Magneticfield - Blog Posts

Meet Parker Solar Probe, Our Mission to Touch the Sun

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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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.

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

Incoming! We’ve Got Science from Jupiter!

Our Juno spacecraft has just released some exciting new science from its first close flyby of Jupiter! 

In case you don’t know, the Juno spacecraft entered orbit around the gas giant on July 4, 2016…about a year ago. Since then, it has been collecting data and images from this unique vantage point.

Juno is in a polar orbit around Jupiter, which means that the majority of each orbit is spent well away from the gas giant. But once every 53 days its trajectory approaches Jupiter from above its north pole, where it begins a close two-hour transit flying north to south with its eight science instruments collecting data and its JunoCam camera snapping pictures.

Space Fact: The download of six megabytes of data collected during the two-hour transit can take one-and-a-half days!

Juno and her cloud-piercing science instruments are helping us get a better understanding of the processes happening on Jupiter. These new results portray the planet as a complex, gigantic, turbulent world that we still need to study and unravel its mysteries.

So what did this first science flyby tell us? Let’s break it down...

1. Tumultuous Cyclones

Juno’s imager, JunoCam, has showed us that both of Jupiter’s poles are covered in tumultuous cyclones and anticyclone storms, densely clustered and rubbing together. Some of these storms as large as Earth!

These storms are still puzzling. We’re still not exactly sure how they formed or how they interact with each other. Future close flybys will help us better understand these mysterious cyclones. 

Seen above, waves of clouds (at 37.8 degrees latitude) dominate this three-dimensional Jovian cloudscape. JunoCam obtained this enhanced-color picture on May 19, 2017, at 5:50 UTC from an altitude of 5,500 miles (8,900 kilometers). Details as small as 4 miles (6 kilometers) across can be identified in this image.

An even closer view of the same image shows small bright high clouds that are about 16 miles (25 kilometers) across and in some areas appear to form “squall lines” (a narrow band of high winds and storms associated with a cold front). On Jupiter, clouds this high are almost certainly comprised of water and/or ammonia ice.

2. Jupiter’s Atmosphere

Juno’s Microwave Radiometer is an instrument that samples the thermal microwave radiation from Jupiter’s atmosphere from the tops of the ammonia clouds to deep within its atmosphere.

Data from this instrument suggest that the ammonia is quite variable and continues to increase as far down as we can see with MWR, which is a few hundred kilometers. In the cut-out image below, orange signifies high ammonia abundance and blue signifies low ammonia abundance. Jupiter appears to have a band around its equator high in ammonia abundance, with a column shown in orange.

Why does this ammonia matter? Well, ammonia is a good tracer of other relatively rare gases and fluids in the atmosphere...like water. Understanding the relative abundances of these materials helps us have a better idea of how and when Jupiter formed in the early solar system.

This instrument has also given us more information about Jupiter’s iconic belts and zones. Data suggest that the belt near Jupiter’s equator penetrates all the way down, while the belts and zones at other latitudes seem to evolve to other structures.

3. Stronger-Than-Expected Magnetic Field

Prior to Juno, it was known that Jupiter had the most intense magnetic field in the solar system…but measurements from Juno’s magnetometer investigation (MAG) indicate that the gas giant’s magnetic field is even stronger than models expected, and more irregular in shape.

At 7.766 Gauss, it is about 10 times stronger than the strongest magnetic field found on Earth! What is Gauss? Magnetic field strengths are measured in units called Gauss or Teslas. A magnetic field with a strength of 10,000 Gauss also has a strength of 1 Tesla.  

Juno is giving us a unique view of the magnetic field close to Jupiter that we’ve never had before. For example, data from the spacecraft (displayed in the graphic above) suggests that the planet’s magnetic field is “lumpy”, meaning its stronger in some places and weaker in others. This uneven distribution suggests that the field might be generated by dynamo action (where the motion of electrically conducting fluid creates a self-sustaining magnetic field) closer to the surface, above the layer of metallic hydrogen. Juno's orbital track is illustrated with the black curve. 

