Space news topic and space related news

Started by Tsanten Eywa 'eveng, September 23, 2011, 03:31:21 PM

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Scientists use Summit supercomputer to explore exotic stellar phenomena

Astrophysicists at the State University of New York, Stony Brook, and University of California, Berkeley created 3D simulations of X-ray bursts on the surfaces of neutron stars. Two views of these X-ray bursts are shown: the left column is viewed from above while the right column shows it from a shallow angle above the surface. The panels (from top to bottom) show the X-ray burst structure at 10, 20 and 40 milliseconds of simulation time. Credit: Michael Zingale, Department of Physics and Astronomy at SUNY Stony Brook





Searching for clues in a fly-by

The BepiColombo space probe measures carbon ions escaping from the atmosphere of Venus and thus helps to decipher the special development of Venus

During its flyby of Venus, the European-Japanese space probe Bepi Colombo for the first time found carbon ions escaping from the planet's atmosphere into space in a previously unexplored region on the night side of the planet. Investigations of the ion distribution help to understand which processes have shaped the atmosphere of our neighboring planet and why it differs so greatly from Earth's gas envelope. The idea for the new measurements was inspired by a rare cosmic event that occurred 25 years ago - and brought a whiff of Venus to Earth.


Why is Methane Seeping on Mars? NASA Scientists Have New Ideas

The most surprising revelation from NASA's Curiosity Mars Rover — that methane is seeping from the surface of Gale Crater — has scientists scratching their heads.

Living creatures produce most of the methane on Earth. But scientists haven't found convincing signs of current or ancient life on Mars, and thus didn't expect to find methane there. Yet, the portable chemistry lab aboard Curiosity, known as SAM, or Sample Analysis at Mars, has continually sniffed out traces of the gas near the surface of Gale Crater, the only place on the surface of Mars where methane has been detected thus far. Its likely source, scientists assume, are geological mechanisms that involve water and rocks deep underground.

If that were the whole story, things would be easy. However, SAM has found that methane behaves in unexpected ways in Gale Crater. It appears at night and disappears during the day. It fluctuates seasonally, and sometimes spikes to levels 40 times higher than usual. Surprisingly, the methane also isn't accumulating in the atmosphere: ESA's (the European Space Agency) ExoMars Trace Gas Orbiter, sent to Mars specifically to study the gas in the atmosphere, has detected no methane


Buckyballs in space: Weichman combines astrochemistry and spectroscopy to identify complex space molecules

In research that has all the makings of a blockbuster movie — with interstellar chemistry, million-year timescales, and high-powered lasers — Princeton chemists are expanding our understanding of the composition of the universe.

Backed by a three-year grant from the National Science Foundation, researchers led by Princeton's Marissa Weichman will help identify new buckyball-like molecules, formed in space, which "drive the chemistry of planets and stars and galaxy formation," said Weichman, an assistant professor of chemistry.

"These are big, fundamental questions about where we come from and what kind of universe we live in," she said. These molecules are "the prebiotic origins of life, the seeds of molecules that start life. That's why we're looking at them."

Her lab has designed a device that measures the light absorption of particular kinds of molecules called fullerenes. These geodesic hollow "carbon cages" are the largest group of molecules identified in space so far, and they have already redefined our assumptions about molecular complexity in interstellar environments.

Weichman wants to take those assumptions to the next level.

As a postdoc five years ago, Weichman published a paper in Science on the simplest C60 fullerenes, colloquially called buckyballs. Now, using the signature spectrum of the buckyball as a benchmark, Weichman will target three similar molecules: bigger fullerenes; heterofullerenes, in which carbon atoms have been swapped out for other elements; and endofullerenes, which feature smaller molecules trapped inside the cage.

"Interstellar space is a really strange environment," Weichman said. "It's cold. It's really low-pressure. There are not many molecules in a given amount of space, and the molecules that do exist are constantly being irradiated by ultraviolet radiation and bombarded by cosmic particles. So, the chemistry that happens there is totally different from what happens on Earth."

The constant radiation bombardment, from particles blown out by supernovas across the galaxy, creates a hostile environment for molecules, she explained. "Fullerenes happen to be exceptionally stable and robust against fragmentation," she said. "They can last more or less forever in space. Understanding these species is really important for astrochemistry, and spectroscopy is how we detect that a specific given molecule is present."



