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Goddard Space Flight Center

Astrophysics Science Division | Sciences and Exploration

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TIGER in Antarctica, November 15, 2003

First Seals of the Season

Things are working really well with TIGER. Towards the end of the day, we turn TIGER fully on and set up to collect cosmic ray air showers. Most of the cosmic rays that reach the ground are secondaries, i.e. they are the fragments of primary cosmic rays that had collisions at the top of the atmosphere. These secondaries are mostly muons, but electrons, protons, kaons and other particles are mixed in. All of these particles give a much smaller signal than the heavy nuclei that TIGER is designed to measure. So TIGER is pretty insensitive to them. But a very energetic primary cosmic ray can generate a large (square kilometers in area) shower of these secondaries. In those cases, there can be enough secondary particles coming through TIGER in one burst to give us a measurable signal. This only happens once or twice an hour, however. The TIGER team is going to take tomorrow (Sunday) off, but we'll leave TIGER collecting data.

In the evening, I walk out to Scott's Hut. I have pictures of the Hut from my 2001 journal (see An Evening Hike ). But this time there are seals out on the ice. This is earlier than they appeared in 2001. I took this panorama to show how close Hut Point and the seals are to McMurdo. The seals are the small black slugs on the very bottom right of the panorama.

McMurdo and seals

Seals on the ice shelf right outside McMurdo


Dr. Eric R. Christian
Washington, DC 20546 USA
This page was last modified on November 17, 2003