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Cargo Dream Chaser solidifies ULA deal by securing six Vulcan Centaur flights – NASASpaceflight.com

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Cargo Dream Chaser solidifies ULA deal by securing six Vulcan Centaur flights – NASASpaceFlight.com

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Let's Talk Asteroid Apophis, Planetary Defense and Elon Musk – Space.com

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It’s time to talk about Apophis again, I guess. Please calm down first.

The asteroid is about 1,100 feet (340 meters) wide, was discovered in 2004 and will make a reasonably close flyby of Earth on Friday, April 13, 2029. Apophis will not hit Earth during that flyby; more on that later. Nevertheless, it’s large and close and has a snappy name, and the internet loves its asteroids.

That’s presumably how SpaceX CEO Elon Musk ended up retweeting podcaster Joe Rogan’s post of an Express story (lacking any news relevance) about Apophis. “Great name!” Musk tweeted yesterday (Aug. 18). “Wouldn’t worry about this particular one, but a big rock will hit Earth eventually & we currently have no defense.”

Infographic: Asteroid Apophis’ Close Earth Flyby of 2029 Explained

Let’s dissect all this a bit. Musk and Rogan made headlines in September when Musk appeared on the latter’s podcast for a three-hour discussion of Tesla and whether the universe is a simulation. During that appearance, Musk infamously smoked marijuana and sipped whiskey, which prompted a NASA review of commercial space partnerships, according to The Washington Post.

It is unclear from his tweet whether Musk is referring to the asteroid’s actual name, Apophis, or the “God of Chaos” terminology inserted by the news outlet Rogan cited. 

Asteroid 99942 was first dubbed 2004 MN4 based on a formula marking its discovery and was given a formal name Apophis the next year. According to the International Astronomical Union, which oversees all official names in space, the name Apophis commemorates the “Egyptian god of evil and destruction who dwelled in eternal darkness.”

Musk is mostly correct in his assessment of Apophis itself. The rock is dubbed a Potentially Hazardous Asteroid for its relatively large size and relatively close approaches, but it’s a very long way from potentially hazardous to actually impacting. Asteroid experts are confident it will not hit Earth at that time: They’ve calculated a trajectory 7.4 miles (12 kilometers) wide that passes thousands of miles away from our home planet during that close encounter. Scientists have also ruled out a 2036 impact.

Related: Huge Asteroid Apophis Flies By Earth on Friday the 13th in 2029

ESA’s Herschel Space Observatory captured asteroid Apophis in its field of view during the approach to Earth on January, 5-6, 2013. This image shows the asteroid in Herschel’s three PACS wavelengths: 70, 100 and 160 microns.

(Image credit: ESA/Herschel/PACS/MACH-11/MPE/B.Altieri (ESAC) and C. Kiss (Konkoly Observatory))

Apophis is just one of thousands of asteroids that scientists have identified. That includes nearly 900 near Earth objects more than 0.6 miles (1 km) wide and nearly 9,000 of them more than 459 feet (150 m), the class into which Apophis falls. A host of instruments on the ground and in space continue to spot more and more of these objects and gather the data necessary for scientists to calculate the rocks’ trajectories.

That said, these scientists can’t guarantee Apophis and Earth will never meet. Although they have a very good sense of the rock’s current trajectory, the tug of Earth’s gravity during its 2029 encounter will likely skew its path, throwing off orbital calculations into the future. Potentially, many many decades from now, humans may indeed need to worry about Apophis.

Other space rocks could also be a problem on that sort of time scale, but right now, NASA hasn’t spotted any asteroids with worrying trajectories. “No known asteroid poses a significant risk of impact with Earth over the next 100 years,” according to the website of NASA’s Planetary Defense Coordination Office.

If that status changes, although it would be scary, it wouldn’t mark a new risk in the world, just a new knowledge of our risk; the asteroid would hit us whether or not we had identified it.

Related: Even If We Can Stop a Dangerous Asteroid, Being Human May Mean We Don’t Succeed

And that’s the entire point of scientists’ efforts to find and study asteroids in our neighborhood: If we learn about an approaching asteroid a day in advance, there’s nothing we can do, as Musk implies. That was the case, most recently, for the asteroid that exploded over Chelyabinsk, Russia, in 2013. On other short timescales, humans may be able only to mitigate the worst damage, by evacuating people or perhaps using a nuclear explosion to split the asteroid into smaller pieces more likely to break up in Earth’s atmosphere.

But say hypothetically that someone spotted an asteroid 10 years before it were to slam into Earth. That’s a long enough timescale that humans could realistically muster a response, depending on the particular constraints of the asteroid. Such a mission would knock an asteroid to travel a smidge faster or slower along its orbit in such a way that it would miss its appointment with Earth.

