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The Daily Galaxy -Great Discoveries Channel, is an eclectic text and video presentation of news and original insights on science, space exploration and the environment and their reflections in popular culture (film, books, events). It provides news and original insights on science, space exploration, cosmology, astrobiology, and astrophysics.
Elon Musk's grand stunt sending his cherry red Tesla out into the reaches of our Solar System last week makes one wonder what that galactic hitch-hiker and alien journalist, Ford Prefect, star with Arthur Dent of The Hitchhikers Guide to the Galaxy, would have made of the caper.
The Tesla Roadster that was recently shot into space as part of SpaceX's rocket test flight will likely collide with Earth or Venus eventually, according to new University of Toronto research. will likely end up colliding with Earth or Venus, but there's no need to panic since the probability of that happening even within the next million years is very small," says the research's author Hanno Rein, an assistant professor of physics at U of Toronto Scarborough and director of the Centre for Planetary Sciences.
The car was sent into space as part of the payload for SpaceX's Falcon Heavy test flight on Feb. 6. While rocket test flights usually have a dummy payload, SpaceX founder Elon Musk sent up his personal Tesla Roadster instead.
Though it's mostly a publicity stunt – the car doesn't have any scientific instruments on board – it's now classified as a near-earth object, meaning it is catalogued and being tracked by NASA's Jet Propulsion Laboratory along with other objects that will travel relatively close to Earth.
What motivated Rein and his team was the question of what will be the car's long-term fate. After running a series of simulations using sophisticated software that can track the motion of objects in space, they determined the probability of it colliding with Earth and Venus over the next one million years to be six per cent and 2.5 per cent, respectively.
They also determined that the first close encounter the Tesla will have with us will be in 2091, when it will pass within a few hundred thousand kilometres of Earth.
The car is currently on a Mars and Earth crossing orbit, meaning it will travel on an elliptical path that repeatedly carries it beyond Mars and then back to Earth's orbital distance from the sun. How the car's orbit evolves over time will depend a lot on its encounters with Earth, especially how close it will get to Earth since any small change in its trajectory could have a large effect on its orbit.
While the path of the Tesla can be accurately predicted in terms of years, after hundreds of years and many close encounters with Earth it becomes impossible to predict the object's precise orbit. By studying a large number of orbital simulations, however, the researchers were able to arrive at a statistical distribution of possible outcomes.
"Each time it passes Earth, the car will get a gravitational kick," says Dan Tamayo, a postdoctoral fellow at U of T Scarborough who is a co-author on the paper that has yet to be published.
"Depending on the details of these encounters, the Tesla can be kicked onto a wider or smaller orbit, so it's random. Over time the orbit will undergo what's called a random walk, similar to the fluctuations we see in the stock market, that will allow it to wander the inner solar system."
While they only ran simulations for the first three million years of its space journey, Rein says the most likely outcome for the Tesla is for it to crash into Earth or Venus in the next 10 million years or so.
"Although we are not able to tell on which planet the car will ultimately end up, we're comfortable saying it won't survive in space for more than a few tens of millions of years," he says.
While the car's likely final destination is Earth, they note there's nothing to fear since much or all of it will likely burn up in the atmosphere.
"Five thousand sols after the start of our 90-sol mission, this amazing rover is still showing us surprises on Mars," said Opportunity Project Manager John Callas, of NASA's Jet Propulsion Laboratory, Pasadena, California.
The Sun will rise on NASA's solar-powered Mars rover Opportunity for the 5,000th time on Saturday, sending rays of energy to a golf-cart-size robotic field geologist that continues to provide revelations about the Red Planet.
A Martian "sol" lasts about 40 minutes longer than an Earth day, and a Martian year lasts nearly two Earth years. Opportunity's Sol 1 was landing day, Jan. 25, 2004 (that's in Universal Time; it was Jan. 24 in California). The prime mission was planned to last 90 sols. NASA did not expect the rover to survive through a Martian winter. Sol 5,000 will begin early Friday, Universal Time, with the 4,999th dawn a few hours later. Opportunity has worked actively right through the lowest-energy months of its eighth Martian winter.
