Hunting mystery giant lightning from space
Thunderstorms are some of the most spectacular events in nature, yet what we can see from the surface of our planet is only the beginning.
There are bizarre goings on in Earth's upper atmosphere, and a new mission aims to learn more about them.
Launched to the International Space Station on Monday, the Atmosphere-Space Interactions Monitor (ASIM) will observe the strange electrical phenomena that occur above thunderstorms.
Sky lab
Orbiting at an altitude of just over 400km, the ISS provides the perfect view of Earth's turbulent weather systems.
ASIM will be deployed aboard the station later this month.
The electrifying effects of storms are frequently observed from the space station.
Yet when lightning strikes downward, something very different is happening above the cloud tops.
Known as Transient Luminous Events (TLEs), these unusual features were first spotted by accident in 1989.
Minnesota professor John R Winckler was testing a television camera in advance of an upcoming rocket launch, when he realised that two frames showed bright columns of light above a distant storm cloud.
Sprites, elves and jets
So, what's causing these events?
"They are slightly different to lightning," Dr Neubert told BBC News. "It's a pulse of the electric field that travels up. For the sprite - when the atmosphere gets thin, the field can get a discharge."
Sprites appear milliseconds after a powerful cloud-to-ground lightning strike.
Elves, on the other hand, are caused by the electromagnetic pulse the strike produces. A brief, aurora-like expanding halo in the ionosphere, they occur too quickly to be spotted by the human eye and last less than a millisecond.
Although they are more elusive, "elves are incredibly well understood," says Dr Martin Fullekrug from the University of Bath.
They are the most common TLE, thought to occur twice as often as sprites
Blue jets - upward electrical discharges from cloud tops - are the least well known.
"The jets are not very well studied because they're very faint. They're mainly blue. Also they're not necessarily associated with lightning. They pop up now and again and they're very mysterious," Dr Fullekrug added.
While elves are mainly spotted over warm ocean waters, sprites tend to occur over land.
North America, the Democratic Republic of the Congo and South Africa are all good places to see them.
"In Britain we also have [these storms] from time to time," explained
Dr Fullekrug. "We're conducting research on one that happened in May last year. It produced a wonderful sequence of sprites [over Cornwall]."
Dr Fullekrug. "We're conducting research on one that happened in May last year. It produced a wonderful sequence of sprites [over Cornwall]."
The sprites were spotted by meteor observers, who had cameras trained on the sky to follow the trails of shooting stars.
Stormchasing from space
ASIM's main goals are to study the physics of TLEs, and the characteristics of thunderstorms that produce them.
The payload includes two cameras, which can capture 12 frames per second,
plus X-ray and gamma ray detectors.
plus X-ray and gamma ray detectors.
This will allow the international team of researchers, for many of whom this is the culmination of decades of work, to determine where in the cloud sprites or jets
originate.
originate.
With the aid of the European Space Agency, ASIM's minimum mission length is two years.
During this period, it is expected to
observe a minimum of one TLE per day, although it is thought that they occur
at least every minute, somewhere in the world.
observe a minimum of one TLE per day, although it is thought that they occur
at least every minute, somewhere in the world.
For Dr Neubert, this will be an incredibly exciting time.
"We don't really know what's inside lighting. It happens so fast and it's so dangerous... it's hard to get to the real inside physics," he said.
In the thin upper atmosphere, TLEs are larger and easier to measure.
"To me," he added, "they represent a window to the inside of lightning."
Facebook to verify major page owners
Facebook will verify the identity of people running popular pages, as part of its continued efforts to stem fake news and propaganda.
Chief executive Mark Zuckerberg said all “large” pages would be audited - any which did not clear the process would be prevented from posting.
The move is designed to prevent users who run pages using fake accounts from hiding their true identity.
Mr Zuckerberg said he backed proposed political ads regulation.
It would require technology companies to collect more data on the source of those advertisements.
"Election interference is a problem that's bigger than any one platform," he wrote.
"And that's why we support the Honest Ads Act. This will help raise the bar for all political advertising online."
Also announced today, Facebook will add more transparency over the funding of "issue-based" political ads.
"These steps by themselves won't stop all people trying to game the system," Mr Zuckerberg said.
"But they will make it a lot harder for anyone to do what the Russians did during the 2016 election and use fake accounts and pages to run ads."
Russian manipulation
The firm will ask those placing political ads for a US government-issued ID and a physical mailing address. A unique code will be sent to the address - and will need to be inputted before the advertising is allowed to run.
The measures are to counter some of the tactics apparently used by the Internet Research Agency, the Russian “troll farm” said to have manipulated Facebook in order to target American voters.
One of the group’s most effective techniques was to set up pages that appeared to be run by passionate US-based campaigners. In some cases, these pages successfully encouraged people to take to the streets and engage in protests.
A spokeswoman told the BBC that Facebook had not finalised what would qualify as a large page, but that it would include other indicators as well as simply the number of followers a page has.
It will also make it clear if the page has changed its name. It is understood Russian trolls used innocuous titles to attract followers to a page, only to then switch the page into promoting a political view.
Facebook already verifies the identity of celebrities and other public figures, and the system for verifying page owners will likely work a similar way, the spokeswoman said.
Crunch hearings
The changes have been announced ahead of a critical week for Facebook. On Tuesday, Mr Zuckerberg will begin a round of Congressional hearings into Facebook’s handling of data and other issues.
It will be the first time the 33-year-old has personally appeared to represent the social network he founded, and comes following intense pressure to do so. Likely on the minds of senators and representatives will be the extent to which Facebook is able to prevent attempts to manipulate voters in the future.
In October 2017, the company began forcing those placing ads to support specific candidates to make it clear who was funding that promotion.
“We're extending that requirement to anyone that wants to show 'issue ads’ - like political topics that are being debated across the country,” the company said.
"We are working with third parties to develop a list of key issues, which we will refine over time. To get authorised by Facebook, advertisers will need to confirm their identity and location.
"Advertisers will be prohibited from running political ads - electoral or issue-based - until they are authorised."
Perhaps foreshadowing Mr Zuckerberg’s response to politicians next week, the statement admitted this system would not solve the problem entirely.
"We know we were slow to pick-up foreign interference in the 2016 US elections.
"Today's updates are designed to prevent future abuse in elections - and to help ensure you have the information that you need to assess political and issue ads, as well as content on pages.
"By increasing transparency around ads and pages on Facebook, we can increase accountability for advertisers — improving our service for everyone."
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