A fireball lit up the skies over Ontario on November 19, 2022. NASA predicted the asteroid impact with its Scout impact hazard assessment program. Image via NASA/ Robert Weryk.
2022 WJ1 was a tiny asteroid on a collision course with Earth. But astronomers saw it coming, and NASA’s Scout impact hazard assessment system calculated where it would hit.
In the early hours of Saturday, November 19, 2022, the skies over southern Ontario, Canada, lit up as a tiny asteroid harmlessly streaked across the sky high in Earth’s atmosphere, broke up, and likely scattered small meteorites over the southern coastline of Lake Ontario. The fireball wasn’t a surprise. Roughly 1 meter (3 feet) wide, NASA detected the asteroid 3 ½ hours before impact, making this event the sixth time in history a small asteroid has been tracked in space before impacting Earth’s atmosphere.
One of NASA’s tasks is to detect and track the larger near-Earth objects that could survive passage through Earth’s atmosphere and cause damage on the ground, but those objects can also be detected much further in advance than small ones like the asteroid that disintegrated over southern Ontario. Such small asteroids are not a hazard to Earth, but they can be a useful test for NASA’s planetary defense capabilities for discovery, tracking, orbit determination, and impact prediction.
Kelly Fast, Near-Earth Object Observations program manager for the Planetary Defense Coordination Office (PDCO) at NASA Headquarters in Washington, said:
The planetary defense community really demonstrated their skill and readiness with their response to this short-warning event. Such harmless impacts become spontaneous real-world exercises and give us confidence that NASA’s planetary defense systems are capable of informing the response to the potential for a serious impact by a larger object.
The NASA-funded Catalina Sky Survey in Tucson, Arizona, discovered the asteroid on the evening of November 18, during routine search operations for near-Earth objects. The observations were quickly reported to the Minor Planet Center – the internationally recognized clearinghouse for the position measurements of small celestial bodies – and the data was then automatically posted to the Near-Earth Object Confirmation Page.
NASA’s Scout impact hazard assessment system, which is maintained by the Center for Near Earth Object Studies (CNEOS) at the agency’s Jet Propulsion Laboratory in Southern California, automatically fetched the new data from that page and began calculating the object’s possible trajectory and chances of impact. CNEOS calculates every known near-Earth asteroid orbit to provide assessments of potential impact hazards in support of NASA’s PDCO.
Seven minutes after the asteroid was posted on the confirmation page, Scout had determined it had a 25% probability of hitting Earth’s atmosphere, with possible impact locations stretching from the Atlantic Ocean off the East Coast of North America to Mexico. More observations were then provided by the astronomical community, including amateur astronomers in Kansas, to better refine the asteroid’s trajectory and possible impact location.
Shantanu Naidu, navigation engineer and Scout operator at JPL, said:
Small objects such as this one can only be detected when they are very close to Earth, so if they are headed for an impact, time is of the essence to collect as many observations as possible. This object was discovered early enough that the planetary defense community could provide more observations, which Scout then used to confirm the impact and predict where and when the asteroid was going to hit.
As Catalina continued to track the asteroid over the next few hours, Scout used this new data to continually update the asteroid’s trajectory and the system’s assessment of the chance of impact, posting those results on the hazard-assessment system’s webpage.
Community effort helped confirm the asteroid impact
Many astronomers check the Scout webpage throughout the night to determine the most important asteroids to track. A group of amateur astronomers at Farpoint Observatory in Eskridge, Kansas, tracked the asteroid for more than an hour, providing critical additional data that enabled Scout to confirm a 100% impact probability and determine the expected location of atmospheric entry as being over southern Ontario at 3:27 a.m. EST (12:27 a.m. PST) November 19. With more than two hours remaining before impact, there was time to alert scientists in southwestern Ontario of the bright fireball that would occur.
A total of 46 observations of the asteroid’s position were ultimately collected, the final one being made only 32 minutes before impact by the University of Hawaii 88-inch (2.2-meter) telescope on Mauna Kea.
As predicted, at 3:27 a.m. EST (12:27 a.m. PST), the asteroid streaked through Earth’s atmosphere at a shallow angle and broke up, likely producing a shower of small meteorites and leaving no reported damage on the surface. After this harmless disintegration, the Minor Planet Center designated the asteroid 2022 WJ1 to acknowledge its discovery while still in space.
Many sightings
Dozens of sightings were reported to the American Meteor Society, and scientists who were alerted to the Scout prediction were able to photograph the asteroid’s atmospheric entry. Videos of the fireball collected by the public were also posted online. NASA’s Meteorite Falls website also reported weather radar detections of fragments of the fireball falling as meteorites at the predicted time over Lake Ontario. Small meteorites might be found east of the town of Grimsby while larger meteorites might be nearer the town of McNab.
The first asteroid to be discovered and tracked well before hitting Earth was 2008 TC3, which entered the atmosphere over Sudan and broke up in October 2008. That 13-foot-wide (4-meter-sized) asteroid scattered hundreds of small meteorites over the Nubian Desert. Earlier this year, asteroid 2022 EB5 entered the atmosphere over the Norwegian Sea after Scout accurately predicted its location, becoming the fifth object to be detected before impact. As surveys become more sophisticated and sensitive, more of these harmless objects are being detected before entering the atmosphere, providing real exercises for NASA’s planetary defense program.
Bottom line: NASA predicted the asteroid impact in Ontario, Canada, with its Scout impact hazard assessment system. The goal of Scout is to track impact hazards to Earth.
Members of the EarthSky community – including scientists, as well as science and nature writers from across the globe – weigh in on what’s important to them.
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.
