Astronauts returning from extended space missions are reported to experience significant changes in eye health, linked to prolonged exposure to microgravity. Researchers have identified that the altered blood flow and pressure conditions in space can lead to vision problems. These changes are primarily associated with a condition termed spaceflight-associated neuro-ocular syndrome (SANS), affecting around 70 percent of astronauts during six- to twelve-month stays on the International Space Station (ISS). This raises potential challenges for longer missions, such as a journey to Mars.

Study Identifies Key Ocular Changes

According to a study published in the IEEE Open Journal of Engineering in Medicine and Biology, three critical ocular parameters were analysed: ocular rigidity, intraocular pressure, and ocular pulse amplitude. Measurements were conducted on data from 13 astronauts, whose missions spanned 157 to 186 days. The researchers observed a 33 percent reduction in ocular rigidity, an 11 percent decrease in intraocular pressure, and a 25 percent decline in ocular pulse amplitude. These findings indicate biomechanical changes in the eye, accompanied by symptoms such as reduced eye size, optic nerve swelling, and retinal folds.

Potential Long-Term Effects

Dr Santiago Costantino, an ophthalmologist at Université de Montréal, highlighted to phys.org that microgravity alters blood flow and venous circulation in the eye, potentially leading to structural changes in the sclera and choroid. The observed changes could persist, raising concerns about the impact on missions exceeding one year. While most astronauts studied returned to normal vision after their missions, corrective lenses were sometimes necessary during recovery.

Mars Missions Pose New Risks

Experts remain cautious about the unknown implications of prolonged exposure to microgravity during extended missions like those to Mars. The research team emphasised that additional studies and preventive strategies are essential to address these risks. The findings serve as early indicators to identify astronauts at risk, paving the way for more targeted solutions to ensure the safety of space exploration’s next frontier.

For the first time, astronomers have directly observed a supermassive black hole ejecting a jet of plasma traveling at one-third the speed of light. This rare phenomenon, located 270 million light-years away in the constellation Draco, centers around the black hole at the heart of galaxy 1ES 1927+654, which holds a mass 1.4 billion times that of the Sun. The discovery provides groundbreaking insights into the formation and behavior of black hole jets, previously unseen at their inception.

Study Published in The Astrophysical Journal Letters

The study, published in The Astrophysical Journal Letters, details how researchers observed jets emerging after a significant radio flare in the galaxy’s core in 2023. Data collected by the Very Long Baseline Array (VLBA) revealed highly ionized plasma jets erupting from the black hole’s poles. Initially obscured by dense gas, the jets broke through by early 2024, each extending about half a light-year. Lead researcher Dr. Eileen Meyer, an astrophysicist at the University of Maryland Baltimore County, emphasised the uniqueness of capturing such an event in real time, in a statement by an official press release from NASA.

A Rare Insight into Black Hole Jet Formation

As reported by space.com, supermassive black holes in active galaxies often eject twin jets of plasma propelled by intense magnetic fields. While these jets, sometimes stretching millions of light-years, have been studied extensively, their formation remained elusive. This observation offers a rare opportunity to investigate the mechanisms by which black holes channel material from their accretion disks into high-speed outflows.

Significance of the Discovery

The black hole in 1ES 1927+654 first garnered attention in 2018 due to unusual outbursts in multiple wavelengths of light. After a dormant period, activity resumed in 2023, leading to this unprecedented observation. By capturing the jet’s emergence, the study provides valuable data to refine models of black hole activity and better understand the role of magnetic forces in generating these massive, high-energy jets.

NASA is preparing to launch two rockets through the aurora borealis to investigate the unique phenomena of these luminous ribbons of light over Alaska. This mission is designed to understand the distinct behaviours of auroras, including their flickering, pulsating patterns and the mysterious dark voids known as “black auroras.” The launches will take place at the Poker Flat Research Range in Fairbanks, Alaska, and are part of a coordinated effort to explore the interaction between charged solar particles and Earth’s magnetic field.

Two Missions to Explore Auroral Behaviour

As reported by space.com, according to the missions, led by NASA’s Goddard Space Flight Center scientists Marilia Samara and Robert Michell, each rocket will focus on a specific type of aurora. The GIRAFF (Ground Imaging to Rocket investigation of Auroral Fast Features) mission, headed by Robert Michell, will examine differences between fast-pulsating and flickering auroras. Instruments aboard the rocket will collect data on the energy, quantity, and arrival patterns of electrons contributing to these auroral forms.

In the second mission, the Black and Diffuse Aurora Science Surveyor, led by Marilia Samara, attention will turn to “black auroras,” characterised by patches of missing light within the otherwise colourful display. As per the project’s details, reported by space.com, the aim is to study whether outgoing electrons reverse direction, causing these voids.

Precision Timing for the Launch

Reports have indicated that the launches are dependent on optimal auroral activity. Ground-based cameras at the launch site and a distant observatory in Venetie, Alaska, are being used to determine the perfect timing. The rockets require about five minutes to reach the necessary altitude, demanding precise calculations to align their trajectory with the auroral activity. This study is expected to provide deeper insights into how auroras form and evolve, advancing our understanding of space weather and its effects on Earth.