The planetary defense community is already working to develop smarter and more effective responses to the intricacies of an individual asteroid threat through hypothetical exercises.

Related: A Fake Asteroid Headed to Earth Can Really Make You Think

And while humans have yet to launch any planetary defense missions, that will change soon. One of SpaceX’s own Falcon 9 rockets is due to launch NASA’s Double Asteroid Redirect Test, or DART. In October 2022, the spacecraft will crash into the smaller half of a binary asteroid, then measure the deflection the impact causes. The exercise will help planetary defense experts better calibrate any future necessary missions to the size of the threatening asteroid.

It’s also worth pointing out that Musk’s statement was made in the context of a retweet of an Express headline and link. Now is probably a good time to remind you that Express is one of several media outlets notorious for overhyping asteroid flybys to draw clicks.

That said, the Express headline does actually make a very good point about the 2029 flyby, intentionally or not. NASA and other experts are certainly preparing for the asteroid’s visit — because it’s an incredible opportunity for scientists to better understand the asteroids that are all around us.

Scientists believe Apophis matches at least superficially about 80% of the potentially hazardous asteroids they’ve spotted around Earth to date, and the 2029 close approach will bring it well within reach of a host of instruments. Scientists want to know, for example, how much the flyby stretches and distorts Apophis and how solar radiation warming one side of the space rock affects its orbital path.

And yes, that information, once gathered, will feed into the continuing work of planetary defense experts who have spent years working on the precise problem of predicting and mitigating asteroid impacts. 

Email Meghan Bartels at mbartels@space.com or follow her @meghanbartels. Follow us on Twitter @Spacedotcom and on Facebook.

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The weird, repeating signals from deep space just tripled – CNET

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We’re picking up more signals from deep space.


Danielle Futselaar

Scientists suddenly have a whole lot more data on one of the strangest and most recent mysteries in the cosmos, so-called fast radio bursts (FRBs). First discovered in 2007, these fleeting blasts of radio waves originate thousands, millions or even billions of light years from Earth. 

FRBs have influenced the design of new radio telescopes like the Canadian Hydrogen Intensity Mapping Experiment (CHIME). And now a team of Canadian and American researchers using CHIME has reported a major new set of FRB detections that could fine-tune our understanding of where these enigmatic signals come from and what produces them. 

The group says it’s discovered eight new FRBs that repeat.


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“Repeating FRBs are highly valuable from an observational perspective since their repeating nature make them better candidates for localizing their host galaxies and multi-wavelength follow-up observations that can help determine if FRBs emit at wavelengths other than radio,” said Ryan McKinven, one of the researchers who is based at the University of Toronto and co-author of a paper about the FRBs.

Those follow-up observations could provide details about the origins of the strange bursts, he added. A larger sample size of repeating FRBs to study could also help scientists answer one of the obvious questions about non-repeating FRBs: Could they actually be repeating FRBs that just haven’t been recorded as repeating yet?

While dozens of FRBs have been detected and cataloged over the past 12 years, few of those deep space signals had been known to repeat themselves. Two have been documented so far in published, peer-reviewed journals. Two others — one via a Russian radio telescope, the other via Australia — have been reported but not yet reviewed. 

So with this batch of bursts, the number of reported repeaters has tripled — from four to 12. 

The team laid out its findings in a draft paper that’s been submitted to the Astrophysical Journal and was posted this month on the Arxiv pre-print site

Discovering different types of FRBs at an unexpected rate, we will soon open new windows into understanding the cosmological origin of these high-energy astrophysical phenomena,” said co-author Masoud Rafiei-Ravandi of the Perimeter Institute for Theoretical Physics. 

In addition to the sheer number of repeating FRBs discovered in one haul, one of the newfound repeaters appears to be much closer to Earth than the handful of fast radio bursts that have been traced back to a source galaxy. So far, traceable FRBs seem to come from sources on the other side of the universe — we’re talking billions of light years away.

However, in the new paper, the authors suggest that one of the repeating FRBs could actually originate near the edge of our own Milky Way galaxy but caution that more study is needed to better localize the signal. 

“Knowing that we are observing every patch of sky visible to CHIME once every day, it was only a matter of time before we detected a very nearby source,” co-author Pragya Chawla of McGill University said.

Studying relatively nearby FRBs will hopefully allow scientists to get a better idea of just what the heck is throwing off these signals, which could be anything from far-fetched notions like alien starships to the less fantastic but literally more powerful sources, like neutron stars.

