NEW YORK –
Scientists discovered the oldest known DNA and used it to reveal what life was like 2 million years ago in the northern tip of Greenland. Today, it’s a barren Arctic desert, but back then it was a lush landscape of trees and vegetation with an array of animals, even the now extinct mastodon.
“The study opens the door into a past that has basically been lost,” said lead author Kurt Kjaer, a geologist and glacier expert at the University of Copenhagen.
With animal fossils hard to come by, the researchers extracted environmental DNA, also known as eDNA, from soil samples. This is the genetic material that organisms shed into their surroundings — for example, through hair, waste, spit or decomposing carcasses.
Studying really old DNA can be a challenge because the genetic material breaks down over time, leaving scientists with only tiny fragments.
But with the latest technology, researchers were able to get genetic information out of the small, damaged bits of DNA, explained senior author Eske Willerslev, a geneticist at the University of Cambridge. In their study, published Wednesday in the journal Nature, they compared the DNA to that of different species, looking for matches.
The samples came from a sediment deposit called the Kap Kebenhavn formation in Peary Land. Today, the area is a polar desert, Kjaer said.
But millions of years ago, this region was undergoing a period of intense climate change that sent temperatures up, Willerslev said. Sediment likely built up for tens of thousands of years at the site before the climate cooled and cemented the finds into permafrost.
The cold environment would help preserve the delicate bits of DNA — until scientists came along and drilled the samples out, beginning in 2006.
During the region’s warm period, when average temperatures were 11 to 19 degrees Celsius higher than today, the area was filled with an unusual array of plant and animal life, the researchers reported. The DNA fragments suggest a mix of Arctic plants, like birch trees and willow shrubs, with ones that usually prefer warmer climates, like firs and cedars.
The DNA also showed traces of animals including geese, hares, reindeer and lemmings. Previously, a dung beetle and some hare remains had been the only signs of animal life at the site, Willerslev said.
One big surprise was finding DNA from the mastodon, an extinct species that looks like a mix between an elephant and a mammoth, Kjaer said.
Many mastodon fossils have previously been found from temperate forests in North America. That’s an ocean away from Greenland, and much farther south, Willerslev said.
“I wouldn’t have, in a million years, expected to find mastodons in northern Greenland,” said Love Dalen, a researcher in evolutionary genomics at Stockholm University who was not involved in the study.
Because the sediment built up in the mouth of a fjord, researchers were also able to get clues about marine life from this time period. The DNA suggests horseshoe crabs and green algae lived in the area — meaning the nearby waters were likely much warmer back then, Kjaer said.
By pulling dozens of species out of just a few sediment samples, the study highlights some of eDNA’s advantages, said Benjamin Vernot, an ancient DNA researcher at Germany’s Max Planck Institute for Evolutionary Anthropology who was not involved in the study.
“You really get a broader picture of the ecosystem at a particular time,” Vernot said. “You don’t have to go and find this piece of wood to study this plant, and this bone to study this mammoth.”
Based on the data available, it’s hard to say for sure whether these species truly lived side by side, or if the DNA was mixed together from different parts of the landscape, said Laura Epp, an eDNA expert at Germany’s University of Konstanz who was not involved in the study.
But Epp said this kind of DNA research is valuable to show “hidden diversity” in ancient landscapes.
Willerslev believes that because these plants and animals survived during a time of dramatic climate change, their DNA could offer a “genetic roadmap” to help us adapt to current warming.
Stockholm University’s Dalen expects ancient DNA research to keep pushing deeper into the past. He worked on the study that previously held the “oldest DNA” record, from a mammoth tooth around a million years old.
“I wouldn’t be surprised if you can go at least one or perhaps a few million years further back, assuming you can find the right samples,” Dalen said.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is solely responsible for all content.
Future Space Telescopes Could be 100 Meters Across, Constructed in Space, and Then Bent Into a Precise Shape – Universe Today
It is an exciting time for astronomers and cosmologists. Since the James Webb Space Telescope (JWST), astronomers have been treated to the most vivid and detailed images of the Universe ever taken. Webb‘s powerful infrared imagers, spectrometers, and coronographs will allow for even more in the near future, including everything from surveys of the early Universe to direct imaging studies of exoplanets. Moreover, several next-generation telescopes will become operational in the coming years with 30-meter (~98.5 feet) primary mirrors, adaptive optics, spectrometers, and coronographs.
Even with these impressive instruments, astronomers and cosmologists look forward to an era when even more sophisticated and powerful telescopes are available. For example, Zachary Cordero
of the Massachusetts Institute of Technology (MIT) recently proposed a telescope with a 100-meter (328-foot) primary mirror that would be autonomously constructed in space and bent into shape by electrostatic actuators. His proposal was one of several concepts selected this year by the NASA Innovative Advanced Concepts (NIAC) program for Phase I development.
