Space News & Blog Articles

(This is Part 2 of a series on primordial black holes. Check out Part 1 here!)

Engineers can be split into two camps - those who just release whatever they’re building and try to fix whatever might be wrong with it as they get feedback on it, and those who test their product in every possible way before releasing it to the public. Luckily, NASA engineers are in the latter camp - it wouldn’t look great if all of the probes we send throughout the solar system failed because of something we could have easily tested for here at home. However, finding analogues for the places we want to send those probes remains a challenge for some NASA projects, so they make due with the best Earth has to offer. For Mars, that means testing technology in the desert’s rolling sand dune and rocky outcrops, and this year several different NASA technologies were tested in deserts throughout the country, as reported in a press release from the agency.

White dwarfs are called stellar remnants because they're what's left of main sequence stars after they've shed most of their mass and ceased fusion. But despite being mere remnants for whom fusion is only a distant memory, they can still be the locations of enormously powerful thermonuclear explosions called novae.

By its very nature, spaceflight is very challenging and very wasteful. As Tsiolkovsky's famous Rocket Equation establishes, propellant accounts for the majority of a rocket's mass, which is burned off during launch. The process also introduces large amounts of greenhouse gases, such as carbon dioxide, water vapor, and black carbon, as well as ozone-depleting chemicals, into the upper atmosphere. On top of that, the disposal process for satellites once they are no longer operational (deorbiting and burning up in the atmosphere) is also wasteful, with no materials retrieved or reused.

Intermediate mass black holes (IMBH), if they exist, have between about 100 and 1000 solar masses, placing them in between stellar black holes and supermassive black holes. But while there's plenty of evidence for both stellar mass black holes and supermassive black holes, the evidence for IMBHs isn't as convincing. There are many candidates, but there's no wide agreement on any of them. Yet our theories of black holes show there should be something in between stellar black holes and supermassive black holes, and IMBHs could be the missing link.

The center of the Milky Way is an extreme environment dominated by the supermassive black hole (SMBH) Sagittarius A star (Sgr A-star). Sgr A-star has about 4 million solar masses, and its powerful gravity and radiation defines the region. Its gravity accelerates the orbits of stars and gas clouds in its vicinity. Radiation from the SMBH's accretion processes, from the stellar winds coming from colliding stars, from abundant supernovae explosions, and from superheated gas falling toward the black hole, saturates the region.