It seems safe to say that the laborers firing clay pavers, bricks and tiles to build the Jesuit mission of Santo Ângelo over 300 years ago had no idea that their toils might someday bear relevance to spacecraft orbiting 600 miles above what is now southern Brazil.
As the bricks and pavers were fired in kilns, magnetite in the clay abandoned its inherent magnetic properties and realigned in response to the magnetic forces exerted by the earth itself. The point at which this occurs – 580 degrees Celsius, in the case of magnetite – is known as the Curie point.
After these building materials cooled and were stacked to form a church, school and other buildings at Santo Ângelo, the magnetite inside retained this reshuffled alignment, a record of the magnetic past sealed away like a proverbial mosquito in amber. Along with several dozen other Jesuit missions built in the same era, Santo Ângelo flourished briefly along what was then the poorly defined border between the Spanish and Portuguese colonies in South America. At its height, the mission was home to about 8,000 people, nearly all of them indigenous Guarani whom the Jesuits were trying to Christianize.
A new paper reports that over half of Earth’s land area has suffered biodiversity loss beyond “safe limits.”
The study, released Thursday in Science, compiles a global dataset of biodiversity change and compares it to human land use patterns. The analysis shows that 58 percent of Earth’s land, which is home to 71 percent of the human population, has surpassed a recently proposed safe limit for biodiversity loss, beyond which ecosystems may no longer support human societies.
While the news sounds dire, other ecologists contend that the very notion of setting “safe limits” is a danger in itself, and criticize this line-in-the-sand approach to assessing the planet’s ecological health. In fact, critics say setting a limit may do more harm than good. Read More
The world was literally shaken before news broke that North Korea detonated what leaders in the Hermit Kingdom claimed was a hydrogen bomb Tuesday morning local time.
Officials and experts around the world quickly cast doubt on that claim, as the amount of energy produced by the explosion was likely too small to be that of a hydrogen bomb. Instead, early evidence suggests North Korea may have instead detonated a boosted-fission bomb, which produces a smaller explosive yield. It will likely take several more days to determine what kind of nuclear device Pyongyang actually detonated. Read More
This article was originally published on The Conversation.
The Earth seems to have been smoking a lot recently. Volcanoes are currently erupting in Iceland, Hawaii, Indonesia and Mexico. Others, in the Philippines and Papua New Guinea, erupted recently but seem to have calmed down. Many of these have threatened homes and forced evacuations. But among their less-endangered spectators, these eruptions may have raised a question: Is there such a thing as a season for volcanic eruptions?
Surprisingly, this may be a possibility. While volcanoes may not have “seasons” as we know them, scientists have started to discern intriguing patterns in their activity.
Amy Shira Teitel is a freelance space writer whose work appears regularly on Discovery News Space and Motherboard among many others. She blogs about the history of spaceflight at Vintage Space, where this post originally appeared, and tweets at @astVintageSpace.
According to YouTube, eight million people watched Felix Baumgartner’s high altitude jump on Sunday morning. It was exciting and death-defying, but at the end of the day it was a just an elaborate publicity stunt that will likely see Red Bull sales skyrocket this month. But I’d argue that the event wasn’t entirely a success from a publicity standpoint. Red Bull, who sponsored the jump, wasted an incredible opportunity. It had an eight million person audience captivated, but did nothing to teach that audience about the context behind Baumgartner’s jump. Joe Kittinger’s 1960 jump was amazing, the heritage behind these types of tests is fascinating, but without any context the audience just saw a daredevil break a record for record-breaking’s sake.
I realize I sound like an irritated historian, but I also have a background (albeit a brief one) in publicity. Not taking advantage of an opportunity to teach eight million people a few awesome things about science is a terrible waste, from an historian’s standpoint and a public relations standpoint.
