Jumat, 09 Desember 2022
NASA's Orion capsule heads home from the moon - Associated Press
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2022-12-09 20:16:28Z
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Yale tech delivers data from 'Hell Planet,' leads astronomers to its orbit - Mirage News
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- Yale tech delivers data from 'Hell Planet,' leads astronomers to its orbit Mirage News
- Insanely Hot 'Hell Planet' Was Doomed by Fatal Attraction ScienceAlert
- How the 'hell planet' got so hot: New measurements reveal the orbital path of planet 55 Cnc e Phys.org
- How a Hellish Planet Could Ignite the Quest to Find Habitable Worlds CNET
- Scientists Gain Unprecedented Look at Infernal ‘Hell World’ In Space VICE
- View Full Coverage on Google News
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2022-12-09 03:40:00Z
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Kamis, 08 Desember 2022
Rare Mars eclipse by the full moon wows stargazers with occultation (video) - Space.com
On Wednesday (Dec. 7), skywatchers around the world were treated to a celestial show as the full moon eclipsed Mars in the night sky.
The rare event, known as a lunar occultation, refers to one celestial body — in this case, Mars — appearing to disappear or hide behind another — in this case, the moon. This occultation was particularly noteworthy because Mars was at opposition, meaning Earth was directly between it and the sun, making the Red Planet appear particularly bright in the night sky.
Related: See Mars at opposition in these free webcasts tonight (Dec. 8)
Last night's occultation of Mars by the full moon produced some gorgeous images from observers around the world. The Griffith Observatory in California had a great view of the moon and Mars joining up on Dec. 7 and caught a time-lapse of the Red Planet disappearing behind Earth's celestial companion as seen in the video above.
In addition, skywatchers around the world have been posting gorgeous images of the lunar occultation of Mars on social media, offering a look at one of the year's most-watched celestial events.
Astrophotographer Andrew McCarthy caught Mars and the full moon (opens in new tab) in a beautiful close-up:
This is the moment Mars peeked out from behind our moon after being hidden for an hour. This shot was captured using my largest telescope and a special high-speed camera. Seeing another planet rising on the horizon of our moon was such a surreal experience. pic.twitter.com/8IctbVXuUMDecember 8, 2022
Spaceflight photographer John Kraus caught a stunning shot of Mars (opens in new tab) as it appeared behind the moon following occultation:
Amateur astrophotographer Tom Williams produced a gorgeous image of the moon and Mars by combining multiple photographs, and offered an explanation of how he made the image (opens in new tab) on Twitter.
The 2022 Lunar #Occultation of #Mars!This is a crop of a wider image, and shows the red planet on it's descent behind the eastern lunar limb captured last night from home. Sinus Gomer is central with Syrtis Major at top. See thread for processing. What an event!#astrophotography pic.twitter.com/IBNiW8mA9cDecember 8, 2022
Amateur astronomer and photographer Tom Glenn produced a breathtaking image of Mars (opens in new tab) rising above the moon by stacking 15 different photograph frames.
#Mars rising above the lunar limb. This is a stack of 15 frames captured within a 2s interval during the end of the occultation by the #Moon. Captured with a C9.25 Edge HD and ASI678mc. pic.twitter.com/xrDiI3d7keDecember 8, 2022
Astronomer and science communicator Phil Plait caught Mars creeping behind the moon (opens in new tab) just prior to occultation.
The Moon and Mars a few minutes before #occultation. I shot this through my bedroom window using my spotting 'scope and a phonecam (that's why there's a strong Moon reflection to the upper left). Look at the color contrast! The occultation was cool, taki… https://t.co/lpxYVpmbmi pic.twitter.com/SUISrvttx7December 8, 2022
The lunar occultation of Mars by the full Cold Moon was particularly noteworthy because the Red Planet only appears at opposition every 26 months, so the next opposition won't occur until January 2025.
Mars was also especially close to Earth during this event, which occurred while the planet was at perigee, or its closest point to Earth in its orbit. The record for closest approach between Mars and Earth was set in 2003 at just 34.8 million miles (56 million kilometers); according to NASA, Mars and Earth won't be this close for another 265 years, until 2287.
Editor's Note: If you snap a great photo of either Mars at opposition or the lunar occultation and would like to share it with Space.com's readers, send your photo(s), comments, and your name and location to spacephotos@space.com.
Editor's Note: This piece was updated at 4:30 p.m. EST (2130 GMT) on Dec. 8 to indicate that the record for Mars' closest approach to Earth was set in 2003.
