Posts Tagged ‘space’


A NASA artist visualized what Earth would look like if it entered the “snowball state” predicted by new research from the University of Washington

By Chelsea Gohd

Earth-like planets with severe tilts and orbits could enter abrupt “snowball states,” in which entire oceans freeze and surface life cannot survive, according to new research.

Researchers at the University of Washington (UW) have found a new reason why, just because a planet is located in a “habitable zone” — meaning it’s close enough to its host star to sustain liquid water — it isn’t necessarily habitable. The team found that the axial tilt and orbital dynamics of planets in the habitable zone around “G dwarf” stars like our own sun can lead to “snowball states,” which are essentially extreme ice ages.

This new research looked at how a planet’s obliquity, or the angle at which a planet’s rotation axis tilts, and its orbital eccentricity, a parameter that determines the amount that an orbit deviates from a perfect circle, could affect that planet’s potential to be habitable.

Previous research suggested that planets in a habitable zone with a sun-like star that had a severe axial tilt or tilting orbit would be warmer, according to the statement. The team’s research found that the opposite holds true, which was quite a shock, they said.”We found that planets in the habitable zone could abruptly enter ‘snowball’ states if the eccentricity or the semi-major axis variations — changes in the distance between a planet and star over an orbit — were large or if the planet’s obliquity increased beyond 35 degrees,” Russell Deitrick, lead author of the new work and a postdoctoral researcher at the University of Bern who completed this research at UW, said in a statement.

Luckily, Earth’s axial tilt varies ever so slightly, leaving Earth “a relatively calm planet, climate-wise,” co-author Rory Barnes, an astronomer at UW, said in the statement. But, as it pertains to exoplanets, Deitrick “has essentially shown that ice ages on exoplanets can be much more severe than on Earth, that orbital dynamics can be a major driver of habitability and that the habitable zone is insufficient to characterize a planet’s habitability,” Barnes said.

A planet’s position in the habitable zone is typically a major factor in considering whether it may be habitable. However, this new research shows that even if a planet seems Earth-like and is orbiting at the right distance from its star, if “its orbit and obliquity oscillate like crazy, another planet might be better for follow-up with telescopes of the future,” Deitrick said.

With this research in mind, orbital dynamics should be considered an important part of determining a planet’s habitability, Deitrick added.

The work will be published in The Astronomical Journal, according to the statement.

https://www.space.com/40606-exoplanets-sudden-ice-age-snowball-states.html

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By Jeanna Bryner

Congress is talking about spending a bunch of money on the search for extraterrestrial intelligence (or SETI) for the first time in 25 years.

The U.S. House of Representatives has proposed a bill that includes $10 million in NASA funding for the next two years “to search for technosignatures, such as radio transmissions, in order to meet the NASA objective to search for life’s origin, evolution, distribution, and future in the universe.” Such technosignatures would come in the form of radio waves that have the telltale features of being produced by TV- or radio-type technologies. An intelligent civilization could also produce those signals intentionally to communicate with other civilizations like ours.

“If it passes, it would definitely be a sea-change in Congressional attitude since Sen. [Richard] Bryan terminated NASA’s SETI program, the High Resolution Microwave Survey, in 1993,” renowned astronomer Jill Tarter, former diretor of the SETI Institute, told Live Science in an email.

Here’s what Tarter is referring to: In 1992, a huge NASA SETI initiative was launched in order to build instrumentation so that observatories could comb the cosmos for signals from alien civilizations. For instance, the high resolution microwave survey was hooked up to the Arecibo telescope in Puerto Rico for just that. A year later, however, Nevada Sen. Bryan shut it down, and “SETI” became an unmentionable.

“[Bryan] made it clear to the administration that if they came back with SETI in their budget again, it wouldn’t be good for the NASA budget,” Tarter told Marina Koren of The Atlantic. “So, we instantly became the four-letter S-word that you couldn’t say at headquarters anymore, and that has stuck for quite a while.”

She added that the funding proposal seems to be an extension of the efforts of Rep. Lamar Smith, R–Texas, to bring attention to the search for life beyond Earth when he was the chairman of the House Science Committee. (Smith, who announced that he will retire at the end of his term this year, is a known denier of human-caused climate change.)

