Residents of the northern hemisphere, look up: In the faint light of the closest star in the night sky, astronomers have discovered evidence of an alien world.
The proposed new planet is unlike anything in our own solar system, the researchers say — larger than Earth but smaller than Neptune, and far enough from its dim, red sun that any water on its surface is locked away in ice.
But this frozen “super Earth,” the second-closest exoplanet known to science, is a tantalizing clue to what else might be out there. And in the not-so-distant someday when telescopes become capable of photographing planets around other stars, it may well be the first new world we see.
SPACE explosion nicknamed “the Cow” keeps getting stranger. After months of observations, we still aren’t quite sure what it is but it may be part of a whole new class of blasts.
In June, astronomers spotted a remarkably fast and luminous explosion. It took just a few days to reach peak brightness, whereas most supernovae – which occur when stars blow up and die – take a few weeks or longer. And it was 10 to 100 times brighter than most normal supernovae.
Telescopes around the world were turned to face the blast, dubbed the Cow after it was officially listed as AT2018cow, simply because these cosmic events get three-letter labels in alphabetical order based on when they are seen. Initial observations couldn’t explain it, so lots of astronomers continued to watch.
Using 12 telescopes, Raffaella Margutti at Northwestern University in Illinois and her team examined the explosion in several wavelengths of light. None of those observations resembled a regular supernova, she says.
They found that high-energy X-rays from the Cow, which should die down as the blast goes on, were increasing. “That was a huge surprise,” says Margutti. They redid the analysis but the result was the same.
The visible light coming from the Cow added to the mystery too. “It was very blue, which means it was hot. And it stayed blue, which means something is keeping it hot,” says Brian Metzger at Columbia University in New York.
They also detected irregular X-ray frequencies, which suggest that the Cow is asymmetrical, and that it may also have a ring of dust and gas around it (arxiv.org/abs/1810.10720).
““It shares features with many things but doesn’t fit into one category. It’s really, totally strange””
Another group led by Anna Ho at the California Institute of Technology came to similar conclusions. They found that radio waves emitted by the Cow suggest the explosion is spreading through a dense medium, like the clouds of gas that some stars belch out before becoming supernovae (arxiv.org/abs/1810.10880).
“It has some features in common with many different types of things, but it doesn’t fit neatly into any one category,” says Ho. “It’s really, totally strange.”
Together, the two sets of observations paint a picture of a very powerful explosion, blasting through gas clouds and lent extra oomph by a central energy source, or “engine”. The whole thing is ringed with debris.
We may not know for a while how the Cow gets its power. It could be a rapidly spinning neutron star, a newborn black hole, or a delayed shock wave from a failed supernova. The problem is a lot of central energy sources look alike, says Metzger.
The Cow sits in a not too distant dwarf galaxy. We have seen other explosions that look similar, but they have always been so far away that we haven’t been able to study them in any detail. Observations of the Cow may mark the first time we are witnessing the finer features of a new type of space explosion.
“We’re entering this era now where the zoo of astronomical events has just gotten out of hand,” says Metzger. “This is a rare opportunity to examine the bestiary up close.”
This article appeared in print under the headline “Space explosion is too bright, too fast”
An artistic impression of a Jupiter-like planet roaming in space without a starNASA/JPL-Caltech
By Leah Crane of NewScientist
Some planets float alone through space, with no sun and skies that are always dark. These rogue worlds are incredibly difficult to spot, but two new ones have been discovered. One of them is among the smallest we’ve ever seen, and there may be more small planets like it in the Milky Way than stars.
When astronomers normally spot planets beyond our solar system, they do so by observing a planet passing in front of its star, blocking out some of the starlight. But for planets without stars, this method doesn’t work.
Instead, anyone looking for these wondering worlds must rely on a phenomenon called gravitational microlensing, which occurs when a planet passes in front of a distant background star and the planet’s gravity behaves like a lens, warping and magnifying the star’s light.
Przemek Mróz at Warsaw University in Poland and his colleagues used this method to find two new starless worlds, using data from the Optical Gravitational Lensing Experiment, a sky survey that looks for gravitational lensing events.
Based on the few Earth-mass worlds like this we have found and how difficult they are to spot, the team calculated that rogue planets might even be more common than stars in the Milky Way, even though only 10 have been discovered so far.
This photo(shown below) of Ceres and the bright regions of Occator Crater was one of the last views NASA's Dawn spacecraft transmitted before it completed its mission. This view, which faces south, was captured on Sept. 1 at an altitude of 2,340 miles (3,370 kilometers) as the spacecraft was ascending in its elliptical orbit. Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA › Full image and caption
› Asteroids, comets and other small objects in space hold clues to our origins, but may also pose hazards.
