Earthshine blog

Earthshine blog

"Earthshine blog"

A blog about a system to determine terrestrial albedo by earthshine observations. Feasible thanks to sheer determination.

Meteor caught in the act!

Showcase images and animationsPosted by Daddy-o Feb 21, 2013 09:17AM
During processing a strange signal was found in a frame combined from 100 images. It turns out that in one image of this stack we have what appears to be a meteor or a satellite flash - or something:

The image is from Jan 17 2012: (UTC 2012-01-17T13:28:48). The exposure time was 0.009 seconds! The trail is about 3/4 of the lunar diameter in length - i.e. about 22 arc minutes. The orientation is such that it is travelling almost Due North (or South!).

What is it? Well - it is clearly between us and the Moon! If it is a meteor its height would be something like 50-100 km. The speed would then be 35 - 70 km/s. A satellite in low earth orbit has speed 8 km/s. Since the image is taken from Hawaii at UTC 13:28 it is near midnight on Hawaii - i.e. the Sun is behind the Earth and unlikely to be illuminating a LEO satellite.

An airplane flies at 800 km/hr at altitude 10 km, so the distance covered in 0.009 s is 2 m which would subtend an angle of 1 arc minute. This is no airplane - or it is much closer, in which case we should see details of the plane.

As far as I can tell there is no pronounced peak in meteorite activity in January.

  • Comments(2)//earthshine.thejll.com/#post302