Science

NASA’s STEREO-A flies by Earth after a 17-year trip around the sun

Published

1 year ago

August 21, 2023

For nearly 17 years, NASA’s Solar Terrestrial Relations Observatory-A spacecraft drifted through space on a lonely mission. It traveled around the sun far ahead of Earth, conducting groundbreaking research on the solar system’s star.

Like many NASA spacecraft, STEREO-A outlived its mission life span of two years. Instead, it traveled further and further away from Earth on a journey that became fraught with uncertainty as it passed behind the sun in 2015, temporarily severing contact with NASA. The same year, the agency lost contact with STEREO-A’s sibling vessel, STEREO-B, which was traveling a similar path.

But STEREO-A kept going. And its orbital trajectory around the sun meant that it had a chance to do what very few other NASA spacecraft could: eventually make its way back toward home.

That came to fruition earlier this month, when STEREO-A passed between the sun and the Earth for the first time since its launch in 2006, NASA announced. The flyby marked a milestone for the spacecraft and the team that has monitored its progress — and a chance for STEREO-A to prove its relevance almost two decades later. As it continues to pass by Earth, STEREO-A will be used to perform new research on the sun, aided by newer NASA satellites that have been developed since its launch.

“This is a point in time for this mission to shine again,” Lika Guhathakurta, STEREO’s program scientist, told The Washington Post.

The two STEREO spacecraft launched in October 2006 with an ambitious mission: to generate a 360-degree view of the sun by observing the star from two vantage points as they circled it on orbits that diverged from the Earth in opposite directions. STEREO-A maneuvered into an orbit around the sun ahead of Earth, and STEREO-B began circling the sun in the opposite direction behind the Earth.

The difference in perspective was groundbreaking, Guhathakurta said. Earthbound instruments can only ever observe one Earth-facing slice of the sun at a time, while the rest of the rapidly changing solar surface remains obscured. The twin STEREO spacecraft, from their offset positions, allowed scientists to capture a 360-degree view of the sun for the first time, a feat that still awes Guhathakurta.

“Seeing the sun from the front and from the far side at the same time — extraordinary,” she said. “We are on planet Earth, human beings, and we are achieving that.”

The STEREO craft also allowed scientists to better study the sun’s roiling surface and the hazards that erupt from it. The two craft, operating the same way two eyes create depth perception, provided a three-dimensional view of the sun and of coronal mass ejections — a phenomenon in which plumes of plasma and magnetic field shoot outward from the sun’s outer atmosphere at hundreds or thousands of miles per second, potentially threatening Earth’s power grid and satellites, as well as other planets and NASA spacecraft. That imagery allowed scientists to track the shape, density and velocity of coronal mass ejections as they rippled across the solar system.

As STEREO-A and STEREO-B continued on their orbits, they neared the far side of the sun in 2014. It was a testament to how far they’d traveled, but also a huge risk — moving directly behind the sun would sever communication between the spacecraft and NASA for a period of several months.

The two wayward spacecraft, years past their expiration dates, had not been designed to operate without communication from NASA for that long. While conducting tests in preparation for the downtime, the agency lost contact with STEREO-B. NASA briefly regained contact with the spacecraft in 2016 but determined that a malfunctioning component had sent it into an uncontrollable spin, leaving it unable to orient its antenna or solar panels properly, and the agency gave up on recovery efforts.

STEREO-A, however, emerged from the far side of the sun unscathed — and began the long trip back toward Earth. Earlier this month, the spacecraft passed between Earth and the sun, coming within around 5 million miles of Earth, according to NASA.

The spacecraft arrived back near Earth at an opportune time, Guhathakurta said. When STEREO-A was launched 17 years ago, it viewed the sun during a solar minimum, a low point in the sun’s 11-year cycle of high and low solar activity. That limited the number of coronal mass ejections and other phenomena that the spacecraft initially observed. This year, STEREO-A’s return has coincided with a period of intense solar activity.

And its flyby means it can finally return to the work it once performed with its lost sibling. A capable fleet of satellites and probes near Earth will help STEREO-A re-create the 3D imaging of the sun it once captured with STEREO-B, the agency said.

STEREO-A will continue to work on the edge of solar physics. Scientists hope to use the new data gathered during the spacecraft’s flyby to examine a recent theory that coronal loops — giant arcs of solar material that crisscross the sun’s surface when viewed in ultraviolet light — may be optical illusions.

For Guhathakurta, who began working on the STEREO mission in 1998, STEREO-A’s perseverance after such a long journey is heartening.

“It’s like seeing your children grow up and do extraordinary things,” Guhathakurta said. She added that STEREO-A’s mission may not be finished, depending on NASA’s budgeting decisions. Either way, STEREO-A will continue on its course for another orbit around the sun.

“They don’t stay home,” Guhathakurta added, laughing. “They drift away very quickly.”

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Science

The body of a Ugandan Olympic athlete who was set on fire by her partner is received by family

Published

6 days ago

September 13, 2024

Anne Joseph

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.

Kenya’s high rates of violence against women have prompted marches by ordinary citizens in towns and cities this year.

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.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

Published

1 week ago

September 11, 2024

Anne Joseph

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.”

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News

B.C. sets up a panel on bear deaths, will review conservation officer training

Published

1 week ago

September 10, 2024

Anne Joseph

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.

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