Follow Brett on Twitter at @bretttingley (opens in new tab). Follow us on Twitter @Spacedotcom (opens in new tab) or on Facebook (opens in new tab).
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2022-12-08 20:06:06Z
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Oldest DNA – 2 million years – reveals Greenland's lost world - CGTN
Scientists have identified DNA from animals, plants and microbes dating to about 2 million years ago – the oldest on record by far – from sediment at Greenland's northernmost point dug up around the mouth of an Arctic Ocean fjord, revealing an amazing lost world at this remote frontier.
Researchers said on Wednesday fragments of DNA were detected for a panoply of animals including mastodons, reindeer, hares, lemmings and geese as well as plants including poplar, birch and thuja trees and microorganisms including bacteria and fungi. DNA is the self-replicating material carrying genetic information in living organisms – sort of a blueprint of life.
The mastodon was an elephant relative that roamed North and Central America until its extinction alongside many other large Ice Age mammals roughly 10,000 years ago. The discovery shows that it had a wider range than previously known.
"The mastodon was a great surprise. It's never been found on Greenland before. However, the greatest surprise was this unique ecosystem of Arctic and temperate species mixed together with no modern analog," said Eske Willerslev, director of the Lundbeck Foundation GeoGenetics Centre and leader of the study published in the journal Nature.
"I don't think anyone would have predicted Greenland holding such a diversity of plants and animals 2 million years ago at a time when the climate was very similar to what we expect to witness in a few years because of global warming," added Willerslev, who is affiliated with the University of Cambridge and University of Copenhagen.
Though ancient DNA is highly perishable, the study showed that under the right conditions – in this case permafrost – it can survive longer than previously believed possible. Willerslev said he now would not be surprised to find DNA from at least 4 million years ago.
The researchers extracted and sequenced DNA from 41 organic-rich sediment samples obtained from five sites on the Peary Land peninsula jutting into the Arctic Ocean. Microscopic fragments of DNA were extracted from clay and quartz in the sediment. They identified more than 100 types of animals and plants.
The samples were first dug up in 2006, but earlier DNA detection efforts failed. Methods used to extract ancient DNA have since improved, eventually allowing a breakthrough.
"We think it's because the DNA bound itself to mineral particles that enabled its survival beyond what was thought possible. The bond reduces the rate of spontaneous chemical degradation," Willerslev said.
Willerslev said the fragmentary DNA cannot be used to resurrect extinct species – as in the "Jurassic Park" books and films – but could reveal secrets of how plants can become more resistant to a warming climate.
"You cannot use them for cloning," Willerslev said of the DNA remnants, "but you may use it to genetically modify living organisms such as plants to become more adapted to a warmer climate."
The oldest previous DNA on record was extracted from the molar of a mammoth, another elephant relative, in northeastern Siberia dating to up to 1.2 million years ago, also preserved in permafrost conditions. By way of comparison, our species, Homo sapiens, arose roughly 300,000 years ago.
Most knowledge about prehistoric organisms comes from studying fossils, but there is a limit to what these can reveal, particularly relating to genetic relationships and traits. That is where ancient DNA proves invaluable.
Most of modern Greenland is covered by a thick ice sheet, with ice-free areas along the coastline. The region in the study is considered a polar desert. But 2 million years ago Greenland's average temperatures were 11 to 17 degrees Celsius higher, according to study first author Kurt Kjaer of the University of Copenhagen.
The presence of marine species including horseshoe crab and green algae, also among the DNA detected, illustrated that warmer climate, the researchers said.
The DNA has revealed this ancient ecosystem in detail, with an open boreal forest featuring trees, shrubs and smaller plants and teeming with animals. It did not identify which large predators were present but these may have included wolves, bears and saber-toothed cats, according to study co-author Mikkel Pedersen of the University of Copenhagen.
Study co-author Nicolaj Larsen of the University of Copenhagen said the researchers are targeting sites in northern Canada for even-older DNA.
"I think you may find such long-term survival of DNA in many places in the world," Willerslev said. "It's simply going out there and trying."
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2022-12-08 03:36:35Z
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Rabu, 07 Desember 2022
World's oldest DNA has been found - CTV News
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.
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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.
