperature and speed of the neutral atmosphere. There are two identical MIGHTI instruments onboard ICON.

2 IVMs (Ion Velocity Meter): Built by the University of Texas at Dallas to observe the speed of the charged particle motions, in response to the push of the high-altitude winds and the electric fields they generate. ICON carries two, and they are the mission’s only in situ instruments.  

EUV (Extreme Ultra-Violet instrument): Built by the University of California, Berkeley to capture images of oxygen glowing in the upper atmosphere, in order to measure the height and density of the daytime ionosphere.

FUV (Far Ultra-Violet instrument): Built by UC Berkeley to capture images of the upper atmosphere in the far ultraviolet light range. At night, FUV measures the density of the ionosphere, tracking how it responds to weather in the lower atmosphere. During the day, FUV measures changes in the chemistry of the upper atmosphere — the source for the charged gases found higher up in space.

360 miles above Earth

ICON orbits about 360 miles above Earth, near the upper reaches of the ionosphere — the region of Earth's atmosphere populated by electrically charged particles. From this vantage point, ICON combines remote measurements looking down along with direct measurements of the material flowing around it to connect changes throughout this region.

2 missions working together

NASA's GOLD mission — short for Global-scale Observations of the Limb and Disk — launched aboard a commercial communications satellite on Jan. 25, 2018. From its vantage point in geostationary orbit over Brazil, GOLD gets a full-disk view of the same region of space that ICON studies, helping scientists connect the big picture with the details.

1 gigabit of data per day

Together, ICON's instruments produce and downlink about 1 gigabit of data per day — about 125 megabytes. This adds up to about 1 gigabyte per week. ICON produces 10 different data products, ranging from measurements of wind speeds and ionospheric density to more complex models, that will help scientists shed new light on this ever-changing region.

ICON’s launch is scheduled for 4 a.m. EDT on Oct. 26, and NASA TV coverage begins at 3:45 a.m. Stay tuned on Twitter and Facebook for the latest on ICON. 

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A Year on the Sun Through Our Satellite’s Eyes

Did you know we’re watching the Sun 24/7 from space?

We use a whole fleet of satellites to monitor the Sun and its influences on the solar system. One of those is the Solar Dynamics Observatory. It’s been in space for eight years, keeping an eye on the Sun almost every moment of every day. Launched on Feb. 11, 2010, this satellite (also known as SDO) was originally designed for a two-year mission, but it’s still collecting data to this day — and one of our best ways to keep an eye on our star.

To celebrate another year of SDO, we’re sharing some of our favorite solar views that the spacecraft sent back to Earth in 2017.

 March: A long spotless stretch

For 15 days starting on March 7, SDO saw the yolk-like spotless Sun in visible light.

The Sun goes through a natural 11-year cycle of activity marked by two extremes: solar maximum and solar minimum. Sunspots are dark regions of complex magnetic activity on the Sun’s surface, and the number of sunspots at any given time is used as an index of solar activity.

Solar maximum = intense solar activity and more sunspots

Solar minimum = less solar activity and fewer sunspots

This March 2017 period was the longest stretch of spotlessness since the last solar minimum in April 2010 – a sure sign that the solar cycle is marching on toward the next minimum, which scientists expect in 2019-2020. For comparison, the images on the left are from Feb. 2014 – during the last solar maximum –  and show a much spottier Sun.

June: Energized active regions

 A pair of relatively small but frenetic active regions – areas of intense and complex magnetic fields – rotated into SDO’s view May 31 – June 2, while spouting off numerous small flares and sweeping loops of plasma. The dynamic regions were easily the most remarkable areas on the Sun during this 42-hour period.

July: Two weeks in the life of a sunspot

On July 5, SDO watched an active region rotate into view on the Sun. The satellite continued to track the region as it grew and eventually rotated across the Sun and out of view on July 17.  

With their complex magnetic fields, sunspots are often the source of interesting solar activity: During its 13-day trip across the face of the Sun, the active region — dubbed AR12665 — put on a show for our Sun-watching satellites, producing several solar flares, a coronal mass ejection and a solar energetic particle event. 

