Here you are friend. I think that you were having issues because this is a .gz file rather than a .tar.gz. I used the gunzip function available with the R.utils package and st_read from sf to read the KML at the end.
library(R.utils)
#> Loading required package: R.oo
#> Loading required package: R.methodsS3
#> R.methodsS3 v1.7.1 (2016-02-15) successfully loaded. See ?R.methodsS3 for help.
#> R.oo v1.22.0 (2018-04-21) successfully loaded. See ?R.oo for help.
#>
#> Attaching package: 'R.oo'
#> The following objects are masked from 'package:methods':
#>
#> getClasses, getMethods
#> The following objects are masked from 'package:base':
#>
#> attach, detach, gc, load, save
#> R.utils v2.7.0 successfully loaded. See ?R.utils for help.
#>
#> Attaching package: 'R.utils'
#> The following object is masked from 'package:utils':
#>
#> timestamp
#> The following objects are masked from 'package:base':
#>
#> cat, commandArgs, getOption, inherits, isOpen, parse, warnings
library(sf)
#> Linking to GEOS 3.6.1, GDAL 2.2.3, proj.4 4.9.3
zipFileName <- "http://satepsanone.nesdis.noaa.gov/pub/volcano/FIRE/HMS_ARCHIVE/2010/KML/smoke20100101.kml.gz"
smokeFileName <- "smoke20100101.kml.gz"
smokeKZName <- "smoke20100101.kml"
download.file(url = zipFileName, dest = smokeFileName)
gunzip(smokeFileName)
st_read(smokeKZName)
#> Reading layer `Layer #0' from data source `C:\Users\whaleyry\AppData\Local\Temp\Rtmpcj3gyI\smoke20100101.kml' using driver `KML'
#> Simple feature collection with 24 features and 2 fields
#> geometry type: GEOMETRY
#> dimension: XY
#> bbox: xmin: -156.126 ymin: 19.301 xmax: -78.302 ymax: 34.738
#> epsg (SRID): 4326
#> proj4string: +proj=longlat +datum=WGS84 +no_defs