4. Sounds of Jupiter

Juno also observed plasma wave signals from Jupiter’s ionosphere. This movie shows results from Juno's radio wave detector that were recorded while it passed close to Jupiter. Waves in the plasma (the charged gas) in the upper atmosphere of Jupiter have different frequencies that depend on the types of ions present, and their densities. 

Mapping out these ions in the jovian system helps us understand how the upper atmosphere works including the aurora. Beyond the visual representation of the data, the data have been made into sounds where the frequencies and playback speed have been shifted to be audible to human ears.

5. Jovian “Southern Lights”

The complexity and richness of Jupiter’s “southern lights” (also known as auroras) are on display in this animation of false-color maps from our Juno spacecraft. Auroras result when energetic electrons from the magnetosphere crash into the molecular hydrogen in the Jovian upper atmosphere. The data for this animation were obtained by Juno’s Ultraviolet Spectrograph. 

During Juno’s next flyby on July 11, the spacecraft will fly directly over one of the most iconic features in the entire solar system – one that every school kid knows – Jupiter’s Great Red Spot! If anybody is going to get to the bottom of what is going on below those mammoth swirling crimson cloud tops, it’s Juno.

Stay updated on all things Juno and Jupiter by following along on social media: Twitter | Facebook | YouTube | Tumblr

Learn more about the Juno spacecraft and its mission at Jupiter HERE.

Over a 22-hour period (May 2-3, 2017), strands of plasma at the sun’s edge shifted and twisted back and forth. In this close-up, the strands are being manipulated by strong magnetic forces associated with active regions on the sun. 

To give a sense of scale, the strands hover above the sun more than several times the size of Earth! The images were taken in a wavelength of extreme ultraviolet light. 

Learn more: http://go.nasa.gov/2qT2C4B

Credits: NASA/SDO

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Diving into New Magnetic Territory with the MMS Mission

Our Magnetospheric Multiscale Mission, or MMS, is on a journey to study a new region of space.  

On May 4, 2017, after three months of precisely coordinated maneuvers, MMS reached its new orbit to begin studying the magnetic environment on the ever-rotating nighttime side of Earth.

The space around Earth is not as empty as it looks. It’s packed with high energy electrons and ions that zoom along magnetic field lines and surf along waves created by electric and magnetic fields.  

MMS studies how these particles move in order to understand a process known as magnetic reconnection, which occurs when magnetic fields explosively collide and re-align.

After launch, MMS started exploring the magnetic environment on the side of Earth closest to the sun. Now, MMS has been boosted into a new orbit that tops out twice as high as before, at over 98,000 miles above Earth’s surface.

The new orbit will allow the spacecraft to study magnetic reconnection on the night side of Earth, where the process is thought to cause the northern and southern lights and energize particles that fill the radiation belts, a doughnut-shaped region of trapped particles surrounding Earth.  

MMS uses four separate but identical spacecraft, which fly in a tight pyramid formation known as a tetrahedron. This allows MMS to map the magnetic environment in three dimensions.

MMS made many discoveries during its first two years in space, and its new orbit will open the door to even more. The information scientists get from MMS will help us better understand our space environment, which helps in planning future missions to explore even further beyond our planet. Learn more about MMS at nasa.gov/mms.

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The magnetic field lines between a pair of active regions formed a beautiful set of swaying arches, seen in this footage captured by our Solar Dynamics Observatory on April 24-26, 2017. 

These arches, which form a connection between regions of opposite magnetic polarity, are visible in exquisite detail in this wavelength of extreme ultraviolet light. Extreme ultraviolet light is typically invisible to our eyes, but is colorized here in gold. 

Take a closer look: https://go.nasa.gov/2pGgYZt

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Cascading loops on the surface of the sun highlight an active region that had just rotated into view of our solar-observing spacecraft. We have observed this phenomenon numerous times, but this one was one of the longest and clearest sequences we have seen in years. 

The bright loops are actually charged particles spinning along the magnetic field lines! The action was captured in a combination of two wavelengths of extreme ultraviolet light over a period of about 20 hours. 

Take a closer look: https://sdo.gsfc.nasa.gov/gallery/potw/item/798

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