August: An eclipse in space

While millions of people in North America experienced a total solar eclipse on Aug. 21, SDO saw a partial eclipse from space. SDO actually sees several lunar transits a year from its perspective – but an eclipse on the ground doesn’t necessarily mean that SDO will see anything out of the ordinary. Even on Aug. 21, SDO saw only 14 percent of the Sun blocked by the Moon, while most US residents saw 60 percent blockage or more.

September: A spate of solar activity

In September 2017, SDO saw a spate of solar activity, with the Sun emitting 31 notable flares and releasing several powerful coronal mass ejections between Sept. 6-10. Solar flares are powerful bursts of radiation, while coronal mass ejections are massive clouds of solar material and magnetic fields that erupt from the Sun at incredible speeds.

One of the flares imaged by SDO on Sept. 6 was classified as X9.3 – clocking in at the most powerful flare of the current solar cycle. The current cycle began in December 2008 and is now decreasing in intensity, heading toward solar minimum. During solar minimum, such eruptions on the Sun are increasingly rare, but history has shown that they can nonetheless be intense.

September: A trio of tempests

Three distinct solar active regions with towering arches rotated into SDO’s view over a three-day period from Sept. 24-26. Charged particles spinning along the ever-changing magnetic field lines above the active regions trace out the magnetic field in extreme ultraviolet light, a type of light that is typically invisible to our eyes, but is colorized here in gold. To give some sense of scale, the largest arches are many times the size of Earth.

December: A curling prominence

SDO saw a small prominence arch up and send streams of solar material curling back into the Sun over a 30-hour period on Dec. 13-14. Prominences are relatively cool strands of solar material tethered above the Sun’s surface by magnetic fields.

 December: Solar question mark

An elongated coronal hole — the darker area near the center of the Sun’s disk — looked something like a question mark when seen in extreme ultraviolet light by SDO on Dec. 21-22. Coronal holes are magnetically open areas on the Sun that allow high-speed solar wind to gush out into space. They appear as dark areas when seen in certain wavelengths of extreme ultraviolet light.

For all the latest on the Solar Dynamics Observatory, visit nasa.gov/sdo. Keep up with the latest on the Sun on Twitter @NASASun or at facebook.com/NASASunScience.

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Get Ready to Watch Us Go for GOLD

The boundary where Earth’s atmosphere gives way to outer space is a complex place: Atmospheric waves driven by weather on Earth compete with electric and magnetic fields that push charged particles, all while our signals and satellites whiz by.

On Jan. 25, we’re launching the GOLD instrument (short for Global-scale Observations of the Limb and Disk) to get an exciting new birds-eye view of this region, Earth’s interface to space.

High above the ozone layer, the Sun’s intense radiation cooks some of the particles in the upper atmosphere into an electrically charged soup, where negatively charged electrons and positively charged ions flow freely. This is the ionosphere. The ionosphere is co-mingled with the highest reaches of our planet’s neutral upper atmosphere, called the thermosphere.

Spanning from just a few dozen to several hundred miles above Earth’s surface, the ionosphere is increasingly part of the human domain. Not only do our satellites, including the International Space Station, fly through this region, but so do the signals that are part of our communications and navigation systems, including GPS. Changes in this region can interfere with satellites and signals alike.  

Conditions in the upper atmosphere are difficult to predict, though. Intense weather, like hurricanes, can cause atmospheric waves to propagate all the way up to this region, creating winds that change its very makeup.

Because it’s made up of electrically charged particles, the upper atmosphere also responds to space weather. Space weather – which is usually driven by activity on the Sun – often results in electric and magnetic fields that push and pull on the ionosphere’s charged particles, changing the region’s makeup. On top of that, space weather can also mean incoming showers of high-energy particles that can affect satellites or endanger astronauts, and, in extreme cases, even cause power outages on Earth.

That’s where GOLD comes in. GOLD takes advantage of its host satellite’s geostationary orbit over the Western Hemisphere to maintain a constant view of the upper atmosphere, day and night. By scanning across, GOLD builds up a complete picture of Earth’s disk every half hour.

