The NASA spacecraft spent more than three years winding its way by planets and creeping gradually closer to our star to learn more about the origin of the solar wind, which pushes charged particles across the solar system.
Since solar activity has a large effect on living on Earth, from generating auroras to threatening infrastructure like satellites, scientists want to know more about how the sun operates to better make predictions about space weather.
An artist’s depiction of NASA’s Parker Solar Probe at work observing the sun. (Image credit: NASA/Johns Hopkins APL/Steve Gribben)
Observations from Parker’s April 28 flyby, which was the eighth time the spacecraft whizzed by the sun, show that the spacecraft managed to get inside the sun’s atmosphere, or the corona, for the first time. The results generated two science papers that NASA explored in a recent statement.
“We were fully expecting that, sooner or later, we would encounter the corona for at least a short duration of time,” Justin Kasper, lead author on a new paper about the coronal milestone published in Physical Review Letters, said in the statement. Kasper is also deputy chief technology officer at BWX Technologies and a University of Michigan professor.
An annular eclipse captured by the Hinode satellite on Jan. 4, 2011. (Image credit: NASA/Hinode/XRT)
The sun isn’t a solid sphere like our Earth, but it does have a zone in which the immense gravity of the star keeps in the solar material it spews through fusion.
At a particular distance from the sun, however, gravity and magnetic fields are no longer able to keep that material close. It’s from that point where the solar wind flows away from the sun, never to return. The point of no return is called the Alfvén critical surface and scientists had not been able to measure exactly where it was, before Parker reached it.
Previously, faraway pictures of the corona suggested that the critical surface was somewhere between 4.3 to 8.6 million miles (6.9 to 13.8 million kilometers) from the surface of the sun, or in relative terms, the equivalent of 10 to 20 times the radius of the sun. As it turns out, these estimates were not too far off. Parker’s data suggests it crossed the critical surface at 18.8 solar radii, or 8.1 million miles (13 million km) above the sun’s surface.
More importantly, Parker found the critical surface is not uniform, and there are “spikes and valleys” (as NASA termed it) in which the surface protrudes higher or lower from the center of the sun. The surface also likely varies with solar wind activity, which in turn depends on the sun’s 11-year solar cycle.
“Discovering where these protrusions line up with solar activity coming from the surface can help scientists learn how events on the sun affect the atmosphere and solar wind,” NASA officials wrote in the statement.
This illustration shows our solar system suspended in the “bubble” of protective solar wind known as the heliosphere. Where the sphere ends, harsh cosmic rays butt up against our solar system. (Image credit: NASA Goddard Space Flight Center/ Ryan Fitzgibbons, Walt Feimer, Chris Meaney, Swarupa Nune, and Merav Opher))
Parker could only spend a few hours in the corona due to the intense conditions there, but it did manage to go as low as 15 solar radii from the sun’s surface. In that zone, it found a “pseudostreamer,” one of the huge structures you can see from Earth during total solar eclipses.
“Passing through the pseudostreamer was like flying into the eye of a storm,” NASA said in the same statement, noting that Parker saw changes such as quieter conditions and fewer particles.
On future flybys, Parker is expected to creep even closer to the sun, coming as low as 8.86 solar radii (3.83 million miles or 6.16 million km) from the sun’s photosphere, its visible surface.
Farther away from the sun, the spacecraft has been exploring the physics of “switchbacks,” or zig-zag-shaped structures in the solar wind.
An artist’s depiction of magnetic switchbacks in the solar wind. (Image credit: NASA Goddard/CIL/Adriana Manrique Gutierrez)
Parker’s work on this aspect of solar physics, now in press at the Astrophysical Journal, suggests that switchbacks originate at the visible surface of the sun, known as the photosphere. The switchbacks have been known for some time and were first discovered by the NASA-European Space Agency mission Ulysses, which orbited the sun’s poles in the 1990s.
While scientists at first assumed the switchbacks were confined to solar regions, Parker found the switchbacks were quite common in the solar wind in 2019. Now fresh findings, from the mission’s sixth solar flyby, suggest that switchbacks “occur in patches and have a higher percentage of helium” than other elements, NASA said.
Scientists also found that the patches line up with magnetic funnels coming from the photosphere, called supergranules. This is helpful to understanding solar physics because the funnels may be where fast particles of the solar wind originate.
The crisp, bright specks in this detail from the first-light image taken by the Daniel K. Inouye Solar Telescope are the anchors of the sun’s magnetic field. (Image credit: NSO/NSF/AURA)
“The structure of the regions with switchbacks matches up with a small magnetic funnel structure at the base of the corona,” Stuart Bale, a professor at the University of California, Berkeley, and lead author on the new switchbacks paper, said in the NASA statement. “This is what we expect from some theories, and this pinpoints a source for the solar wind itself.”
If scientists could better understand the physics of switchbacks, this may also point to why the corona is millions of degrees Fahrenheit or Celsius, which is far above the temperature of the solar surface.
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“While the new findings locate where switchbacks are made, the scientists can’t yet confirm how they’re formed,” NASA added. “One theory suggests they might be created by waves of plasma that roll through the region like ocean surf. Another contends they’re made by an explosive process known as magnetic reconnection, which is thought to occur at the boundaries where the magnetic funnels come together.”
Parker Solar Probe’s next solar flyby is scheduled for late February 2022, although the spacecraft will gather observations for weeks before and after the closest approach.
NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
