China’s Tianzhou 7 cargo spacecraft has ended its mission after delivering essential supplies to the Tiangong space station. According to the China Manned Space Agency (CMSA), the spacecraft re-entered Earth’s atmosphere on November 17 at 8:25 am EST (6:55 pm IST), marking the conclusion of its operations. The spacecraft, launched on January 17 aboard a Long March 7 rocket from Wenchang, was designed to support Tiangong’s ongoing activities, including the delivery of food, experiments, materials, and propellant.

Mission Details and Controlled Reentry

A Space.com report, quoting CMSA, revealed that Tianzhou 7 was undocked from Tiangong on November 10 after being loaded with waste from the station. The deorbiting process was conducted in a controlled manner, with the spacecraft’s engines fired to ensure its descent over the South Pacific Ocean, commonly used for spacecraft reentry due to its remoteness. While CMSA released visuals of Tianzhou 7’s atmospheric entry showing intense flashes caused by heat and friction, specific details of the landing zone remain undisclosed.

Deployment of a Cubesat Pre-Reentry

Ahead of its controlled descent, Tianzhou 7 reportedly released a 6U cubesat named Bayi-08 on November 16. The satellite, developed by the China Aerospace Science and Technology Corporation (CASC), carries a medium-resolution Earth observation camera and an optical communication payload. It is part of a science outreach programme aimed at promoting understanding of space technology.

Operations at Tiangong Ongoing

While Tianzhou 7 concluded its mission, operations at Tiangong continue. The report stated that Tianzhou 8 was launched on November 15, carrying supplies to sustain astronauts aboard the station. Preparations are also underway for the Shenzhou 20 mission, scheduled for spring 2025. The cargo included lunar soil simulant bricks for experimental purposes and materials to support the Shenzhou.

China’s advancements in its space programme remain a focal point, with the Tiangong station playing a critical role in supporting long-term human spaceflight and research objectives.

New research has uncovered that the Ninetyeast Ridge, a 5,000-kilometre-long underwater mountain range in the Indian Ocean, was shaped by a moving hotspot rather than a stationary one. The study, published in Nature Communications, analysed mineral samples from the ridge and dated its formation to between 83 and 43 million years ago. This discovery challenges earlier assumptions about its origin and sheds light on how tectonic plates have shifted over millions of years.

Implications for Plate Tectonics and Dating

Findings from Curtin University’s School of Earth and Planetary Sciences indicate that the Kerguelen hotspot responsible for the ridge moved several hundred kilometres within the Earth’s mantle during its activity. Dr Hugo Olierook, a co-author of the study, told Phys.org that this kind of hotspot movement, while believed to be common, has rarely been proven. He noted that this is the first confirmed instance of such movement in the Indian Ocean.

Precise dating methods employed in the research have revised earlier age estimates for the Ninetyeast Ridge, which have long informed tectonic models. According to Professor Fred Jourdan, also a co-author from Curtin University and the John de Laeter Centre, these updated models offer more accurate reconstructions of the Earth’s tectonic history. The study highlights the importance of such refinements for understanding ancient geological events.

Future Insights into Earth’s Internal Processes

Lead author Associate Professor Qiang Jiang, now with the China University of Petroleum, stressed the importance of comprehending Earth’s internal dynamics to predict natural disasters more effectively. He noted that studies like this enhance understanding of processes such as earthquakes and volcanic activity.

The research provides a pivotal contribution to geological science by documenting the interplay between tectonic shifts and mantle dynamics.

Magnetic vortices descending from Jupiter’s ionosphere into its deep atmosphere are believed to trigger the formation of ultraviolet-absorbing anticyclonic storms, according to a study published on November 26 in Nature Astronomy. These storms, appearing as dark ovals, span the size of Earth and have been observed primarily in Jupiter’s polar regions. The phenomenon was first detected in ultraviolet (UV) light by the Hubble Space Telescope in the 1990s and later confirmed by NASA’s Cassini spacecraft in 2000.

Research Unveils Tornado Dynamics

The study, published in the Nature journal, was led by Troy Tsubota, an undergraduate researcher at the University of California, Berkeley, in collaboration with Michael Wong from UC Berkeley, Amy Simon of NASA’s Goddard Space Flight Center, and others.

The findings suggest these dark ovals are formed by swirling magnetic tornadoes generated due to friction between Jupiter’s immense magnetic field lines and those in its ionosphere. These tornadoes are thought to stir aerosols, creating dense patches of UV-absorbing haze in the stratosphere.

The Role of the Io Plasma Torus

The study highlights that Jupiter’s magnetic field, among the strongest in the solar system, interacts with the Io Plasma Torus — a ring of charged particles released by volcanic activity on Jupiter’s moon Io. This interaction generates friction, potentially initiating magnetic vortices that descend into the planet’s atmosphere.

The exact mechanism remains unclear, with researchers debating whether these tornadoes dredge up material from deeper atmospheric layers or create the hazes independently.

Regular Observations Confirm Patterns

The Outer Planet Atmospheres Legacy (OPAL) project, which captures annual images of Jupiter using the Hubble Space Telescope, played a pivotal role in the discovery. Between 2015 and 2022, dark ovals were observed at the south pole in 75% of images but were significantly rarer at the north pole. These formations typically appear over a month and dissipate within two weeks, resembling a magnetic “tornado alley.”