GOLD is an imaging spectrograph, a type of instrument that breaks light down into its component wavelengths. Studying light in this way lets scientists track the movement and temperatures of different chemical species and build up a picture of how the upper atmosphere changes over time. Capturing these measurements several times a day means that, for the first time, scientists will be able to record the short-term changes in the region -- our first look at its day-to-day ‘weather.’

GOLD is our first-ever mission to fly as a hosted payload on a commercial satellite. A hosted payload flies aboard an otherwise unrelated satellite, hitching a ride to space. GOLD studies the upper atmosphere, while its host satellite supports commercial communications.

Later this year, we’re launching another mission to study the ionosphere: ICON, short for Ionospheric Connection Explorer. Like GOLD, ICON studies Earth’s interface to space, but with a few important distinctions. ICON employs a suite of different instruments to study the ionosphere both remotely and in situ. The direct in situ measurements are possible because ICON flies in low-Earth orbit, giving us a detailed view to complement GOLD’s global perspective of the regions that both missions study.  

How to watch the launch on Jan. 25

Arianespace, a commerical aerospace company, is launching GOLD’s host commercial communications satellite, SES-14, for SES from Kourou, French Guiana.

Watch liftoff live on NASA Television - nasa.gov/live Launch Coverage starts at 5 p.m. EST  (2 p.m. PST, 7 p.m. Kourou local time)

We’ll be streaming the launch live on NASA TV! You can also follow along on Twitter (@NASA and @NASASun), Facebook (NASA and NASA Sun Science), Instagram, and on our Snapchat (NASA). 

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Going for GOLD

On Jan. 25, we’re going for GOLD!

We’re launching an instrument called Global-scale Observations of the Limb and Disk, GOLD for short. It’s a new mission that will study a complicated — and not yet fully understood — region of near-Earth space, called the ionosphere.

Space is not completely empty: It’s teeming with fast-moving energized particles and electric and magnetic fields that guide their motion. At the boundary between Earth’s atmosphere and space, these particles and fields — the ionosphere — co-exist with the upper reaches of the neutral atmosphere.

That makes this a complicated place. Big events in the lower atmosphere, like hurricanes or tsunamis, can create waves that travel all the way up to that interface to space, changing the wind patterns and causing disruptions.

It’s also affected by space weather. The Sun is a dynamic star, and it releases spurts of energized particles and blasts of solar material carrying electric and magnetic fields that travel out through the solar system. Depending on their direction, these bursts have the potential to disrupt space near Earth.

This combination of factors makes it hard to predict changes in the ionosphere — and that can have a big impact. Communications signals, like radio waves and signals that make our GPS systems work, travel through this region, and sudden changes can distort them or even cut them off completely.

Low-Earth orbiting satellites — including the International Space Station — also fly through the ionosphere, so understanding how it fluctuates is important for protecting these satellites and astronauts.  

GOLD is a spectrograph, an instrument that breaks light down into its component wavelengths, measuring their intensities. Breaking light up like this helps scientists see the behavior of individual chemical elements — for instance, separating the amount of oxygen versus nitrogen. GOLD sees in far ultraviolet light, a type of light that’s invisible to our eyes.

GOLD is a hosted payload. The instrument is hitching a ride aboard SES-14, a commercial communications satellite built by Airbus for SES Government Solutions, which owns and operates the satellite.

Also launching this year is the Ionospheric Connection Explorer, or ICON, which will also study the ionosphere and neutral upper atmosphere. But while GOLD will fly in geostationary orbit some 22,000 miles above the Western Hemisphere, ICON will fly just 350 miles above Earth, able to gather close up images of this region.

Together, these missions give us an unprecedented look at the ionosphere and upper atmosphere, helping us understand the very nature of how our planet interacts with space.

To learn more about this region of space and the GOLD mission, visit: nasa.gov/gold.

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

Why We Study the Sun-Earth Connection – Explained Through Songs

We're launching a new mission to the International Space Station to continue measurements of the Sun's energy reaching Earth.

The Total and Spectral solar Irradiance Sensor (TSIS-1) will precisely measure the total amount of sunlight that falls on Earth and how that light is distributed among different wavelengths, including the ultraviolet, visible and infrared. This will give us a better understanding of Earth’s primary energy supply and help improve models simulating Earth’s climate.