A little background first. Austrian-born Baumgartner started skydiving at 16. He perfected the art and in 1988 began performing skydiving exhibitions for Red Bull. His adventurous spirit and Red Bull’s out-of-the-box thinking meshed well, sparking a now decades-long collaboration. The idea for a free fall from the stratosphere, a planned altitude of 120,000 feet, was conceived in 2005. It was finally named The Red Bull Stratos project, and its goal was defined as transcending “human limits that have existed for 50 years.”
Baumgartner during the record-setting event. Courtesy of Red Bull Stratos.
Ostensibly, the jump was designed to expand the boundaries of human flight. More concrete goals listed on the project’s website include: developing new spacesuits with enhanced mobility and visual clarity to assist in “passenger/crew exit from space”; developing protocols for exposure to high-altitude and high-acceleration environments; exploring the effects of supersonic acceleration and deceleration on the human body; and testing the latest innovations in parachute systems.
It’s not entirely clear what applications this data would have, like the research on “passenger/crew exit from space.” The morning of the jump, people asked me whether the point was to prove that astronauts could jump from the International Space Station in an emergency. It wasn’t. Baumgartner’s 128,000-foot altitude (he overshot his mark) is only about 24 miles; the ISS orbits at an altitude of about 200 miles. Not to mention the astronauts on the ISS are weightless because they’re falling (i.e., orbiting) around the Earth at the same rate as the station, and that wouldn’t change if they stepped outside. It’s also unclear what other high-altitude/high-acceleration and supersonic environments in which people would find themselves that we need to know more about. Yes, there may have been some interesting data gathered from the jump, but it’s not enough to classify the stunt as any kind of research program.
Amy Shira Teitel is a freelance space writer whose work appears regularly on Discovery News Space and Motherboard among many others. She blogs, mainly about the history of spaceflight, at Vintage Space, and tweets at @astVintageSpace.
Last week, NASA announced its next planetary mission. In 2016 the agency is going back to the surface of Mars with a spacecraft called InSight. The mission’s selection irked some who were hoping to see approval for one of the other, more ambitious missions up for funding: either a hopping probe sent to a comet or a sailing probe sent to the methane seas of Saturn’s moon Titan. Others were irked by NASA’s ambiguity over the mission’s cost during the press announcement.
An artist’s rendition of InSight deploying its seismometer and heat-flow experiments on Mars.
InSight is part of NASA’s Discovery program, a series of low-cost missions each designed to answer one specific question. For InSight, that question is why Mars evolved into such a different terrestrial planet than the Earth, a mystery it will investigate by probing a few meters into the Martian surface. The agency says InSight’s selection was based on its low cost—currently capped at $425 million excluding launch costs—and relatively low risk. It has, in short, fewer known unknowns than the other proposals.
But while InSight costs less than half a billion itself, the total value of the mission by the time it launches will be closer to $2 billion. How can NASA get that much zoom for so few bucks? By harnessing technologies developed for and proven on previous missions. The research, development, and testing that has gone into every previous lander take a lot of guesswork out of this mission, helping it fly for (relatively) cheap.
Aside from the Moon, Mars is the only body in the solar system that NASA has landed on more than once. With every mission, the agency learns a little more, and by recycling the technology and methods that work, it’s able to limit expensive test programs. This has played no small part in NASA’s success on the Red Planet thus far. When it comes to the vital task of getting landers safely to the surface, NASA has been reusing the same method for decades. It has its roots way back in the Apollo days.
Seth Shostak is Senior Astronomer at the SETI Institute in California, and the host of the weekly radio show and podcast, “Big Picture Science.”
The Moon is a ball of left-over debris from a cosmic collision that took place more than four billion years ago. A Mars-sized asteroid—one of the countless planetesimals that were frantically churning our solar system into existence—hit the infant Earth, bequeathing it a very large, natural satellite.
OK, that’s a bit of modestly engaging astrophysics. But some scientists think there’s a biological angle here. Namely, that elaborate terrestrial life might never have appeared if that asteroid had arrived a few hours earlier, and sailed silently by. Put another way, if every night were moonless, you wouldn’t be around to notice the lack of a moon.
But is that true? Did our cratered companion really make our existence possible?