NASA has produced a breathtaking 12-year time lapse movie of the entire sky, demonstrating how the world around us has changed.
A NASA satellite observatory has developed a time-lapse film that shows how the sky has changed over the course of a decade. We can see cosmic wonders in photographs, but we can feel them in motion images. NASA’s NEOWISE space telescope is creating fascinating videos of the sky’s movement and change. NASA’s Near-Earth Object Wide Field Infrared Survey Explorer, or NEOWISE, captures photographs in all directions as it orbits the Sun every six months. When the photos are stitched together, hundreds of millions of things appear on this map. In essence, scientists made a time-lapse movie utilizing 18 all-sky maps (the 19th and 20th will be revealed in March 2023), demonstrating developments over the last ten years.
Each map has a wealth of information about the universe for astronomers. However, when viewed as a time-lapse, they become even more helpful resources for helping students understand it. The maps can be compared using time-domain astronomy to detect distant objects that have changed brightness or position over time.
“The night sky appears to alter relatively minimally,” said Amy Mainzer, principle investigator of NEOWISE at the University of Arizona. “Stars are constantly erupting and flashing throughout the sky.” Asteroids fly by. Black holes are tearing up stars. “The universe is a tremendously lively and busy place.”
from WISE to NEOWISE
WISE was launched in 2009 as an observatory charged with scouring our galaxy for and studying things outside our solar system. NEOWISE began as a data processing project to retrieve WISE asteroid detections. Cryogenically cooled detectors on the spaceship detected infrared light. Some of the world’s brightest galaxies and cool, nearby stars emit infrared light, which the human eye cannot see. The WISE mission ended in 2011 when the coolant on board ran out, but the spacecraft and part of its infrared detectors remained operational. As a result, NASA reconfigured the device in 2013 to track asteroids and other near-Earth objects. Both the mission and the spacecraft were renamed NEOWISE. Despite the shift, astronomers continue to investigate objects outside our solar system using data from infrared telescopes.
As part of the CatWISE project, a catalogue of objects from 12 NEOWISE all-sky maps was provided in 2020. Brown dwarfs, which are distributed around the galaxy and lurk in the dark near to our Sun, are studied in this collection. Even though they originate like stars, brown dwarfs do not undergo the fusion process that causes stars to light. Brown dwarfs appear to travel quicker than more distant stars moving at the same speed because of their proximity to Earth. Brown dwarfs can be found in the catalogue by looking for things that move among billions of others. Backyard Worlds: Planet 9 is a companion project to CatWISE that invites citizen scientists to pore through NEOWISE data.
Brown Dwarf Mapping
Using WISE’s original two all-sky scans, some 200 brown dwarfs were discovered within 65 light-years of our Sun. As a result of the new maps, 60 more Y-dwarfs, the coldest brown dwarfs, have been detected. Warmer brown dwarfs could provide a different story about how and when they formed than Y-dwarfs. As a result of these discoveries, our solar neighbourhood is now ornamented with a variety of objects. A more complete census of brown dwarfs close to the Sun allows scientists to calculate how efficient star creation is in our galaxy.
A decade of studying the sky has also helped scientists comprehend how stars emerge. Dusty blankets shroud protostars as they evolve into stars, allowing NEOWISE to look inside their obscuring cocoons. Over time, the dust clouds that surround protostars gather mass, causing them to flicker and flare. To gain a better understanding of how stars originate, astronomers utilize NEOWISE to track the lifecycles of almost 1,000 protostars through time.
NEOWISE data has also contributed to a better understanding of black holes. As part of the original WISE study, millions of supermassive black holes were identified at the centres of distant galaxies. Recently, NEOWISE data and an echo mapping approach were utilized to determine the size of hot gas discs surrounding faraway black holes. A telescope cannot see these objects because they are too small. Overall, NEOWISE has made significant contributions to our understanding of the solar system, neighbouring stars, as well as distant, hidden objects like supermassive black holes.