If the legislation clears the House and passes the Senate, the result would be huge. “It allows for new instrumentation to be built, and data collected and analyzed at scale, by a global community,” Tarter said of the $10 million.

Of course, the hunt for intelligence beyond Earth has not stopped, as private companies and other organizations have funded it, but a buy-in from the federal government is a big deal. [7 Huge Misconceptions about Aliens]

“You need to remember that this is an authorization bill, not an appropriations bill. Even if it passes, the appropriators may not provide any SETI funding in their bill. But if they do, that would be a very big deal,” said Tarter, who was the basis for the heroine Ellie Arroway in Carl Sagan’s novel “Contact” and in the adapted movie by the same name.

Tarter is admittedly ecstatic about the possibility of such a federal focus on SETI. But you don’t become the director of the SETI Institute by keeping your feet on the ground.

“Bring it on! But don’t stop there,” Tarter said about the potential funding. “Earthlings everywhere are fascinated with this search and care about the answer. So, we should create an international endowment for searching for intelligent life beyond Earth. The backers should be private individuals, enlightened corporations, U.S. federal agencies and agencies from other governments around the world.”

She added, “By smoothing out the funding roller coaster that has characterized this research field from the beginning, it will be possible to attract the best and brightest minds with the best ideas from everywhere, and commit to the long-term search efforts that might be required for success.”

Are alien greetings just around the corner? Tarter said we have the technology now to search for more distant and fainter signals in ways we haven’t tried before. “But that doesn’t guarantee success in the ‘near future.’ The cosmos is vast, and we may not yet be looking in the right way, although we are doing the best job possible with what we now know.”

The “correct perspective on timing,” Tarter said, is summed up in a line from a paper published in 1959 in the journal Nature by Giuseppe Cocconi and Philip Morrison: “‘The probability of success is difficult to estimate; but if we never search, the chance of success is zero,'” Tarter said.

https://www.livescience.com/62529-congress-search-for-intelligent-aliens.html?utm_source=notification

Nineteen-year-old Amber Yang has her head in the clouds. Actually, it’s beyond the clouds and well into the Earth’s atmosphere. While some teens are focused on cleaning up the land and water on our planet, Yang has made it her mission to clean up the litter clogging space. And she may just save lives and billions of dollars while she’s at it.

Yang was 15 when she first heard about the escalating issue of space debris that is polluting the Earth’s lower atmosphere. After watching the 2013 movie, “Gravity,” Yang imagined a world in which colliding space debris could set off a series of catastrophic events that threaten lives and technology. While the plot of “Gravity” broke some of the major rules of physics, the underlying premise — that a collision of space debris could lead to disaster — rang true and stuck in Yang’s mind.

That year, over her winter break in Florida, she brushed up on astrophysics, computer coding, and the ins and outs of space junk and developed a program called Seer Tracking to provide an accurate location for each piece of junk orbiting the Earth. Currently, there are millions of pieces of space debris, ranging in size from defunct satellites to tiny specks of paint. Traveling at a rate of around 17,500 miles per hour, each item has the potential to cause a catastrophic collision.

The Department of Defense’s Space Surveillance Network currently analyzes Earth’s space debris using tracking and data that could detect a potential collision as far as 10 days in advance, But according to Yang, her Seer Tracking program is able to predict issues weeks ahead. And the scientific community concurs. Her work has earned her the top award at the Intel International Science and Engineering Fair as well as a spot on Forbes 30 under 30 list. Yang has presented her research at the European Organization for Nuclear Research (CERN) in Geneva, Switzerland and was asked to speak at a TEDx Conference about the issues that women face in STEM careers.

Seer Tracking uses artificial neural networks to track space debris. In other words, Yang has developed an algorithim that allows the program to learn from its mistakes, so that its predictions become more accurate over time. As the data accumulates, Seer Tracking increases in its ability to pinpoint debris locations and predict collisions well in advance.

