POV: You're A NASA Probe Skimming The Surface Of The Sun

Bradley Brownell
Tue, September 19, 2023 


Gif: NASA

The Parker Space Probe is described by NASA as being “about the size of a small car,” and its only goal is to fly as close to the sun as possible to try to unravel some solar mysteries. What exactly is going on in the ‘solar corona,’ and what do solar flares really do? The space car, launched back in 2018, is currently sitting about 5.8 million miles from the sun and just over a year ago it flew right through a massively powerful sun explosion. Here is what that looked like.

The explosion is called a coronal mass ejection, and this is the first time in history that any spacecraft has ever flown straight through one. A stream of particles erupted from their orbit around the sun, interplanetary space dust blown away from the sun by the CME event. You can see in the gif from NASA that at the start the view of the satellite’s sensor is obscured by lots of dust and debris, and the surrounding stars get clearer as the dust is vacuumed away from view. Without the interplanetary dust in view, there’s nothing to reflect the light of the sun.

Massive solar flare strikes Nasa spacecraft sent to study Sun

Vishwam Sankaran
Tue, September 19, 2023 

Massive solar flare strikes Nasa spacecraft sent to study Sun

A massive solar flare has struck the closest spacecraft ever sent by humans to the Sun, revealing unprecedented insights into eruptions that have the potential to cause blackouts spanning continents.

Nasa’s Parker spacecraft, the fastest human-made object and the first-ever mission to ever “touch the Sun”, has now added another first to its belt by flying through a powerful solar explosion called a coronal mass ejection (CME).

The probe first detected the CME remotely before skirting along its flank, then passed into the structure and finally exited through the other side, scientists pointed out in a study published recently in The Astrophysical Journal.

It cruised in at about 9.2 million km (5.7 million miles) from the solar surface – closer than Mercury ever gets to the Sun.

Eruptions from the Sun expel billions of tons of charged particles at speeds ranging from 100-3,000km per second (60-1,900 miles per second).

When directed towards Earth, they can alter the planet’s magnetic field, generate spectacular auroras and also devastate satellite electronics and electrical grids on the ground, if strong enough.

“The potential damage of this class of event, large and very fast CMEs, can be colossal,” said Parker project scientist Nour Raouafi at the Johns Hopkins University.

“This is the closest to the Sun we’ve ever observed a CME. We’ve never seen an event of this magnitude at this distance,” Dr Raouafi said.

The research was published earlier this month, a full year after the spacecraft experienced the massive solar storm.

In the process, the spacecraft spent about two days observing the solar storm, revealing an unparalleled view into these stellar events.

As the probe passed behind the CME’s shockwave, its suite of instruments clocked particles accelerating up to 1,350km (840 miles) per second.

If such a flare had been directed towards Earth, Dr Raouafi suspects it may have been close in magnitude to the Carrington Event – an 1859 solar storm held as the most powerful on record to hit Earth.

Such an event today, if detected too late, could disable communications systems and lead to continent-wide blackouts, researchers said.

However, the Parker probe was unfazed thanks to its heat shield and radiators, while its thermal protection system ensured its temperatures never changed.

Scientists are currently working to piece together how the event unfolded by comparing measurements collected by the probe within the CME with those gathered outside it.

“You try simplified models to explain certain aspects of the event, but when you are this close to the Sun, none of these models can explain everything,” said study lead author Orlando Romeo from the University of California, Berkeley.

“We’re still not exactly sure what is happening there or how to connect it,” Dr Romeo said.

Researchers said the spacecraft is likely to observe more such massive CMEs as the Sun approaches solar maximum – a peak in its 11-year activity cycle that is expected in 2025.

The spacecraft’s next solar flyby is set to occur on 27 September.

Parker Solar Probe and Solar Orbiter team up to tackle 65-year-old sun mystery

Robert Lea
Sun, September 17, 2023 

Two views of the sun, the left looks like a yellow fiery ball of plasma while the right looks like a glowing white light with reddish beams around it.

A new groundbreaking measurement made by the Solar Orbiter spacecraft and the Parker Solar probe brings scientists closer than ever to solving a longstanding mystery surrounding the sun. Oddly enough, our host star's atmosphere, or corona, is staggeringly hotter than the solar surface despite being further away from the obvious source of the sun’s heat — and this is a puzzle that has troubled physicists for about 65 years.

