- It's very rare that we discover something on our planet that was around before we were even a small speck. But every once in a while, we do—and this meteorite is a living testament.
- Scientists estimate the new discovery to be approximately 4.6 billion years old, almost as old as the solar system itself.
- New discoveries like this one bring us a small step closer in piecing together what an earlier version of Earth might have looked like.
For thousands of years, humans were completely unaware of the existence of the solar system. They believed that Earth was the center of the universe.
We have since been proven very wrong. Scientists have discovered that the solar system was created when a supernova exploded and the resulting gas and dust combined around 4.6 billion years ago.
How exactly our planet was formed still remains a mystery.
What is the discovery, and why is it important?
This meteorite is the oldest known volcanic rock in the solar system, dated at 4,565,000,000 years old.
Photo: University of New Mexico
Northwest Africa (NWA) 11119 is a small, baseball-sized rock. It's formed from sparkly green meteorite and has an unusual light green fusion crust. Broken fragments of the interior have revealed bright green and grey crystals that are up to 3mm in size. Scientists expect that it is approximately 4.6 billion years old, almost as old as the solar system itself.
The rock was acquired by a meteorite dealer in Mauritania, Africa, in 2016. It weighs 453g, and it is currently located at the Maine Mineral and Gem Museum.
For those who don't know much about meteorites, distinguishing between a terrestrial rock and an actual meteorite can be challenging. To make matters worse, there are many sellers who try to disguise terrestrial rocks as meteorites to scam their customers.
Many people are surprised that meteorites can actually be bought, sold, and collected outside of museums and labs. However, since the invention of the Internet, there has been a surge in the number of collectors and dealers.
eBay is actually one of the most popular websites for people to buy and sell meteorites. However, before using such websites, it is important that you take the required precautions and buy from reputable dealers. For example, websites like Meteorite Exchange has a page that summarizes the listings from known dealers in order to help buyers make more informed decisions.
To make the process of buying and selling meteorites safer, meteorite dealers are often hired to confirm that what the customer is buying is an actual meteorite (this means it came from space) and not just a rock.
At first glance, this meteorite didn't look like much
When the rock was first found, the planetary geologist and meteorite curator at the University of New Mexico, Carl Agee, didn't think that it was a meteorite at all. In fact, he thought it was a rock from Earth.
He then passed it on to his doctoral student, Poorna Srinivasan, to examine it.
Despite the rock bearing a close resemblance to volcanic rocks on Earth, its chemical composition revealed that it was definitely from space and that it wasn't just a regular meteorite.
What is special about the meteorite?
Skeleton of a tridymite crystal.
Photo: Fred Kruijen/Wikimedia Commons
NWA 11119 was revealed to be 4.6 billion years old. This makes it the oldest igneous meteorite (meaning that it was formed by the cooling and solidification of either magma or lava) ever discovered. Scientists have discovered several non-igneous meteorites that are even older than this.
About 30% of the meteorite is comprised of tridymite, which are essentially large silica crystals. Such a high tridymite content is virtually unheard of in meteorites. It's comparable to the levels found in volcanic rocks on Earth.
How often do we come across things that are older than Earth?
It's easy to see why this discovery is so exciting. It's not very often that we come across things that are older than our planet—but there have been a couple of instances over the past few years.
In fact, analysis of NWA 11119 has revealed that it has a strong chemical resemblance to two other known unusual meteorites: NWA 7235 (discovered in 2011), and Almahata Sitta (discovered in 2008). The link is strong enough to suggest that all three of these space rocks could potentially have originated from the same parent body.
In November 2015, geologists working in outback South Australia recovered a primordial meteorite from Kati Thanda-Lake Eyre. This meteorite was thought to be a chondrite or stony meteorite and serves as an example of the material that was created when the solar system was being formed over 4.5 billion years ago.
What's more, as little as a couple of months ago, scientists discovered stardust particles on Earth that are even older than our solar system. Its chemical composition, which shows us how far the particles had traveled, suggested that the grains had to be significantly older than 4.6 billion years.
What happens next?
There is still so much we have yet to understand about how planets are formed, and in particular, how the Earth's crust might have been formed.
However, every once in a while, new discoveries like this one bring us a small step closer in piecing together what an earlier version of Earth might have looked like. Over the past few years, scientists have even discovered frozen meteorites in the Antarctic.
Hopefully one day we might be able to collect enough pieces of such evidence to come to a reasonable conclusion.
Reactive oxygen species (ROS) accumulate in the gut of sleep-deprived fruit flies, one (left), seven (center) and ten (right) days without sleep.
- A study provides further confirmation that a prolonged lack of sleep can result in early mortality.
- Surprisingly, the direct cause seems to be a buildup of Reactive Oxygen Species in the gut produced by sleeplessness.
- When the buildup is neutralized, a normal lifespan is restored.