Yang is now finishing up her sophomore year at Stanford University, pursuing a degree in physics while operating Seer Tracking on the side. She’s still working on improving her software and exploring other avenues of “deep learning” in which computers learn from their mistakes.

https://www.mnn.com/family/family-activities/blogs/meet-teen-whos-cleaning-space-junk

By Nola Taylor Redd

Alien civilizations with technology on a par with humanity’s could be detectable using today’s instruments. A new study suggests that if geostationary satellites are thick enough around an alien world, they could be spotted with telescopes already hunting for undiscovered planets.

Both governments and private corporations on our own world use geostationary satellites — which orbit such that they hover over the same spot on Earth — for science, communications, espionage and military applications.

If advanced alien civilizations loft enough satellites into their own geostationary belts, these spacecraft could create a dense, ring-like structure visible from Earth, according to the study.

“It’s … a small chance, but the point is that it’s free,” study lead author Hector Socas-Navarro, of Astrophysics Institute of the Canary Islands, told Space.com by email.

Socas-Navarro simulated the presence of belts of geostationary satellites around exoplanets, to see whether they could be detected by instruments like NASA’s Kepler space telescope and the agency’s recently launched Transiting Exoplanet Survey Satellite (TESS). He found that the belt would need to be about 0.01 percent full for such spacecraft to detect it, whether populated by many small satellites or a handful of large, city-size objects.

“We just need to look for the right signature in the data,” he said.

Socas-Navarro calls this hypothetical structure the Clarke exobelt (CEB), after famed sci-fi author Arthur C. Clarke.

Hunting alien satellites
Both Kepler and TESS detect planets using what’s known as the transit method. The spacecraft watch a field of stars for an extended amount of time. If a planet has the right orbit, and the timing is right, that world will pass in front of its host star from the telescope’s perspective, causing a small, potentially detectable dip in brightness.

In addition to working as an astrophysicist, Socas-Navarro hosts a weekly radio show and podcast. That work helped him come up with the Clarke exobelt idea, he said. One day, a listener asked about a geostationary satellite for the sun.

“As I was doing the calculations to answer this question, I had this mental image of a satellite transiting across the solar disk,” Socas-Navarro said. “That led me to ask myself the question of whether satellites around distant exoplanets would be observable during transit.”

Sufficient material orbiting an exoplanet causes a small dip in starlight before and after the body of the world makes its transit. Scientists have used this method to discover rings around planets outside the solar system and even around distant solar system bodies.

Socas-Navarro said the putative alien-satellite signal would have a signature similar to that of rings — both an exobelt and rings are made up of a swarm of objects orbiting a planet — but there are subtle technical differences in how that signature would look. The signal would also reveal the altitude of the orbiting objects, which could provide a significant clue as to whether the objects were natural or alien-made.

A ring system can occur at any number of distances from the surface of the planet. But if the objects orbited at a planet’s geostationary height — about 22,200 miles (35,700 kilometers) — they are “almost certainly artificial,” Socas-Navarro said.

Similarly, a massive space city or a large station close to a space elevator could look like an exomoon. Again, Socas-Navarro said, altitude is key. If the object hovers at geostationary height, it’s likely to be artificial. [10 Exoplanets That Could Host Alien Life]

“It doesn’t seem to matter too much if they are many small or [a] few large [objects],” he said. “As long as they are spread out all over the orbit, they will basically produce the same signature.”

He also found that the ideal conditions to spot such a satellite belt would be around dim red dwarf stars located within 100 light-years of Earth.

The new study was published last month in The Astrophysical Journal. You can read it for free at the online preprint server arXiv.org.

https://www.space.com/40436-search-alien-life-et-satellites.html


Most believers in a flat Earth think the planet is a flat disk surrounded by an ice wall.

By Jeanna Bryner

More than 200 flat-Earth enthusiasts descended on West Midlands, England, this past weekend to “engage freely in deep and meaningful discussions,” according to the Flat Earth Convention UK.

The Earth’s glorious globular-ness was proved more than 2,000 years ago by the ancient Greeks, but there’s a small subset of people who think the planet is a disk despite enjoying the downward pull of gravity that could only result from living on a sphere.

At this conference, they were presenting their scientific evidence for such a disk. One of the more interesting pieces of evidence came from speaker Darren Nesbit, who referred to the “Pac-Man effect” as the reason why planes don’t fall off the edge of a flat Earth, according to the science news website Physics-Astronomy.org. When a plane or other object reaches the edge of the horizon, such as when Pac-Man reaches the end of the screen, that object will teleport from one side of the planet to the other, a la Pac-Man entering from the other side of the screen.

