Plasma physics

RHESSI’s time in orbit officially came to an end on Wednesday as NASA’s defunct Sun-observing satellite plunged through Earth’s atmosphere, likely burning up in a fiery flame.Astronomers Could Soon Get Warnings When SpaceX Satellites Threaten Their ViewThe Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) spacecraft reentered Earth’s atmosphere on April 19 at 8:21 p.m. ET, flying over the Egyptian-Sudanese border on a trajectory towards northern Egypt, Jonathan McDowell, an astronomer at the…

A retired NASA spacecraft is about to meet its fiery demise, burning up in Earth’s atmosphere after its expected free-fall from orbit later this week. Astronomers Could Soon Get Warnings When SpaceX Satellites Threaten Their ViewThe Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) spacecraft is expected to reenter Earth’s atmosphere on April 19 at around 9:30 p.m. ET, give or take 16 hours, NASA announced based on the most recent estimate by the Department of Defense. The 660 pound (300 kilograms) satellite…

NASA’s Solar Dynamics Observatory captured this image of a solar flare on January 9, 2023.Image: NASA/SDOEarth’s host star can be quite temperamental, compelling astronomers to launch satellites and probes on missions to keep a close watch of the Sun’s massive flares. But instruments pointed towards the Sun have a tendency to acquire cloudy vision as the result of a mysterious layer that’s puzzled scientists for years.Instruments on board NASA’s Solar Dynamics Observatory (SDO), which has been observing the Sun since…

The aurorae over Teriberka, Russia.Photo: Jose D. RiquelmeTaken in Northern Russia in February 2022, getting this image required braving frigid temperatures. At about -22 degrees Fahrenheit, “you can only leave your tripod in one position because it will freeze, and you won’t be able to get it up or down,” said photographer Jose D. Riquelme. Behold the result: an arresting shot of the aurora’s arcs, sweeping across the sky. The aurorae over Teriberka, Russia.Photo: Jose D. RiquelmeTaken in Northern Russia in February…

The Cygnus X-1 system is one of the brightest sources of X-rays in the Milky Way, consisting of a black hole called Cygnus X-1 and its giant companion, a star packing 41 times the mass of our Sun. Researchers recently measured the polarization of those X-rays to better understand the geometry of the superheated plasma in the Cygnus X-1 system.01:25Randall Park's Favorite SuperheroesMonday 5:02PMThough nothing is visible beyond any black hole’s event horizon, superheated matter usually surrounds a black hole. Atmillions…

Artist’s depiction of Solar Orbiter.Illustration: ESA/ATG medialabSolar Orbiter has been traveling through space for more than two years, making several close flybys of Venus as it steadily inches closer to the Sun. On September 4, the small spacecraft was in the midst of its most recent gravitational assist when it felt the violent wrath of our host star.The Sun fired off a gigantic coronal mass ejection on August 30, reaching the spacecraft just a few days later. Thankfully, Solar Orbiter is built to withstand these…

Northern Lights seen from the coast of Scotland in February, 2021.Photo: Peter Summers (Getty Images)If you happen to live on the northern end of the U.S., and you’re not completely engulfed by ambient light pollution, you might be in for a once-in-a-lifetime celestial light show, though a lot of things have to happen to make the aurora borealis, often called the Northern Lights, appear overhead.This disturbance in the night sky is being called by a coronal mass ejection, otherwise known as a CME. These range in severity…

A solar flare, as imaged by NASA’s Solar Dynamics Observatory on October 14, 2014.Image: NASA/SDOWe’re in the third year of the Sun’s 11-year solar cycle, and satellites in low Earth orbit are already experiencing the deleterious effects. Scientists are now warning that the worst is yet to come, as the current cycle is proving to be stronger than forecasters anticipated. Apanel of space weather experts expressed these concerns at the recently concluded 36th Small Satellite Conference organized by the Secure World…