We don't have to tell you what it feels like when you don't get enough sleep. A night or two of that can be miserable; long-term sleeplessness is out-and-out debilitating. Though we know from personal experience that we need sleep — our cognitive, metabolic, cardiovascular, and immune functioning depend on it — a lack of it does more than just make you feel like you want to die. It can actually kill you, according to study of rats published in 1989. But why?
A new study answers that question, and in an unexpected way. It appears that the sleeplessness/death connection has nothing to do with the brain or nervous system as many have assumed — it happens in your gut. Equally amazing, the study's authors were able to reverse the ill effects with antioxidants.
The study, from researchers at Harvard Medical School (HMS), is published in the journal Cell.
An unexpected culprit
The new research examines the mechanisms at play in sleep-deprived fruit flies and in mice — long-term sleep-deprivation experiments with humans are considered ethically iffy.
What the scientists found is that death from sleep deprivation is always preceded by a buildup of Reactive Oxygen Species (ROS) in the gut. These are not, as their name implies, living organisms. ROS are reactive molecules that are part of the immune system's response to invading microbes, and recent research suggests they're paradoxically key players in normal cell signal transduction and cell cycling as well. However, having an excess of ROS leads to oxidative stress, which is linked to "macromolecular damage and is implicated in various disease states such as atherosclerosis, diabetes, cancer, neurodegeneration, and aging." To prevent this, cellular defenses typically maintain a balance between ROS production and removal.
"We took an unbiased approach and searched throughout the body for indicators of damage from sleep deprivation," says senior study author Dragana Rogulja, admitting, "We were surprised to find it was the gut that plays a key role in causing death." The accumulation occurred in both sleep-deprived fruit flies and mice.
"Even more surprising," Rogulja recalls, "we found that premature death could be prevented. Each morning, we would all gather around to look at the flies, with disbelief to be honest. What we saw is that every time we could neutralize ROS in the gut, we could rescue the flies." Fruit flies given any of 11 antioxidant compounds — including melatonin, lipoic acid and NAD — that neutralize ROS buildups remained active and lived a normal length of time in spite of sleep deprivation. (The researchers note that these antioxidants did not extend the lifespans of non-sleep deprived control subjects.)
Image source: Tomasz Klejdysz/Shutterstock/Big Think
The experiments
The study's tests were managed by co-first authors Alexandra Vaccaro and Yosef Kaplan Dor, both research fellows at HMS.
You may wonder how you compel a fruit fly to sleep, or for that matter, how you keep one awake. The researchers ascertained that fruit flies doze off in response to being shaken, and thus were the control subjects induced to snooze in their individual, warmed tubes. Each subject occupied its own 29 °C (84F) tube.
For their sleepless cohort, fruit flies were genetically manipulated to express a heat-sensitive protein in specific neurons. These neurons are known to suppress sleep, and did so — the fruit flies' activity levels, or lack thereof, were tracked using infrared beams.
Starting at Day 10 of sleep deprivation, fruit flies began dying, with all of them dead by Day 20. Control flies lived up to 40 days.
The scientists sought out markers that would indicate cell damage in their sleepless subjects. They saw no difference in brain tissue and elsewhere between the well-rested and sleep-deprived fruit flies, with the exception of one fruit fly.
However, in the guts of sleep-deprived fruit flies was a massive accumulation of ROS, which peaked around Day 10. Says Vaccaro, "We found that sleep-deprived flies were dying at the same pace, every time, and when we looked at markers of cell damage and death, the one tissue that really stood out was the gut." She adds, "I remember when we did the first experiment, you could immediately tell under the microscope that there was a striking difference. That almost never happens in lab research."
The experiments were repeated with mice who were gently kept awake for five days. Again, ROS built up over time in their small and large intestines but nowhere else.
As noted above, the administering of antioxidants alleviated the effect of the ROS buildup. In addition, flies that were modified to overproduce gut antioxidant enzymes were found to be immune to the damaging effects of sleep deprivation.
The research leaves some important questions unanswered. Says Kaplan Dor, "We still don't know why sleep loss causes ROS accumulation in the gut, and why this is lethal." He hypothesizes, "Sleep deprivation could directly affect the gut, but the trigger may also originate in the brain. Similarly, death could be due to damage in the gut or because high levels of ROS have systemic effects, or some combination of these."
The HMS researchers are now investigating the chemical pathways by which sleep-deprivation triggers the ROS buildup, and the means by which the ROS wreak cell havoc.
"We need to understand the biology of how sleep deprivation damages the body so that we can find ways to prevent this harm," says Rogulja.
Referring to the value of this study to humans, she notes,"So many of us are chronically sleep deprived. Even if we know staying up late every night is bad, we still do it. We believe we've identified a central issue that, when eliminated, allows for survival without sleep, at least in fruit flies."
