From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from tuna.sandelman.ca (tuna.sandelman.ca [IPv6:2607:f0b0:f:3:216:3eff:fe7c:d1f3]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id A1EDC3B29E for ; Tue, 14 Jun 2022 08:54:25 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by tuna.sandelman.ca (Postfix) with ESMTP id 71C4638DD5 for ; Tue, 14 Jun 2022 09:10:05 -0400 (EDT) Received: from tuna.sandelman.ca ([127.0.0.1]) by localhost (localhost [127.0.0.1]) (amavisd-new, port 10024) with LMTP id SxaRftRL4sDD for ; Tue, 14 Jun 2022 09:10:04 -0400 (EDT) Received: from sandelman.ca (obiwan.sandelman.ca [IPv6:2607:f0b0:f:2::247]) by tuna.sandelman.ca (Postfix) with ESMTP id 5A68E38DD3 for ; Tue, 14 Jun 2022 09:10:04 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=sandelman.ca; s=mail; t=1655212204; bh=dMab1RP5Z7QqoYPVC9VVznHC+fMD0RjqNkEZzia88Jk=; h=From:To:Subject:In-Reply-To:References:Date:From; b=oWVOjnnNZg5M1JPArF1ZcCXqEyOXbl+XNNYeWD9K4upnlK77pm8ahrsdYnJXA8z3l Ur+VJ5g4GVH+Zj2/n+x1PqjbySKRH9lAjSd+FbX7bgOZhrhjbNDj4FE1Cyt4P3TXrO POpCGzrBKEVVtS94tJN32QI6mgmHvWOguPdY34pC5HLrGo0cm10M97VapzLCGyRlzf BBJry2DcJiFwpU1pUQSnzKQwhgLZqBCx6dTGlvhkbHgeBSuyqIgxRllNQNhTJ8zJaB WoCIXvJ5KNnGSBajcDcjahHh4vXRa6rKFFuzAmVkQ/ky7THDFOoMJRfXT8+965hwYB dUBK/ftq0levw== Received: from localhost (localhost [IPv6:::1]) by sandelman.ca (Postfix) with ESMTP id 1D86034A for ; Tue, 14 Jun 2022 08:54:23 -0400 (EDT) From: Michael Richardson To: starlink@lists.bufferbloat.net In-Reply-To: References: X-Mailer: MH-E 8.6+git; nmh 1.7+dev; GNU Emacs 27.1 X-Face: $\n1pF)h^`}$H>Hk{L"x@)JS7<%Az}5RyS@k9X%29-lHB$Ti.V>2bi.~ehC0; <'$9xN5Ub# z!G,p`nR&p7Fz@^UXIn156S8.~^@MJ*mMsD7=QFeq%AL4m Subject: [Starlink] starlink and astronomy X-BeenThere: starlink@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Starlink has bufferbloat. Bad." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 Jun 2022 12:54:25 -0000 --=-=-= Content-Type: text/plain https://apod.nasa.gov/apod/ap220614.html Explanation: What are all those streaks across the background? Satellite trails. First, the foreground features picturesque rock mounds known as Pinnacles. Found in the Nambung National Park in Western Australia, these human-sized spires are made by unknown processes from ancient sea shells (limestone). Perhaps more eye-catching, though, is the sky behind. Created by low-Earth orbit satellites reflecting sunlight, all of these streaks were captured in less than two hours and digitally combined onto the single featured image, with the foreground taken consecutively by the same camera and from the same location. Most of the streaks were made by the developing Starlink constellation of communication satellites, but some are not. In general, the streaks are indicative of an increasing number of satellites nearly continuously visible above the Earth after dusk and before dawn. Understanding and removing the effects of satellite trails on images from Earth's ground-based cameras and telescopes is now important not only for elegant astrophotography, but for humanity's scientific understanding of the distant universe. Catastrophies in astrophotography aside, I think that the picture may be useful to people who want to explain how many satellites can be seen in the sky at the same time. --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQFFBAEBCgAvFiEEbsyLEzg/qUTA43uogItw+93Q3WUFAmKohP4RHG1jckBzYW5k ZWxtYW4uY2EACgkQgItw+93Q3WXwSwf8DMNssPypMBpE7yRbTKY+ml31+rfkKYjk vYNzrG8H1T11ZLhfDcKoR/nzW78B2WznXeyobwfHAdoyU1DuPSy3YQsJko/KlR4B IMGEARHADM2GNXZaXJrf4lODfMv2JMz58iIBfsd8kcOeHEY3l2l0iLL6r0/EX1pD vhNfPFRcN+0CsGE1hgk4TUGNT0Ixxzp56FCUvcvel1EsQWbxBOPcNH1JKTzJWFXK isLfNq2GOiIVD1c3gzficwKOd/kzKj59HVhcWrcv9Wks7EYgrmQgBEtoNQdELKW8 QfpEDBR8bKW0z2ZEsZa2MfcFZPhLyBYPVJF4vULoPfdOY+QdZ2b1IA== =RAfl -----END PGP SIGNATURE----- --=-=-=--