The collaboration between these two instruments was made possible when the Solar Orbiter, operated by the European Space Agency (ESA) performed some space-based gymnastics. These maneuvers allowed the spacecraft to observe the sun and NASA’s Parker Solar Probe at the same time. Ultimately, that allowed for simultaneous solar observations between the two, which together indicated that turbulence is likely heating the solar corona to incredible temperatures.

"The ability to use both Solar Orbiter and Parker Solar Probe has really opened up an entirely new dimension in this research," Gary Zank, co-author of a study on the results and a researcher at the University of Alabama in Huntsville, said in a statement.

This team-up could finally solve the so-called "coronal heating mystery," which revolves around that heat discrepancy between the corona, made of wispy and nebulous electrically charged gas called plasma, and the sun’s surface, or photosphere.

What is the coronal heating mystery?

The corona can reach temperatures as great as 1.8 million degrees Fahrenheit (1,000,000 degrees Celsius), while 1,000 miles below it, the photosphere only reaches temperatures of around 10,800 degrees Fahrenheit (6,000 degrees Celsius).

That is a troubling fact because the sun’s core, where the nuclear fusion of hydrogen to helium occurs, is where the vast majority of the sun’s heat comes from. This is like air about one foot above a campfire being hotter than air one inch away from the flames.

The discrepancy in heat also means there must be another heating mechanism at play directly on the corona. Until now, that mechanism has evaded scientists, but turbulence in the atmosphere of the sun significantly heating coronal plasma has long been considered a plausible explanation. However, that hypothesis had been impossible to investigate with data from one spacecraft.

Satellites can investigate the sun in two ways: they can get up close and personal, making in-situ measurements like NASA’s Parker Solar Probe does, or they can make more remote investigations like the Solar Orbiter. The Solar Orbiter studies the corona from around 26 million miles (42 million kilometers) away from the sun, while the Parker Solar Probe braves the blazing hot plasma of the sun as it passes around 4 million miles (6.4 million km) from the solar surface.

But, there is a trade-off between the two approaches.

Remote sensing can see broad details about the sun, but suffers when it comes to making observations of what physics is at play in coronal plasma. On the other hand, in-situ observations can measure that plasma in greater detail but tend to miss the bigger solar picture.

That means uniting the large-scale measurements of events on the sun from the Solar Orbiter with the detailed observations of the same phenomenon by the Parker Solar Probe could present us with the total picture of the sun with all intricate details filled in — the best of both worlds.

This isn’t as straightforward as it sounds, however. To facilitate this team-up, the Parker Solar Probe would have to be within the field of view of one of the Solar Orbiter’s instruments as the two observe the sun from their relative positions.
How scientists achieved the 'best of both worlds' to potentially solve a solar mystery

A team of astronomers, including Italian National Institute for Astrophysics (INAF) researcher Daniele Telloni, discovered that on June 1, 2022, the two solar observatories would be within touching distance of the desired orbital configuration to engage in such a team-up.

As the Solar Orbiter would be looking at the sun, the Parker Solar Probe would be just off to the side, only a little bit out of view of the ESA spacecraft’s Metis instrument — a device called a "coronagraph" that blocks out light from the photosphere to image the corona and is ideal for large-scale, distant observations.

An artist's illustration of the sun, the Earth, the Parker Solar Probe and Solar Orbiter in one scene.


To perfectly line up the two spacecraft and get the Parker Solar Probe in view of Metis, the Solar Orbiter performed a 45-degree roll and was then pointed slightly away from the sun.

The data that was collected as a result of this well-planned maneuver authorized by the spacecraft’s operation team paid off, revealing turbulence that could indeed be transferring energy in the way solar physicists had theoretically predicted would be causing coronal heating.

The turbulence drives coronal heating in a way that is similar to what happens when coffee is stirred here on Earth. Energy is transferred to smaller scales by random movements in a fluid or gas — coffee and plasma — and this converts that energy to heat. In the case of the corona, plasma is magnetized, and that means stored magnetic energy can also be converted to heat.

The transfer of magnetic and movement or kinetic energy from larger to smaller scales is the very essence of this turbulence, and at the smallest scales, it allows the fluctuations to interact with individual particles, mostly positively charged protons, heating them.

That isn’t to say the mystery of coronal heating is "case closed," however. Solar scientists still need to confirm the mechanism that has been hinted at by these results and by the collaboration between the Parker Solar Probe and the Solar Orbiter.

"This is a scientific first. This work represents a significant step forward in solving the coronal heating problem," Solar Orbiter Project Scientist Daniel Müller said.

