When NASA’s Voyager 2 spacecraft flew past Uranus in January of 1986, it gave us our first up-close look at the distant ice giant. Now, over three decades later, the data collected by the probe’s sensors has revealed that it flew straight through an immense magnetic bubble, known as a plasmoid, that was ejected from the planet’s atmosphere.
Uranus is certainly the oddball of all the worlds orbiting our Sun.
Tilted over on its side by some cataclysmic event in the early years of the solar system, this ice giant has a bizarre ‘wobbly’ magnetic field that scientists are still trying to make sense of, even now.
“The structure, the way that it moves… Uranus is really on its own,” Gina DiBraccio, a space physicist at NASA’s Goddard Space Flight Center and project scientist for the MAVEN mission, said in a press release.
Roughly 34 years ago, Voyager 2 discovered rings around Uranus, found never-before-seen moons circling it, and it took readings of the planet’s extremely frigid atmosphere.
Voyager 2 flies past Uranus on January 24, 1986. Credit: NASA/JPL-Caltech
According to a new study, data from Voyager 2’s flyby also picked up one other thing, which was missed at the time.
DiBraccio and fellow NASA Goddard scientist Dan Gershman were in the midst of planning possible missions for NASA to revisit the Ice Giant planets, Uranus and Neptune, but to stay this time. One aspect of this process is to look for compelling mysteries that a planetary spacecraft could investigate and potentially solve. Poring through the data collected by Voyager 2’s Magnetometer instrument, over three decades ago, they found something interesting.
As the spacecraft swung by, at around 80,000 km above Uranus’ cloudtops, it picked up a weird magnetic blip that lasted for just one minute of the total 45-hour flyby.
Magnetometer data from Voyager 2’s Uranus flyby, showing the data averaged over 8-minute periods (red), and the same data plotted every 1.92 seconds (black), revealing the zigzag signature of a ‘plasmoid’. Credits: NASA/Dan Gershman
After examining this blip closely, DiBraccio and Gershman came to the conclusion that it was a ‘plasmoid’ – an immense magnetic bubble being expelled from Uranus’ magnetic field.
A plasmoid often forms as a planet’s magnetic field is shaped by the solar wind, and influenced by solar storms. While the magnetic field lines near to the planet form a fairly spherical ‘shield’, the flow of the solar wind causes the outer field lines to stretch back into a ‘magnetotail’ on the night side the planet. If a solar storm or a fast stream of the solar wind pushes the field lines in the magnetotail closer together, they can ‘reconnect’, closing off a magnetic bubble that then gets caught up in the solar wind’s flow.
Magnetic reconnection in Earth’s magnetotail forms a plasmoid bubble. Credit: NASA’s Scientific Visualization Studio/Scott Sutherland
Based on what Voyager 2’s Magnetometer picked up, the spacecraft apparently passed straight through one of these plasmoids as it was passing Uranus. At roughly 400,000 kilometres wide, this magnetic bubble was found to be filled with mostly ionized hydrogen. There was a bonus, too. The magnetic field inside the bubble was found to form smooth, closed loops. This told DiBraccio and Gershman that the ionized hydrogen was very likely a blob of Uranus’ atmosphere, being carried away by the plasmoid.
While plasmoids are known to form in Earth’s magnetotail, and they’ve been observed at Mercury, Jupiter and Saturn, this is the very first evidence that this process happens at Uranus too.
Currently, there is great interest in the space exploration community to send new missions out to the Ice Giants, as we have with the Gas Giants, Jupiter and Saturn. After Voyager 1 & 2’s flybys of the outer planets, NASA sent Galileo, and then Juno, to orbit Jupiter. Cassini explored Saturn, and its rings and moons, for over 14 years.
Sending spacecraft to Uranus and Neptune would give us new up-close looks at these distant worlds. It would provide new data that could help scientists solve existing mysteries that were discovered, either by telescopes or the Voyager probes. It would undoubtedly give us new mysteries to study, about the Ice Giants themselves and about our solar system in general.
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.
