A near-Earth asteroid named Kamo`oalewa could be a fragment of our moon, according to a new paper published in Nature Communications Earth and Environment by a team of astronomers led by the University of Arizona. Kamo`oalewa is a quasi-satellite --... Continue Reading →
Why doesn't the nearby galaxy create a gravitational lensing effect on the background galaxy? It does, but since both galaxies are so nearby, the angular shift is much smaller than the angular sizes of the galaxies themselves. The featured Hubble image of NGC 3314 shows two large spiral galaxies... Continue Reading →
The joint European-Japanese BepiColombo mission captured this view of Mercury on 1 October 2021 as the spacecraft flew past the planet for a gravity assist manoeuvre. The image was taken at 23:44:12 UTC by the Mercury Transfer Module’s Monitoring Camera... Continue Reading →
What happening above that volcano? Something very unusual -- a volcanic light pillar. More typically, light pillars are caused by sunlight and so appear as a bright column that extends upward above a rising or setting Sun. Alternatively, other light pillars -- some quite colorful --... Continue Reading →
Why, sometimes, does part of the Sun's atmosphere leap into space? The reason lies in changing magnetic fields that thread through the Sun's surface. Regions of strong surface magnetism, known as active regions, are usually marked by dark sunspots. Active regions can channel charged... Continue Reading →
NGC 2438 is a planetary nebula, formed after the death of a Sun-like star. The medium-sized star would have expelled its outer layers of gas into space as it died, leaving behind a white-dwarf core. A halo of glowing gas... Continue Reading →
The Horsehead Nebula is one of the most famous nebulae on the sky. It is visible as the dark indentation to the orange emission nebula at the far right of the featured picture. The horse-head feature is dark because it is really an opaque dust cloud that lies in... Continue Reading →
We've seen this same supernova three times -- when will we see it a fourth? When a distant star explodes in a supernova, we're lucky if we see it even once. In the case of AT 2016jka ("SN Requiem"), because the exploding star... Continue Reading →
Significant Solar Flare The Sun emitted a significant solar flare peaking at 11:35 a.m. EDT on Oct. 28, 2021. NASA’s Solar Dynamics Observatory, which watches the Sun constantly, captured an image of the event. Solar flares are powerful bursts of radiation.... Continue Reading →