› Small worlds likely delivered the ingredients of life to Earth.
› Several NASA missions are either on their way to these small worlds, or are in development.
The entire history of human existence is a tiny blip in our solar system's 4.5-billion-year history. No one was around to see planets forming and undergoing dramatic changes before settling in their present configuration. In order to understand what came before us -- before life on Earth and before Earth itself -- scientists need to hunt for clues to that mysterious distant past.
Hubble and Keck Observatories Uncover Black Holes Coalescing
These images reveal the final stage of a union between pairs of galactic nuclei in the messy cores of colliding galaxies.
The image at top left, taken by Hubble's Wide Field Camera 3, shows the merging galaxy NGC 6240. A close-up of the two brilliant cores of this galactic union is shown at top right. This view, taken in infrared light, pierces the dense cloud of dust and gas encasing the two colliding galaxies and uncovers the active cores. The hefty black holes in these cores are growing quickly as they feast on gas kicked up by the galaxy merger. The black holes' speedy growth occurs during the last 10 million to 20 million years of the merger.
Images of four other colliding galaxies, along with close-up views of their coalescing nuclei in the bright cores, are shown beneath the snapshots of NGC 6240. The images of the bright cores were taken in near-infrared light by the W. M. Keck Observatory in Hawaii, using adaptive optics to sharpen the view.
The reference images (left) of the merging galaxies were taken by the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS).
The two nuclei in the Hubble and Keck Observatory photos are only about 3,000 light-years apart — a near-embrace in cosmic terms. If there are pairs of black holes, they will likely merge within the next 10 million years to form a more massive black hole.
These observations are part of the largest-ever survey of the cores of nearby galaxies using high-resolution images in near-infrared light taken by the Hubble and Keck observatories.
The survey galaxies' average distance is 330 million light-years from Earth.
Credits
NASA, ESA, and M. Koss (Eureka Scientific, Inc.); Hubble image: NASA, ESA, and M. Koss (Eureka Scientific, Inc.); Keck images: W. M. Keck Observatory and M. Koss (Eureka Scientific, Inc.); Pan-STARRS images: Panoramic Survey Telescope and Rapid Response System and M. Koss (Eureka Scientific, Inc.)
(CNN)A mysterious cigar-shaped object spotted tumbling through our solar system last year may have been an alien spacecraft sent to investigate Earth, astronomers from Harvard University have suggested.
The object, nicknamed 'Oumuamua, meaning "a messenger that reaches out from the distant past" in Hawaiian, was discovered in October 2017 by the Pan-STARRS 1 telescope in Hawaii.
Sugata Mitra believes knowledge should be learned, not taught. by Murdo MacLeod Educationalist Sugata Mitra's pioneering experiments suggest teaching facts doesn't work in the internet age – fostering creativity and collaboration is the key.
By Bob Holmes of NewScientist
IN 1999, an inquisitive physicist named Sugata Mitra installed a computer in a slum in New Delhi, India, and then walked away. Local children congregated and began trying to use the unfamiliar device. When Mitra returned a few days later, they had already taught themselves to surf the internet.
Mitra is now a professor of educational technology at Newcastle University in the UK. In the decades since the “hole in the wall” experiment, he has found that groups of children aged 8 to 12, left alone with the internet, can teach themselves even technical subjects such as evolutionary biology to a level several years ahead of their school age. In 2013, he won a $1 million TED prize to help his work.
How can children learn on their own, without guidance?
The learning I’m talking about appears spontaneously in response to a query, which may be posed by an adult, or by the children themselves. I need the internet to be available on large, publicly visible screens in a safe space. I need to have mixed groups of children – boys and girls of different ages together, not each child on a different computer. Then I need to remove all supervision. We have got to keep the adults away.
Everybody says, who taught them? How clever they are! But this doesn’t have anything to do with cleverness or teaching. It has to do with a hive-like mind with a common desire.
But are the children really learning, or just repeating phrases they don’t really understand?
I could give them questions on quantum mechanics, and they would come back, not with the understanding that a physicist like me would have, but with a child’s understanding. I teased 9-year-olds by saying something could be in two places at the same time. They said no, if you have a pencil, it is here when you put it here and there when you put it there. I said there are some things that can be here and there at the same time – then I left. They came back with quantum entanglement, and said it means that the two particles know about each other, but we don’t know how those particles know.