From the rover's perspective on the inside slope of the western rim of Endeavour Crater, the milestone sunrise will appear over the basin's eastern rim, about 14 miles (22 kilometers) away. Opportunity has driven over 28 miles (45 kilometers) from its landing site to its current location about one-third of the way down "Perseverance Valley," a shallow channel incised from the rim's crest of the crater's floor. The rover has returned about 225,000 images, all promptly made public online.
"We've reached lots of milestones, and this is one more," Callas said, "but more important than the numbers are the exploration and the scientific discoveries."
The mission made headlines during its first months with the evidence about groundwater and surface water environments on ancient Mars. Opportunity trekked to increasingly larger craters to look deeper into Mars and father back into Martian history, reaching Endeavour Crater in 2011. Researchers are now using the rover to investigate the processes that shaped Perseverance Valley.
The growth of the biggest black holes in the Universe is outrunning the rate of formation of stars in the galaxies they inhabit, according to two new studies using data from NASA's Chandra X-ray Observatory and other telescopes and described in our latest press release.
In this graphic an image from the Chandra Deep Field-South is shown. The Chandra image (blue) is the deepest ever obtained in X-rays. It has been combined with an optical and infrared image from the Hubble Space Telescope (HST), colored red, green, and blue. Each Chandra source is produced by hot gas falling towards a supermassive black hole in the center of the host galaxy, as depicted in the artist's illustration.
One team of researchers, led by Guang Yang at Penn State, calculated the ratio between a supermassive black hole's growth rate and the growth rate of stars in its host galaxy and found it is much higher for more massive galaxies. For galaxies containing about 100 billion solar masses worth of stars, the ratio is about ten times higher than it is for galaxies containing about 10 billion solar masses worth of stars.
A Tour of Black Hole Growth in Chandra Deep Field South - YouTube
Using large amounts of data from Chandra, HST and other observatories, Yang and his colleagues studied the growth rate of black holes in galaxies at distances of 4.3 to 12.2 billion light years from Earth. The X-ray data included the Chandra Deep Field-South and North surveys and the COSMOS-Legacy surveys.
Another group of scientists, led by Mar Mezcua of the Institute of Space Sciences in Spain, independently studied 72 galaxies located at the center of galaxy clusters at distances ranging up to about 3.5 billion light years from Earth and compared their properties in X-ray and radio waves. Their work indicates that the black hole masses were about ten times larger than masses estimated by another method using the assumption that the black holes and galaxies grew in tandem.
The Mezcua study used X-ray data from Chandra and radio data from the Australia Telescope Compact Array, the Karl G. Jansky Very Large Array (VLA) and Very Long Baseline Array. One object in their sample is the large galaxy in the center of the Hercules galaxy cluster. The image shown above includes Chandra data (purple), VLA data (blue) and HST optical data (appearing white).
"We started out analyzing 275 candidates, of which 149 were validated as real exoplanets. In turn, 95 of these planets have proved to be new discoveries," said U.S. doctoral student Andrew Mayo at the National Space Institute (DTU Space) at the Technical University of Denmark. "This research has been underway since the first K2 data release in 2014." This brings the total number of new exoplanets found with the K2 mission up to almost 300.
The research was conducted partly as a senior project during his undergraduate studies at Harvard College. It also involved a team of international colleagues from institutions such as NASA, Caltech, UC Berkeley, the University of Copenhagen, and the University of Tokyo. The Kepler spacecraft was launched in 2009 to hunt for exoplanets in a single patch of sky, but in 2013, a mechanical failure crippled the telescope. However, astronomers and engineers devised a way to repurpose and save the space telescope by changing its field of view periodically. This solution paved the way for the follow-up K2 mission, which is still ongoing as the spacecraft searches for exoplanet transits.
These transits can be found by registering dips in light caused by the shadow of an exoplanet as it crosses in front of its host star. These dips are indications of exoplanets, which must then be examined more closely in order to confirm their nature. Exoplanetary research is a relatively young field. The first planet orbiting a star similar to our own sun was detected in 1995. Today some 3,600 exoplanets have been found, ranging from rocky Earth-sized planets to large gas giants like Jupiter.