According to the group that put on the convention, the gathering also included some “alternative viewpoints.”

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Flat-Earthers Explain Why We Don’t Fall Off the Edge of Our Planet, and It Involves Pac-Man
Most believers in a flat Earth think the planet is a flat disk surrounded by an ice wall.
Credit: Getty
More than 200 flat-Earth enthusiasts descended on West Midlands, England, this past weekend to “engage freely in deep and meaningful discussions,” according to the Flat Earth Convention UK.

The Earth’s glorious globular-ness was proved more than 2,000 years ago by the ancient Greeks, but there’s a small subset of people who think the planet is a disk despite enjoying the downward pull of gravity that could only result from living on a sphere.

At this conference, they were presenting their scientific evidence for such a disk. One of the more interesting pieces of evidence came from speaker Darren Nesbit, who referred to the “Pac-Man effect” as the reason why planes don’t fall off the edge of a flat Earth, according to the science news website Physics-Astronomy.org. When a plane or other object reaches the edge of the horizon, such as when Pac-Man reaches the end of the screen, that object will teleport from one side of the planet to the other, a la Pac-Man entering from the other side of the screen. [7 Ways to Prove the Earth Is Round]

According to the group that put on the convention, the gathering also included some “alternative viewpoints.” (You think?)

“In conjunction with a select number of well-known flat-earth speakers, we have also provided some alternative viewpoints. We truly hope that new friendships are forged, ideas and experiments are brain stormed and future actions are set in motion,” they state on their website.

Among the nine speakers were Nesbit, a musician who became interested in flat-Earth beliefs in 2014; Dave Marsh, a manager with England’s National Health Service; and Gary John, an independent flat-Earther who put on the convention.

Marsh was one of four speakers who are associated with the flat-Earth research group called FEcore. His research focuses on the moon, “as he believes it is the key to unlocking the globe earth deception,” according to the convention website: https://www.flatearthconventionuk.co.uk/home.html

He studies the speed of the moon across the night sky. (Flat-Earthers believe the moon and sun orbit around Earth’s North Pole.) “My research destroys big bang cosmology,” he said, according to Physics-Astronomy.org. “It supports the idea that gravity doesn’t exist and the only true force in nature is electromagnetism.”

Another speaker, Martin Kenny, purports to have broader views of a flat Earth than other believers. “It is my innerstanding that there are other lands, dimensions and civilizations yet to be discovered across and within the plane of our Earth. The whole earth consists of 4 concentric rings of land, each ring having its own sun and moon, which would be our wandering stars,” he says on the convention website.

Flat-Earthers like Kenny agree that the planet is a flat plane, though they have varied ideas for the disk’s particular layout. Many seem to think the Earth is a disk surrounded by an ice wall and that those who show evidence to the contrary — including NASA, with its many satellite pics beamed down of our blue marble — are fakes. These conspiracy theorists believe NASA and others are trying to keep this secret from the public.

As for how many people buy into this clearly mistaken belief, that is unknown. However, the oldest flat-Earth organization, the Flat Earth Society, claims to have 555 registered members as of August 2016. According to the society’s website, the group was founded by an English inventor named Samuel Birley Rowbotham in the 1800s.

In addition to the Q&A’s with the nine speakers at the three-day convention, there was apparently a talk entitled “Heliocentric v Geocentric experts Debate.” The convention’s site doesn’t indicate who was debating these two views, one proved ages ago, and the other suggesting Earth is fixed in space with the universe revolving around it.

This isn’t the first flat-Earth convening. In November 2017, the Flat Earth International Conference was held in Raleigh, North Carolina. That convention hosted some big-name (in flat-Earth circles, at least) speakers, such as founder of the Flat Earth Clues series on YouTube, Mark Sargent, who thinks we are all locked inside a “Truman Show”-like dome structure. The next FEIC is scheduled for Nov. 15 -16 in Denver.

https://www.livescience.com/62454-flat-earthers-explain-pac-man-effect.html?utm_source=notification

Stephen Hawking submitted the final version of his last scientific paper just two weeks before he died, and it lays the theoretical groundwork for discovering a parallel universe.

