Category Astronomy/Space

Astronomers have discovered the first example of a second-generation planet orbiting a white dwarf, a world that appears to have formed from the remains of the dead star it now orbits.

A team of astronomers led by the University of Warwick has identified the first second-generation planet ever found around a white dwarf. While similar “reborn” worlds have been suspected to exist around pulsars, this discovery shows that a second generation of planets can form around this much more common stellar remnant.

First author Jamie Williams, a Ph.D. student in the Department of Physics at the University of Warwick, said, “Second-generation planets are worlds that form out of the material a star casts off as it dies...

ESA’s Juice spacecraft raced past Earth on September 28, using our planet’s gravity to dramatically reshape its path toward Jupiter without burning much fuel. The flyby changed its direction by 20 degrees and increased its speed by 3.5 km/s, while also giving scientists a rare chance to test its instruments on Earth and the Moon.

The European Space Agency’s Jupiter Icy Moons Explorer (Juice) made a close pass by Earth on September 28, skimming the outer reaches of the atmosphere and using our planet’s gravity to reshape its path toward Jupiter while consuming very little fuel.

The carefully planned gravity assist changed Juice’s direction by 20° relative to its previous trajectory and increased its speed by 3.5 km/s...

On Earth, most of us rarely have to think about the signals that keep our internal clocks aligned. The sun rises, daylight changes, darkness arrives and morning comes again.

Our bodies have evolved alongside this roughly 24-hour cycle. Light is one of the strongest signals our bodies use to synchronize the circadian clock. But what happens when the sun no longer provides a reliable schedule?

A spacecraft orbits Earth roughly every 90 minutes, so astronauts experience about 16 sunrises and sunsets every 24 hours. They cannot go to sleep every time the sun disappears—but their bodies still need to know when it is time to sleep, wake, eat, exercise and work.

This makes spaceflight more than just an engineering cha...

Magnetic fields in the chromosphere above a quiet-Sun region observed by the SCIP instrument onboard Sunrise-III (right box), and magnetic structures reproduced by a numerical simulation (left box). The thin, thread-like magnetic structures detected by SCIP are reproduced in the simulation as twisted magnetic field lines (enlarged view inside the circle at the lower left). （Credit: NAOJ / MPS / Sunrise-III/SCIP）

A team of researchers led by the National Astronomical Observatory of Japan discovered unexpectedly intricate magnetic structures above quiet-sun regions by observing the sun with the balloon-borne solar observatory Sunrise-III during its 2024 flight in Earth’s stratosphere. The work is published in The Astrophysical Journal Letters.

Threads within the magnetic canop...