Pre-Sputnik Satellites

An example of repeating glints in a blue Palomar Sky Survey II image taken in 1980s, here with a faint streak linking them together. The left column shows the POSS-II image, and the right column the Pan-STARRS image (> year 2015). The example uses the VASCO citizen science web interface. An actual case of a “train of glints”, can have significantly sparser spacing and can be composed of fewer glints than shown here.

The 48-inch Samuel Oschin Telescope on Mount Palomar

Before the launch of the first satellites in 1957, our Sky was free from the thousands of satellites and millions of pieces of debris at geosynchronous orbits that haunt the skies. All pieces give off fast, bright flashes of lights that contaminate our view of the universe.

We scour old photographic plates for signatures of satellites and space junk. As we know humans had nothing up there at an altitude of tens of thousands of kilometers, such an object could not be of human origin. We use images that were taken in the early 1950s with the 1.2m (48 inch) Samuel Oschin telescope at Mount Palomar in California. In those times, astronomers used photographic plates. Today these plates have been digitized and can be found for public use.

Searches for these satellites are done in collaboration with the Spanish Virtual Observatory and in conjunction with the VASCO citizen science project (http://ml-blink.org)

One published article on pre-sputnik satellites: https://earthsky.org/space/9-weird-transients-palomar-observatory-1950/

One published research paper on our search for pre-sputnik satellites: https://www.nature.com/articles/s41598-021-92162-7

Depictions of glints that can occur from satellites, detectable in telescope photographs taken before 1959.