We recently examined how and why the planet Mars could answer the longstanding question: Are we alone? There is evidence to suggest that it was once a much warmer and wetter world thanks to countless spacecraft, landers, and rovers having explored—and currently exploring—its atmosphere, surface, and interior. Here, we will examine another one of Saturn’s 83 moons, an icy world that spews geysers of water ice from giant fissures near its south pole, which is strong evidence for an interior ocean, and possibly life. Here, we will examine Enceladus.
In terms of space exploration, Enceladus was briefly visited by NASA’s Voyager 1 and Voyager 2 in 1980 and 1981, respectively, and wasn’t visited again until NASA’s Cassini spacecraft explored the Saturn system, ultimately performing multiple flybys of this icy moon starting in 2005. It was these flybys that revealed Enceladus’ unique geology and composition.
“Enceladus has many of the ingredients we think are necessary for life: a liquid water ocean beneath an icy shell; an energy source (tidal heating); and nutrients (we’ve detected carbon compounds, which could be used as food),” said Dr. Francis Nimmo, who is a Professor in the Department of Earth & Planetary Sciences at the University of California, Santa Cruz. “In this respect it is not so different from other moons with subsurface oceans, like Europa. What makes Enceladus unique is that it’s giving us free samples of its ocean: there are geysers which jet water vapor and ice crystals into space, where we can scoop them up with a passing spacecraft and analyze them. So, Enceladus is a very good place to go and look for potential life, because we can *directly* sample material from the ocean.”
A two-image mosaic of geysers on the south pole of Enceladus imaged by NASA’s Cassini spacecraft and published on February 23, 2010. (Credit: NASA/JPL/Space Science Institute)
NASA’s Cassini spacecraft used its mass spectrometer to discover organic materials, water vapor, carbon dioxide, carbon monoxide, and a mixture of volatile gases within these geysers, which could indicate the presence of life. Not only do the active geysers indicate the presence of an internal ocean, but it’s also indicative of a source of energy within Enceladus.
“Enceladus has captivated the astrobiology community because it is the first icy ocean world for which we have strong evidence supporting its habitability,” said Dr. Christopher Glein, who is a Lead Scientist and geochemist at the Southwest Research Institute in Texas. “Data from the Cassini mission show that Enceladus has the three ingredients that are required for life as we know it. Those are liquid water, essential elements (including organic molecules), and a source of energy that can be harnessed by life. Recently, we found that the geochemistry of Enceladus’s ocean makes phosphate minerals unusually soluble there. This strongly suggests that phosphorus availability will not impede the prospects for life but should instead serve as an opportunity.”
With the Cassini mission ending in 2017, there are currently no active missions exploring the Saturn system, let alone Enceladus. However, there are several future missions currently under study which could help us further understand Enceladus and whether it can support life. This includes NASA’s Enceladus Orbilander, whose science goals include determining if Enceladus has life, how it has life, and also to locate a suitable landing site for a potential surface mission.
“Orbilander is designed to answer the question of whether there is life in the Enceladus ocean as unambiguously as possible,” said Dr. Nimmo. “Because we don’t know what form life would take, Orbilander uses several different techniques to look for the presence of life-like attributes. And because most of the material that comes out of the geysers ends up back on the surface, Orbilander will look in the “snow” on the surface for signs of life, as well as in material that goes into orbit around Enceladus. After Orbilander, we should have a very good idea of whether or not Enceladus is inhabited.”
While we wait for another spacecraft to re-visit Enceladus, scientists continue to pour over data from the Cassini mission to try and squeeze every last bit of science about Saturn’s icy moon. We know it has an ocean, which indicates the possibility for life, but what kinds of life could be thriving in its oceanic depths? How has it evolved, and is it similar to life on the Earth?
“Enceladus is perhaps the most puzzling of ocean worlds. It’s so small that it should not have an ocean, yet it does. After over a decade of study, we now have a better understanding of how powerful tidal forces keep the interior warm and make Enceladus geologically alive. Could those same forces also sustain biological activity?”
And with this, we wonder if Enceladus will finally answer, “Are we alone?”
As always, keep doing science & keep looking up!
Featured Image: Saturn’s moon, Enceladus, taken by NASA’s Cassini spacecraft on October 9, 2008, after it skimmed within 25 kilometers (15.6 miles) of the surface. (Credit: NASA/JPL/Space Science Institute)
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.