1. You are my sunshine, my only sunshine. You make me happy when skies are gray.

The Sun is Earth's sunshine and it does more than make us happy; it gives us life. Our Sun's energy drives our planet's ocean currents, seasons, weather and climate. Changes in the Sun also alter our climate in at least two ways.

First, solar radiation has a direct effect where it heats regions of Earth, like our oceans, land, and atmosphere. Second, the solar radiation can cause indirect effects, such as when sunlight interacts with molecules in the upper atmosphere to produce ozone which can affect human health.  

Earth’s energy system is in a constant dance to maintain a balance between incoming energy from the Sun and outgoing energy from Earth to space, which scientists call Earth’s energy budget. If you have more energy absorbed by the Earth than leaving it, its temperature increases and vice versa. Because the Sun is Earth's fundamental energy source and only sunshine, we need a quantitative record of the Sun's solar energy output. TSIS-1 will provide the most accurate measurements ever made of sunlight as seen from above Earth’s atmosphere.

2. You're hot then you're cold…You're in then you're out. You're up then you're down.

The energy flow between the Earth and Sun's connection is not a constant thing. The Sun can be fickle, sometimes it puts out slightly more energy and some years less. Earth is no better. The Earth absorbs different amounts of the Sun's energy depending on many factors, such as the presence of clouds and tiny particles in the atmosphere called aerosols.  

What we do know is that the Sun's cycle is about 11 years rolling through periods of quiet to times of intense activity. When the Sun is super-intense it releases explosions of light and solar material. This time is a solar maximum.

When the Sun is in a quiet state this period is called the solar minimum.

Over the course of one solar cycle (one 11-year period), the Sun’s total emitted energy varies on average at about 0.1 percent. That may not sound like a lot, but the Sun emits a large amount of energy – 1,361 watts per square meter. Even fluctuations at just a tenth of a percent can affect Earth. That's why TSIS-1 is launching: to help scientists understand and anticipate how changes in the Sun will affect us on Earth.

3. You're so vain. You probably think this climate model is about you.

Scientists use computer models to interpret changes in the Sun’s energy input. If less solar energy is available, scientists can gauge how that affects Earth’s atmosphere, oceans, weather and seasons by using computer simulations. But the Sun is just one of many factors scientists use to model Earth’s climate. A lot of other factors come into play in addition to the energy from the Sun. Factors like greenhouse gases, clouds scattering light and small particles in the atmosphere called aerosols all can affect Earth’s climate so they all need to be included in climate models. So, while we need to measure the total amount of energy from the Sun, we also need to understand how these other factors alter the amount of energy reaching Earth's surface and affect our climate.

4. Someday we'll find it, the rainbow connection. The lovers, the dreamers and me.

We receive the Sun's energy in many different wavelengths, including visible light (rainbows!) as well as light we can't see like infrared and ultraviolet wavelengths. Each color or wavelength of light from the Sun affects Earth’s atmosphere differently.

For instance, ultraviolet light from the Sun can affect Earth's ozone. High in the atmosphere is a layer of protective ozone gas. Ozone is Earth’s natural sunscreen, absorbing the Sun’s most harmful ultraviolet radiation and protecting living things below. But ozone is vulnerable to certain gases made by humans that reach the upper atmosphere. Once there, they react in the presence of sunlight to destroy ozone molecules. Currently, several satellites from us and the National Oceanic and Atmospheric Administration (NOAA) track the ozone in the upper atmosphere and the solar energy that drives the photochemistry that creates and destroys ozone. Our new instrument, TSIS-1, will join that fleet with even better accuracy.

TSIS-1 will see different types of ultraviolet (UV) light, including UV-B and UV-C. Each plays a different role in the ozone layer. UV-C rays are essential in creating ozone. UV-B rays and some naturally occurring chemicals regulate the abundance of ozone in the upper atmosphere. The amount of ozone is a balance between these natural production and loss processes.