The team’s research was published on Thursday (Sept. 14) in the Astrophysical Journal Letters.

See the sun's atmosphere like never before thanks to a simple Solar Orbiter camera hack (video)

Tereza Pultarova
September 6, 2023

A composite image of the sun consisting of the view of the sun's atmosphere as observed by the Solar Orbiter's EUI instrument and an image of the sun's disk taken by NASA's STEREO spacecraft.


The European Solar Orbiter spacecraft has peered into previously unexplored parts of the sun's atmosphere thanks to scientists who applied a simple hack to its main camera.

Solar Orbiter, launched in 2020, has delivered an impressive string of new discoveries during its three years studying the sun so far. The spacecraft, fitted with a suite of ten instruments, has proven to be especially capable of unraveling mysteries surrounding the sun's atmosphere. From the discovery of miniature flares, called campfires, in the spacecraft's first images to the recent finding of the likely mechanism driving the solar wind, Solar Orbiter has been consistently delivering ground-breaking science about the star at the center of our solar system. And more is to come.

Researchers behind one of Solar Orbiter's most powerful instruments, the Extreme Ultraviolet Imager (EUI) — a camera that studies the most energetic parts of ultraviolet light emitted by the sun — have now, for the first time, revealed a completely new way of using this powerful instrument.

Related: Solar Orbiter catches Mercury crossing the sun. Here's the amazing video.

Solar Orbiter took this image of the sun during its close approach in March 2022. At that time, the spacecraft was closer to the star than the solar system's innermost planet Mercury.

This new mode of operation works similarly to an instrument called the coronagraph. The coronagraph is a device that shields the sun's disk to allow scientists to view the surrounding atmosphere that is up to a million times fainter than the blocked-out region. Though Solar Orbiter actually carries a coronagraph, called METIS, that instrument observes the solar atmosphere in visible light and in the lower-energy ultraviolet part of the electromagnetic spectrum.

But it is in the part of the light spectrum that is only visible to EUI that scientists can study the most intriguing phenomena that occur at the boundary between the sun's atmosphere and its surface.

"Physics is changing there, the magnetic structures are changing there, and we never really had a good look at it before," David Berghmans, EUI principal investigator and solar physicist at the Royal Observatory of Belgium, said in the statement. "There must be some secrets in there that we can now find."

EUI science team member Frédéric Auchère, an astrophysicist at the Institute of Astrophysics of the Université Paris-Sud in France, described the new imaging mode as a result of "a hack," a last-minute modification devised before the launch of Solar Orbiter in early 2020.

"I had the idea to just do it and see if it would work," Auchère said in a European Space Agency (ESA) statement. "It is actually a very simple modification to the instrument."

The scientists added a tiny protruding "thumb" to the instruments shutter. When the shutter opens only halfway, this thumb obscures the sun's disk, allowing EUI to see with great clarity the faint solar atmosphere.

In the video sequence obtained through the new imaging mode, scientists combined the Solar Orbiter's EUI view of the sun's atmosphere with an image of the star taken by NASA's STEREO mission, which orbits the sun at a slightly closer distance than Earth does. Solar Orbiter, for comparison, follows an elliptical orbit that periodically takes the spacecraft within the orbit of the solar system's innermost planet, Mercury.

By coincidence, STEREO happened to be looking at the sun from the same angle as Solar Orbiter was during the experiments with the new EUI imaging mode. That allowed scientists to combine the images and study the links between phenomena observed on the surface and in the atmosphere.

Observers on Earth can naturally see the outermost parts of the sun's atmosphere during total solar eclipses. The new EUI imaging mode, however, allows scientists to peer into regions of the atmosphere that are much closer to the sun's surface than what such rare events and conventional coronagraphs allow.

EUI images the sun in very high resolution, and although Earth-based telescopes with large mirrors can study the sun's surface in even greater resolution, they can't observe the fascinating high-energy, ultraviolet light that EUI sees. This is because that light gets absorbed by Earth's atmosphere before it reaches the telescopes' lenses. Solar Orbiter, on the other hand, travelling in the vacuum of space has a perfectly clear view of the star. The mission takes the closest ever images of the star and in a few years will take a look a the star's poles — the world's first. Scientists hope that studying the sun's polar regions up close will shed light on the mysterious forces driving the sun's magnetic field, which in turns drives the generation of sunspots, solar flares and eruptions.