Titan’s underground ocean, and similar oceans inside other icy moons in the outer solar system, may lack the organic chemistry necessary for life, according to new astrobiological research.
Titan is Saturn‘s largest moon, and the second largest moon in the entire solar system. It’s famous for being shrouded in a smog of petrochemicals and for possessing a veritable soup of organic molecules — molecules that contain carbon — on its surface. Yet, despite all this fascinating chemistry, Titan is cold. Very cold. It has surface temperatures no warmer than –179 degrees Celsius (–290 degrees Fahrenheit). And in these frigid conditions, chemical reactions for life progress very slowly.
However, deep underground where it’s warmer — the exact depth is not certain, but estimates suggest it’s on the order of 100 kilometers (62 miles) — a liquid ocean with a volume 12 times that of Earth’s oceans combined is thought to exist. Similar oceans inhabit the interiors of Titan’s fellow Saturnian moon Enceladus, and Jupiter‘s moonsEuropa and Ganymede.
And where there is liquid water, there could be life. Right? Not so fast, says Catherine Neish of Western University in Ontario, Canada.
A planetary scientist, Neish led an international team that challenged the assumption Titan’s ocean, and indeed the oceans of other icy moons, could be habitable.
The researchers worked on the basis that, for Titan’s ocean to be habitable, a large supply of organic molecules from the surface must be able to physically reach the ocean in order to facilitate prebiotic chemistry that can produce and feed life.
The route for this organic material to reach the ocean is via comet impacts. Such impacts can melt surface ice, creating a pool of liquid water filled with organic molecules. Because liquid water is denser than ice, it sinks. But, Neish’s modeling found that the rate of impacts is not high enough for sufficient organic material to reach Titan’s ocean.
A diagram showing the interior of Saturn’s moon diagram, including its deep ocean. (Image credit: A. D. Fortes/UCL/STFC)
For example, Neish’s team estimates only about 7,500 kilograms (16,534 pounds) of the simplest amino acid, glycine, reaches Titan’s ocean every year. It may sound like a lot, but that’s equivalent to the mass of one male African elephant spread across an ocean with a dozen times the volume of Earth’s oceans. If you’ll excuse the pun, it’s barely a drop in the ocean.
“We assumed that the majority of melt deposits — 65% — would sink all the way to the ocean,” Neish told Space.com. “Recent modeling work suggests that this is very likely an overestimate, but even in this most optimistic scenario, there is not enough organics moving into Titan’s ocean to support life there.”
There may be other possibilities. On Europa, where there are very few organic molecules on the surface, it is postulated that hydrothermal vents may exist on the seafloor where the ocean comes into contact with the moon’s rocky core. These vents would spew all kinds of molecules and trigger complex chemical reactions that could support life. Further evidence for carbon in Europa’s ocean has been discovered by the James Webb Space Telescope. The JWST identified carbon dioxide that has welled up from the ocean onto Europa’s surface.
So, could the same happen on Titan, with organic material coming from the moon’s interior, rather than its surface?
An artist’s impression of Dragonfly, which is a ‘quad-copter’ that will head to Saturn’s moon Titan in 2028 (Image credit: NASA/Johns Hopkins APL/Steve Gribben)
Neish doesn’t rule it out, saying that colleagues such as Kelly Miller at the Southwest Research Institute in San Antonio, Texas, are investigating the possibility — but Neish does highlight one particular caveat.
“One concern that has come up is whether the organics sourced from the interior would be useful for life,” she said. “We think they may be primarily aromatic compounds, and it is difficult to form biomolecules — such as amino acids — from such compounds.”
While we are still some ways away from being able to probe the oceans of these icy moons directly to say for certain whether they contain life or not, Neish’s research does raise some promising opportunities for NASA‘s Dragonfly mission to Titan, on which Neish is a co-investigator.
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Dragonfly is a helicopter mission, inspired in part by the IngenuityMars helicopter, which is planned to launch in 2028 for arrival on Titan in 2034. It will explore the moon from the air, touching down to take samples for analysis. If Neish’s work is correct, it’d mean there could be many impact sites on the surface where liquid water mixed with organics, possibly sparking some complex chemistry before freezing again and sinking. By studying these sites, scientists could learn more about the prebiotic chemistry that went all the way to forming life on Earth.
The findings from Neish’s team were published on 2nd February in the journal Astrobiology.
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.