Children in India worked together to teach themselves when provided with a “hole in the wall” computer
The children get as confused as you and I. However, when they work in groups, they can detect extreme points of view and avoid those. Working in groups is key: the hive mind is more discriminating and less gullible than an individual in front of the screen.
If I show kids a picture of the Colosseum in Rome and ask “what’s that building? And why is it broken?”, they come back with a lot of information about the Roman Empire. But now I go on to ask “how do we know what you said is true?” They start by saying that every website says so, which is good, but then they start going deeper, toward understanding historical evidence.
Is this method effective even for very young children?
You can push it down to the point where the child is beginning to read, which might be age 4 or 5. And it accelerates reading development. With the TED prize, I set up labs in seven schools – five in India and two in England. We have got all the data now, and there is a definite, measurable improvement in reading comprehension over and above what would be expected.
What role does this leave for teachers, and what do they think of your approach?
It’s not that you don’t need a teacher. You just don’t need the teacher to tell children things they could look up for themselves. You need the teacher to ask them questions that make them sit up and wonder. My teacher friends tell me it is harder than preparing for a lesson where they just read out facts.
In the 20 years I’ve been doing this work, the opinion of teachers has changed dramatically – from saying this is rubbish to saying, isn’t what you say obvious?
“You just don’t need teachers telling children things they can look up on their own”
But isn’t there a set of basic knowledge that needs to be learned by every child for them to get by in society?
I’m very glad that you said needs to be learned, not needs to be taught. All my work is about making that distinction. My answer is yes, but I’m not able to define that basic set very well. How much should I keep in my head, and how much should I rely on the internet? I tend toward thinking that we should know how to make the information infrastructure answer a question just in time, when we need it to. This is as opposed to the old system, which is to teach the child everything we think they need, just in case.
Does that mean I can go through life without knowing what the solar system is? That’s a horrifying thought. So perhaps we can agree on the big questions that children should engage with at various ages, then give teachers the liberty to pose the questions as they wish.
Should we allow internet access during exams, then?
I think we should. But then we have a problem: who is going to evaluate the answer, and how? I don’t know yet – that’s what I’m working on now. But for example, when you are learning to play an instrument, the exam is to play the instrument, and judges assess how good you are. Maybe we should move toward that kind of assessment in an internet-assisted world.
If knowledge is in the cloud, not our heads, what happens if the internet fails?
If the internet goes down, we will live very uninformed. But that doesn’t mean that we should learn how to live without the internet – no more than we should learn how to tell the time of day without looking at a watch, just in case watches disappear. If I don’t have a watch, I won’t be able to tell the time. Sorry.
You have faced scepticism because you haven’t published much comparative data in top-tier journals. What has stopped you?
I find it hard to publish – I get one rejection after another. I’m not from the social sciences. In the natural sciences, if results are unexpected, others repeat the experiment and report whether they got the same results. In the social sciences, people just seem to point at the holes in your work, but nobody ever says they repeated the experiment and got something else. So I have a humble request to social scientists: replicate my work and see if you get the same results.
This article appeared in print under the headline “Hey, teacher! Leave those kids alone”
How did water survive Earth's searingly hot birth? A radical new answer turns planetary history on its head – and could revolutionise the search for alien life.
This planet is a lush world of rivers, lakes and streams. But it shouldn’t be, according to our traditional interpretation of Earth’s past. Our measurements at the Open University in Milton Keynes provide a strong indication that this explanation is past its sell-by date. The true story of how Earth got its water looks to be far stranger. If we are right, it means water, and potentially life that thrives in it, is probably far more widespread in the universe than we dared dream.
To understand why the presence of so much water on Earth is so unlikely, we need to go back more than 4.6 billion years. The young sun is shining, and encircling it is a maelstrom of gas and dust that will clump into the planets. Any water exists as ice in interstellar space. If any of that ice found itself in the inner part of the solar system, where the rocky planets like Earth will form, the heat and radiation split it into its constituent atoms of hydrogen and oxygen. This means the material that formed Earth shouldn’t have contained a speck of moisture.
Planet-forming disk around a fledgling star casts a colossal shadow
Like a fly that wanders into a flashlight’s beam, a young star’s planet-forming disk is casting a giant shadow, nicknamed the “Bat Shadow.” Hubble’s near-infrared vision captured the shadow of the disk of this fledgling star, which resides nearly 1,300 light-years away in a stellar nursery called the Serpens Nebula. In this Hubble image, the shadow spans approximately 200 times the length of our solar system. It is visible in the upper right portion of the picture. The young star and its disk likely resemble what the solar system looked like when it was only 1 or 2 million years old.
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