VLASS Progress

This map of the VLA Sky Survey coverage is updated continually!

There are over 41,253 square degrees in the sky, and of that, the VLA Sky Survey can observe 33,885 square degrees from its position in New Mexico. Observing the sky in terms of its vast area means that we have to break down the area into small observing blocks. We divided the sky into a set of tiles, with each tile covering an area of approximately 40 square degrees (10 x 4 degrees). To give you an idea of the scale of that area, let’s look at our closest celestial neighbor, the Moon. The full Moon is only a half degree wide, corresponding to an area of only .2 square degrees. So, with one of our 10 x 4 tiles, we could fit up to 200 Moons — a lot of radio data are packed into these tiles! We expect to observe approximately 5 million radio sources three times over 7 years, providing one of the largest radio catalogs ever assembled.

The radio data VLASS has observed so far is highlighted and is overlaid upon the latest optical data from the Digitized Sky Survey (DSS). The current data presented here contains the entire Epoch 1 survey, which was completed in July 2019. In May of 2020 the Epoch 2 survey will begin. Make sure to check back regularly as we continue to scan the sky in three distinct epochs spanning 7 years.

Note: The images here are our first look at the radio data, and they may have features such as spikes and other artifacts due to the way the data is gathered. Astronomical images don’t have to be pretty to be useful to astronomers.