TSIS-1 data of the Sun's UV energy will help improve computer models of the atmosphere that need accurate measurements of sunlight across the ultraviolet spectrum to model the ozone layer correctly. While UV light represents a tiny fraction of the total sunlight that reaches the top of Earth's atmosphere, it fluctuates from 3 to 10 percent, a change that, in turn causes small changes in the chemical composition and thermal structure of the upper atmosphere.

This is just one of the important applications of TSIS-1 measurements. TSIS-1 will measure how the Sun's energy is distributed over 1,000 different wavelengths.

5. Every move you make…every step you take, I'll be watching you.

TSIS-1 will continue our nearly 40 years of closely studying the total amount of energy the Sun sends to Earth from space. We've previously studied this 'total solar irradiance' with nine previous satellites, currently with Solar Radiation and Climate Experiment, (SORCE).

NASA’s SORCE collected this data on the total amount of the Sun’s radiant energy throughout Sept. 2017. The satellite actually detected a dip in total irradiance – or the total amount of energy from the Sun- during the month’s intense solar activity.

But there's still very much we don't know about total solar irradiance. We do not know how it varies over longer timescales. Longer term observations are especially important because scientists have observed unusually quiet magnetic activity from the Sun for the past two decades with previous satellites. During the last prolonged solar minimum in 2008-2009, our Sun was the quietest it has ever been since we started observations in 1978. Scientists expect the Sun to enter a solar minimum within the next three years, and TSIS-1 will be primed to take measurements of the next minimum and see if this is part of a larger trend.

For all the latest Earth updates, follow us on Twitter @NASAEarth or Facebook. 

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The Daredevil Spacecraft That Will Touch the Sun

In the summer of 2018, we’re launching Parker Solar Probe, a spacecraft that will get closer to the Sun than any other in human history.

Parker Solar Probe will fly directly through the Sun’s atmosphere, called the corona. Getting better measurements of this region is key to understanding our Sun. For instance, the Sun releases a constant outflow of solar material, called the solar wind. We think the corona is where this solar wind is accelerated out into the solar system, and Parker Solar Probe’s measurements should help us pinpoint how that happens.  

The solar wind, along with other changing conditions on the Sun and in space, can affect Earth and are collectively known as space weather. Space weather can trigger auroras, create problems with satellites, cause power outages (in extreme cases), and disrupt our communications signals. That’s because space weather interacts with Earth’s upper atmosphere, where signals like radio and GPS travel from place to place.

Parker Solar Probe is named after pioneering physicist Gene Parker. In the 1950s, Parker proposed a number of concepts about how stars — including our Sun — give off energy. He called this cascade of energy the solar wind. Parker also theorized an explanation for the superheated solar atmosphere, the corona, which is hotter than the surface of the Sun itself.

Getting the answers to our questions about the solar wind and the Sun’s energetic particles is only possible by sending a probe right into the furnace of the Sun’s corona, where the spacecraft can reach 2,500 degrees Fahrenheit. Parker Solar Probe and its four suites of instruments – studying magnetic and electric fields, energetic particles, and the solar wind – will be protected from the Sun’s enormous heat by a 4.5-inch-thick carbon-composite heat shield.

Over the course of its seven-year mission, Parker Solar Probe will make two dozen close approaches to the Sun, continuously breaking its own records and sending back unprecedented science data.

Getting close to the Sun is harder than you might think, since the inertia of a spacecraft launched from Earth will naturally carry it in repeated orbits on roughly the same path. To nudge the orbit closer to the Sun on successive trips, Parker Solar Probe will use Venus’ gravity.

This is a technique called a gravity assist, and it’s been used by Voyager, Cassini, and OSIRIS-REx, among other missions. Though most missions use gravity assists to speed up, Parker Solar Probe is using Venus’ gravity to slow down. This will let the spacecraft fall deeper into the Sun’s gravity and get closer to our star than any other spacecraft in human history.

Get a behind-the-scenes view of the Parker Solar Probe under construction in a clean room on the NASA Sun Science Facebook page.

Keep up with all the latest on Parker Solar Probe at nasa.gov/solarprobe or on Twitter @NASASun.