Corder is the Boeing Career Development Professor in Aeronautics and Astronautics at MIT and a member of the Aerospace Materials and Structures Lab (AMSL) and Small Satellite Center. His research integrates his expertise in processing science, mechanics, and design to develop novel materials and structures for emerging aerospace applications. His proposal is the result of a collaboration with Prof. Jeffrey Lang (from MIT’s Electronics and the Microsystems Technology Laboratories) and a team of three students with the AMSL, including Ph.D. student Harsh Girishbhai Bhundiya.
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Their proposed telescope addresses a key issue with space telescopes and other large payloads that are packaged for launch and then deployed in orbit. In short, size and surface precision tradeoffs limit the diameter of deployable space telescopes to the 10s of meters. Consider the recently-launched James Webb Space Telescope (JWST), the largest and most powerful telescope ever sent to space. To fit into its payload fairing (atop an Ariane 5 rocket), the telescope was designed so that it could be folded into a more compact form.
This included its primary mirror, secondary mirror, and sunshield, which all unfolded once the space telescope was in orbit. Meanwhile, the primary mirror (the most complex and powerful ever deployed) measures 6.5 meters (21 feet) in diameter. Its successor, the Large UV/Optical/IR Surveyor (LUVOIR), will have a similar folding assembly and a primary mirror measuring 8 to 15 meters (26.5 to 49 feet) in diameter – depending on the selected design (LUVOIR-A or -B). As Bhundiya explained to Universe Today via email:
“Today, most spacecraft antennas are deployed in orbit (e.g., Northrop Grumman’s Astromesh antenna) and have been optimized to achieve high performance and gain. However, they have limitations: 1) They are passive deployable systems. I.e. once you deploy them you cannot adaptively change the shape of the antenna. 2) They become difficult to slew as their size increases. 3) They exhibit a tradeoff between diameter and precision. I.e. their precision decreases as their size increases, which is a challenge for achieving astronomy and sensing applications that require both large diameters and high precision (e.g. JWST).”
While many in-space construction methods have been proposed to overcome these limitations, detailed analyses of their performance for building precision structures (like large-diameter reflectors) are lacking. For the sake of their proposal, Cordero and his colleagues conducted a quantitative, system-level comparison of materials and processes for in-space manufacturing. Ultimately, they determined that this limitation could be overcome using advanced materials and a novel in-space manufacturing method called Bend-Forming.
This technique, invented by researchers at the AMSL and described in a recent paper co-authored by Bhundiya and Cordero, relies on a combination of Computer Numerical Control (CNC) deformation processing and hierarchical high-performance materials. As Harsh explained it:
“Bend-Forming is a process for fabricating 3D wireframe structures from metal wire feedstock. It works by bending a single strand of wire at specific nodes and with specific angles, and adding joints to the nodes to make a stiff structure. So to fabricate a given structure, you convert it into bending instructions which can be implemented on a machine like a CNC wire bender to fabricate it from a single strand of feedstock. The key application of Bend-Forming is to manufacture the support structure for a large antenna on orbit. The process is well-suited for this application because it is low-power, can fabricate structures with high compaction ratios, and has essentially no size limit.”
In contrast to other in-space assembly and manufacturing approaches, Bend-Forming is low-power and is uniquely enabled by the extremely low-temperature environment of space. In addition, this technique enables smart structures that leverage multifunctional materials to achieve new combinations of size, mass, stiffness, and precision. Additionally, the resulting smart structures leverage multifunctional materials to achieve unprecedented combinations of size, mass, stiffness, and precision, breaking the design paradigms that limit conventional truss or tension-aligned space structures.
In addition to their native precision, Large Bend-Formed structures can use their electrostatic actuators to contour a reflector surface with sub-millimeter precision. This, said Harsh, will increase the precision of their fabricated antenna in orbit:
“The method of active control is called electrostatic actuation and uses forces generated by electrostatic attraction to precisely shape a metallic mesh into a curved shape which acts as the antenna reflector. We do this by applying a voltage between the mesh and a ‘command surface’ which consists of the Bend-Formed support structure and deployable electrodes. By adjusting this voltage, we can precisely shape the reflector surface and achieve a high-gain, parabolic antenna.”