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Climate Crisis: Hurricanes Are Making Some Spiders More Aggressive – Inverse

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In the most uncomfortable piece of climate crisis-related news yet, a team of scientists believe that the increasing tropical cyclones may be changing the temperament of a “super abundant” spider. As the storms continue to increase in tandem with the planet’s temperature, some of our eight-legged friends are starting to get more aggressive, report scientists in a paper published Monday in Nature Ecology and Evolution.

Specifically, these findings refer to a species of group-dwelling spiders called Anelosimus studiosus. They’re “hardly majestic,” lead study author Jonathan Pruitt, Ph.D., an associate professor at the University of California Santa Barbara, tells Inverse, but they happen to have very intricate social lives. Along the Gulf Coast, the spiders form multi-female groups that hunt in packs, dwell in group webs, and sometimes rear each other’s children. But the climate crisis may be shifting these old spider traditions toward a less interconnected lifestyle.

In the paper, Pruitt and his team show that hurricanes are actually changing the social and behavior dynamics of these spider colonies. The aggressive spiders in the colonies are well-equipped to handle the chaos, but the less aggressive ones are not. That inequality, he explains, may reshape life in the colony.

“There’s a behavioral tipping point when very very aggressive colonies stop working together, start killing each other, and the group wisely disbands,” he says. “Combine hurricane increases with global warming and I think you could get something like that.”

Anelosimus studiosus, a social cobweb spider, can live in groups, but if the group becomes too aggressive it can disband. 

The species as a whole will fare just fine, he says, in case you’re worried about losing even more animal and insect species to climate change. But the spiders are a good example of the way incomprehensibly large events — say, increases in large storms — can cause minute but significant changes too, like the behavior of a five-millimeter-long spider.

How Storms Change Spider Behavior

Anelosimus studiosus have two “behavioral” phenotypes (traits) that seem to be heritable, suggesting that they each have a genetic underpinning.

Some individuals are naturally more aggressive, which means that they swiftly attack in large numbers, kill their mates, are more wasteful their their prey, and are prone to fight among themselves; they also happen to be better at foraging when resources are scarce. The other individuals tend to be more docile, so they’re better at coexisting. To survive in a colony, you need a balance of both.

But Pruitt’s work suggests that tropical cyclones are selecting for the aggressive spiders. He observed 240 colonies before and after Hurricane Florence, Hurricane Michael, and tropical storm Alberto in the fall of 2018, finding that, while roughly 75 percent of each colony survived the storm, the colonies with more aggressive foraging responses produced more egg cases than the colonies with less aggressive tendencies.

Over time, this process shifts the nature of the colony toward the more aggressive types.

What Aggressive Behavior Means For the Species

While this shift likely won’t impact the species’ chances of survival, it does edge in on a “behavioral” tipping point. A colony of overly aggressive spiders, honed by the hostile summer cyclones of the Southern USA, is unlikely to cohabitate, says Pruitt. So if this trend continues, these spiders, which traditionally live in tight communities, may each decide to go it alone.

“I think the species as a whole will fare fine. But, if tropical cyclones start striking some regions all of the time (e.g., annually), then we might see this species revert back to is ancestral solitary state, where females no longer work together and they go it alone,” he explains.

Already, we know that extreme environmental disturbances (like the once predicted with increasing global temperature), will profoundly affect which species will live and die. But Pruitt’s work also shows a more nuanced approach to how climate change will impact species, as Eric Ameca, an ecologist who studies biodiversity and response to extreme climate events, adds in a commentary accompanying the new paper. While some species do have adaptive responses (so they’ll probably make it out okay), Ameca writes, they may look or behave a lot differently due to these extreme weather events.

Pruitt for one, sees the changing behavior of his spiders as a puzzle to be solved — and maybe applied across species in the future.

“It also means that the future of life, how it operates, and who prevails in the face of changing environments is going to be a very difficult puzzle to solve. Thankfully, humans like puzzles,” he says.

Abstract:

Extreme events, such as tropical cyclones, are destructive and influential forces. However, observing and recording the ecological effects of these statistically improbable, yet pro- found ‘black swan’ weather events is logistically difficult. By anticipating the trajectory of tropical cyclones, and sampling populations before and after they make landfall, we show that these extreme events select for more aggressive colony phe- notypes in the group-living spider Anelosimus studiosus. This selection is great enough to drive regional variation in colony phenotypes, despite the fact that tropical cyclone strikes are irregular, occurring only every few years, even in particularly prone regions. These data provide compelling evidence for tropical cyclone-induced selection driving the evolution of an important functional trait and show that black swan events contribute to within-species diversity and local adaptation.

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