Hawking, who passed away on Wednesday aged 76, was co-author to a mathematical paper which seeks proof of the “multiverse” theory, which posits the existence of many universes other than our own.

The paper, called “A Smooth Exit from Eternal Inflation”, had its latest revisions approved on March 4, ten days before Hawking’s death.

According to The Sunday Times newspaper, the paper is due to be published by an unnamed “leading journal” after a review is complete.

ArXiv.org, Cornell University website which tracks scientific papers before they are published, has a record of the paper including the March 2018 update.

According to The Sunday Times, the contents of the paper sets out the mathematics necessary for a deep-space probe to collect evidence which might prove that other universes exist.

The highly theoretical work posits that evidence of the multiverse should be measurable in background radiation dating to the beginning of time. This in turn could be measured by a deep-space probe with the right sensors on-board.

Thomas Hertog, a physics professor who co-authored the paper with Hawking, said the paper aimed “to transform the idea of a multiverse into a testable scientific framework.”

Hertog, who works at KU Leuven University in Belgium, told The Sunday Times he met with Hawking in person to get final approval before submitting the paper.

https://www.sciencealert.com/stephen-hawking-submitted-a-paper-on-parallel-universes-just-before-he-died

Thanks to Kebmodee for bringing this to the It’s Interesting community.

By Rafi Letzter

Russian scientists have a plan to deal with a hypothetical asteroid threat that’s straight out of the movie “Armageddon.”

A team of government scientists has proposed that nuclear weapons well within the power of those already developed could be used to break up incoming asteroids, protecting the planet from a major asteroid strike. They then demonstrated, in a paper published online March 8 in the Journal of Experimental and Theoretical Physics, the effect of a nuclear strike on an asteroid, using scale model “asteroids” and powerful lasers.

Striking a tiny model asteroid with a powerful laser on Earth is obviously not the exact same thing as striking a full-size asteroid with a laser out in space. But there’s a reasonable degree of comparison between the two situations.

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Russian Scientists Tested Their Asteroid-Nuking Plan with Powerful Lasers
This photo of the asteroid Eros was taken during the NEAR Shoemaker mission.
Credit: NASA
Russian scientists have a plan to deal with a hypothetical asteroid threat that’s straight out of the movie “Armageddon.”

A team of government scientists has proposed that nuclear weapons well within the power of those already developed could be used to break up incoming asteroids, protecting the planet from a major asteroid strike. They then demonstrated, in a paper published online March 8 in the Journal of Experimental and Theoretical Physics, the effect of a nuclear strike on an asteroid, using scale model “asteroids” and powerful lasers.

Striking a tiny model asteroid with a powerful laser on Earth is obviously not the exact same thing as striking a full-size asteroid with a laser out in space. But there’s a reasonable degree of comparison between the two situations. [Crash! The 10 Biggest Impact Craters on Earth]

The researchers took careful steps to make sure the scale models were created from the same materials and had similar structures to chondrites (common, stony asteroids). And the immense energy deposited by a pulsed laser onto a single point on the model was reasonably similar to the effect of a nuclear blast on a single point on the asteroid’s surface. They wrote that their experiment showed they could use a a 3-megaton bomb to blast a 656-foot-wide (200 meters) asteroid — 10 times wider than the asteroid that detonated over Russia in 2013 — to harmless bits that would spread out and miss Earth.

The first thermonuclear weapon ever detonated had a strength of about 10.4 megatons, according to the Nuclear Weapon Archive. That bomb was detonated on Elugelab Island, Enewetak Atoll, in the Pacific Ocean in 1952.

There are other methods for diverting incoming asteroids, the researchers acknowledged, like the gravity tug— using the force of gravity to move the space rock to a better orbit. But they require more advanced knowledge of the incoming strike and planning. The advantage of a nuclear strike, they wrote, is that it can work against even surprise asteroids discovered late.

Russia isn’t alone in considering the possibility of a nuclear strike on an asteroid. U.S. government researchers also raised the possibility in a February paper.

https://www.livescience.com/62057-asteroid-nuclear-bomb-russia-laser.html?utm_source=notification