Harsh and his colleagues deduce that this technique will allow for a deployable mirror measuring more than 100 meters (328 ft) in diameter that could achieve a surface precision of 100 m/m and a specific area of more than 10 m2/kg. This capability would surpass existing microwave radiometry technology and could lead to significant improvements in storm forecasts and an improved understanding of atmospheric processes like the hydrologic cycle. This would have significant implications for Earth Observation and exoplanet studies.
The team recently demonstrated a 1-meter (3.3 ft) prototype of an electrostatically-actuated reflector with a Bend-Formed support structure at the 2023 American Institute of Aeronautics and Astronautics (AIAA) SciTech Conference, which ran from January 23rd to 27th in National Harbor, Maryland. With this Phase I NIAC grant, the team plans to mature the technology with the ultimate aim of creating a microwave radiometry reflector.
Looking ahead, the team plans to investigate how Bend-Forming can be used in geostationary orbit (GEO) to create a microwave radiometry reflector with a 15km (9.3 mi) field of view, a ground resolution of 35km (21.75 mi) and a proposed frequency span of 50 to 56 GHz – the super-high and extremely-high frequent range (SHF/EHF). This will enable the telescope to retrieve temperature profiles from exoplanet atmospheres, a key characteristic allowing astrobiologists to measure habitability.
“Our goal with the NIAC now is to work towards implementing our technology of Bend-Forming and electrostatic actuation in space,” said Harsh. “We envision fabricating 100-m diameter antennas in geostationary orbit with have Bend-Formed support structure and electrostatically-actuated reflector surfaces. These antennas will enable a new generation of spacecraft with increased sensing, communication, and power capabilities.”
Further Reading: NASA
Amateur N.S. astronomer captures magic of the green comet – CBC.ca
Tim Doucette with the Deep Sky Eye Observatory in southwestern Nova Scotia has captured a dazzling time-lapse of the green comet that’s making a rare pass near Earth.
Comet C/2022 E3 (ZTF) making its closest approach to Earth on Wednesday
An amateur astronomer from southwestern Nova Scotia has captured a dazzling time-lapse of the green comet that’s making a rare pass near Earth.
The last time the comet was this close to our planet was 50,000 years ago. Many Canadians are looking up at the stars this week as the comet gets ready to make its closest approach on Wednesday.
Tim Doucette with the Deep Sky Eye Observatory near Yarmouth, N.S., is among them.
He took a two-hour time-lapse of the comet during the early-morning hours of Jan. 28.
“If you’ve got a telescope and you look closely at the comet and the background stars, it’s travelling relative in our sky about one-quarter degrees per hour,” he told CBC Radio’s Mainstreet Halifax. “So within a few minutes you can see that the comet’s actually making motion in the night sky.”
You can listen to Doucette’s full interview with host Jeff Douglas here:
Mainstreet NS8:09Astronomer Tim Doucette captures images of rare green comet
With files from CBC Radio’s Mainstreet Halifax
Kemptville author’s book being sent to the moon
An author from North Grenville, Ont., is going to be part of a small club of authors whose works will be sent to the moon.
Michael Blouin of Kemptville says he’s been interested in space travel since the Apollo 11 mission that landed humans on the moon for the first time.
To be part of a group of hundreds of authors having their work immortalized within the vast expanse of space has him “gobsmacked.”
“I take comfort in the fact that no matter what happens, it looks like my books … will survive and be there,” he said.
“I sometimes wake up at night and say ‘Oh yeah, I’m going to the moon. Wow.’ It’s kind of amazing.”
How it came to be
Blouin said he’s been a lifelong fan of NASA and space exploration, so when the opportunity to get his work in the Writers on the Moon project came up, he had to take it.
Then around the deadline to apply, his house burned down.
Amid the chaos of not having anywhere to live and then moving into his son’s house, he realized he’d missed his chance.
“I had missed the deadline to apply for this program for books to go to the moon by 12 hours and I was just kicking myself,” he said.
“I lost everything and now I’d missed out on my chance to do something I’d always dreamed about doing.”
Luckily a friend and author in Newfoundland, Carolyn R. Parsons, said she had managed to get some of her work included in the project and had enough space on her microdisk to include him as well.
When do the books go?
The NASA launch is scheduled for Feb. 25 at Cape Canaveral in Florida, which will see his book Skin House brought to the stars along with other works of independent fiction.
Blouin is getting the chance to see the launch.
“These launches sometimes get delayed due to technical reasons or due to weather,” he said.
“But I’m hoping to give myself a big enough window that I’ll actually be on site.”
Blouin had some advice for people who aspire to write or create.
“Any young person aspiring in the arts just shouldn’t give up. Keep trying,” he said. “It can be a tough go but it’s worth every moment.”
He’s getting another of his books — I am Billy the Kid — up to the moon in 2024.
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