Blogology

Where do comet tails come from? There are no obvious places on the nuclei of comets from which the jets that create comet tails emanate. One of the best images of emerging jets is shown in the featured picture, taken in 2015 by ESA’s robotic Rosetta spacecraft that orbited Comet 67P/Churyumov-Gerasimenko (Comet CG) from 2014 to 2016. The picture shows plumes of gas and dust escaping numerous places from Comet … Read More →

Sometimes, even rovers on Mars stop to admire the scenery. Just late last November the Curiosity rover on Mars paused to photograph its impressive surroundings. One thing to admire, straight ahead, was Central Butte, an unusual flat hill studied by Curiosity just a few days before this image was taken. To its right was distant Mount Sharp, the five-kilometer central peak of entire Gale crater, the interior of which Curiosity … Read More →

In this Hubble Space Telescope image the bright, spiky stars lie in the foreground toward the heroic northern constellation Perseus and well within our own Milky Way galaxy. In sharp focus beyond is UGC 2885, a giant spiral galaxy about 232 million light-years distant. Some 800,000 light-years across compared to the Milky Way’s diameter of 100,000 light-years or so, it has around 1 trillion stars. That’s about 10 times as … Read More →

On January 21, 2019 moonwatchers on planet Earth saw a total lunar eclipse. In 35 frames this composite image follows the Moon that night as it crossed into Earth’s dark umbral shadow. Taken 3 minutes apart, they almost melt together in a continuous screen that captures the dark colors within the shadow itself and the northern curve of the shadow’s edge. Sunlight scattered by the atmosphere into the shadow causes … Read More →

Some 13,000 light-years away toward the southern constellation Pavo, the globular star cluster NGC 6752 roams the halo of our Milky Way galaxy. Over 10 billion years old, NGC 6752 follows clusters Omega Centauri and 47 Tucanae as the third brightest globular in planet Earth’s night sky. It holds over 100 thousand stars in a sphere about 100 light-years in diameter. Telescopic explorations of the NGC 6752 have found that … Read More →

It is the closest cluster of stars to the Sun. The Hyades open cluster is bright enough to have been remarked on even thousands of years ago, yet is not as bright or compact as the nearby Pleiades (M45) star cluster. Pictured here is a particularly deep image of the Hyades which has brings out vivid star colors and faint coincidental nebulas. The brightest star in the field is yellow … Read More →

What does the solar wind sound like? A wind of fast moving particles blows out from our Sun, and although space transmits sound poorly, particle impact and variable-field data from NASA’s near-Sun Parker Solar Probe is being translated into sound. The disarming audio track of the featured video recounts several of these reverberations, including spooky-sounding Langmuir Waves (heard first), hurricane-sounding Whistler Mode Waves (heard next), and hard-to-describe Dispersive Chirping Waves … Read More →