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A Total Solar Eclipse Revealed Solar Storms 100 Years Before Satellites

Just days from now, on Aug. 21, 2017, the Moon will pass between the Sun and Earth, casting its shadow down on Earth and giving all of North America the chance to see a solar eclipse. Remember that it is never safe to look at the partially eclipsed or uneclipsed Sun, so make sure you use a solar filter or indirect viewing method if you plan to watch the eclipse.

Eclipses set the stage for historic science. Past eclipses enabled scientists to study the Sun’s structure, find the first proof of Einstein’s theory of general relativity, and discover the element helium — 30 years before it was found on Earth..

We’re taking advantage of the Aug. 21 eclipse by funding 11 ground-based scientific studies. As our scientists prepare their experiments for next week, we’re looking back to an historic 1860 total solar eclipse, which many think gave humanity our first glimpse of solar storms — called coronal mass ejections — 100 years before scientists first understood what they were.  

Coronal mass ejections, or CMEs, are massive eruptions made up of hot gas, plasma and magnetic fields. Bursting from the Sun’s surface, these giant clouds of solar material speed into space up to a million miles per hour and carry enough energy to power the world for 10,000 years if we could harness it. Sometimes, when they’re directed towards Earth, CMEs can affect Earth’s space environment, creating space weather: including triggering auroras, affecting satellites, and – in extreme cases – even straining power grids.

Scientists observed these eruptions in the 1970s during the beginning of the modern satellite era, when satellites in space were able to capture thousands of images of solar activity that had never been seen before.

But in hindsight, scientists realized their satellite images might not be the first record of these solar storms. Hand-drawn records of an 1860 total solar eclipse bore surprising resemblance to these groundbreaking satellite images.

On July 18, 1860, the Moon’s shadow swept across North America, Spain and North Africa. Because it passed over so much populated land, this eclipse was particularly well-observed, resulting in a wealth of scientific observations.  

Drawings from across the path of the 1860 eclipse show large, white finger-like projections in the Sun’s atmosphere—called the corona—as well as a distinctive, bubble-shaped structure. But the observations weren’t uniform – only about two-thirds of the 1860 eclipse sketches showed this bubble, setting off heated debate about what this feature could have been.

Sketches from the total solar eclipse of July 1860.

One hundred years later, with the onset of space-based satellite imagery, scientists got another piece of the puzzle. Those illustrations from the 1860 eclipse looked very similar to satellite imagery showing CMEs – meaning 1860 may have been humanity’s first glimpse at these solar storms, even though we didn’t understand what we were seeing.

While satellites provide most of the data for CME research, total solar eclipses seen from the ground still play an important role in understanding our star. During an eclipse, observers on the ground are treated to unique views of the innermost corona, the region of the solar atmosphere that triggers CMEs.

This region of the Sun’s atmosphere can’t be measured at any other time, since human-made instruments that create artificial eclipses must block out much of the Sun’s atmosphere—as well as its bright face—in order to produce clear images. Yet scientists think this important region is responsible for accelerating CMEs, as well as heating the entire corona to extraordinarily high temperatures.

When the path of an eclipse falls on land, scientists take advantage of these rare chances to collect unique data. With each new total solar eclipse, there’s the possibility of new information and research—and maybe, the chance to reveal something as astronomical as the first solar storm.

Learn all about the Aug. 21 eclipse at eclipse2017.nasa.gov, and follow @NASASun on Twitter and NASA Sun Science on Facebook for more. Watch the eclipse through the eyes of NASA at nasa.gov/eclipselive starting at 12 PM ET on Aug. 21.

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This composite image shows a coronal mass ejection, a type of space weather linked to solar energetic particles, as seen from two space-based solar observatories and one ground-based instrument. The image in gold is from NASA’s Solar Dynamics Observatory, the image in blue is from the Manua Loa Solar Observatory’s K-Cor coronagraph, and the image in red is from ESA and NASA’s Solar and Heliospheric Observatory.

Our constantly-changing sun sometimes erupts with bursts of light, solar material, or ultra-fast energized particles — collectively, these events contribute to space weather. A new study shows that the warning signs of one type of space weather event can be detected tens of minutes earlier than with current forecasting techniques – critical extra time that could help protect astronauts in space. 

Credits: NASA/ESA/SOHO/SDO/Joy Ng and MLSO/K-Cor