Hubble Celebrates 34th Anniversary with a Look at the Little Dumbbell Nebula

Glowing Bipolar Bubble from Dying Star Expands into Space

In celebration of the 34th anniversary of the launch of NASA's legendary Hubble Space Telescope on April 24, 1990, astronomers took a snapshot of the Little Dumbbell Nebula. Also known as Messier 76, M76, or NGC 650/651, it is composed of a ring, seen edge-on as the central bar structure, and two lobes on either opening of the ring.

Before a red giant star burned out, it ejected a ring of gas and dust. The ring was probably sculpted by the effects of a binary companion star. This sloughed off material created a thick disk of dust and gas along the plane of the companion's orbit. The hypothetical companion star isn't seen in the Hubble image, and so it could have been later swallowed by the central star. The disk would be forensic evidence for that stellar cannibalism.

The photogenic nebula is a favorite target of amateur astronomers. Professional astronomers first took a spectrum in 1891, which indicated it was a nebula instead of a galaxy or a star cluster. They suggested that M76 might be similar to the donut-shaped Ring Nebula (M57), as seen instead from a side view.


Mysterious rainbow 'glory' lights observed on distant planet

For the first time, signs of the rainbow-like 'glory effect' have been detected on a planet outside our solar system. Glory are colourful concentric rings of light that occur only under peculiar conditions.

Glory occurs when light is reflected off clouds made up of a perfectly uniform, but so far unknown, substance. The effect, similar to a rainbow, forms when light passes between a narrow opening, for example between water droplets in clouds or fog, causing it to diffract and create ring-like patterns.

Data, analysed by astronomers including those at the University of Warwick, suggests this phenomenon is beaming from the hellish atmosphere of ultra-hot gas giant WASP-76b some 637 light-years away.

Observations from the European Space Agency's Characterising Exoplanet Satellite (CHEOPS) suggests that between the unbearable heat and light of exoplanet WASP-76b's sunlit face, and the endless night of its dark side, there may be 'glory'.

Seen often on Earth, the effect has only been found once on another planet, Venus. If confirmed, this first glory outside of the solar system will reveal more about the nature of this puzzling exoplanet.

Co-Author Thomas Wilson from the University of Warwick, said: "Never before have we seen these colourful, concentric rings on an extrasolar body. So this first exoplanetary glory, if confirmed with future studies, would make WASP-76b a truly unique body, and give us a beautiful tool for understanding the atmospheres of distance exoplanets and how habitable they could be."

Lead Author Olivier Demangeon from the Institute of Astrophysics and Space Sciences, Portugal, said: "There's a reason no glory has been seen before outside our solar system – it requires very peculiar conditions. First, you need atmospheric particles that are close-to-perfectly spherical, completely uniform and stable enough to be observed over a long time. The planet's nearby star needs to shine directly at it, with the observer at just the right orientation."

WASP-76b is an ultra-hot Jupiter-like planet. While has less mass than our striped cousin, it is almost double its size. Tightly orbiting its host star twelve times closer than scorched Mercury orbits our Sun, the exoplanet's large size is caused by it being 'puffed up' by intense radiation.

Since its discovery in 2013, WASP-76b's bizarrely hellish environment has emerged. One side of the planet always faces the Sun, reaching temperatures of 2400 degrees Celsius. Here, elements that would form rocks on Earth melt and evaporate, only to condense on the slightly cooler night side, creating iron clouds that drip molten iron rain.

But scientists have been puzzled by an apparent asymmetry, or wonkiness, in WASP-76b's 'limbs' – its outermost regions seen as it passes in front of its host star.

Cheops intensively monitored WASP-76b as it passed in front of and around its Sun-like star. After 23 observations over three years, the data showed a surprising increase in the amount of light coming from the planet's eastern 'terminator' – the boundary where night meets day. This allowed scientists to determine the origin of the signal.

Olivier Demangeon added: "This is the first time that such a sharp change has been detected in the brightness of an exoplanet. This discovery leads us to hypothesise that this unexpected glow could be caused by a strong, localised and directionally dependent reflection – the glory effect."

NASA's James Webb Space Telescope (JWST) could now be used to officially confirm that this is glory, say scientists. Confirmation would imply that the temperature of WASP-76b's atmosphere must be stable over time, enabling the presence of clouds made up of perfectly spherical water droplets crucial to glory formation.


New NASA Black Hole Visualization Takes Viewers Beyond the Brink

Ever wonder what happens when you fall into a black hole? Now, thanks to a new, immersive visualization produced on a NASA supercomputer, viewers can plunge into the event horizon, a black hole's point of no return.


