x-ray (& gamma ray) telescopes

It is pretty hard to access the X-Ray wavelength range from Earth.

As one can(t) see, the atmosphere is pretty hungry for these types of radiation, eating it all before it gets to a human’s eye. The only hope of reaching it is sending a balloon (Victor Hess style), or a rocket. Which is exactly what was done!

This cute little german rocket was launched by the US Naval Research Lab in 1949 from New Mexico (the state where Breaking Bad takes place; alternatively, also the location of the observatory behind SDSS). The mission was successful, reaching 151.1 km into the upper atmosphere: the geiger counters & x-ray plates aboard helped detect the X-rays emitted by the Sun.

In 1962, we discovered that Sun isn’t the only one:

This cute little sounding (not sure what that means) rocket called Aerobee also had geiger counters on board; and this time they detected Scorpius X-1. Sounds quite mysterious, but it’s just a low-mass X-ray binary: a neutron star and a “normal” star of the spectral class M. But that wasn’t the only discovery. The whole sky possessed an X-ray background. Which means…

More deadly lazers. Everywhere.

After this, came Uhuru in 1970. I actually quite like the image below.

The name of this appartus translates to “freedom” from Swahili, the national language of Kenya, in recognition of the hospitality of this country $-$ Uhuru was launched off its coast. Also, something I didn’t know before starting to write this: the project was managed by Marjorie Townsend $-$ the first woman to become a spacecraft project manager at Goddard Spaceflight Center.

Uhuru could only localize sources with a precision of ~1’, which… isn’t impressive currently, but was certainly quite an achievement for the FIRST X-ray satellite.

Finally, people were able to resolve the ~300 deadly lazers that had been detected as background before. People also started measuring their strengths in um. Crabs.

You had to have seen this before:

The Crab Nebula. It’s the remnant of a supernova explosion from 1054, with a pulsar inside it. People used to think the X-ray it emits is constant, and that’s why they used it as a unit of measurement. (But it is not. Despite already being perfect, crabs do change.)