Astronomy

NASA / GSFC / SDO The Sun is waking up. In recent weeks, NASA has announced X-class solar flares, observers have seen large sunspot groups with the unaided eye, and online services have issued multiple aurora alerts even for mid-latitudes.   After years of quiescence — the Sun was more often spotless than not in 2018, 2019, and 2020 — the change of pace is exciting solar observers. The Sun goes through 11-year cycles of magnetically instigated activity, which include sunspots, flares, and massive eruptions. While such activity last peaked around 2012 through 2014, that maximum was meager at best. In fact, it marked one of the quietest cycles in 100 years. Now, the uptick in activity seems to mark a change in the Sun’s behavior. Lisa Upton (Space Sy...

For millennia, the universe did a pretty good job of keeping its secrets from science. Ancient Greeks thought the universe was a sphere of fixed stars surrounding smaller spheres carrying planets around the central Earth. Even Copernicus, who in the 16th century correctly replaced the Earth with the sun, viewed the universe as a single solar system encased by the star-studded outer sphere. But in the centuries that followed, the universe revealed some of its vastness. It contained countless stars agglomerated in huge clusters, now called galaxies. Then, at the end of the 1920s, the cosmos disclosed its most closely held secret of all: It was getting bigger. Rather than static and stable, an everlasting and ever-the-same entity encompassing all of reality, the universe ...

Sand blown by wind into ripples within Victoria Crater at Meridiani Planum on Mars, as photographed by NASA’s Mars Reconnaissance Orbiter on October 3, 2006. Credit: NASA/JPL-Caltech/University of Arizona/Cornell/Ohio State University What is it like to be on the surface of Mars or Venus? Or even further afield, such as on Pluto, or Saturn's moon Titan? This curiosity has driven advances in space exploration since Sputnik 1 was launched 65 years ago. Bu...

Be sure to watch the skies on the last morning of May, for a possible Tau Herculid meteor outburst. If predictions hold true, we may be in for a rare meteor outburst from an obscure meteor shower on May 31st… or we may see nothing at all. Welcome to the wonderful world of meteor shower predictions and prognostications. The story starts with the discovery of periodic Comet 73P/Schwassmann-Wachmann 3 back in 1930 from the Hamburg Observatory. (We’ll be referring to it as simply ‘Comet 73P’ from here on out). Astronomers Arthur Wachmann and Carl Schwassmann caught this fuzzball comet on glass plate captures as a +9.5 magnitude object, moving through the constellation Hercules. Remove All Ads on Universe Today Join our Patreon for as little as $3! Get the ad-free experience for life ...