Brilliance at Night: The Americas in Darkness


This image of North and South America at night is a composite assembled from data acquired by the Suomi NPP satellite in April and October 2012. via NASA https://ift.tt/2t0s3rd

N63A: Supernova Remnant in Visible and X-ray


What has this supernova left behind? As little as 2,000 years ago, light from a massive stellar explosion in the Large Magellanic Cloud (LMC) first reached planet Earth. The LMC is a close galactic neighbor of our Milky Way Galaxy and the rampaging explosion front is now seen moving out - destroying or displacing ambient gas clouds while leaving behind relatively dense knots of gas and dust. What remains is one of the largest supernova remnants in the LMC: N63A. Many of the surviving dense knots have been themselves compressed and may further contract to form new stars. Some of the resulting stars may then explode in a supernova, continuing the cycle. Featured here is a combined image of N63A in the X-ray from the Chandra Space Telescope and in visible light by Hubble. The prominent knot of gas and dust on the upper right -- informally dubbed the Firefox -- is very bright in visible light, while the larger supernova remnant shines most brightly in X-rays. N63A spans over 25 light years and lies about 150,000 light years away toward the southern constellation of Dorado. via NASA https://ift.tt/2E77r2W

Earth's Changing Ice


Meltwater lakes form on the surface of Greenland’s Petermann Glacier. via NASA https://ift.tt/35jfLJ3

Starlink Satellite Trails over Brazil


What are those streaks over the horizon? New Starlink satellites reflecting sunlight. SpaceX launched 60 Starlink communication satellites in May and 60 more in November. These satellites and thousands more are planned by communications companies in the next few years that may make streaks like these relatively common. Concern has been voiced by many in the astronomical community about how reflections from these satellites may affect future observations into space. In the pictured composite of 33 exposures, parallel streaks from Starlink satellites are visible over southern Brazil. Sunflowers dot the foreground, while a bright meteor was caught by chance on the upper right. Satellite reflections are not new -- the constellation of 66 first-generation Iridium satellites launched starting 20 years ago produced some flares so bright that they could be seen during the day. Most of these old Iridium satellites, however, have been de-orbited over the past few years. via NASA https://ift.tt/2LFeT9I