Weekend geomagnetic storm: Experts can discuss potential US impacts

A severe geomagnetic storm watch beginning this evening and continuing through the weekend has been issued by the National Oceanic and Atmospheric Administration (NOAA)—the first since 2005.
The storm watch is the result of five coronal mass ejections, bundles of plasma and magnetic field, that launched toward Earth from the sun. They could be strong enough to disrupt Earth's magnetic field, potentially moving aurora further south than usual and disrupting radio and GPS communications.
University of Michigan researchers developed the space weather model used by NOAA's Space Weather Prediction Center and experts on the sun, aurora and Earth's magnetic field are available to discuss geomagnetic storms and how a severe one could impact the U.S. this weekend.


The search is on for signs of the first stars in the universe

Yale's Priyamvada Natarajan and colleagues say the first stars left behind distinctive flares that can be detected by a new generation of space telescopes.

Astronomers at Yale and the University of Hong Kong have proposed a new strategy for finding the universe's first stars — by looking for signs of their final, fiery flares.

For years, scientists have searched for direct evidence of "Population III" stars, the first generation of stars that lit up the universe just a few hundred million years after the Big Bang. Formed from the pristine gas of the early universe, these first stars played a crucial role in the evolution of the cosmos and the development of later generations of stars.

Astronomers say the first stars were initially metal-free, made up primarily of hydrogen and helium. However, they eventually began to produce metals in their core, making them a bridge to the stars that would form billions of years later.

"Population III" stars are predicted to be distinct in other ways, as well. They are expected to be much more massive and hotter than Earth's sun and other, younger stars; they also had shorter lifespans.

However, these first stars have yet to be observationally detected. The key to finding them, researchers say, is to look for the flares they left behind.

"The recent detection of the first black holes by the James Webb Space Telescope suggests that they are also in place around the same time as the first stars," said Priyamvada Natarajan, the Joseph S. and Sophia S. Fruton Professor and Chair of Astronomy and professor of physics in Yale's Faculty of Arts and Sciences (FAS), and co-author of a new study published in The Astrophysical Journal Letters.

"We realized that the fireworks created by the ripping apart of a Population III star that strays too close to a black hole should be detectable," Natarajan said.

In the new study, the researchers suggest that if a "Population III" star encounters a black hole, the resulting "tidal disruption event" (TDE), in which the black hole tears the star apart, would create a particularly bright flare — bright enough and long-lived enough to reach across billions of light years to reach Earth today. What's more, the flare would have an identifiable "signature" that is discernable to astronomers.

"As the energetic photons travel from a very faraway distance, the timescale of the flare will be stretched due to the expansion of the universe," said astronomer Jane Dai of the University of Hong Kong, principal investigator of the research team. "These TDE flares will rise and decay over a very long period of time, which sets them apart from the TDEs of solar type stars in the nearby universe."

Importantly, the wavelength of the flares' light is also stretched, according to the study's first author, Rudrani Kar Chowdhury from the University of Hong Kong. "The optical and ultraviolet light emitted by the TDE will be transferred to infrared wavelengths when reaching the Earth," she said.

And that infrared light can be detected, the researchers said.

They say that two flagship NASA missions, the James Webb Space Telescope and the upcoming Nancy Grace Roman Space Telescope, both have the capability to detect infrared emission — even from great distances.

"Roman's unique capabilities of simultaneously being able to observe a large area of the sky and peek deep into the early universe makes it a promising probe for detecting these Pop III TDE flares," Natarajan said. "This may be the only way in which we can infer the presence of Pop III stars."

Such discoveries are possible in the next decade, the researchers said.


A once-dormant magnetic neutron star is emitting strangely polarised light

CSIRO telescope detects unprecedented behaviour from nearby magnetar

Magnetars are neutron stars with strong magnetic fields. With CSIRO astronomers, Dr Manisha Caleb from the School of Physics has found one of the most powerful magnets discovered - XTE J1810-197 - and it doesn't quite fit existing theory.

Astronomers using Murriyang, CSIRO's radio telescope at Parkes NSW, have detected unusual radio pulses from a previously dormant star with a powerful magnetic field.

New results published today in Nature Astronomy describe radio signals from magnetar XTE J1810-197 behaving in complex ways.

Magnetars are a type of neutron star and the strongest magnets in the Universe. At roughly 8000 light years away, this magnetar is also the closest known to Earth.

Most magnetars are known to emit polarised light, though the light this magnetar is emitting is circularly polarised, where the light appears to spiral as it moves through space.

