On Dec. 18, 2018, a large “fireball” — the term used for exceptionally bright meteors that are visible over a wide area — exploded about 16 miles (26 kilometers) above the Bering Sea. The explosion unleashed an estimated 173 kilotons of energy, or more than 10 times the energy of the atomic bomb blast over Hiroshima during World War II.
Two NASA instruments aboard the Terra satellite captured images of the remnants of the large meteor. The image sequence shows views from five of nine cameras on the Multi-angle Imaging SpectroRadiometer (MISR) instrument taken at 23:55 Coordinated Universal Time (UTC), a few minutes after the event. The shadow of the meteor’s trail through Earth’s atmosphere, cast on the cloud tops and elongated by the low sun angle, is to the northwest. The orange-tinted cloud that the fireball left behind by super-heating the air it passed through can be seen below and to the right of the GIF’s center.
“By 2015, the number of different sources mapped by Fermi’s LAT had expanded to about 3,000 — 10 times the number known before the mission,” said Goddard’s Elizabeth Ferrara, who led the constellation project. “For the first time ever, the number of known gamma-ray sources was comparable to the number of bright stars, so we thought a new set of constellations was a great way to illustrate the point.”
This view looks toward the sunlit side of the rings from about 19 degrees above the ringplane. The image was taken in green light with the Cassini spacecraft wide-angle camera on Aug. 12, 2017. Pandora was brightened by a factor of 2 to increase its visibility.
The view was obtained at a distance to Saturn of approximately 581,000 miles (935,000 kilometers) from Saturn. Image scale is 35 miles (56 kilometers) per pixel. The distance to Pandora was 691,000 miles (1.1 million kilometers) for a scale of 41 miles (66 kilometers) per pixel.
NGC 1032 is located about a hundred million light-years away in the constellation Cetus (the Sea Monster). Although beautiful, this image perhaps does not do justice to the galaxy’s true aesthetic appeal: NGC 1032 is actually a spectacular spiral galaxy, but from Earth, the galaxy’s vast disk of gas, dust and stars is seen nearly edge-on.
A handful of other galaxies can be seen lurking in the background, scattered around the narrow strip of NGC 1032. Many are oriented face-on or at tilted angles, showing off their glamorous spiral arms and bright cores. Such orientations provide a wealth of detail about the arms and their nuclei, but fully understanding a galaxy’s three-dimensional structure also requires an edge-on view. This gives astronomers an overall idea of how stars are distributed throughout the galaxy and allows them to measure the “height” of the disk and the bright star-studded core.
This timelapse of images captured by the Hubble Space Telescope of V838 Monocerotis is often posted on Internet forums and elsewhere as if it represents the expansion of a star having gone supernova. The reality is even more interesting and odd. According to NASA,
What caused this outburst of V838 Mon? For reasons unknown, star V838 Mon’s outer surface suddenly greatly expanded with the result that it became the brightest star in the entire Milky Way Galaxy in January 2002. Then, just as suddenly, it faded. A stellar flash like this had never been seen before–supernovas and novas expel matter out into space. Although the V838 Mon flash appears to expel material into space, what is seen in the above image from the Hubble Space Telescope is actually an outwardly moving light echo of the bright flash.
In a light echo, light from the flash is reflected by successively more distant rings in the complex array of ambient interstellar dust that already surrounded the star. V838 Mon lies about 20,000 light years away toward the constellation of the unicorn (Monoceros), while the light echo above spans about six light years in diameter.