Mercury's 'tail' is longer than thought

U.S. scientists have used sodium atoms to determine Mercury's comet-like tail is much longer than had been thought.

Mercury's gravity is too weak to hold a permanent atmosphere, so when atoms are evaporated from the planet's surface by solar photons or other processes, some of the atoms form a tail that points away from the sun.

Jeffrey Baumgardner and colleagues at Boston University's Center for Space Physics studied the bright yellow-orange light emitted by the sodium atoms in Mercury's tail and discovered the tail, previously detected to 15 times the radius of Mercury, actually extends more than 100 times that distance, or 1.6 million miles from the planet.

The physicists also discovered the time it takes for the sodium atoms to leave Mercury's surface and reach the tail's maximum length is approximately 15 hours.

The research by Baumgarder, Jody Wilson and Michael Mendillo appears in the journal Geophysical Research Letters.

Copyright 2008 by United Press International


Explore further

New revelations about Mercury's volcanism, magnetic substorms, exosphere from MESSENGER (w/ Video)

Citation: Mercury's 'tail' is longer than thought (2008, February 27) retrieved 16 September 2019 from https://phys.org/news/2008-02-mercury-tail-longer-thought.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
0 shares

Feedback to editors

User comments

Feb 28, 2008
there is no "dispersed manner" about the tail. if the atoms where just atoms they'd fly off every which way. in fact the atoms are actually highly charged ions and as such form a plasma-tail. the "end" of the tail will fall into the plasma system within our solar system. this hasn't yet been mapped.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more