The Fermi Bubbles are two enormous gamma-ray lobes extending roughly 25,000 light-years above and below the Galactic Center, discovered in 2010, with sharp edges, hard spectra, and X-ray counterparts (the larger eROSITA bubbles enclosing them). Their origin story is contested between past activity of Sagittarius A*, a nuclear jet or accretion outburst a few million years ago, and nuclear starburst winds, and neither account is settled. The asymmetry sharpens the puzzle: the bubbles are not mirror images, differing in extent, brightness, spectral detail, and edge morphology between north and south, and the southern bubble hosts the enigmatic "cocoon" substructure. A symmetric central engine blowing into a roughly symmetric halo should produce more symmetric lobes than observed, so the asymmetry must be blamed on environmental density gradients, engine precession, or successive outbursts, each an added epicycle.
For ΛCDM the bubbles are local astrophysics, but they carry cosmological freight: they sit across the sky regions where CMB and 21-cm foreground cleaning operates, their hard leptonic or hadronic content biases diffuse-emission templates, and their unexplained energetics, of order 10^55 to 10^56 erg, must fit within the Galactic Center's activity budget. The asymmetry specifically resists the simplest engine narratives: a single brief jet episode struggles to produce lobes this different, while multiple-episode histories multiply free parameters.
The standing is an unresolved morphology problem in our own backyard: the structures are exquisitely mapped, their cause is not, and the north-south differences remain the discriminating data that any engine-plus-environment model must hit. eROSITA's full-sky X-ray view and forthcoming radio polarization surveys are tightening the field constraints.