Meteorologists Monitor Meteor
According to the JPL site, there was a bright meteor (or bolide) on September 29, 2021 over the Gulf of Alaska. (The JPL and a similar NASA site are posted under the GLM tab on this link of links.) This event was seen by both the ABI and GLM on NOAA‘s GOES-17, as well as the AHI on Japan’s Himawari-8. What may be unique about his event is that the imagers monitored the meteor soon after it’s explosion, and not just the resulting plume (as was done in this case over Russia in 2013). This is based on the length of the event, during which the various spectral bands displayed a signature and other information.
| Peak Brightness Date | Peak Brightness Time (UT) | Latitude (deg.) | Longitude (deg.) | Altitude (km) | Total Radiated Energy (J) | Calculated Total Impact Energy (kt) |
| 2021-09-29 | 10:50:59 | 53.9N | 148.0W | 28 | 13.7e10 | 0.4 |
Entry from table via the JPL site.
GOES-17
The GLM and ABI observed this event, but given it’s faster readout, the GLM offers much more information than the ABI. The apparent location of the meteor as seen by the ABI is different than the reported location, in part due to parallax. More on the concept of parallax is available here.
Hotter brightness temperatures can be seen in the GOES-17 ABI band 12 at 10:50:59 UTC.
Indicative of a short duration event, coupled with how the ABI scans, the meteor signature was only clearly seen at one time in nearly every ABI spectral band (although possibly the ABI band 11 as well). Due to the layout of the focal plane array on the ABI, not all spectral bands observe the Earth at the precisely same time. [Figure a modification from the GOES-R Series Data Book.] A similar loop as above, but as an animated gif, is available here. In addition,. while a bit hard to see, the longwave split window infrared difference also showed a subtle signature of the meteor.
Spectral difference images (over time) can also be useful in the monitoring of meteors. An ABI 10.3 – 12.3 micrometer band difference is shown below. An shortwave minus longwave difference loop.
The GLM on GOES-17 also observed this event. A similar loop as below, but as an animated gif, is available.
The rapid movement of the meteor to the south is clearly evident. As well as the GLM group map and the key (blue is early times and red is later times).
As well as the changes over time, most likely monitoring the meteor break-ups.
More on the GLM’s light curves from NASA AMES.
AHI
Both the ABI and Japan’s AHI scan space around the edge of the Earth. However, with the ABI data the process of making calibrated, navigated, and remapped radiance only pixels located on the Earth are included in the Level 1b radiance files. Hence, the ABI may scan meteors in space, but the data are not available to most users.
A similar loop as above, but as an animated gif, is available here (and an 8-panel AHI image at this same time is available here). This example helps to illustrate that each AHI detector doesn’t sense radiation from the same exact location at the same time.
H/T
NOAA GOES–17 data were accessed via the University of Wisconsin-Madison SSEC Satellite Data Services. McIDAS-X and Geo2Grid was used to generate imagery. Thanks also to Todd Beltracchi and Scott Bachmeier, and to CIRA/RAMMB Slider images/movies.