It's difficult work to distinguish which signals are actually coming from exoplanets. Mayo and his colleagues analyzed hundreds of signals of potential exoplanets to determine which signals were created by exoplanets and which were caused by other sources. "We found that some of the signals were caused by multiple star systems or noise from the spacecraft. But we also detected planets that range from sub Earth-sized to the size of Jupiter and larger," said Mayo.
One of the planets detected was orbiting a very bright star. "We validated a planet on a 10-day orbit around a star called HD 212657, which is now the brightest star found by either the Kepler or K2 missions to host a validated planet. Planets around bright stars are important because astronomers can learn a lot about them from ground-based observatories," said Mayo.
"Exoplanets are a very exciting field of space science. As more planets are discovered, astronomers will develop a much better picture of the nature of exoplanets which in turn will allow us to place our own solar system into a galactic context."
The Kepler space telescope has made huge contributions to the field of exoplanets both in its original mission and its successor K2 mission. So far these missions have provided over 5,100 exoplanet candidates that can now be examined more closely.
With new, upcoming space missions like the James Webb Space Telescope and the Transiting Exoplanet Survey Satellite, astronomers will take exciting new steps toward characterizing and studying exoplanets like the rocky, habitable, Earth-sized planets that might be capable of supporting life.
The Daily Galaxy via Technical University of Denmark
A star about 100 light years away in the Pisces constellation, GJ 9827, hosts what may be one of the most massive and dense super-Earth planets detected to date according to new research led by Carnegie's Johanna Teske. This new information provides evidence to help astronomers better understand the process by which such planets form.
The GJ 9827 star actually hosts a trio of planets, discovered by NASA's exoplanet-hunting Kepler/K2 mission, and all three are slightly larger than Earth. This is the size that the Kepler mission determined to be most common in the galaxy with periods between a few and several-hundred-days.
Intriguingly, no planets of this size exist in our Solar System. This makes scientists curious about the conditions under which they form and evolve.
One important key to understanding a planet's history is to determine its composition. Are these super-Earths rocky like our own planet? Or do they have solid cores surrounded by large, gassy atmospheres?
To try to understand what an exoplanet is made of, scientists need to measure both its mass and its radius, which allows them to determine its bulk density.
When quantifying planets in this way, astronomers have noticed a trend. It turns out that planets with radii greater than about 1.7 times that of Earth are have a gassy envelope, like Neptune, and those with radii smaller than this are rocky, like our home planet.
Some researchers have proposed that this difference is caused by photoevaporation, which strips planets of their surrounding envelope of so-called volatiles--substances like water and carbon dioxide that have low boiling points--creating smaller-radius planets. But more information is needed to truly test this theory.
This is why GJ 9827's three planets are special--with radii of 1.64 (planet b), 1.29 (planet c) and 2.08 (planet d), they span this dividing line between super-Earth (rocky) and sub-Neptune (somewhat gassy) planets.
Luckily, teams of Carnegie scientists including co-authors Steve Shectman, Sharon Wang, Paul Butler, Jeff Crane, and Ian Thompson, have been monitoring GJ 9827 with their Planet Finding Spectrograph (PFS), so they were able to constrain the masses of the three planets with data in hand, rather than having to scramble to get many new observations of GJ 9827.
"Usually, if a transiting planet is detected, it takes months if not a year or more to gather enough observations to measure its mass," Teske explained. "Because GJ 9827 is a bright star, we happened to have it in the catalog of stars that Carnegie astronomers been monitoring for planets since 2010. This was unique to PFS."
The spectrograph was developed by Carnegie scientists and mounted on the Magellan Clay Telescopes at Carnegie's Las Campanas Observatory.
The PFS observations indicate that planet b is roughly eight times the mass of Earth, which would make it one of the most-massive and dense super-Earths yet discovered. The masses for planet c and planet d are estimated to be about two and a half and four times that of Earth respectively, although the uncertainty in these two determinations is very high.
This information suggests that planet d has a significant volatile envelope, and leaves open the question of whether planet c has a volatile envelope or not. But the better constraint on the mass of planet b suggests that that it is roughly 50 percent iron.
