One million alien visitors from another star system could already be lurking in the solar system. We aren’t talking about “little green men” here, however — more “little (and not so little) gray rocks,” asteroids from the triple star system Alpha Centauri. Alpha Centauri is the closest star system to our own, lying around 4.3 … Read more
The secrets of the solar wind will soon come under renewed scrutiny thanks to the launch of an upcoming NASA mission that will gaze at the sun and the inner solar system. The mission, called PUNCH, which stands for the Polarimeter to Unify the Corona and Heliosphere, is a constellation of four suitcase-sized satellites that … Read more
The great solar storm of May 2024, which sparked beautiful auroral displays over much of the world, also created two new radiation belts that were observed with a satellite that came back from the dead. “This is really stunning,” Xinlin Li, a professor at the Laboratory for Atmospheric and Space Physics at the University of … Read more
Scientists believe that two asteroids might be fragments of long-lost “planetary embryos” from the early solar system. These embryos, somewhere between small planetesimals and fully formed planets, were abundant during the solar system’s formative stages and played a critical role in planetary formation. Two asteroids in the main asteroid belt between Mars and Jupiter, (246) … Read more
The sun, for all its glitz, tends to hide behind a veil of mystery. For instance, its outer atmosphere, the corona, appears to be hotter than its surface — like, way hotter — and scientists aren’t sure why. There’s also a big puzzle concerning how the solar wind, which is a stream of charged particles … Read more
It’s been a busy year on the sun, as it officially entered the peak of its roughly 11-year cycle of activity, known as solar maximum. In 2024, the sun launched over 50 X-class solar flares — the most powerful type of solar flare — at Earth. Solar flares are categorized by the level of X-rays … Read more
A NASA spacecraft is about to give astronomers an epic early Christmas present with the closest ever flyby of the sun on Dec. 24, but if you’re wondering exactly when the ambitious solar encounter will occur, don’t worry. We’ve got you covered. The NASA spacecraft, called the Parker Solar Probe, is on course for what … Read more