relative to the central source. The lobes contain the majority of the material in the Homunculus Nebula, in relatively thin shells concentrated towards the poles. The shells consist of two components, an inner warm region and a more massive outer cool skin. The shells are smooth and thin suggesting they were ejected in as little as five years, but there are streaks of thicker dust detectable within the shells. Each lobe has polar "hole" although it is not known whether it is an actual gap in the shell of the lobe or just a deep indentation. Surrounding each polar hole is a "trench". The trenches are visible as approximate semicircles centred on the axis of the lobes but may form complete circles. There are other smaller irregular indentations and protrusions to the lobes, which are symmetrical with the same features appearing on each lobe. These include flattened protrusions at about 10° latitude, one on each lobe (labeled "Protrusions" in the illustrated model), with other smaller protrusions near the equatorial skirt. The mass of the nebula cannot be determined directly. However, the amount of dust can be measured fairly accurately and estimates of the gas to dust ratio used to calculate the total mass. The total dust mass is calculated at , leading to estimates that up to of gas are contained in the Homunculus itself. Nearly as much material is detected within outer ejecta, which formed earlier, but within the last thousand years. Older calculations had produced consensus estimates of Weigelt Blobs Early speckle interferometry showed that the central region of the Homunculus contains four point-like sources, originally designated A1, A2, A3, and A4. The four speckle objects were later referred to as A, B, C, and D. Higher resolution studies showed that only the brightest source A was truly stellar, and the other three were small nebular condensations. The three Weigelt Blobs are visible primarily in light directly reflected from the Eta Carinae stars. The blobs are believed to lie near the equatorial plane of the stellar system, but their origin is unclear. Their speed has been measured, but within uncertainties they could have been emitted in the 1890 outburst or a 1941 event. The situation is complicated further by the likely acceleration of their slow movement due to the intense stellar winds. Spectrum The spectrum of the Homunculus is complex, consisting of reflected, thermal, and emission components at