"More observations are needed to pin down the compositions of these three planets," Wang said. "But they do seem like some of the best candidates to test our ideas about how super-Earths form and evolve, potentially using NASA's upcoming James Webb Space Telescope."
If there is intelligent life out there, it might be broadcasting signals across the universe. Scientists listening out for broadcasts by extra-terrestrials are struggling to get the computer hardware they need, thanks to the crypto-currency mining craze, a radio-astronomer has said.
SETI (Search for Extraterrestrial Intelligence) researchers want to expand operations at two observatories. However, it has found that key computer chips are in short supply. "We'd like to use the latest GPUs [graphics processing units]... and we can't get 'em," said Dan Werthimer, Chief Scientist, SETI at the University of California, Berkeley.
Demand for GPUs has soared recently thanks to crypto-currency mining. "That's limiting our search for extra-terrestrials, to try to answer the question, 'Are we alone? Is there anybody out there?'," Dr Werthimer told the BBC. "This is a new problem, it's only happened on orders we've been trying to make in the last couple of months."
Mining a currency such as Bitcoin or Ethereum involves connecting computers to a global network and using them to solve complex mathematical puzzles. This forms part of the process of validating transactions made by people who use the currency. As a reward for this work, the miners receive a small crypto-currency payment, making it potentially profitable.
GPUs are high-performance chips and aren't just used for powering video games - they may be stacked together by Bitcoin miners, radio-astronomers or others interested in processing large amounts of data for certain applications.
"At Seti we want to look at as many frequency channels as we possibly can because we don't know what frequency ET will be broadcasting on and we want to look for lots of different signal types - is it AM or FM, what communication are they using?" explained Dr Werthimer, who is chief scientist at the Berkeley Seti Research Center. "That takes a lot of computing power."
Don't miss this! Podcasting superstar Joe Rogan interviews physicist and cosmologist Lawrence Krauss, Foundation Professor of the School of Earth and Space Exploration at Arizona State University, and director of its Origins Project.
Joe Rogan and Lawrence Krauss on artificial intelligence - YouTube
Sixty Five million years ago, the most famous asteroid in history slammed into Earth and most likely exterminated the dinosaurs. Disconcertingly, we are no less likely to be to hit by an asteroid today than our ancient reptilian counterparts were — but luckily we have helpful tools at our disposal.
The impact occurred 65 million years ago when an asteroid approximately 12 kilometers (7 miles) wide slammed into Earth. The collision took place near what is now the Yucatán peninsula in the Gulf of Mexico. The asteroid is often cited as a potential cause of the Cretaceous-Paleogene extinction event, a mass extinction that erased up to 75 percent of all plant and animal species.
In 2015 European Southern Obsevatory (ESO) joined the International Asteroid Warning Network (IAWN). To find out what this entails, they talked to Andy Williams, ESO’s Institutional Relations Officer, and Olivier Hainaut, an ESO astronomer in charge of Near Earth Objects follow-up at the Very Large Telescope (VLT).
Chicxulub impact visualization - YouTube
A 100-meter asteroid (with the same composition and speed as the 10-metre asteroid) would release 1000 Hiroshimas. An asteroid with a diameter of one kilometre would do much greater damage, and an asteroid of 10 kilometres would be like the one that killed off the dinosaurs. It would sterilise an entire continent and cause major global damage.
On average, one of these huge 10-km asteroids strikes Earth every 50 million years, and the last one was 65 million years ago — meaning we are now overdue. We know about most asteroids of this size in the Solar System – we’ve studied their orbits, their characteristics, and we can predict their chance of impact. But as the asteroids get smaller, the less we know of them.
The ESO team estimates that about 70–80% of asteroids from 500 metres to 1 kilometre in diameter are known, but only about 10% of asteroids 100 metres in diameter are known. The International Asteroid Warning Network (IAWN) is working to improve these numbers.
A hole at the heart of a stunning rose-like interstellar cloud has puzzled astronomers for decades. But new research, led by the University of Leeds, offers an explanation for the discrepancy between the size and age of the Rosetta Nebula's central cavity and that of its central stars.
