Thirty years ago, no one knew if there were planets outside of our solar system. As astronomers figure out increasingly clever ways to observe even the tiniest (meaning Earth-size) planets in neighboring star systems, we now know that our galaxy is lousy with planets. Yet how many of them are like Earth — and how common Earth-like worlds may be — is still up for debate.
Yet the just-announced discovery of a rocky planet orbiting the nearest solar system to ours, the star Proxima Centauri, came as a surprise to many. Moreover, the finding suggests that Earth-like worlds could be far more common than we imagined.
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According to new research published on Jan. 15 in the journal Science Advances, a new exoplanet orbiting our closest stellar neighbor, Proxima c, is a viable candidate for being a “super-Earth” — the designation for rocky worlds slightly larger than Earth, yet without the huge gas envelope that encases gas giants like Saturn and Neptune. Those massive gas giants are believed to have rocky cores around the mass and shape of Earth, once you lift away the hydrogen and helium.
Proxima Centauri is a red dwarf star located 4.2 light years away from Earth. Though that is extremely close in astronomy terms, note that there are 5.88 trillion miles in one light-year, meaning it would take thousands of human years to travel such a distance. For comparison, Pluto, the most distant dwarf planet visited by a human spacecraft, orbits the sun at about 3.67 billion miles, or 5.5 light hours; the New Horizons probe that flew by Pluto took 9 years to travel there and is considered among the fastest-moving man-made objects ever to exist.
In any case, Proxima Centauri is the closest sun-like star we have to our solar system, meaning that once humans start sending out interstellar probes it is certain to be one of the first stars visited.
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In the paper, researchers from Italy and Greece propose that the closest super-Earth is not Proxima b, another planet orbiting Proxima Centauri which researchers discovered in 2016, but instead Proxima c. Researchers say that the existence of Proxima c is “highly significant for planet formation models.”
“This planet would be the one with the longest period and a minimum mass in the super-Earth regime presently detected with the [radial velocity] technique around a low-mass star,” the paper states. “It would also be the first at a distance from the parent star much larger than the expected original location of the snowline in the protoplanetary disk, which was within 0.15 AU.”
The “radial velocity technique” is a discovery method used by researchers to identify new worlds by tracking how their parent stars “wobble” in response to gravitational tugs from those planets. Beyond the “snowline” of the solar system means that any water on the planet would likely be frozen. The researchers estimate that Proxima c orbits its host star, Proxima Centauri, every 5.2 Earth years.
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“The formation of a super-Earth well beyond the snowline challenges formation models, according to which the snowline is a sweet spot for the accretion of super-Earths, due to the accumulation of icy solids at that location,” Mario Damasso, study author and postdoctoral researcher at Italy’s National Institute for Astrophysics, told CNN. “Or it suggests that the protoplanetary disk was much warmer than usually thought. In general, there’s nothing preventing the existence of Proxima c there where we spot it, but the formation and evolutionary history is a subject worthy of deeper investigation.”
The international team of researchers analyzed 17 years of data from the High Accuracy Radial Velocity Planet Searcher (HARPS) and the Ultraviolet and Visual Echelle Spectrograph (UVES) which are both part of the European Southern Observatory telescopes in Chile. They noticed that Proxima Centauri experienced an unknown wobble that could be the result of the gravitational pull of another planet, which came as a bit of a surprise.
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“Even the closest planetary system to us may retain interesting surprises,” Fabio Del Sordo, an author of the study and postdoctoral researcher in the department of physics at the University of Crete, told CNN. “Proxima Centauri hosts a planetary system that is much more complex than we knew, and we do not know how many unknown features are waiting to be discovered.”
As mentioned above, Proxima c isn’t the only exoplanet in Proxima Centauri’s solar system. In 2016, researchers discovered Proxima b, which is believed to have a similar mass to Earth, and an orbital period of 11 days. While it is also within Proxima Centauri’s habitable zone, it is tidally locked, which means only one side of the planet faces its sun. Tidally locked planets are less likely to be hospitable to life, as one side of these worlds would be very hot and the other extremely cold. However, some theorists believe that there may be a “ring” of habitability at the boundary between the hot and cold side, where the sky would appear to be in perpetual twilight, and within which life could theoretically thrive.
As Salon has previously reported, astronomers have catalogued 1,822 potential stars where Earth-like planets could exist. It seems like the chances are high that Earth’s twin exists somewhere, although it is questionable whether humans would ever be able to visit.
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.