Dr Marcus Lower, a postdoctoral fellow at Australia's national science agency CSIRO, led the research and said the results are unexpected and totally unprecedented.

"Unlike the radio signals we've seen from other magnetars, this one is emitting enormous amounts of rapidly changing circular polarisation. We have never seen anything like this before," Dr Lower said.


Hubble Views a Galaxy with a Voracious Black Hole

Bright, starry spiral arms surround an active galactic center in this new NASA Hubble Space Telescope image of the galaxy NGC 4951.

Located in the Virgo constellation, NGC 4951 is located roughly 50 million light-years away from Earth. It's classified as a Seyfert galaxy, which means that it's an extremely energetic type of galaxy with an active galactic nucleus (AGN). However, Seyfert galaxies are unique from other sorts of AGNs because the galaxy itself can still be clearly seen – different types of AGNs are so bright that it's nearly impossible to observe the actual galaxy that they reside within.

AGNs like NGC 4951 are powered by supermassive black holes. As matter whirls into the black hole, it generates radiation across the entire electromagnetic spectrum, making the AGN shine brightly.

Hubble helped prove that supermassive black holes exist at the core of almost every galaxy in our universe. Before the telescope launched into low-Earth orbit in 1990, astronomers only theorized about their existence. The mission verified their existence by observing the undeniable effects of black holes, like jets of material ejecting from black holes and disks of gas and dust revolving around those black holes at very high speeds.

These observations of NGC 4951 were taken to provide valuable data for astronomers studying how galaxies evolve, with a particular focus on the star formation process. Hubble gathered this information, which is being combined with observations with the James Webb Space Telescope (JWST) to support a JWST Treasury program. Treasury programs collect observations that focus on the potential to solve multiple scientific problems with a single, coherent dataset and enable a variety of compelling scientific investigations.


MIT researchers discover the universe's oldest stars in our own galactic backyard
Three stars circling the Milky Way's halo formed 12 to 13 billion years ago.

MIT researchers, including several undergraduate students, have discovered three of the oldest stars in the universe, and they happen to live in our own galactic neighborhood.

The team spotted the stars in the Milky Way's "halo" — the cloud of stars that envelopes the entire main galactic disk. Based on the team's analysis, the three stars formed between 12 and 13 billion years ago, the time when the very first galaxies were taking shape.

The researchers have coined the stars "SASS," for Small Accreted Stellar System stars, as they believe each star once belonged to its own small, primitive galaxy that was later absorbed by the larger but still growing Milky Way. Today, the three stars are all that are left of their respective galaxies. They circle the outskirts of the Milky Way, where the team suspects there may be more such ancient stellar survivors.

"These oldest stars should definitely be there, given what we know of galaxy formation," says MIT professor of physics Anna Frebel. "They are part of our cosmic family tree. And we now have a new way to find them."

As they uncover similar SASS stars, the researchers hope to use them as analogs of ultrafaint dwarf galaxies, which are thought to be some of the universe's surviving first galaxies. Such galaxies are still intact today but are too distant and faint for astronomers to study in depth. As SASS stars may have once belonged to similarly primitive dwarf galaxies but are in the Milky Way and as such much closer, they could be an accessible key to understanding the evolution of ultrafaint dwarf galaxies.

"Now we can look for more analogs in the Milky Way, that are much brighter, and study their chemical evolution without having to chase these extremely faint stars," Frebel says.

She and her colleagues have published their findings today in the Monthly Notices of the Royal Astronomical Society (MNRAS). The study's co-authors are Mohammad Mardini, at Zarqa University, in Jordan; Hillary Andales '23; and current MIT undergraduates Ananda Santos and Casey Fienberg.


Discovery of biomarkers in space
Conditions on Saturn's moon Enceladus simulated in the laboratory

In 2018, very large organic molecules were discovered in ice particles on Saturn's moon Enceladus. It is still unclear whether they indicate the existence of life or were created in some other way. A recent study could help to answer this question. It is possible, that conditions that support or maintain life in extraterrestrial oceans could leave molecular traces in grains of ice. The research on this was conducted at the FU Berlin, and the lead scientist, Dr. Nozair Khawaja, has recently relocated to the University of Stuttgart.


Squeezed by neighbors, planet glows with molten lava
Extreme conditions on rocky planet surprise scientists

UC Riverside astrophysicist Stephen Kane had to double check his calculations. He wasn't sure the planet he was studying could be as extreme as it seemed. Kane never expected to learn that a planet in this faraway star system is covered with so many active volcanoes that seen from a distance it would take on a fiery, glowing-red hue. 