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2022-12-07 22:40:18Z
CBMiYmh0dHBzOi8vd3d3LmN0dm5ld3MuY2Evc2NpLXRlY2gvb2xkZXN0LWRuYS1yZXZlYWxzLWxpZmUtaW4tZ3JlZW5sYW5kLTItbWlsbGlvbi15ZWFycy1hZ28tMS42MTg0NTMy0gEA
Watch Mars be eclipsed by the moon tonight in free webcast - Space.com
Update for Dec. 7: The first of several webcasts of Mars at opposition will begin tonight, Dec. 7, at 9 p.m. EST (0200 Dec. 8 GMT) and you can watch it live above. The livestream will show views of Mars and the moon from the Griffith Observatory in Los Angeles.
This week offers multiple opportunities to get a great look at the Red Planet.
On Wednesday (Dec. 7), the full moon will be in close proximity to a bright Mars during an event known as a lunar occultation. And on Thursday (Dec. 8), Mars will be at opposition, meaning that in Earth's skies, it will be found directly opposite the sun. These events also happen to coincide with Mars being close to perigee (its closest point to Earth), which occurred on Nov. 30.
The perfect storm of astronomical events means that this is a wonderful week to watch Mars in the night sky, appearing larger and brighter than usual and making itself easy to spot next to a full Cold Moon. And even if you have cloudy skies or can't make it outside, you're still in luck: There are plenty of opportunities to see Mars at its best this week thanks to several free online livestreams.
Related: Mars at opposition will meet up with the full moon next week (Dec. 7). Here's how to see it
Read more: December full moon 2022: The Cold Moon occults Mars
How to see Mars in person this week
For many parts of North America, Europe and some parts of North Africa, the lunar occultation will be visible in the night sky on Dec. 7 and Dec. 8.
The spectacle begins roughly an hour after sunset in the Taurus constellation on Dec. 7 for North American skywatchers as the full moon and Mars move close together (in Europe, the event will happen just before sunrise on Dec. 8). Depending on one's location, the Red Planet will then disappear behind the moon before reappearing an hour later.
Sky and Telescope has put together a guide on when and where you can see Mars (opens in new tab)disappear behind the moon this week during lunar occultation.
Griffith Observatory livestream of the lunar occultation of Mars
On Wednesday (Dec. 7), the Griffith Observatory in Los Angeles, California will host a free online livestream (opens in new tab) of the lunar occultation of Mars. The broadcast will begin at 9 p.m. EST (0200 GMT on Dec. 8), weather permitting. Mars will disappear behind the moon at 9:31 p.m. EST (0231 GMT) and reappear one hour later.
The observatory will also upload a time-lapse recording of the event on Thursday (Dec. 8) at 11 a.m. EST (1600 GMT).
McDonald Observatory livestream of Mars at opposition
The McDonald Observatory at the University of Texas at Austin, in conjunction with the Lowell Observatory in Arizona, will host a livestream of Mars at opposition. The broadcast begins on Thursday (Dec. 8) at 9 p.m. EST (0200 GMT on Dec. 9) and can be found on the McDonald Observatory's YouTube channel (opens in new tab).
Hosts from both observatories will provide commentary during the event that will include discussions of Martian geology and history as well as spaceflight missions to the Red Planet. If weather permits, the livestream will include live views of Mars at opposition from telescopes at both observatory sites.
The Virtual Telescope Project livestream of the moon occulting Mars at opposition
The Virtual Telescope Project (opens in new tab) will host a free livestream of the moon occulting Mars at opposition. The broadcast will begin at 10 p.m. EST on Thursday (0300 GMT on Dec. 9) and can be found on the project's YouTube channel (opens in new tab).
What does it mean when Mars is at opposition?
When astronomers say that a planet is at opposition, it means that the planet, Earth, and the sun are all in a straight line, with Earth in the middle. This arrangement means that the planet is literally opposite the sun, hence the term "opposition," making the planet appear brightly lit from our vantage point on Earth.
When the Red Planet is in opposition, it is much brighter than usual and therefore much easier to see in the night sky. This event only happens every 26 months, and the planet's elliptical orbit means during some oppositions Mars is closer to Earth than others.
During this week's opposition, Mars will be closer to Earth than it will be until 2033. The Royal Astronomical Society has put together a great explainer (opens in new tab) on the event, including the video below.
What is a lunar occultation of Mars?
The word "occult" means to conceal or hide from view; when astronomers refer to an occultation, they mean an event in which one celestial object passes in front of another from an observer's perspective, hiding the object behind it. In the case of this week's lunar occultation of Mars, it means that from Earth, the moon will appear to conceal or "cover up" the Red Planet. For many viewers, Mars will disappear behind the moon for roughly an hour before reemerging into view.
There are enough occultations throughout any given year that there is an International Occultation Timing Association (opens in new tab) which provides detailed information such as exact locations and times of other occultations.
