Toggle light / dark theme

The discovery of an East German secret police ID card wouldn’t normally attract much attention, but things get a lot more interesting when it’s Vladimir Putin’s.

Issued in 1985, the document belonged to the then mid-ranking Soviet officer, now the President of Russia. At the time, Putin worked for the KGB spy service as a liaison with the East German State Security Service (Staatssicherheitsdienst), nicknamed the “Stasi.”

From 1985 to 1990, Putin was stationed in Dresden, East Germany. The German newspaper Bild says the ID card found in the archives proves Putin was working for the Stasi, but the Stasi Records Agency (BStU) says it served a purely practical purpose.

A group of Chinese researchers has developed a compact, sabre-like antenna for unmanned aerial vehicles (UAVs) that can switch between two radiation patterns for better communication coverage. They describe their work in a study published 26 February in IEEE Transactions on Antennas and Propagation.

For UAVs cruising at high speeds, it’s desirable to have small, aerodynamic antennas that limit drag but can still yield sufficient bandwidth and coverage. Zhijun Zhang, a researcher at Tsinghua University, notes that sabre-shaped antennas are beneficial in the sense that they are very aerodynamic—but there is a major limitation that comes with this design.

“Conventional sabre-like antennas generate a donut-shape radiation pattern, which provides an omnidirectional coverage and is ideal for air-to-ground communication. However, a donut-shape pattern has a null at its zenith,” Zhang explains.

WASHINGTON — Two of the world’s largest geostationary satellite fleet operators said March 10 that launch providers who compete with them by deploying their own constellations could influence their choice of rockets.

Executives from SES and Eutelsat at the Satellite 2020 conference here said they are watching as SpaceX deploys its own Starlink constellation of broadband satellites, which could make SpaceX one of their competitors.

Blue Origin could also become a competitor if it launches Amazon’s Kuiper broadband constellation, according to Eutelsat Deputy CEO Michel Azibert and Hughes President Pradman Kaul, since Jeff Bezos owns both Amazon and Blue Origin.

The virtually identical oxygen isotope compositions of the Earth and Moon revealed by Apollo return samples have been a challenging constraint for lunar formation models. For a giant impact scenario to explain this observation, either the precursors to the Earth and Moon had identical oxygen isotope values or extensive homogenization of the two bodies occurred following the impact event. Here we present high-precision oxygen isotope analyses of a range of lunar lithologies and show that the Earth and Moon in fact have distinctly different oxygen isotope compositions. Oxygen isotope values of lunar samples correlate with lithology, and we propose that the differences can be explained by mixing between isotopically light vapour, generated by the impact, and the outermost portion of the early lunar magma ocean. Our data suggest that samples derived from the deep lunar mantle, which are isotopically heavy compared to Earth, have isotopic compositions that are most representative of the proto-lunar impactor ‘Theia’. Our findings imply that the distinct oxygen isotope compositions of Theia and Earth were not completely homogenized by the Moon-forming impact, thus providing quantitative evidence that Theia could have formed farther from the Sun than did Earth.