Oumuamua as it appeared using the William Herschel Telescope on the night of October 29. Credit: Queen’s University Belfast/William Herschel Telescope
In October 19th, 2017, the first interstellar object ever detected flew past Earth on its way out of the solar system. Less than two years later, a second object was detected, an easily identified interstellar comet designated as 2I/Borisov. The appearance of these two objects verified earlier theoretical work that concluded that interstellar objects (ISOs) regularly enter our solar system.
The question of how often this happens has been the subject of considerable research since then. According to a new study led by researchers from the Initiative for Interstellar Studies (i4is), roughly seven ISOs enter our solar system every year and follow predictable orbits while they are here. This research could allow us to send a spacecraft to rendezvous with one of these objects in the near future.
The research that describes these findings was conducted by multiple researchers from i4is, a nonprofit organization dedicated to the realization of interstellar flight in the very near future. They were joined by researchers from the Florida Institute of Technology, Harvard’s Institute for Theory and Computation (ITC), the University of Texas at Austin, the Technical University of Munich, and the Observatoire de Paris.
The study of ‘Oumuamua in October of 2017 set off a revolution in astronomy and the study of celestial objects. Not only was this an object that had formed in another star system, but its arrival and detection implied a large population of such objects. The detection of 2I/Borisov in 2019 confirmed what many astronomers already suspected—that ISOs enter our solar system on a pretty regular basis.
In addition to being a physicist with the i4is (and the lead author on the study), Marshall Eubanks is the chief scientist of Space Initiatives Inc. and CEO of Asteroid Initiatives LLC. As he told Universe Today via email, the discovery of “Oumuamua and 2I/Borisov is significant in a way that cannot be understated:
Artist’s impression of the interstellar object, `Oumuamua, experiencing outgassing as it leaves our Solar System. Credit: ESA/Hubble, NASA, ESO, M. Kornmesser
“[J]ust by proving that they exist, it has had a profound impact, creating a field of study almost from nothing (a field that funding authorities are just beginning to recognize). Interstellar objects provide us with the opportunity to study, and in the future literally touch, exobodies decades before the earliest possible missions to even the nearest stars, such as Proxima Centauri.”
This led to multiple proposals for missions that could rendezvous with future ISOs that were spotted passing through our system. One such proposal was Project Lyra, which researchers from the i4is shared in a 2017 study (with support from Asteroid Initiatives LLC). There’s also the ESA’s Comet Interceptor mission, which they plan to launch in 2029 to rendezvous with a long-period comet.
“We started working on potential missions to interstellar objects in 2017, right after the discovery of “Oumuamua and we initially rather focused on chasing that specific object, in contrast to Seligman and Laughlin, who focused on ISOs that might be discovered in the future,” said Eubanks. “The Comet Interceptor mission would fall into a similar category (build-and-wait).”
Given that ISOs formed in another star system, the opportunity to study them up close would offer scientists insight into the conditions that are present there. In fact, the study of ISOs is the next best thing to sending interstellar probes to neighboring star systems. Of course, any such mission entails a lot of technical challenges, not to mention the need for advance warning. As Eubanks explained:
“There are two basic types of missions here—plan-and-wait or launch-and-wait missions, such as the ESA Comet Interceptor; and chase missions, such as would be needed to reach 1I/”Oumuamua. It is very unlikely that any chase missions will be able to rendezvous with a retreating ISO—these will almost certainly be restricted to fast flybys. Rendezvous missions, missions to match velocities and orbit or land the ISO, will need advance warning.”
Artist’s impression of 2I/Borisov beyond our solar system. Credit: NRAO/AUI/NSF, S. Dagnello
To illustrate, when astronomers first became aware of “Oumuamua, it was only after the object had already made its closest approach to the sun (perihelion passage) and made a close pass by Earth. Because of this, observers had only 11 days to conduct observations as it made its way out of the solar system and was beyond the reach of their instruments.
In the case of 2I/Borisov, amateur astronomer and telescope-maker Gennadiy Borisov caught sight of it on August 30th, 2019, roughly three months before it reached perihelion (December 8th, 2019). But for future missions to rendezvous with them, it is imperative to know as much as possible about how often ISOs arrive and how fast they are traveling when they do.
For the sake of their study, Eubanks and his colleagues sought to place better constraints on these two variables. To do this, they began by taking into account how an interstellar object’s velocity is influenced by the local standard of rest (LSR) – the mean motion of stars, gas, and dust in the Milky Way in the vicinity of the sun:
“We assume that ISOs come from or are formed with stars and their planetary systems, and that after they are on their own they share the same galactic dynamics as stars do. We use the two known ISOs, 1I/”Oumuamua and 2I/Borisov, and the efficiency of past and current astronomical surveys to estimate the number of these objects in the galaxy, and stellar velocity estimates from the Gaia mission to estimate the velocity spread we should expect.”
What they found was that in an average year, the solar system would be visited by up to seven ISOs that are asteroid-like. Meanwhile, objects like 2I/Borisov (comets) would be rarer, appearing around once every 10 to 20 years. They further found that many of these objects would be moving at velocities greater that of “Oumuamua—which was moving at over 26 km/s before and after picking up a boost from the sun.
Swarm of laser-sail spacecraft leaving the solar system. Credit: Adrian Mann
Knowing these parameters will help scientists prepare for possible rendezvous missions with ISOs, something which Eubanks and his colleagues covered in more detail in a previous study—”Interstellar Now! Missions to Explore Nearby Interstellar Objects.” As Universe Today reported at the time of its release, the study addressed a wider range of potential ISOs and the feasibility of reaching them.
In the meantime, this latest study provides basic information that will support the planning and implementation of these missions. In addition to Project Lyra and the ESA’s Comet Interceptor, there are numerous proposals for spacecraft that could rendezvous with interstellar objects (or even make the interstellar journey themselves).
These include Project Dragonfly, a small spacecraft and laser sail that was the subject of a conceptual design study hosted by the Initiative for Interstellar Studies (i4iS) in 2013. Another is Breakthrough Starshot, a concept put forward by Yuri Milner and Breakthrough Initiatives that also calls for a tiny spacecraft to be sent to Alpha Centauri using a light sail and a powerful laser array.
This proposal has been articulated in recent years by Prof. Abraham Loeb and Prof. Manasvi Lingam. Whereas Leob is the founder of the ITC and Chair of the Starshot Advisory Committee, Lingham is a longtime researcher with the ITC and a co-author on the “Interstellar Now!” and this latest paper. In addition to going interstellar, these concepts have been proposed as a possible way of chasing objects that enter our solar system.
One way or another, we will be peeking at other star systems soon—and knowing how to intercept and study the objects they periodically kick our way is a good way to start.
More information:
Interstellar Objects in the Solar System: 1. Isotropic Kinematics from the Gaia Early Data Release 3. arxiv.org/abs/2103.03289 arXiv:2103.03289v1 [astro-ph.EP]
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About 7 interstellar objects pass through the inner solar system every year, study estimates (2021, March 15)
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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.