The Griffith Observatory has published a video explainer (opens in new tab) of the event, found below.
Read more: What is an occultation?
Whether you're new to skywatching or have been it at for years, be sure not to miss our guides for the best binoculars and the best telescopes to view the occultation of Mars and other incredible things in the night sky. For capturing the best Mars or moon pictures you can, check out our recommendations for the best cameras for astrophotography and best lenses for astrophotography.
Editor's Note: If you snap a great photo of either Mars at opposition or the lunar occultation and would like to share it with Space.com's readers, send your photo(s), comments, and your name and location to spacephotos@space.com.
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2022-12-07 21:59:40Z
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Webb telescope promises new age of the stars - RFI English
Issued on: Modified:
Paris (AFP) – The James Webb Space Telescope lit up 2022 with dazzling images of the early universe after the Big Bang, heralding a new era of astronomy and untold revelations about the cosmos in years to come.
The most powerful observatory sent into space succeeds the Hubble telescope, which is still operating, and began transmitting its first cosmic images in July.
"It essentially behaves better than expected in almost every area," said Massimo Stiavelli, head of the Webb mission office at the Space Telescope Science Institute, in Baltimore.
Already scientists say the Webb telescope, now orbiting the sun at a million miles (1.6 million kilometres) from Earth, should last 20 years, twice its guaranteed lifetime.
"The instruments are more efficient, the optics are sharper and more stable. We have more fuel and we use less fuel," said Stiavelli.
Stability is vital for the clarity of the images.
"Our requirement was similar to that of Hubble, in terms of pointing accuracy. And we ended up being seven times better," the mission office chief added.
Public appetite for the discoveries has been fed by the colouring of the telescope's images.
Light from the most distant galaxies has been stretched from the visible spectrum, viewable by the naked eye, to infrared -- which Webb is equipped to observe with unprecedented resolution.
This enables the telescope to detect the faintest glimmers from the distant universe at an unprecedented resolution, to see through the veil of dust that masks the emergence of stars in a nebula and to analyse the atmosphere of exoplanets, which orbit stars outside our solar system.
18 petals
"The first year (of observation) is a way to test out the tool for the small rocky planets in the habitable zone that could potentially be like Earth," said Lisa Kaltenegger, associate professor in Astronomy at Cornell University.
"And the tests are beautiful. They're spectacular."
Webb blasted off aboard an Ariane 5 rocket at the end of 2021 crowning a 30-year project at the US space agency NASA.
It took 10,000 people and 10 billion dollars to put the 6.2-tonne observatory into space.
En route to final orbit, Webb deployed a five-layer sunshield the size of a tennis court followed by a 6.5 metre primary mirror made up of 18 hexagonal, gold-coated segments or petals.
Once calibrated to less than a millionth of a metre, the 18 petals began to collect the light pulsing stars.
Last July 12, the first images underlined Webb's capabilities unveiling thousands of galaxies, some dating back close to the birth of the Universe, and a star nursery in the Carina nebula.
Jupiter has been captured in incredible detail which is expected to help understand the workings of the giant gas planet.
'Too many' galaxies
The blue, orange and grey tones of the images from the "Pillars of Creation", giant dust columns where stars are born, proved captivating.
Scientists saw the revelations as a way of rethinking their models of star formation.
Researchers using the new observatory have found the furthest galaxies ever observed, one of which existed just 350 millions years after the Big Bang some 13.8 billion years ago.
The galaxies appear with extreme luminosity and may have started forming 100 million years earlier than theories predicted.
"In the distant Universe, we have an excess of galaxies compared to models," David Elbaz, scientific director for astrophysics at France's Alternative Energies and Atomic Energy Commission, told AFP.
Another surprise has been that where Hubble essentially observed irregular shaped galaxies, the precision of the Webb telescope produces magnificent spiral galaxies similar to our own.
This has led to musings over a potential universal model which could be one of the keys to star formation.
Webb also opened up a profusion of clusters of millions of stars leading, which could be the potential missing link between the first stars and the first galaxies.
In the field of exoplanets, Webb honed in on a faraway gas giant called WASP-96 b, which was discovered in 2014.
Nearly 1,150 light-years from Earth, WASP-96 b is about half the mass of Jupiter and zips around its star in just 3.4 days
Webb provided the first confirmation that carbon dioxide is present in the atmosphere of Wasp 39-b.
But for Stiavelli, "Some of the big things either haven't been observed yet, or haven't been revealed yet."
© 2022 AFP
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2022-12-07 06:06:36Z
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