Feel tiny in this gigantic, zoomable galaxy map charting 3 billion stars
Astronomers have released one of the biggest data dumps of the Milky Way ever, cataloging an incredible 3.32 billion cosmic objects in detail. The end result is a gigantic image that can be zoomed in and out for a stunning sense of scale.
Anyone who’s ever looked up at the sky on a clear night, far from any light pollution, has marveled at just how many stars there are. It may seem like an impossible task to ever try to count and catalog them all, but generations of surveys like PAN-STARRS, Sloan and Gaia have tried to do just that. Each one has produced ever more detailed views of the cosmos, and now we may have the most in-depth one yet.
The latest is the second data release of the Dark Energy Camera Plane Survey (DECaPS2), which is observing the disk of the Milky Way at optical and near-infrared wavelengths of light. The instrument is located on the Victor M. Blanco 4-meter Telescope in Chile, at an altitude of 2,200 m (7,200 ft), which gives it a clear view of the southern sky.
Following the first data release in 2017, DECaPS2 is made up of 21,400 individual exposures totaling over 10 TB of data, with astronomers identifying around 3.32 billion objects in the images. The combination of both data releases now covers 6.5% of the entire night sky, or an area about 13,000 times the size of the full Moon in the sky.
The Milky Way disk appears as a bright blob of light, shrouded in dust, which can make it hard to differentiate individual stars and objects. The telescope’s near-infrared view helped it peer through the dust, while a new data-processing technique that predicts the background behind each star helps pluck stars out from crowds and nebulae.
And the end result is incredible. The image starts from a view that looks like what you’d see with the naked eye staring up at the sky, but zooming in on any random patch that catches your eye reveals more and more specific stars. If you want to feel absolutely awestruck and simultaneously tiny and insignificant, this is the photo for you.
“One of the main reasons for the success of DECaPS2 is that we simply pointed at a region with an extraordinarily high density of stars and were careful about identifying sources that appear nearly on top of each other,” said Andrew Saydjari, lead author of the study. “Doing so allowed us to produce the largest such catalog ever from a single camera, in terms of the number of objects observed.”
The data collected for this survey will likely fuel astronomers’ curiosities and studies for years to come.