Where did Earth get its abundant water? Was it really delivered by asteroids and comets? New evidence from Mars supports a different idea — that our planet has had its water all along, no impacts required.
As the only planet we know of with abundant oceans of liquid water on its surface, scientists have invested considerable effort into figuring out exactly where Earth’s water originated. We know that there’s water locked up in asteroids and comets. At the same time, we also know that Earth suffered heavy bombardment from these objects shortly after it formed over 4.5 billion years ago. Suggesting that there could be a possible link between these two facts isn’t too much of a stretch.
Still, it’s not the only hypothesis that’s been considered.
“There are two hypotheses about the emergence of water. One is that it arrives on planets by accident, when asteroids containing water collide with the planet in question. The other hypothesis is that water emerges in connection with the formation of the planet,” said Martin Bizzarro, from the University of Copenhagen’s Centre for Star and Planet Formation, said in a press release.
Bizzarro is co-author of a new study led by Zhengbin Deng, an assistant professor at the Centre for Star and Planet Formation, which carefully examined the mineral structure of an ancient Mars meteorite known as NWA 7533 (aka “Black Beauty”). The research team’s conclusions suggest that the second hypothesis — where water is simply a natural byproduct of planet formation — may be the correct one.
Meteorite ‘Northwest Africa 7533’, discovered in Morocco in 2012, was found to be an ancient piece of the planet Mars, which was blasted into space by an immense impact before eventually crossing paths with Earth. Credit: University of Copenhagen/Deng et al.
Black Beauty was revealed to be an ancient piece of Mars after scientists examined gases trapped in bubbles inside the meteorite. Previous studies have also shown that this meteorite was ejected from the surface of Mars during an impact that took place around 4.4 billion years ago.
During their study of NWA 7533, Deng and his colleagues discovered signs that there was already water on Mars’s surface at the time of that impact.
“We have developed a new technique that tells us that Mars, in its infancy, suffered one or more severe asteroid impacts. The impact, Black Beauty reveals, created kinetic energy that released a lot of oxygen. And the only mechanism that could likely have caused the release of such large amounts of oxygen is the presence of water,” Deng said in the press release.
This false-colour elevation map of Mars reveals the likely location where the Black Beauty meteorites originated. Credit: NASA/University of Copenhagen
“If that is true, it is extremely exciting, because it means that the presence of water is a bioproduct of the planet formation process,” Bizzarro said.
A WARMER MARS?
Additionally, as study co-author Takashi Mikouchi pointed out in a University of Tokyo press release, “such an impact would have released a lot of hydrogen, which would have contributed to planetary warming at a time when Mars already had a thick insulating atmosphere of carbon dioxide.”
This combination may solve the mystery of why we see abundant evidence of liquid water on Mars’ surface, despite the planet being colder in the distant past. Any water on Mars now is either completely frozen or in the form of briny deposits buried under its thick glaciers. Billions of years ago, the Sun was even cooler than it is today and would have provided less heat to Mars. So, even with a thicker atmosphere, the planet wouldn’t have been warm enough for liquid water without some added help.
Related: ROM scientist shows off meteorites from Mars and the Moon
IMPLICATIONS FOR LIFE, HERE AND BEYOND
This new 4.4 billion year timeline for water on Mars’ surface is roughly 700 million years earlier than previous estimates. According to Bizzarro, it would have also been long before water-rich asteroids could have bombarded Mars. So, where did the water come from? This study provides a compelling answer.
“It suggests that water emerged with the formation of Mars. And it tells us that water may be naturally occurring on planets and does not require an external source like water-rich asteroids,” Bizzarro explained.
The TRAPPIST-1 planetary system, compared here to our own solar system, could be an ideal location to search for life, with three rocky planets in its ‘habitable zone’. Credit: NASA/JPL-Caltech
This shifting of the narrative for water — from an accident requiring very specific conditions to simply something that happens naturally during planet formation — could make the emergence of biological life far less complicated. This has implications for Earth and Mars, and possibly even Venus. It also could change our perspective slightly as we continue to discover more rocky planets around other stars.
If this study’s findings are correct, it becomes far more likely that most rocky exoplanets will have abundant water on their surface. Since water is essential for the development of life — at least life as we know it — that also increases our chances of discovering that we’re not alone in the universe!
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.
This false-colour elevation map of Mars reveals the likely location where the Black Beauty meteorites originated. Credit: NASA/University of Copenhagen
The TRAPPIST-1 planetary system, compared here to our own solar system, could be an ideal location to search for life, with three rocky planets in its ‘habitable zone’. Credit: NASA/JPL-Caltech