The Rosette Nebula is located in the Milky Way Galaxy roughly 5,000 light-years from Earth and is known for its rose-like shape and distinctive hole at its center. The nebula is an interstellar cloud of dust, hydrogen, helium and other ionized gases with several massive stars found in a cluster at its heart.
Stellar winds and ionising radiation from these massive stars affect the shape of the giant molecular cloud. But the size and age of the cavity observed in the centre of Rosette Nebula is too small when compared to the age of its central stars.
Through computer simulations, astronomers at Leeds and at Keele University have found the formation of the Nebula is likely to be in a thin sheet-like molecular cloud rather than in a spherical or thick disc-like shape, as some photographs may suggest. A thin disc-like structure of the cloud focusing the stellar winds away from the cloud's centre would account for the comparatively small size of the central cavity.
Study lead author, Dr Christopher Wareing, from the School of Physics and Astronomy said: "The massive stars that make up the Rosette Nebula's central cluster are a few millions of years old and halfway through their lifecycle. For the length of time their stellar winds would have been flowing, you would expect a central cavity up to ten times bigger.
"We simulated the stellar wind feedback and formation of the nebula in various molecular cloud models including a clumpy sphere, a thick filamentary disc and a thin disc, all created from the same low density initial atomic cloud.
"It was the thin disc that reproduced the physical appearance - cavity size, shape and magnetic field alignment -- of the Nebula, at an age compatible with the central stars and their wind strengths
Applying this data to our models gave us new understanding of the roles individual stars play in the Rosette Nebula. Next we'll look at the many other similar objects in our Galaxy and see if we can figure out their shape as well."
The simulations, published today in the Monthly Notices of the Royal Astronomical Society, were run using the Advanced Research Computing centre at Leeds. The nine simulations required roughly half a million CPU hours -- the equivalent to 57 years on a standard desktop computer.
Rosette Nebula image at the top of the page is based on data obtained as part of the INT Photometric H-Alpha Survey of the Northern Galactic Plane, prepared by Nick Wright, Keele University, on behalf of the IPHAS Collaboration.
The research paper, A new mechanical stellar wind feedback model for the Rosette Nebula is published in the Monthly Notices of the Royal Astronomical Society 13 February 2018 (DOI: 10.1093/mnras/sty148)
Quayside is a nondescript, 12-acre chunk of land on the southern edge of Toronto’s downtown. It’s just three miles from my apartment, but getting there takes almost an hour by subway, bus, and foot. When I finally arrive at 333 Lake Shore Boulevard East on a windy day in early January, I find a vacant parking lot full of snow. The abandoned Victory Soya Mills silos loom at its edge—a remnant of the city’s industrial heyday. The plot is half of the future site of Sidewalk Toronto, a “neighborhood built from the internet up” by Google’s sister company, Sidewalk Labs. Lake Ontario is frozen and it’s colder than the surface of Mars the day I go to look at the site.
It’s a far cry from the vision that fills the Sidewalk Toronto webpage, reports today's The Atlantic, where a crisp video shot on a sunny day makes the Victory silos look cheerful and full of potential. Torontonians in puffer vests and toques describe a vibrant city bursting at the seams. Toronto’s population grew by 4.5 percent between 2011 and 2016. The city tolerates a high cost of living and a low rental-vacancy rate.
According to Dan Doctoroff, Sidewalk Labs’ CEO, these “incredible challenges of growth” can be surmounted with the right application of innovative technology. But Sidewalk Labs’ offer doesn’t come with guarantees or without strings. For locals, an obvious question arises: What’s in it for Toronto?
Sidewalk Labs is the realization of Google’s long-standing dream to “give us a city and put us in charge,” as the former Alphabet executive chairman Eric Schmidt once put it. As Alphabet’s smart-cities division, the company works to “accelerate urban innovation” through technology deployments undertaken in collaboration with cities. Before establishing Sidewalk with Google CEO Larry Page, Doctoroff had served as the deputy mayor for economic development under New York Mayor Michael Bloomberg. He led New York’s two unsuccessful Olympic bids, then catalyzed those efforts into PlaNYC, a large environmental and economic redevelopment plan.