"It was one of those discovery moments that you think, 'wow, it's amazing this can actually exist," Kane said. A paper detailing the discovery has been published in The Astronomical Journal.

Launched in 2018, NASA's Transiting Exoplanet Survey Satellite, or TESS, searches for exoplanets — planets outside our solar system — that orbit the brightest stars in the sky, including those that could support life.

Kane was studying a star system called HD 104067 about 66 light years away from our sun that was already known to harbor a giant planet. TESS had just discovered signals for a new rocky planet in that system. In gathering data about that planet, he unexpectedly found yet another one, bringing the total number of known planets in the system to three.

The new TESS-discovered planet is a rocky planet like Earth, but 30% larger. However, unlike Earth, it has more in common with Io, Jupiter's rocky innermost moon and the most volcanically active body in our solar system.

"This is a terrestrial planet that I would describe as Io on steroids," Kane said. "It's been forced into a situation where it's constantly exploding with volcanoes. At optical wavelengths you would be able to see a glowing, red-hot planet with a molten lava surface."

Kane calculated that the surface temperature of the new planet, TOI-6713.01, would be 2,600 degrees Kelvin, which is hotter than some stars.

Gravitational forces are to blame for the volcanic activity both on Io and on this planet. Io is very close to Jupiter. Kane explained that Jupiter's other moons force Io into an elliptical or "eccentric" orbit around the planet, which itself has a very strong gravitational pull.

"If the other moons weren't there, Io would be in a circular orbit around the planet, and it would be quiet on the surface. Instead, Jupiter's gravity squeezes Io so much that it erupts in volcanoes constantly," Kane said.

Similarly, there are two planets in the HD 104067 system that are farther away from the star than this new planet. Those outer planets are also forcing the inner rocky planet into an eccentric orbit around the star that squeezes it as it orbits and rotates.

Kane likens this scenario to racquetball, where the small rubber game ball bounces more and gets hotter as it is constantly hit with paddles.  This effect is called tidal energy, a term used when referencing one body's gravitational effect on another body. On Earth, tides are mostly the result of the moon's gravity dragging our oceans along.

Moving forward, Kane and his colleagues would like to measure the mass of the flaming planet and learn its density.  This would tell them how much material is available to blow out of the volcanoes.

Kane said that tidal effects on planets hasn't historically been a big focus of exoplanet research. Perhaps that will change with this discovery.

"This teaches us a lot about the extremes of how much energy can be pumped into a terrestrial planet, and the consequences of that," Kane said. "While we know that stars contribute to the heat of a planet, the vast majority of the energy here is tidal and that cannot be ignored."


NASA's Webb Hints at Possible Atmosphere Surrounding Rocky Exoplanet

Gas bubbling up from a lava-covered surface on 55 Cancri e may feed an atmosphere rich in carbon dioxide or carbon monoxide.

These days, detecting a planetary atmosphere tens or even hundreds of light-years from Earth might not sound like such a big deal. Scientists have found signs of atmosphere surrounding dozens of exoplanets over the past two decades. The catch is, all those planets have thick, hydrogen-dominated atmospheres that are relatively easy to study. The much thinner blankets of gas that almost certainly surround some small, rocky exoplanets have remained elusive.

Researchers think they may have finally caught a glimpse of a volatile-rich atmosphere surrounding a rocky planet. Light emitted by the hot, highly-irradiated exoplanet 55 Cancri e shows compelling evidence for an atmosphere, probably rich in carbon dioxide or carbon monoxide, which may be bubbling from a vast ocean of lava covering the planet's surface.

The result is the best evidence to date for a rocky planet atmosphere outside our solar system.


NASA's Webb Maps Weather on Planet 280 Light-Years Away

WASP-43 b is cloudy on the nightside and clear on the dayside, with equatorial winds howling around the planet at 5,000 miles per hour.

Sometimes not finding something is just as exciting and useful as finding it. Take hot Jupiter WASP-43 b, for example. This tidally locked world has a searing-hot, permanent dayside and a somewhat cooler nightside. Astronomers using Webb to map the temperature and analyze the atmosphere around the planet expected to detect methane, a common carbon molecule, on the nightside. But there is clearly no sign of it. Why? The result suggests that supersonic winds of hot gas are blowing around from the dayside, thoroughly churning up the atmosphere, and preventing the chemical reactions that would otherwise produce methane on the nightside.